TOUGHNESS REQUIREMENTS FOR STEELS

An International Compendium

R Phaal and C S Wiesner

A B I N G T O N P U B L I S H I N G Woodhead Publishing Ltd in association with The Welding Institute

Cambridge England

Published by Abington Publishing Woodhead Publishing Limited Abington Hall, Abington Cambridge CB1 6AH, England www.woodheadpublishing.com

First published 1993, Abington Publishing

© Woodhead Publishing Limited, 1993

Conditions of sale All rights reserved. No part of this publication may be reproduced or transmitted in any form or by any means, electronic or mechanical, including photocopy, recording, or any information storage and retrieval system, without permission in writing from the publisher.

British Library Cataloguing in Publication Data A catalogue record for this book is available from the British Library.

ISBN 978-1-85573-132-5

NOMENCLATURE

c

CTOD

Cy

Cv.

E

J

K

K,,

Kfc

Kid

K»

H

*NDT

T

Tr

RÏ^Njyr

<rf

fc

*1

flaw half-length

crack tip opening displacement

Charpy V~notch impact energy

Charpy V-notch impact energy per unit area

Young's modulus

J-integral or experimental equivalent

stress intensity factor

plane strain crack arrest toughness

static plane strain toughness

dynamic plane strain toughness

reference plane strain toughness

correction factor

nil-ductility temperature

permissible minimum temperature

reference temperature

reference nil-ductility temperature

flow strength

hoop stress

yield strength

SUMMARY

Most structural design codes and fabrication, material and welding consumable specifications include fracture toughness requirements. This compendium includes over 150 individual specifications, covering national, international and industrial toughness requirements for ferritic materials, including applications such as pressure vessels, storage tanks, offshore structures, shipping, bridges and pipelines.

Most code toughness requirements are based on considerations of quality control and assurance, experience and simple measures of toughness such as Charpy impact energy and lateral expansion. These requirements are usually expressed in tabular form, as a function of test temperature (related to service temperature), section thickness, applied stress, heat treatment condition, material grade and tensile properties. Some code requirements are based on fitness for purpose and fracture mechanics toughness measurements, such as critical values of K, CTOD or J.

Sections 1 to 5 of this report provide an overview of codified toughness require-ments, describing strategies for fracture control, as well as presenting a summary of toughness requirements in the various codes. The Compendium presents detailed accounts of the codified toughness requirements, organised according to application.

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1. INTRODUCTION

Most structural fabrication, material and welding consumable codes and specifica-tions include fracture toughness requirements. These requirements are commonly stated in terms of Charpy impact energy and lateral expansion. Alternatively, requirements may be based on fracture mechanics measurements of toughness, such as critical values of crack tip opening displacement (CTOD). In general, toughness requirements are presented as functions of test temperature (related to service temperature), section thickness, applied stress, heat treatment condition, material grade and tensile properties. All of these factors can influence the toughness temperature transition curve. Code toughness requirements are intended to minimise the risk of brittle fracture.

This compendium includes over 150 individual specifications, covering national, international and industrial fracture toughness requirements for ferritic materials, including applications such as pressure vessels, offshore structures, shipping, bridges, storage tanks and pipelines.

1.1. Scope of Compendium

There is a vast amount of literature which incorporates fracture toughness requirements. The sources of such information include national and international standards and codes of practice, material specifications, as well as requirements developed by specific companies. The information contained in this compendium is based on published literature available to TWI (formerly The Welding Institute). It cannot be guaranteed that all possible sources of fracture toughness have been covered, or that all standards which have been reviewed are the latest revisions.

1.2. Organisation of Compendium

Because of the broad scope of this report the primary objective has been to collect together the available published fracture toughness requirements. Hence, the bulk of this report consists of a Compendium, describing in detail the toughness require-ments of the various codes and specifications. The Compendium is divided into eight parts (A-H): pressure vessels, pipelines, fixed offshore structures, mobile offshore structures and shipping, petrochemical plant and storage tanks, bridges, materials and welding consumables. These divisions are not absolute, and the reader is referred to the relevant Compendium Section for details.

For comparisons between equivalent material types, the reader should consult a handbook such as Reference 1, which defines equivalent material grades. Some of the reviewed codes specify tensile properties, which may permit rough comparisons to be made.

The units have been preserved as they are presented in the codes. The following conversion factors may be of use: U = 0.737ft.lb, 1 N/mm2 = 0.145ksi, 1 Nmm"30

= 0.0316ksiVin, 1mm = 0.0394in., lmil = 0.0254mm, °F = 9/5 °C + 32.

2. GENERAL APPROACHES FOR FRACTURE CONTROL

Fracture toughness requirements for critical structural components form only one part of fracture control procedures. Other factors which influence fracture are temperature; constraint; location, type and size of flaws; applied and residual stresses, heat treatment and embrittlement in service. Different components require different approaches, depending on the severity of operating environment, and the consequences of failure.

Bearing in mind these factors, there are two basic approaches to fracture control (as well as combinations of the two):

i) Quality control based toughness requirements ii) Fracture assessment based toughness requirements

2.1. Quality Control Based Toughness Requirements

This kind of toughness requirement is the most common, based on small scale toughness tests such as the Charpy impact test, the drop weight test (DWT, often referred to as the Tellini' test) and the drop weight tear test (DWTT). Other procedures, such as bend and weld ductility tests, are also used. Bend and weld ductility tests involve straining a fabricated test weld to a given amount, with the requirement that no cracking occurs. Although these tests do not directly relate to fracture toughness, they provide a qualitative measure of the weld ductility, ensuring that the weld is not too brittle at the test temperature. Such methods have not been reviewed in this report, with the exception of The American Petroleum Institute API 5L and API 5CT specifications (2, 3), reviewed in Section B of the Compendium for illustrative purposes.

The drop weight test (4) is employed by several standards (including ASME, British Gas, API, Australian and Canadian Codes, reviewed in the Compendium). The DWT specimen consists of a rectangular beam which is impact loaded by a falling weight. A brittle weld bead is deposited and saw-notched to provide a crack initiation site. The falling weight causes a crack to initiate and to propagate into the test material. The DWT test is intended for establishing the nil-ductility-temperature C^W), the maximum temperature at which the specimen breaks. Some codes (e.g., API Standards) require a "no-break" result at the specified test temperature.

A second type of impact test is the drop weight tear test (DWTT) (5), which consists of a full-thickness rectangular plate with a pressed notch, impact loaded by a falling hammer, resulting in complete fracture. The DWTT is used to establish the temperature transition curve in terms of the percentage shear fracture appearance. Codes in the gas and pipeline industry (such as British Gas and API) require a specified percentage shear fracture area (typically 50 or 80%) at a specified test temperature. In this way, the DWTT is used to ensure that the fracture made is primarily ductile.

The Charpy impact test (6) is the most simple and most widely used fracture toughness test. This test consists of a beam with a machined notch which is impact loaded by a pendulum hammer. V and U notches are used, although the V notch is

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more frequently employed. Standard specimens are 10 x 10 x 55mm in dimension, although many codes permit sub-size specimen testing. Results from Charpy impact tests which are commonly referenced are: the impact energy required to fracture the specimen, the lateral expansion, and the percentage shear fracture appearance at the specified test temperature. The latter two are intended as measures of ductility.

22. Fracture Assessment Based Toughness Requirements

The fracture toughness requirements which are based on DWT, DWTT and Charpy impact tests do not address the effects of applied stress, constraint, flaw location and size on the integrity of critical structural components. Instead, the requirements for these tests are based on correlations with more rigorous fracture mechanics tests, such as wide plate tests. Such toughness requirements, combined with the good workmanship requirements in most fabrication codes ensure that structures rarely fail. However, for critical components a fracture mechanics based assessment procedure is appropriate.

The ASME III (Appendix G) and ASME XI (Appendices A and G) approaches (7) are based on linear elastic fracture mechanics principles. For design purposes, a maximum planar flaw size is postulated. If flaws are detected during inspection their effect on the structural integrity of the component can be assessed. Fabrication standards such as BS4515 (8) and BS5500 (9) also permit fracture mechanics assessment procedures, such as BSI PD6493 (10, 11) CEGB R6 (12, 13) or Appendix H of BS4515 (8), to be employed if the workmanship requirements of these standards are not achieved. Assessment based fracture approaches require that material fracture toughness be known in terms of a critical value of the stress intensity factor K, the J-integral, or crack tip opening displacement CTOD (see, for example, BS5447 (14) and BS5762 (15), which have now been superseded by a new unified British Standard (BS7448), including static and dynamic K, CTOD, J and R-curve testing, of which Part 1 has been published (16)).

3. TEMPERATURE TRANSITION EFFECTS

A dominant parameter which influences fracture toughness in ferritic materials is temperature. At higher temperatures, in the upper shelf régime, a ferritic material behaves in a fully ductile manner, and is capable of absorbing considerable amounts of energy when deformed. At these temperatures, ferritic materials are generally considered as being tough. As the temperature is reduced, a transition to lower shelf behaviour occurs (see Fig.I). In this régime ferritic materials are brittle, and fracture occurs in a cleavage mode. The decrease in toughness from upper shelf behaviour can be substantial.

Most structural codes attempt to ensure that components do not operate at or near to the lower shelf. Usually this requirement is not explicitly stated in terms of a temperature transition curve. Rather, Charpy impact energy levels are required at, or below, specific temperatures which have been chosen to ensure that the specific material does not operate on the lower shelf. Occasionally, lateral expansion and percentage shear fracture appearance are stipulated to ensure that behaviour is ductile. The code requirements based on the nil ductility temperature are directly related to the temperature transition curve, as are the codes which require Charpy

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more frequently employed. Standard specimens are 10 x 10 x 55mm in dimension, although many codes permit sub-size specimen testing. Results from Charpy impact tests which are commonly referenced are: the impact energy required to fracture the specimen, the lateral expansion, and the percentage shear fracture appearance at the specified test temperature. The latter two are intended as measures of ductility.

22. Fracture Assessment Based Toughness Requirements

The fracture toughness requirements which are based on DWT, DWTT and Charpy impact tests do not address the effects of applied stress, constraint, flaw location and size on the integrity of critical structural components. Instead, the requirements for these tests are based on correlations with more rigorous fracture mechanics tests, such as wide plate tests. Such toughness requirements, combined with the good workmanship requirements in most fabrication codes ensure that structures rarely fail. However, for critical components a fracture mechanics based assessment procedure is appropriate.

The ASME III (Appendix G) and ASME XI (Appendices A and G) approaches (7) are based on linear elastic fracture mechanics principles. For design purposes, a maximum planar flaw size is postulated. If flaws are detected during inspection their effect on the structural integrity of the component can be assessed. Fabrication standards such as BS4515 (8) and BS5500 (9) also permit fracture mechanics assessment procedures, such as BSI PD6493 (10, 11) CEGB R6 (12, 13) or Appendix H of BS4515 (8), to be employed if the workmanship requirements of these standards are not achieved. Assessment based fracture approaches require that material fracture toughness be known in terms of a critical value of the stress intensity factor K, the J-integral, or crack tip opening displacement CTOD (see, for example, BS5447 (14) and BS5762 (15), which have now been superseded by a new unified British Standard (BS7448), including static and dynamic K, CTOD, J and R-curve testing, of which Part 1 has been published (16)).

3. TEMPERATURE TRANSITION EFFECTS

A dominant parameter which influences fracture toughness in ferritic materials is temperature. At higher temperatures, in the upper shelf régime, a ferritic material behaves in a fully ductile manner, and is capable of absorbing considerable amounts of energy when deformed. At these temperatures, ferritic materials are generally considered as being tough. As the temperature is reduced, a transition to lower shelf behaviour occurs (see Fig.I). In this régime ferritic materials are brittle, and fracture occurs in a cleavage mode. The decrease in toughness from upper shelf behaviour can be substantial.

Most structural codes attempt to ensure that components do not operate at or near to the lower shelf. Usually this requirement is not explicitly stated in terms of a temperature transition curve. Rather, Charpy impact energy levels are required at, or below, specific temperatures which have been chosen to ensure that the specific material does not operate on the lower shelf. Occasionally, lateral expansion and percentage shear fracture appearance are stipulated to ensure that behaviour is ductile. The code requirements based on the nil ductility temperature are directly related to the temperature transition curve, as are the codes which require Charpy

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impact temperature transition curves. These approaches are described in the relevant sections of the Compendium, and are reviewed in Section 4, below.

3.1. Factors which Influence the Temperature Transition Curve

Willoughby (17) has reviewed the factors which commonly influence the toughness temperature transition curve. One important factor is the effect of strain rate (see Fig.II). An increase in strain rate decreases ductility, shifts the temperature transition curve to higher temperatures, and may increase the upper shelf toughness. Thus, for a given level of impact toughness and ductility in the transition regime, one would expect greater toughness and ductility for quasi-staticaily loaded structures, although this trend may be reversed on the upper shelf.

In contrast, the blunt notch and small size of the Charpy specimen tend to decrease the transition temperature with respect to real flaws in large structures. Figure ΠΙ shows the effect of increasing or decreasing specimen dimensions: increasing the dimensions shifts the temperature transition curve to higher temperatures and increases the upper shelf toughness. The effect of increasing the section thickness, while keeping the specimen width and crack depth constant, is illustrated in Fig.IV. The effect of altering the crack depth in a fracture toughness specimen, without changing its other dimensions, is shown in Fig.V.

4. TOUGHNESS REQUIREMENTS IN INDUSTRY

Most codified fracture toughness requirements address several factors which influence the material toughness, including temperature, tensile properties, heat treatment condition, constraint and material grade. All of these factors influence the material ductility and the toughness temperature transition curves. The material grade defines the material tensile properties as well as inherent toughness, both dependent on the steel metallurgy and microstructure, as affected by alloying, levels of impurities and heat treatments.

These factors are more uncertain in weldments, which may have complex geometries, chemistry, heat cycles and stresses, with the increased likelihood of impurities, inclusions, flaws and local brittle regions, such as grain coarsened HAZs.

4.1. Pressure Vessel Toughness Requirements

One of the most influential pressure vessel standards is the ASME Boiler and Pressure Vessel code (7). The ASME code is extensively reviewed in Sections A, G and H of the Compendium (pressure vessel, material and welding consumable toughness requirements). The reader is referred to Reference 18 for an account of the history and organisation of the ASME code, which originated in 1914 (Power Boilers). The ASME code consists of eleven sections (I to XI): Power Boilers, Material Specifications, Nuclear Power, Heating Boilers, Non-destructive Testing, Care of Heating Boilers, Care of Power Boilers, Pressure Vessels, Welding, Reinforced Plastic Pressure Vessels and Nuclear In-service Inspection.

Other pressure vessel codes reviewed in this report include the British, French, German, Australian, Dutch, Swedish, Austrian, Japanese, Norwegian and some

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impact temperature transition curves. These approaches are described in the relevant sections of the Compendium, and are reviewed in Section 4, below.

3.1. Factors which Influence the Temperature Transition Curve

Willoughby (17) has reviewed the factors which commonly influence the toughness temperature transition curve. One important factor is the effect of strain rate (see Fig.II). An increase in strain rate decreases ductility, shifts the temperature transition curve to higher temperatures, and may increase the upper shelf toughness. Thus, for a given level of impact toughness and ductility in the transition regime, one would expect greater toughness and ductility for quasi-staticaily loaded structures, although this trend may be reversed on the upper shelf.

In contrast, the blunt notch and small size of the Charpy specimen tend to decrease the transition temperature with respect to real flaws in large structures. Figure ΠΙ shows the effect of increasing or decreasing specimen dimensions: increasing the dimensions shifts the temperature transition curve to higher temperatures and increases the upper shelf toughness. The effect of increasing the section thickness, while keeping the specimen width and crack depth constant, is illustrated in Fig.IV. The effect of altering the crack depth in a fracture toughness specimen, without changing its other dimensions, is shown in Fig.V.

4. TOUGHNESS REQUIREMENTS IN INDUSTRY

Most codified fracture toughness requirements address several factors which influence the material toughness, including temperature, tensile properties, heat treatment condition, constraint and material grade. All of these factors influence the material ductility and the toughness temperature transition curves. The material grade defines the material tensile properties as well as inherent toughness, both dependent on the steel metallurgy and microstructure, as affected by alloying, levels of impurities and heat treatments.

These factors are more uncertain in weldments, which may have complex geometries, chemistry, heat cycles and stresses, with the increased likelihood of impurities, inclusions, flaws and local brittle regions, such as grain coarsened HAZs.

4.1. Pressure Vessel Toughness Requirements

One of the most influential pressure vessel standards is the ASME Boiler and Pressure Vessel code (7). The ASME code is extensively reviewed in Sections A, G and H of the Compendium (pressure vessel, material and welding consumable toughness requirements). The reader is referred to Reference 18 for an account of the history and organisation of the ASME code, which originated in 1914 (Power Boilers). The ASME code consists of eleven sections (I to XI): Power Boilers, Material Specifications, Nuclear Power, Heating Boilers, Non-destructive Testing, Care of Heating Boilers, Care of Power Boilers, Pressure Vessels, Welding, Reinforced Plastic Pressure Vessels and Nuclear In-service Inspection.

Other pressure vessel codes reviewed in this report include the British, French, German, Australian, Dutch, Swedish, Austrian, Japanese, Norwegian and some

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industrial Codes. (See Section A of the Compendium, and Sections 4.15 to 4.19, below).

4.1.1. ASME III: Rules for construction of nuclear power plant components

Section III of the ASME code provides rules for the construction of components in nuclear power plants, with Division 1 specific to metallic components and Division 2 applying to concrete pressure vessels and containment structures. Chockie (19) describes the development of ASME Section III, as well as a more detailed description of the content.

Subsections NB, NC, ND, NE, NF and NG of ASME III Division 1 include the fracture toughness requirements for Class 1, 2, 3 and MC components, component supports and core support structures. The procedures for Charpy impact and drop weight testing are described, including frequency of sampling, number, location and orientation of specimens. Retesting procedures and exemptions from impact testing are presented. Impact testing of parent material, weld metal and HAZ are required. Account must be taken of the effects of irradiation embrittlement.

Exemptions to toughness testing include material with nominal section thicknesses less than 5/8" (15.9mm) and austenitic stainless steels and non-ferrous materials that do not show a pronounced temperature transition. Class 1 materials require the determination of the reference nil ductility temperature RTNDT: firstly, the nil ductility temperature T ^ must be established by drop weight testing. At a temperature not greater than T^y + 60°F (33°C), Charpy requirements of 35mils (0.89mm) lateral expansion and 50ft.lb (68J) impact energy are specified and, if met, define R T ^ T = TNDT. If these requirements are not met then R T , ^ can be established from the Charpy transition curve (17).

The specific ASME III impact toughness requirements are presented in detail in Section A of the Compendium for vessel materials including pumps, valves, piping and bolting. These requirements are presented in tabular form, with the exception of Appendix R of ASME III which defines the material lowest service metal temperature (LST) as a function of section thickness (see Section A. 1.2 of the Compendium). The impact energy and lateral expansion requirements depend on material grade, tensile properties, specified test temperature and section thickness. Required impact energies range from 13 to 55ft.lb (17.6 to 74.6J) and lateral expansion requirements from 13 to 45mils (0.33 to 1.14mm) (average of three specimens).

4.1.2. ASME VIII: Rules for construction of pressure vessels

Division 1 of ASME VIII includes toughness requirements for metallic pressure components, including parent material, weld metal and heat affected zone (HAZ). The materials which are exempt from impact testing are detailed in Sections UCS-66 and UCS-67 of ASME VIII. These exemptions are defined in text, tables and figures, and depend on the minimum design metal temperature, section thickness and applied stress, for various grades and classes of steels. Farr (20) describes the development, scope and organisation of ASME VIII in some detail. The required Charpy energies are defined in Fig.UG-84.1 of ASME VIII (reproduced as Fig.2 of

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the Compendium). These requirements depend on section thickness and the minimum specified yield strength of the material, tested at a temperature equal to or less than the minimum design metal temperature.

Other impact toughness requirements are presented for steels with yield strengths less than 95ksi (oSSN/mm2), in tabular form (average impact energies in the range 13 to 20ft.lb, (17.6 to 27J) depending on yield strength and deoxidization state of the steel). A lateral expansion requirement of 0.015" (0.38mm) is specified for materials with yield strengths in excess of 95ksi (eSSN/mm2). Toughness require-ments for high alloy steels, bolting, and high strength quenched and tempered steels are described in Section AM-213, 214 and Article M.3 of ASME VIII.

4.1.3. ASME ΠΙ Appendix G, XI Appendices A and G

ASME III and XI incorporate Appendices which describe assessment based fracture control procedures. ASME III Appendix G relates to design, where a maximum postulated flaw size is assumed. Linear elastic fracture mechanics procedures are then employed to ensure that under the most severe stress conditions such flaws are not critical to the structural integrity of the component. The material toughness to be used in the assessment is evaluated using the reference toughness curve (Fig.G-2210-1 of ASME III, reproduced as Fig.3 of the Compendium), which is a lower bound to Klc, K,t and Kw data from wide plate test results. Klc, K^ and K,d represent the plane strain static fracture toughness, plane strain crack arrest toughness and the fracture toughness under dynamic loading, respectively. K^ is referenced with respect to the material RT^j, evaluated using drop weight or Charpy specimens, as is described in Section 4.1.1.

ASME XI Appendices A and G describe similar fracture mechanics based procedures, applicable to the assessment of flaws discovered during in-service inspection, using the K^ material toughness curve. Alternatively, Appendix A permits the use of lower bound K,c and K,â curves, also as a function of RT^y. Appendix G is concerned with evaluating the allowable stresses near to known flaws.

The reference toughness K^ curve approach was developed for ASME by the Welding Research Council (WRC) Pressure Vessel Research Committee (PVRC), as summarised in Section A of the Compendium. The reader is referred to the WRC Bulletin 175 (21) which describes the PVRC research and recommendations.

4.1.4. BS5500 Appendix D

The development and organisation of the British Standards Institution Pressure Vessel and Boiler Codes were reviewed by Houston (22). Appendix D of BS5500:1990 (23) specifies the impact toughness requirements for ferritic unfired pressure vessel components.

The relationship of the design reference temperature with the Charpy impact test temperature and the reference thickness is defined graphically in Fig.D.3(l) and D.3(2) of BS5500:1990 (reproduced in Fig.lOa and 10b of the Compendium for as-welded and post-weld heat treated (PWHT) conditions). The design reference

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temperature is the minimum temperature experienced by the component, adjusted by membrane stress, construction category and PWHT correction factors. An average of 27J impact toughness at the Charpy test temperature defined in Fig. 10a and 10b is required for materials with minimum specified tensile strengths less than 450 N/mm2. 40J are required for tensile strengths greater than 450 N/mm2. The same requirements apply to weld metal and HAZs of weldments (except for heat input in the range 1 to 5kJ/mm for HAZs, where no toughness requirement applies).

4.1.5. French Codes

The French Unfired Pressure Vessel Code (CODAP) (24) is applicable to unalloyed and non-austenitic alloyed steels in welded pressure vessel components. Thomas and Grandemange (25) describe the development and organisation of the French boiler and pressure vessel standards, including CODAP.

For each critical component of the pressure vessel it is required to evaluate a permissible minimum temperature Tma (the minimum temperature which a vessel can reach without risking brittle fracture), which must be lower than the minimum design temperature (the lowest temperature reached at the section mid-thickness). The code defines a reference temperature Tr at which a normalised Charpy impact energy of 35 J/cm2 is required. The permissible minimum temperature is evaluated from Fig.4.2.1 of CODAP (reproduced as Fig.9 of the Compendium), for as-welded and PWHT conditions, as a function of the reference thickness and the reference temperature. For sections thinner than 5mm, and for reduced applied stresses, the permissible minimum temperature may be reduced, by up to 50°C.

Lidbury and Morland (26) have briefly summarized the French RCC-M (Règles de Conception et de Construction des Matériaux) nuclear pressure vessel toughness requirements. Low alloy Mn-Ni-Mo steel impact requirements are covered by the relevant material procurement specification. For instance 56 and 40J (average and minimum) is required at 0°C for coreshell components, with 102J minimum required at 20°C. For other pressure vessel forgings 70J minimum is required at 20°C. This code embodies the technical requirements of ASME III (see Section 4.1.1).

Pellissier-Tanon and Grandemange (27) of Framatome describe the French approach to fast fracture resistance of pressurised water reactor (PWR) primary components, based on deterministic safety coefficients evaluated from fracture mechanics analyses of postulated flaws. The 'Département de Sûreté Nucléaire du CEA! is currently developing a statistical approach to assess the risk of failure based on the current design codes. Pellissier-Tannon and Grandemange (27) summarize the French approach as "design by rule"; with "design by analysis" approaches used to assess safety, based on compliance with manufacturing specifications on steel composition and Charpy toughness or R T ^ (for beltline material), and by verification analysis according to Appendix ZG of the RCC-M code. In addition, the licensing requirements on irradiation surveillance must be followed.

Noel (28) has reviewed life duration of French PWR vessels, maintaining that the choice of certain "doubtful" materials in countries other than France resulted in greater sensitivity to irradiation embrittlement. Irradiation of 5 x 1019 n/cm2 for 40

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years is acceptable for the French 900MW PWR materials. The forecast temperature transition shift for these vessel steels is shown in Fig.VI.

4.1.6. German Codes

AD Merkblatt W10 (29) specifies toughness requirements for ferritic pressure vessel steels, while AD Merkblatt HP5/2 (30) presents the impact requirements and test procedures for weldments. The reader is referred to Steffen (31) who described the development and organisation of the German boiler and pressure vessel codes.

Impact toughness requirements depend on stress categories specified in the code, with Charpy tests performed at the lowest permissible operating temperature (Table 1 of (29), a function of steel grade, thickness and stress). The toughness require-ments of the applicable materials apply to both parent material and weldments.

Kussmaul, Roos and Fohl (32) describe the development of assessment based fracture mechanics requirements for welded nuclear pressure vessel materials. This approach is based on correlations between crack initiation toughness Jï and Charpy upper shelf energy, to quantify the upper shelf safety margins of the code requirements. These correlations are suitable for irradiated Charpy surveillance specimens. Leak before break conditions are considered for different loading conditions. The ASME K,c, Kw and KIR curves are used for assessing safety levels in the lower shelf and transition regimes. Pellissier-Tanon and Grandemange (27) describe the German approach to PWR fracture control as based mainly on "design by rule", with safety levels determined from the manufacturing specifications for steel composition and Charpy toughness, and the applicable licensing limitations on end-of-life neutron fluency at the vessel beltline.

4.1.7. Japanese Codes

Nakagawa (33) has reviewed the development and organisation of the Japanese Boiler and Pressure Vessel Codes. The Japanese Industrial Pressure Vessel Standard JIS B 8243-1981 (34) requires that materials (including weldments) for which the minimum design temperature is less than -70°C are impact tested at a temperature equal to or less than the minimum vessel operating temperature. Impact energies of between 20.6 and 27.5J are required.

4.1.8. Australian Codes

The impact toughness requirements for unfired pressure vessels, boiler water-tubes, steel plates and other components are specified in AS1210, AS1228, AS1548 and AS1797 (35). Toughness requirements in AS1210 depend on section thickness, yield strength, PWHT and material grades, with test temperature and impact requirements presented in graphical form (Fig.7 and 8 of the Compendium). Average impact energies of 27 and 40J are required for material with specified minimum yield strengths less than and greater than 450MPa, respectively. Details of toughness requirements in these standards are presented in Section A of the Compendium, including acceptance criteria for weldments for alloyed steels and high strength quenched and tempered steels.

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4.1.9. Other Codes

The fracture toughness requirements of other codes which have been collected together in the Compendium include the Austrian Federal Statute on steam boilers, the Dutch, Norwegian and Swedish pressure vessel codes, an ICI pressure vessel specification, and the API 920 recommendations against brittle fracture in pressure vessels. The reader is referred to Section A of the Compendium for details of the impact requirements in these codes, which are functions of temperature, material grade, tensile properties, heat treatment condition and section thickness.

Lidbury and Morland (26) have reviewed light water reactor (LWR) toughness requirements including the acceptance limits of the Westinghouse Equipment Specification, which requires an upper shelf Charpy energy of 102J in the belt-line region, and 88J in other parts of the vessel. The R T j ^ is required to be lower than -1.1°C for welds in the core region and nozzle welds, and lower than 15.5°C elsewhere. Westinghouse requires that suppliers attempt to achieve RT^y lower than 12.5°C for all materials.

Lidbury and Morland (26) also describe the ASME XI Appendix A and United States Nuclear Regulatory Commission (USNRC) recommendations for predicting the transition temperature shift and Charpy upper shelf toughness decrease due to irradiation embrittlement (see Fig.VII and VIII). This information is presented graphically in Revision 1 of the USNRC Regulatory Guide 1.99 (reproduced as Fig.VIII). The shift in R T ^ T and decrease of upper shelf toughness are functions of neutron dose and steel impurity levels.

4.2. Pipeline Toughness Requirements

The codes which relate to pipeline toughness requirements, reviewed in Section B of the Compendium, include American Petroleum Institute (API), American Iron and Steel Institute (AISI), Australian, British, Canadian, Norwegian and French Standards, as well as industrial requirements of Amoco, British Gas and Battelle.

In general, toughness requirements are expressed in tabular form, as functions of test temperature (related to operating temperature), material grade and tensile properties, applied stress and geometry (section thickness and pipe diameter). Details of these requirements are presented in Section B of the Compendium.

Several of the API, Australian, Canadian and industrial codes include percentage shear fracture area requirements for both drop weight tear and Charpy tests, eg. API 5L (line pipe), AS1697 (gas transmission and distribution systems), AS2885 (gas and liquid petroleum), CSA Z245.1 (steel line pipe), Amoco and British Gas. API 5CT (casing and tubing) presents a Charpy impact requirement in equation form, related to maximum hypothesized flaw dimension and yield strength. Weld ductility requirements are presented in Section B of the Compendium for API 5CT and API 5L, while API 6A (well head and Christmas tree equipment) includes Charpy lateral expansion requirements. British Gas, AISI and Battelle all require impact energies (in equation form) which depend on the pipe dimensions, applied stress and acoustic velocity of the contained fluid for gas pipelines.

17

Gas pipeline toughness requirements are, in general, more severe than for liquid pipelines (36). This is because the speed at which pressure or unloading stress waves travel in gases (typically 400m/s), is slower than the speed of brittle fracture propagation in pipelines (typically 600m/s). Thus, brittle fractures can propagate great distances if the pipeline does not contain crack arrest features, since the stresses are maintained at the propagating crack tip. Shear or ductile fractures propagate at lower rates (between 60 and 250m/s), so that the crack tip is unloaded due to decompression of the gas pipe. However, shear or ductile fractures can still propagate for considerable distances if the material has insufficient upper shelf toughness.

AS2885 (Gas and liquid petroleum pipelines), reviewed in Section B of the Compendium, presents upper shelf toughness requirements to ensure ductile fracture arrest in graphical form (Fig. 13 of the Compendium). Revisions to AS2885 are to include upper shelf requirements in equation form, as a function of pipe dimensions and applied stress.

Battelle have developed upper shelf impact toughness requirements for the American Gas Association (37). Line pipe is designed to resist fracture propagation, while fittings are designed to resist fracture initiation, with the following upper shelf requirement (also presented in graphical form):

E Cvn = 8c of2/n £n (π M, oJ2où

where at = flow strength, oh = hoop stress, Cy,» = Charpy impact energy per unit area, E = Young's Modulus, Mt is a correction factor and 2c is the critical through-thickness flaw length. The Charpy energy is limited by plastic collapse of the ligament.

43. Fixed Offshore Toughness Requirements

The codes relating to fixed offshore structure toughness requirements which have been reviewed in Section C of the Compendium, include American Petroleum Institute (API), American Bureau of Shipping (ABS), British, French, Norwegian, Lloyd's Register, UK Department of Energy and Engineering Equipment Manufac-turers and Users Association (EEMUA) standards.

In general, Charpy impact toughness requirements are presented in tabular form (see Section C of the Compendium for details), as functions of test temperature, material grade and tensile properties, section thickness, heat treatment condition and applied stress.

API 2A (fixed offshore platforms) permits appropriate CTOD toughness require-ments to be used, while API 2Z (pre-production qualification for offshore structures) provides detailed guidance on CTOD test procedures. An average CTOD of 0.25 and 0.38mm is required for as-welded and PWHT weld metal, respectively.

Pisarski and Harrison (38) have described the background to the UK Department of Energy Guidance Notes, specifically related to fracture toughness of primary offshore structure components. Charpy impact requirements for parent plate and

18

HAZ regions have been derived by correlation with approximately 350 wide plate tests (mostly C-Mn steels of yield strengths less than 480N/mm2 and thicknesses between 6-80mm), with a wide plate temperature transition curve established. These correlations were based on two reference temperatures:

i. the temperature at which applied strain levels equivalent to twice the room temperature yield strain of the parent plate could be accommodated by the wide plates without fracture;

ii. the temperature at which survival was obtained at an applied stress not less than 80% of the parent plate room temperature yield strength.

These two criteria were used because of the distinction made in the Guidance notes for higher and lower stressed regions. A minimum design temperature of -10°C is considered appropriate for North Sea offshore structures, although higher tempera-tures may be used for submerged components. A distinction is made between the as-welded and PWHT conditions, increasing the test temperature by 10°C for PWHT weldments. Weld metal Charpy toughness requirements are based on CTOD requirements determined from fracture mechanics assessments. Certain critical welds are required to be heat treated, unless justified by a fracture mechanics analysis (such as BSI PD6493 (9, 12)), combined with CTOD testing of the relevant weld procedures.

4.4. Mobile Offshore Units and Shipping Toughness Requirements

The following codes have been reviewed in Section D of the Compendium: American Petroleum Institute (API), American Bureau of Shipping (ABS), US Coast Guard, Lloyd's Register, German, Norwegian, Japanese and Chinese Standards.

Most Charpy impact toughness requirements are presented in tabular form (see Section D of the Compendium for details), as functions of temperature, section thickness, material grade and tensile properties. The US Coast Guard and ABS requirements include "no-break" drop weight test requirements.

4.5. Petrochemical Plant Toughness Requirements

The Codes which have been reviewed in Section E of the Compendium relate to chemical and petroleum refinery storage tanks and piping, including British, ASME and American Petroleum Institute (API) requirements. These requirements include tabulated Charpy impact energy and lateral expansion requirements, as functions of test temperature (related to operating temperature), material grade, applied stress, tensile properties and section thickness.

Harrison (39) has reviewed petro-chemical storage tank and pressure vessel toughness requirements. The BS5500 (unfired fusion welded pressure vessels) and BS2654 (non-refrigerated storage tanks) requirements are based on a correlation between the 27 and 40J Charpy temperature (depending on yield strength) and the temperatures at which wide plates survive a total applied strain of 4 Oy/E.

19

4.6. Bridge Toughness Requirements

The codes which have been reviewed in Section F of the Compendium and which relate specifically to bridges, are the American Association of State Highway and Transportation Officials" (AASHTO) requirements and BS5400: Part 6 (Steel, concrete and composite bridges). Charpy impact requirements depend on service temperature, applied stress, section thickness, material grade and tensile strength.

Hartbower (40) has assessed the 1974 AASHTO temperature shift methods, where the Charpy impact energy requirement of 15ft.ib (20.4J) is specified at up to 70°F (39°C) above the lowest anticipated service temperature (+10, +40 and +70°F (5.6, 22 and 39°C) shift for Zone 3, 2 and 1 temperature service, see Section F of the Compendium for definition of Zones). Hartbower concluded (based on fracture mechanics and failure investigations) that these temperature shifts were not conservative, and recommended that impact toughness tests should be conducted at the lowest anticipated service temperatures, as currently specified (Section F of the Compendium).

4.7. Materials and Welding Consumable Toughness Requirements

The specifications which have been reviewed in Sections G and H of the Compend-ium include ASME, American Welding Society (AWS), ISO, Euronorm, American Bureau of Shipping (ABS), British, Belgian, Australian, Canadian, Japanese and Swedish Codes. Toughness requirements (impact energy and lateral expansion) are presented for parent plate (Section G of the Compendium) and weld metal (Section H of the Compendium) in tabular form, as functions of section thickness, test temperature, material grade and tensile properties. The ASME parent material requirements (generally identical to ASTM specifications) and consumable requirements (equivalent to AWS specifications) have been reviewed in the most detail.

The reader is referred to the specific sections of Sections G and H of the Compend-ium for details of these toughness requirements.

5. SUMMARY AND CONCLUSIONS

The fracture toughness requirements of national and international standards have been reviewed, covering over 150 individual specifications. These include AASHTO, ABS, AISI, API, ASME, AWS, EEMUA, Euronorm, ISO, Lloyd's Register, UK Department of Energy and US Coast Guard Specifications; Australian, Austrian, Belgian, British, Canadian, Chinese, Dutch, French, German, Italian, Japanese, Norwegian and Swedish Standards; as well as AMOCO, Battelle, British Gas and ICI industrial codes. Sections A to H of the Compendium summarize the various toughness requirements of these standards, grouped into pressure vessel, pipeline, fixed offshore, mobile offshore and shipping, petrochemical plant and storage tanks, bridge, material and consumable applications.

Toughness requirements are usually presented in the form of rules, without explanation as to the development and reasoning behind these rules. Exceptions to this include some pipeline and offshore codes, such as ASME, PVRC, and some

20

4.6. Bridge Toughness Requirements

The codes which have been reviewed in Section F of the Compendium and which relate specifically to bridges, are the American Association of State Highway and Transportation Officials" (AASHTO) requirements and BS5400: Part 6 (Steel, concrete and composite bridges). Charpy impact requirements depend on service temperature, applied stress, section thickness, material grade and tensile strength.

Hartbower (40) has assessed the 1974 AASHTO temperature shift methods, where the Charpy impact energy requirement of 15ft.ib (20.4J) is specified at up to 70°F (39°C) above the lowest anticipated service temperature (+10, +40 and +70°F (5.6, 22 and 39°C) shift for Zone 3, 2 and 1 temperature service, see Section F of the Compendium for definition of Zones). Hartbower concluded (based on fracture mechanics and failure investigations) that these temperature shifts were not conservative, and recommended that impact toughness tests should be conducted at the lowest anticipated service temperatures, as currently specified (Section F of the Compendium).

4.7. Materials and Welding Consumable Toughness Requirements

The specifications which have been reviewed in Sections G and H of the Compend-ium include ASME, American Welding Society (AWS), ISO, Euronorm, American Bureau of Shipping (ABS), British, Belgian, Australian, Canadian, Japanese and Swedish Codes. Toughness requirements (impact energy and lateral expansion) are presented for parent plate (Section G of the Compendium) and weld metal (Section H of the Compendium) in tabular form, as functions of section thickness, test temperature, material grade and tensile properties. The ASME parent material requirements (generally identical to ASTM specifications) and consumable requirements (equivalent to AWS specifications) have been reviewed in the most detail.

The reader is referred to the specific sections of Sections G and H of the Compend-ium for details of these toughness requirements.

5. SUMMARY AND CONCLUSIONS

The fracture toughness requirements of national and international standards have been reviewed, covering over 150 individual specifications. These include AASHTO, ABS, AISI, API, ASME, AWS, EEMUA, Euronorm, ISO, Lloyd's Register, UK Department of Energy and US Coast Guard Specifications; Australian, Austrian, Belgian, British, Canadian, Chinese, Dutch, French, German, Italian, Japanese, Norwegian and Swedish Standards; as well as AMOCO, Battelle, British Gas and ICI industrial codes. Sections A to H of the Compendium summarize the various toughness requirements of these standards, grouped into pressure vessel, pipeline, fixed offshore, mobile offshore and shipping, petrochemical plant and storage tanks, bridge, material and consumable applications.

Toughness requirements are usually presented in the form of rules, without explanation as to the development and reasoning behind these rules. Exceptions to this include some pipeline and offshore codes, such as ASME, PVRC, and some

20

Australian and Canadian Standards. Explicit references to the temperature transition curve (including ductile and brittle behaviour) are rarely made in published codes, even though temperature is a critical parameter, since ferritic materials undergo a transition from ductile to brittle fracture modes with decreasing temperature. (Section 3 of this report discusses the factors which influence the temperature transition curve (including strain rate, constraint and in-service embrittlement)).

Most code toughness requirements are expressed in tabular form, although some are expressed graphically and some analytically, usually as functions of test temperature (related to service temperature), section thickness, applied stress, heat treatment condition, material grade and tensile properties. All of these factors can influence the toughness temperature transition curve.

Owing to the many sources of detailed toughness requirements it has not been possible to analyse in depth the relationships between the various codified toughness requirements. Instead, the main effort has been to compile a condensed summary of requirements, which can be used as a compendium for various applications.

Rule or quality control based toughness requirements include Charpy and drop weight testing. Drop weight tests permit the nil ductility temperature T^y to be evaluated, which is used to reference the temperature transition curve. Another fracture toughness parameter is the required percentage shear fracture area, a measure of ductility, as obtained by the drop weight tear test.

Charpy impact parameters include absorbed energy, lateral expansion and percentage shear area (measures of absolute toughness and ductility). The Charpy and drop weight test results are combined to establish the reference nil ductility temperature, RTJTOT, which provides a reference for the toughness temperature transition curve.

These fracture toughness requirements are generally derived from correlations with wide plate tests, engineering judgement, analytical modelling, or are simply borrowed from other established codes.

For more rigorous fracture toughness assessment, requirements must be based on fracture mechanics assessment principles, where the effects of known or hypothe-sized flaws on the structural integrity of the component are assessed. These procedures require accurate (or conservative) applied stress and toughness data, and are generally based on K, CTOD or J analyses.

Material toughness requirements generally form part of a more comprehensive fracture control plan, which includes quality control of material selection and fabrication, PWHT in some instances, post-fabrication and in-service inspection. Account must also be taken of the service environment, stress and temperature cycles, as well as the risk and consequences of catastrophic failure. Also, the effects of material degradation are important, including strain ageing, age hardening and irradiation embrittlement (which causes a temperature shift of the transition curve and a reduction in upper shelf toughness). Specific guidance on these factors are rarely presented in standards (except for the nuclear codes).

21

6. ACKNOWLEDGEMENTS

This work was funded by The Nuclear Installations Inspectorate (Nil). The authors would like to thank Dr. C. Formby of the Nil and their colleagues at TWI for many useful comments. Thanks are also due to Mrs H L Comwell and Miss F J Watson for preparing the manuscript.

7. REFERENCES

1 Gensure J G, Potts D L (Ed): International metallic materials cross-reference1, Genium, New York, 1979.

2 API 5L: Specification for line pipe1, American Petroleum Institute, Washington D. C, 1990.

3 API 5CT: 'Specification for casing and tubing1, American Petroleum Institute, Washington D. C, 1989.

4 ASTM E 208-91: 'Standard test method for conducting drop weight test to determine nil-ductility transition temperature of ferritic steels1, American Society for Testing and Materials, Philadelphia, 1989.

5 ASTM E 436-74 (Reapproved 1986): Standard test method for drop weight tear tests of ferritic steels1, American Society for Testing and Materials1, Philadel-phia, 1986.

6 BS EN 10045-1:1990: 'Metallic materials - Charpy impact test - Part 1 : Test method1. European Committee for Standardization, Brussels, 1990.

7 ASME: 'Pressure Vessel and Boiler Code', American Society of Mechanical Engineers, New York, 1990.

8 BS4515: 'Process of welding of steel pipelines on land and offshore', British Standards Institution, London, 1984.

9 BS5500: 'Specification for fusion welded pressure vessels', British Standards Institution, London, 1991.

10 BSI PD6493: 'Guidance on some methods for the derivation of acceptance levels for defects in fusion welded joints', British Standards Institution, London, 1980.

11 BSI PD6493: 'Guidance on methods for assessing the acceptability of flaws in fusion welded structures', London, 1991.

12 Harrison R P, Loosemore K, Milne I and Dowling A R: 'Assessment of the integrity of structures containing defects', CEGB R/H/R6 - Rev. 2, April 1980.

13 Milne I, Ainsworth R A, Dowling A R, Stewart A T: 'Assessment of the integrity of structures containing defects', CEGB R/H/R6 - Rev. 3, April 1986.

22

6. ACKNOWLEDGEMENTS

This work was funded by The Nuclear Installations Inspectorate (Nil). The authors would like to thank Dr. C. Formby of the Nil and their colleagues at TWI for many useful comments. Thanks are also due to Mrs H L Comwell and Miss F J Watson for preparing the manuscript.

7. REFERENCES

1 Gensure J G, Potts D L (Ed): International metallic materials cross-reference1, Genium, New York, 1979.

2 API 5L: Specification for line pipe1, American Petroleum Institute, Washington D. C, 1990.

3 API 5CT: 'Specification for casing and tubing1, American Petroleum Institute, Washington D. C, 1989.

4 ASTM E 208-91: 'Standard test method for conducting drop weight test to determine nil-ductility transition temperature of ferritic steels1, American Society for Testing and Materials, Philadelphia, 1989.

5 ASTM E 436-74 (Reapproved 1986): Standard test method for drop weight tear tests of ferritic steels1, American Society for Testing and Materials1, Philadel-phia, 1986.

6 BS EN 10045-1:1990: 'Metallic materials - Charpy impact test - Part 1 : Test method1. European Committee for Standardization, Brussels, 1990.

7 ASME: 'Pressure Vessel and Boiler Code', American Society of Mechanical Engineers, New York, 1990.

8 BS4515: 'Process of welding of steel pipelines on land and offshore', British Standards Institution, London, 1984.

9 BS5500: 'Specification for fusion welded pressure vessels', British Standards Institution, London, 1991.

10 BSI PD6493: 'Guidance on some methods for the derivation of acceptance levels for defects in fusion welded joints', British Standards Institution, London, 1980.

11 BSI PD6493: 'Guidance on methods for assessing the acceptability of flaws in fusion welded structures', London, 1991.

12 Harrison R P, Loosemore K, Milne I and Dowling A R: 'Assessment of the integrity of structures containing defects', CEGB R/H/R6 - Rev. 2, April 1980.

13 Milne I, Ainsworth R A, Dowling A R, Stewart A T: 'Assessment of the integrity of structures containing defects', CEGB R/H/R6 - Rev. 3, April 1986.

22

14 BS5447: 'Plane strain fracture toughness (KIC) of metallic materials1, British Standards Institution, London, 1977.

15 BS5762: 'Crack opening displacement (COD) testing', British Standards Institution, London, 1979.

16 BS7448 Part 1: ' Method for determination of Klc, critical CTOD and critical J values of metallic materials', British Standards Institution, London, 1992.

17 Willoughby A A: 'A graphical reasoning tool to aid the estimation of fracture toughness', 3rd Int. Conf. on Computer Technology in Welding, Brighton, 4-7 June 1990, Abington Publishing, Abington UK, 1990.

18 Farr J R: 'The ASME Boiler and Pressure Vessel Code: Overview', Proc. Conf. Pressure Vessel Codes and Standards - Developments in Pressure Vessel Technology-5', Ed. R W Nichols, Elsevier Applied Science, London, 1987.

19 Chockie L J: 'The ASME Boiler and Pressure Vessel Code: Section III -Rules for construction of nuclear power plant components', Proc. Conf. 'Pressure Vessel Codes and Standards - Developments in Pressure Vessel Technology-5', Ed. R W Nichols, Elsevier Applied Science, London, 1987.

20 Farr J R: The ASME Boiler and Pressure Vessel Code: Section VIII -Pressure Vessels', Proc. Conf. 'Pressure Vessel Codes and Standards - Developments in Pressure Vessel Technology-5', Ed. R W Nichols, Elsevier Applied Science, London, 1987.

21 PVRC Recommendations on toughness requirements for ferritic materials, WRC Bulletin 175, 1972.

22 Houston R: 'British Standards Institution Boiler and Pressure Vessel Design Criteria', Proc. Conf. Pressure 'Vessel Codes and Standards - Developments in Pressure Vessel Technology-5', Ed. R W Nichols, Elsevier Applied Science, London, 1987.

23 BS5500: 'Specification for unfired fusion welded pressure vessels, Appendix D, Requirements for ferritic steels', British Standards Institution, London, 1991.

24 CODAP: 'French Code for the construction of unfired pressure vessels, Part M, Appendix MAZ, 1984.

25 Thomas A, Grandemange J M: 'French Codes and Standards on boiler and pressure vessel Technology', Proc. Conf. Pressure Vessel Codes and Standards -Developments in Pressure Vessel Technology-5', Ed. R W Nichols, Elsevier Applied Science, London, 1987.

26 Lidbury D P G, Morland E: 'Review of fracture toughness requirements and data relevant to LWR reactor pressure vessels', International Journal for Pressure Vessel & Piping, 29, 1987, pp343-428.

23

27 Pellissier-Tanon A, Grandemange J M: 'Consideration on the manner of accounting for fast fracture risk in the design of PWR vessels', International Journal of Pressure Vessel & Piping, 25, 1986, 217-229.

28 Noel R: 'Life duration of PWR nuclear power plants', International Journal of Pressure Vessel & Piping, 32, 1988, 415-436.

29 AD Merkblatt W10: 'Materials for pressure vessels', DIN 1987.

30 AD Merkblatt HP5/2: 'Manufacture and testing pressure vessels', DIN 1984.

31 Steffen H P: 'German boiler and pressure vessel codes and standards: materials, manufacture, testing, equipment, erection and operation', Proc. Conf. 'Pressure Vessel Codes and Standards - Developments in Pressure Vessel Technology-5', Ed. R W Nichols, Elsevier Applied Science, London, 1987.

32 Kussmaul K, Roos E, Fohl J: 'Principles of the German Approach to the analysis of flawed structures', International Journal of Pressure Vessels & Piping, 25, 1986, 185-215.

33 Nakagawa Y: 'Japanese boiler and pressure vessel Codes and Standards', Proc. Conf. "Pressure Vessel Codes and Standards - Developments in Pressure Vessel Technology-5', Ed. R W Nichols, Elsevier Applied Science, London, 1987.

34 JIS B 8243-1981: 'Japanese Industrial Standard for construction of pressure vessels', 1981.

35 Various Australian unfired pressure vessel, boiler and plate standards (see Appendices for specific titles), Standards Association of Australia, Sydney.

36 Jones D G, Nokleybye A: 'Zeepipe fracture toughness requirements', Proc. 'Pipeline Technology Conference', Ed. R Denys, 15-18 October 1990, Oostende, Royal Flemish Society of Engineers, 1990, 10.17-10.23.

37 Lazor R B, Glover A G: 'Post weld stress relief of high strength line pipe steels', Welding Institute of Canada (RC157/2/84), 1984.

38 Pisarski H G, Harrison J D: 'Fracture toughness considerations for offshore structures in UK waters', Metal Construction, 18 (12), 1986, 748-753.

39 Harrison J D: 'Fracture prevention in petro-chemical systems', Proc. Conf. 'Fracture Prevention in energy and transport systems', Eds. I Le May, S N Monteiro, Chameleon Press, London, 1984.

40 Hartbower C E: 'Reliability of the AASHTO temperature shift in material toughness testing', Structural Engineering Series No.7, US Department of Transpor-tation, Washington D.C., 1979.

24

s Upper shelf

Transition region

Lower shelf

Fig. I The variation of toughness with temperature for a ferritic material "

8 C

t Increasing test rate

Fig. II The qualitative effect of altering the test rate on the temperature transition curve.17

25

Temperature

Temperature

CO

c

f .o

Increased dimensions *1

I

^"~" ! Reduced . dimensions

Temperature

Fig. III The qualitative effect of altering the specimen dimensions proportionally on the temperature transition curve.17

Co CO Of

c t /

Increasing thickness

Temperature

FigJV The qualitative effect of altering the specimen thickness (keeping width and crack depth constant) on the temperature transition curve.77

26

Increasing crack depth

Temperature

Fig. V The qualitative effect of altering the specimen crack depth (keeping other dimensions constant) on the temperature transition curve.77

p

u

r—

1 1 1 1 1 1 —

* Critical level (US NRO 1

Envelope forecast

ν ^ Ί

Δ

y ^ ^^^^^^Probable limit

Supervision Sx1019ncm'2

results

I I I 1 I I

4

4

"H

«H

10 20 30 40 Time, years

50 60

Fig. VI Forecast temperature transition shift for French 900 MWPWR, due to irradiation embritt/ement.2'

27

L _ I I I I I I I I I 1 10* * * S * 10" 2 3 5 8 102o

Fast neutron (E^IMeV) fluence, n/cm2

Fig. VII ASME XI, Appendix A: RTNDT shift due to fast neutron fluence:

28

too

300

200

100

SO

y

-

0.35 0.30

(a)

i r

0.25

1 1

1 — 1 1 1 ι —

Upper limit _ _ ^ ^

.—| s ^ s ^ 0.20X Cu 0.1SX Cu 0.10X Cu

XP = 0.012

I I I I

1 r

Lower limit XCu * 0.08 XP * 0.008

I L

A

\

A

2 x 10" Neutron dose, n/cm* (E

Fig. VIII Effect of irradiation embrittlement on RTN0T shift and upper shelf Charpy toughness (USNRC?6)·

29

COMPENDIUM

CODE TOUGHNESS REQUIREMENTS

COMPENDIUM

CODE TOUGHNESS REQUIREMENTS

SECnON A: PRESSURE VESSEL TOUGHNESS REQUIREMENTS

A.L ASME III Rules for Construction of Nuclear Power Plant Components (1989

(1)) 39

A.2. ASME VIII Rules for Construction of Pressure Vessels (1989 (2)) 44

A.3. ASME III Appendix G (Protection Against Non-Ductile Failure) (1989 (3)) . . 45

A.4. ASME XI Appendix A (Analysis of Flaws) (1989 (5)) 46

A.5. ASME XI Appendix G (Fracture Toughness Criteria for Protection Against Failure) (1989(6)) 47

A.6. American Petroleum Institute (7) 47

A.7. PVRC Recommendations on Toughness Requirements for Ferritic Materials (1972,(8)) 48

A.8. Australian Standards (9) 48

A.9. Austrian Federal Statute: Materials and Construction Regulations for Steam Boilers (1949, Amended 1979 (10)) 51

A.IO. French Code for the Construction of Unfired Pressure Vessels CODAP (1980, Revised 1984, (11)) 51

A l l . German Pressure Vessel Code (12) 52

A12. ICI E354C, Specification for Pressure Vessels (1979, (13)) 52

A13. BS5500, Specification for Unfired Fusion Welded Pressure Vessels (1991, (14)) 53

A.14. Japanese Industrial Standard, JIS Β 8243-1981, Construction of Pressure Vessels (1981, (15)) 54

A. 15. Dutch Rules for Pressure Vessels: Sheet No. 110 (1975, Revised 1983, (16)) . 54

A.16. The Norwegian Pressure Vessel Committee, General Rules for Pressure Vessels (1978, (17)) 55

A. 17. The Swedish Pressure Vessel Code (Superseded) (1977, (18)) 55

A. 18. ECISS/TC22 N52, Fracture Toughness Concept of the Swedish Pressure Vessels Code (1989, (19))

33

55

SECTION Β: PIPELINE AND TUBE TOUGHNESS REQUIREMENTS

B.l. AMOCO (1990, (20)) 61

B.2. British Gas, AISI, Batteile (1990 (21)) 61

B.3. American Petroleum Institute (7) 64

B.4. Australian Standards (9) 67

B.5. BS4515: Specification for Welding of Steel Pipelines on Land and Offshore (1984(24)) 69

B.6. Canadian Standards (25) 70

B.7. Det Norske Veritas: Rules for Submarine Pipeline Systems, Norway (1981, (26)) 70

SECTION C: nXED OFFSHORE TOUGHNESS REQUIREMENTS

C I . American Bureau of Shipping (27) 75

C.2. American Petroleum Institute (7) 76

C.3. BS7191, Weldable Structural Steels for Fixed Offshore Structures (198929)) . 79

C.4. Bureau Veritas, France, Rules and Regulations for Offshore Platforms (1975, (30)) 80

C.5. Lloyd's Register, Rules and Regulations for Offshore Platforms (1989, (31)) . . 81

C.6. Department of Energy: Offshore Installations: Guidance on Design, Construction and Certification (1990 (32)) 82

C.7. EEMUA Publ. No. 150: Steel Specification for Fixed Offshore Structures (1987, (33)) 83

C.8. Det Norske Veritas: Rules for the Design, Construction and Inspection of Offshore Structures, Norway (1981, (34)) 84

C.9. Det Norske Veritas Technical Note; Fixed Offshore Installations Fracture Toughness Properties and Post Weld Heat Treatment (35) 84

SECnON D: MOBILE OFFSHORE UNITS AND SHIPPING TOUGHNESS REQUIREMENTS

D.I. Register of Shipping of the People's Republic of China: Rules for the Construction of Sea-Going Steel Ships (1978, (36)) 89

D.2. U.S. Coast Guard (1970, (37))

34

91

D.3. American Bureau of Shipping (27) . 92

D.4. Germanischer Lloyd: Rules for the Classification and Construction of Sea-Going Steel Ships, Vol. Ill Materials and Welding (1976 (38)) . 94

D.5. Lloyd's Register: Rules for the Manufacture, Testing and Certification of Materials (1984 (39)) . 94

D.6. Registro Italiano Navale (RINA): Rules for the Construction and Classification of Ships (1990, (40)) . 95

D.7. Det Norske Veritas: Rules for Classification of Steel Ships, Materials and Welding (1984, (41)) . 96

D.8. Japan: Rules and Regulations for the Construction and Classification of Ships (1978, (42)) . 97

SECTION Ε: PETROCHEMICAL PLANT TOUGHNESS REQUIREMENTS

E.I. ASME B31.3 Chemical Plant and Petroleum Refinery Piping Requirements (1990(43)) . 101

E.2. American Petroleum Institute (7) . 102

E.3. British Standards . 103

SECTION F: BRIDGE TOUGHNESS REQUIREMENTS

F.L AASHTO Requirements . 109

F.2. BS5400: PART 6: Specification for Materials and Workmanship, Steel (1980, (48)) . 110

SECTION G: MATERIAL TOUGHNESS REQUIREMENTS

G.I. ASME II Material Specification, Part A - Ferrous (1989 (49)) . 115

G.2. Australian Standards (9) . 124

G.3. International Standards Organisation . 124

G.4. Norme Belge: Structural Steels, (1976, (51)) . 125

G.5. British Standards . 125

G.6. Japanese Welding Engineering Society Standard (61) . 136

C.7. European Coal and Steel Community Euronorm (62)

35

. 137

SECTION H: WELDING CONSUMABLE TOUGHNESS REQUIREMENTS

H.l. ASME II Part C: Welding Rods, Electrodes and Filler Metals (49) 141

H.2. American Bureau of Shipping 145

H.3. American Welding Society (AWS) (63) 146

H.4. Australian Standards (9) 147

H.5. British Standards 150

H.6. Canadian Standards 153

H.7. Naval Engineering Standard 769: Weld Consumables for Structural Steels. Approval System, (1979, (68)) 155

H.8. Swedish Standard MNC 970E: Welding Electrodes - Covered Electrodes for Manual Metal Arc Welding and Gravity Welding of Carbon Steels, Carbon Manganese Steels and Fine Grained Steels with Increased Yield Stress, (1979, (69)) 156

Compendium References 157

Compendium Figures 162

36

SECTION A:

PRESSURE VESSEL TOUGHNESS REQUIREMENTS

SECTION A:

PRESSURE VESSEL TOUGHNESS REQUIREMENTS

A.l. ASME ΠΙ RULES FOR CONSTRUCTION OF NUCLEAR POWER PLANT COMPONENTS (1989 (1))

A.l.l. ASME III Division 1 - Subsection NB (Class 1 Components) (1)

This subsection (1) requires that pressure retaining material and material welded thereto are impact tested except for: material with a nominal section thickness equal or less than 5/8", bolting and bar of nominal size equal or less than 1", pipe, tube, pumps and valves with nominal pipe size equal or less than 6" diameter, material for pumps, valves and fittings with all pipe connections of size equal or less than 5/8", austenitic stainless steels and non-ferrous materials.

Drop weight tests (DWT) are not required for the martensitic high alloy chromium (series 4xx) steels and precipitation hardening steels (listed in Appendix I of ASME III). For these steels, a lateral Charpy expansion of 40mils is required (for thicknesses greater than 2Vi"). The required locations and orientations of Charpy V-notch specimens are described in Section NB-2322 for forgings, castings, pipe, tube, nozzles, bolting and plate of various heat treatments.

For pressure retaining materials other than bolting, Section NB-2331 requires that the reference nil-ductility temperature RT^j is established. Firstly, a temperature TNDT (equal to or above the nil ductility transition temperature) must be established by DWT tests. At a temperature not greater than TNDT +60°F, each Charpy specimen (described in Section NB-2321.2) shall exhibit at least 35mils lateral expansions and not less than 50ft.lb absorbed energy. Retesting in accordance with NB-2350 is permitted if the average value meets the minimum requirement and the minimum value is not less than 10ft.lb or 5mils below the specified requirements, and not more than one specimen is below the minimum requirement. When these require-ments are met RTj^ = TNDT. Section NB-2331 provides guidance on establishing RTNDT iï ^ese requirements are not met, based on extra Charpy tests or the Charpy transition curve. These procedures must be applied to the parent material, the weld metal and HAZ. Account should be taken of the effects of irradiation on the material properties in the core belt line region of the reactor vessel. Also, consideration should be given to the hydrostatic test temperature requirements of the vessel.

For material for piping, pumps and valves with nominal wall thickness of less than 2ViM, 3 Charpy specimens should be tested at a temperature equal or less than the minimum service temperature in the parent plate, weld metal and HAZ (Section NB-4335). All specimens must meet the following requirements:

39

^^^^^BB-ggBBBUgaB^^^^^^^^^^S^^B^^—gxaasags-BX:

I t s 5/8 5/8 < t s 3/4 3/4 < t s VA

\VA < t s 2Vi

Lateral expansion, mils |

20 25 40

i n n i asssssrMmÊÊÊÊmÊÊÊÊÊaÊÊaaaiÊaÊaaÊÊmÊÊÊÊÊÊÊÊÊÊÊÊÊÊÊÊÊÊÊÊmÊimÊmmm

For materials of nominal thickness greater than 2W\ the lateral expansion and impact energy requirements are 35mils and 50ft.lb at a temperature not greater than RTxrnT + 60°F.

For bolting material the following requirements must be met:

| Nominal diameter D, in.

1 D s l 1 1 < D S 4

[ 4 < D

Lateral expansion, mils

25 25

Absorbed energy, ft.lb |

45

Section NB-2342 provides guidance as to the number of toughness tests required for forgings and castings of different heats and masses, bars, tubular products and fittings and bolting material. Sections NB-2400 and NB-4335 describe the test procedures required for impact testing of the weld metal and HAZ of Class 1 components.

A.1.2. ASME III Division 1 - Subsection NC (Class 2 Components) (1)

This subsection (1) requires that pressure retaining material and material welded there to be impact tested, with similar exceptions as in subsection NB, as well as: materials for which the lowest service temperature (LST) exceeds 150°F, and the materials in the following table, for which the listed value of TNDT is lower than the LST by an amount A established by the rule in ASME III Appendix R. A is presented in graphical form (Fig.l), as a function of section thickness:

| Material

1 SA-537, Class 1 1 SA-516, Grade 70 1 SA-516, Grade 70 1 SA-508, Class 1 1 SA-533, Grade B

SA-299 SA-216 Grades WKB, WCC SA-36

1 SA-508 l·——gaea— uni n n a t ^ a a ^ ^ ^ ^ a a s

Material Condition

N Q & T N Q & T Q & T N Q & T HR Q & T

TNDT» F 1

^ 3 0 1 -10 1

o 1 +10 I +10 1 +20 1 +30 I +40 I +40 I

The reader is referred to Table NC-2311(a) - 1 of ASME III subsection NC (6) for notes on the application of this table.

40

Nominal wall thickness t, in

For materials not exempt from impact testing, Charpy V-notch testing should be performed at or below the lowest service temperature (LST), or by DWT testing to show that the Τ,^τ £ (LST - A) requirement is satisfied in accordance with the rules in Appendix R of ASME III.

Sections NC-2322 and NC-2340 describe the location, number and orientations of impact test specimens, while Section NC-2332 presents impact test acceptance criteria. For pressure retaining materials (parent, weld metal and HAZ) the requirements in Table A.l must be met (3 specimens). (The Tables are given at the end of this Section.)

The reader is referred to Tables NC-2332.1-1 and NC-2332.1-2 in ASME III subsection NC where there are notes concerning the application of these require-ments. In addition, DWT tests must be performed with a requirement of at least two !no break1 specimens. For bolting materials the same requirements as for ASME III subsection NB must be met.

One retest is permitted at the same temperature (Section NC-2350) if the average value meets the minimum requirements, not more than one specimen per test is below the minimum requirement, and that specimen is not lower than 5ft.lb or 5mils below the minimum requirement. A retest consists of two specimens, each of which must give toughness values greater than the average requirement. Sections NC-2400 and NC-4335 describe the test procedures required for impact testing of the weld metal and HAZ of Class 2 components.

A.1.3. ASME III Division 1 - Subsection ND (Class 3 Components) (1)

This subsection (1) requires that pressure retaining materials and material welded thereto are impact tested, with similar exceptions to subsection NB, as well as materials for which the lowest service temperature (LST) exceeds 100°F, and the following materials for which the LST is equal or more than the tabulated temperature. (This exemption does not exclude impact testing of weldments).

1 Material

1 SA-516 Grade 70 1 SA-537 Class 1 1 SA-516 Grade 70 1 SA-508 Class 1 1 SA-508 Class 2 1 SA-533 Grade 1 B - Class 1 1 SA-216 Grades -

WCB, WCC | SA-299

Material Condition

N N Q & T Q & T Q & T Q & T

Q & T

N

LST, °F, for thickness t, inch

5/8<ts3/4

-30 -40 * *

3/4<t=sl

-20 -30 *

*

*

*

1<ί*1^

0 -30

* * *

*

*

\Vi<l*2Vi 1

0 1 -30 1 - io 1 io I 40 I io 1

30 I

20 |

where * indicates that the LST shown in the 1V4 < t £ 2V4" column may be used for these thicknesses.

41

Sections ND-2322 and ND-2340 describe the location, orientation and number of impact specimens, while Section ND-2330 presents the impact test acceptance criteria. Pressure retaining material, including vessels, tanks, piping, pumps, fittings and valves are required to be tested at a temperature lower or equal to the LST, and shall meet the requirements in Table A.2 (3 specimens):

The reader is referred to Tables ND-2332(a)-l and ND-2332(a)-2 in ASME III subsection ND where there are notes concerning the application of these require-ments. For bolting materials the following requirements must be met:

1 Nominal diameter D, in.

1 D s l 1 l<D: î4 | 4 < D

Lateral expansion, mils

15 20

Adsorbed energy, 1 ft.lb

30 35

Retest procedures are similar to those in subsection NC (see Section A.1.2). Sections ND-2400 and ND-4300 describe the test procedures required for impact testing of the weld metal and HAZ of Class 3 components.

A.1.4. ASME ΠΙ Division 1 Subsection NE (Class MC Components) (1)

This subsection (1) requires that pressure retaining materials are impact tested, with exceptions similar to those described in ASME III subsection NB, with the additions that the lowest service temperature (LST) is greater than the T^j values in the following table by an amount A established by ASME III Appendix R, where thickness effects are accounted for (see Fig.l):

1 Material

SA-537 Class 1 1 SA-516 Grade 70 1 SA-516 Grade 70 1 SA-508 Class 1 1 SA-299 | SA-216 Grades WCB, WCC

Material condition

N Q & T N Q & T N Q & T

TNDT» F 1

-30 1 -10 1

o 1 +10 1 +20 +30

Ulis exemption does not apply to either the weld metal or the welding procedure qualification from impact testing. The reader is referred to Table NE-2311(a)-l where there are notes concerning the application of those exemptions.

Sections ΝΈ-2320 and NE-2340 describe the location, orientation and number of impact specimens required, while Section NE-2330 presents the test acceptance criteria. Either Tellini' drop weight testing must show that the requirement T yr £ (LST - A) is satisfied in accordance with the rules of ASME III Appendix R (see Fig.l), or Charpy impact testing must be performed at or below LST. Additional test temperature requirements must be met if a hydrostatic or pneumatic test is required at temperatures less than LST. For pressure retaining materials the same Charpy V -

42

notch lateral expansion and absorbed energy levels as described in ASME III subsection NC are required. Impact testing of bolting material may be performed at the LST, in which case the requirements presented in ASME subsection NB apply. Alternatively, the specimens may be tested at 30°F or more below the LST, in which case the requirements presented in ASME III subsection ND must be met.

Retest procedures are similar to those in Subsection NC (see Section A. 1.2). Sections NE-2400 and NE-4300 describe the test procedures required for impact testing of the weld metal and HAZ of Class MC components.

A.1.5. ASME ΠΙ Division 1-Subsection NF (Component Supports) (1)

The subsection (1) requires that support materials are impact tested with exceptions similar to subsection NB, with the following additions: supports where the maximum stress is less than 6000psi, materials for Class 2 supports for which the lowest service temperature (LST) exceeds 150°F, Class 3 supports where the LST exceeds 100°F, and Class 1, 2 or MC supports (thickness, t * 2W\ LST s 30°F above temperature tabulated in ASME III subsection NC) and Class 3 supports (thickness, t * 2W\ LST * temperature tabulated in ASME III subsection NQ. These exemptions do not apply to the weld metal. Integral attachments to components or piping shall meet the toughness requirements of the component or piping, as described in the relevant subsection.

Sections NF-2320 and NF-2340 describe the location, orientation and number of impact specimens, while Section NF-2320 presents the impact test acceptance criteria. The requirements in Table A.3 apply to support materials other than bolting (3 specimens, parent material, weld metal and HAZ):

For bolting materials an average lateral expansion of 25mils is required for nominal diameters of greater than 1".

Retest procedures are similar to those in Subsection NC (see Section A. 1.2). Sections NF-2400 and NF-4300 describe the test procedure required for impact testing of the weld metal and HAZ of component supports.

Λ.Ι.6. ASME ΠΙ Division 1 - Subsection NG (Core Support Structures) (1)

This subsection (1) requires that core support structures shall be impact tested (although the fracture mechanics based methods of ASME III Appendix G may be used as an alternative procedure for assuring protection against non-ductile fracture), with similar exceptions to those of subsection NB. Sections NG-2320 and NG-2340 describe the location, orientation and number of impact specimens, while Section NG-2330 presents the impact test acceptance criteria. For core support structures (other than threaded structural fasteners) with nominal wall thickness equal or less than 2" the following impact requirements apply (3 specimens tested at a temperature lower than or equal to the lowest service temperature (LST), for parent material, weld metal and HAZ):

43

1 Nominal wall thickness t, in.

1 t s 5/8 5/8 < t s 3/4 3/4 < t s VA

\ VA < t s. 2ιΔ

Lateral expansion, mils |

20 25 40

For core support structures with nominal wall thickness greater than 2" the reference nil ductility temperature ΚΓΝΌτ must be established. The procedures for determining RTNDT and acceptance criteria are the same as those described in ASME III subsections NB (described in Section A.l.l of this report). For threaded fasteners, the same requirements as for ASME III subsection NB apply.

Retest procedures are similar to those in subsection NC (see Section A.1.2). Sections NG-2400 and NG-4300 describe the test procedures required for impact testing of the weld metal and HAZ of Class NG components.

A.2. ASME VIII RULES FOR CONSTRUCTION OF PRESSURE VESSELS (1989 (2))

A.2.L Division 1 (2)

ASME VIII Division 1 (2) requires that Charpy impact tests are carried out on weldments and all materials for shells, heads, nozzles and other vessel parts, subject to the provisions of ASME VIII subsection C (Requirements pertaining to classes of materials). The reader is referred to subsection C, where exemptions to impact testing are described for parent material, weld metal and HAZ (Sections UCS-66 and UCS-67). These exemptions are defined in text, tables and figures, and depend on the minimum design metal temperature, section thickness and applied stress, for various classes and grades of steels.

Section UG-84 of ASME VIII Division 1 describes the location, orientation and number of impact tests, and accounts for the use of sub-size Charpy specimens for thin sections (t < 0.438"). It is required that sub-size specimens are tested at temperatures less than the minimum design metal temperature, by the amounts given in Table UG-84.2 of ASME VIII (0-50°F for full size to 1/4 size specimens).

Figure UG-84.1 of ASME VIII (see Fig.2) shows the Charpy impact energies (average of three specimens) required for full size (10 x 10mm) specimens, tested at a temperature not greater than the minimum design metal temperature. The average required impact energy is a function of the material thickness and the minimum specified yield strength of the material (*65ksi). The minimum impact energy of three specimens shall not be less than 2/3 of the average required energy. A retest is permitted if the average value exceeds the minimum requirement, and when two impact values are less than the average requirement or when the value of a single specimen is less than the minimum requirement. The retest consists of three specimens, all of which must exceed the average toughness requirement.

44

A.2.2. Division 1 - Alternative Rules (2)

This section of ASME VIII Division 1 (2) presents energy requirements for carbon and low alloy steels with specified minimum tensile strengths of less than 95ksi (3 specimens):

BHHBBBBBSBaSSSSSaBSSaBHBHCBBBBBS

1 Tensile strength | ay, ksi

1 ay * 65 1 65 < oy * 75

75 < oy < 95 ■■■■■■■■aaasssaBBasaasaEB

Impact energy, ft.lb 1

Fully deoxidized steels

Average

13 15 20

Minimum

10 12 15

Other steels 1

Average

10 13

Minimum 1

7 1 10

For steels where oy * 95ksi, a lateral expansions of 0.015" or greater is required (minimum of 3 specimens). Provision is made in Section AM-210 of ASME VIII for testing of sub-size Charpy specimens. For full size specimens the test temperature should not be lower than the minimum permissible design temperature. If sub-size specimens are employed then the test temperature must be reduced by an amount given in Table AM-211.2 of ASME VIII (0 to 50°F for full size to VA size specimens).

Retest procedures are similar to those in Section A.2.1, with retest criteria for lateral expansion also presented.

Section AM-213 gives test temperatures for impact testing of high alloy steels, while Section AM-214 presents toughness requirements for bolting materials. Section AM-218 and Fig.AM-218.1 of ASME VIII detail toughness testing exemption criteria for carbon and low alloy steels, based on material type and section thickness.

Article M-3 presents special requirements for impact testing of quench and tempered ferritic steels (with enhanced tensile properties), while Part AT of ASME VIII describes procedures for impact testing of welds and vessel test plates of ferrous materials.

A3. ASME ΠΙ APPENDIX G (PROTECTION AGAINST NON-DUCTILE FAILURE) (1989 (3))

This Appendix (3) presents a procedure for obtaining allowable design loadings for ferritic pressure vessel components, based on linear elastic fracture mechanics principles. A maximum postulated flaw is assumed at each location of interest, and the mode I stress intensity factor, Kj, is evaluated and compared to a reference toughness value Kœ, which is given in Fig.G-2210-1 of Appendix G (see Fig.3). KJR is the lower bound of Klc, Kw and K,a data obtained from SA-533 Grade B Class 1 and SA-508-1, SA-508-2 and SA-508-3 steel. The KK curve is a function of the reference nil ductility temperature RTNDT and has the analytic form:

45

KJR = 26.78 + 1.233 exp (0.0145 (T - R T ^ + 160)) [ksiVin, °F]

Higher toughness values may be used if justified by the particular material and circumstances being considered. This Km curve may be used for ferritic steels which meet the ASME requirements of NB-2331 (concerning toughness test requirements) and which have a specified minimum yield strength at room temperature of 50ksi or less. For materials which have a specified minimum yield strength greater than 50ksi but less than 90ksi then the K^ curve may be used if fracture toughness data is obtained from at least three heats of the material on a sufficient number of specimens to cover the temperature range of interest, including weld metal and heat affected zone, and provided that the data is equal to or above the K^ curve. The effect of radiation on the fracture toughness of these steels must be determined prior to its use in manufacture.

For section thicknesses t of 4M to 12" a maximum postulated surface breaking defect of depth 0.25 t and length 1.5 t is assumed, orientated normal to the direction of maximum stress. For sections greater than 12" thick, the postulated defect for the 12" section is used. For sections less than 4" thick, a 1" deep defect is conserva-tively postulated. Smaller defect sizes may be used if justified (WRCB 175 (4) provides guidance for this). A safety factor of approximately two on flaw size is incorporated into the Appendix G procedures (2).

The applied stress intensity factor is calculated by multiplying the applied membrane and bending stress components by membrane and bending stress magnification factors (Mm and NQ, which are presented in graphical form in Fig.G-2214-1 of Appendix G (3). Mm and Mb are functions of the section thickness. The effect of a radial thermal gradient across the wall thickness is accounted for in Fig.G-2214-2 and G-2214-3 of Appendix G. If the applied stresses exceed the yield strength of the material then the procedures described in WRCB 175 (4) may be used (instead of Fig.G-2214-1 to G-2214-3). Appendix G also provides guidance on the assessment of nozzles, flanges and shell regions near geometric discontinuities. Section G-2400 provides recommendations on hydrostatic test temperatures (RT,^ + 60°F for vessels before loading fuel, and temperatures based on applied stress intensities in the region of postulated flaws after fuel has been loaded).

A.4. ASME XI APPENDIX A (ANALYSIS OF FLAWS) (1989 (5))

This Appendix (5) provides a procedure for determining the acceptability of flaws that have been detected during in-service inspection (excluding pre-service inspection) that exceed the allowable flaw indication standards of IWB-3500. The procedure is based on linear elastic fracture mechanics principles, and applies to ferritic materials 4" and greater in thickness with specified minimum yield strengths of 50ksi or less in components having simple geometries and stress distributions. The basic principles may be extended to other ferritic materials (including clad materials) and complex geometries. The procedure may not be applied to austenitic or high nickel alloys.

Flaws are assumed to be planar and elliptical in shape, projected onto a plane perpendicular to the maximum principle stress direction. The applied Mode I stress intensity factor, K,, is calculated as follows:

46

K, = (omMn + obMb) (Jta/Qf

where om and ob are the membrane and bending components of applied stress, a is the relevant flaw dimension, and Mm, Mb and Q are constants which are functions of the flaw geometry. These constants are presented graphically in Fig.A-3300-1 to A-3300-5 for embedded and surface breaking flaws.

Lower bound material toughnesses values in terms of K^ and K^ are presented in Fig.A-4200-1 of Appendix A (see Fig.4) as a function of the reference nil ductility temperature RTVrox. TTiese curves were derived from data for SA-533 Grade B Class 1, SA-508 Class 2 and SA-508 Class 3 steel.

Guidance on fatigue crack growth rates is given, and Paris law constants are presented in graphical form in Fig.A-4300-1 and A-4300-2 for carbon and low alloy ferritic steels exposed to air and water environments. The effects of irradiation in toughness is accounted for in Section A-4400, determined from surveillance specimens.

A.5. ASME XI APPENDIX G (FRACTURE TOUGHNESS CRITERIA FOR PROTECTION AGAINST FAILURE) (1989(6))

This appendix (6) presents a procedure for calculating the allowable loadings for ferritic pressure vessel materials in components, based on linear elastic fracture mechanics principles. At each location of interest a maximum postulated flaw is assumed, in the same fashion as Appendix G of ASME III, described elsewhere in this report. The mode I stress intensity factor, K„ is evaluated as in ASME III, and is compared to the same reference toughness Kœ curve (Fig.G-2210-1 in Appendix G, Fig.3 of this Compendium). Appendix G in ASME III and XI are almost identical.

A.6. AMERICAN PETROLEUM INSTITUTE (7)

A.6.1. API 920: Prevention of Brittle Fracture of Pressure Vessels (1990, (7))

API 920 (7) covers three levels of confidence against brittle fracture (categories IA, IB and II). This specification recommends that the category into which a vessel falls be identified, according to its intended service.

API 920 (7) recommends that Fig.USC-66 (Fig.D.l of API 920, Fig.5 of this Compendium) of the ASME code be employed to calculate the minimum design metal temperature (DMT), as a function of section nominal thickness and steel grades. These curves may be used to define Category II materials which are exempt from impact testing. The reader is referred to Appendix D of API 920 where the material classes which comprise curves A, B, C and D of Fig.5 are presented. API 920 refers to the ASME impact toughness requirements, reviewed elsewhere in this report.

47

A.7. PVRC RECOMMENDATIONS ON TOUGHNESS REQUIREMENTS FOR FERRTTIC MATERIALS (1972, (8))

The Pressure Vessel Research Committee (PVRC) of the Welding Research Council (WRC) produced these Recommendations (8) at the request of the ASME Boiler and Pressure Vessel Committee, for their use in considering revisions to the requirements of Section III - Nuclear Power Plant Components (reviewed in Section A.1 and A3). Ferritic material toughness requirements were developed, for reactor pressure retaining components operating below 700°F, based on stress limits allowed by the ASME Code. These requirements concerned safe operating procedures for normal, upset and testing conditions. Emergency and faulted conditions must be treated on a case basis. The WRC Bulletin 175 (8) includes recommendations made to the Atomic Energy Commission.

WRCB 175 (8) describes the evolution of fracture control design procedures, beginning with the transition temperature concept, based on the DWT which is used to evaluate the nil ductility temperature (TNOT). Loading of a structure is permitted only at a specific temperature above the TNDT, by an amount depending on the required application.

The PVRC has developed the reference toughness based approach to fracture control. Linear elastic fracture mechanics (LEFM) is used to assess flaws, based on transition temperature methods for estimating the materials fracture toughness, as well as evaluating the sensitivity of toughness to temperature. A reference fracture toughness (K^, see Fig.3) curve is defined, both analytically and graphically, which is a lower bound to Κ , Κ , and K,t data for a large set of pressure vessel steels.

K» = 1.223 exp {0.0145 [T - ( R T ^ - 160)]} + 26.777 [ksiVin, °F]

where

RTJTOT is the reference nil ductility temperature, defined using DWT and Charpy tests (see Section A.1), for parent material HAZ and weld metal. The required RT,^ must be achievable throughout the life of the component, and so account must be taken for irradiation embrittlement. It is expected that for radiation fluencies of less than 1018n/cm2 (>lMeV) no significant irradiation damage occurs. The design procedure recommended by the PVRC was based on a maximum credible hypothesized flaw being located in the location of interest, of depth defined in Fig.6. The PVRC procedures for assessing the effect of flaws on the structural integrity of nuclear pressure components are similar to those of ASME III Appendix G and ASME XI Appendices A and G (reviewed previously), and will not be repeated here in detail. The reader is referred to Reference 8 for details of the PVRC Recommen-dations.

ΑΛ. AUSTRALIAN STANDARDS (9)

ΑΛΛ. AS 1210-1982: Unfired Pressure Vessels (1982, (9))

Parent metal of pressure parts and of non-pressure parts directly attached by welding are required to be impact tested when the design minimum temperature

48

(DMT) thickness limits in Fig.2.6.2(A) and (B) of AS1210 require impact testing (reproduced as Fig.7 and 8), or when required by Table 2.6.2.2 of AS1210. The reader is referred to this table, which lists low alloy, high alloy, cast iron and non-ferrous metal grades impact testing exemptions.

Figure 2.6.2(A) and (B) define the DMT as a function of thickness and Grade, for as-welded and PWHT conditions. The reader is referred to the explanatory table and notes of Fig.7 and 8 where the test temperatures and impact requirements of 27 and 40J for materials of yield strengths less than or equal to 450MPa and greater than 450MPa are presented. Impact testing is not required for sections of less than 3mm thick. Section 2.6.5 of AS1210 presents details of number, orientation and location of Charpy impact specimens, as well as sub-size Charpy testing.

For most wrought C, C-Mn and low alloy steels, 27J impact toughness is required for materials which have yield strengths less than or equal to 450MPa, and 40J for greater than 450MPa, except for 3lA% Ni steel (18-20J at -100°C), and 9% Ni and ASTM A517 steels (0.38mm lateral expansion at -196°C). Martensitic Cr and ferritic high Cr steels require the same impact toughness as the bulk of the low alloy steels, while austenitic Cr-Ni and high Cr steels require 20J. These values are the average of 3 specimen tests. For 9%Ni steels, an additional requirement that the TNDT> determined by DWT is lower than the DMT, for sections of thickness greater than 16mm, and for DMT < -30°C.

Section 5.2 of AS 1210 specifies weld metal and HAZ toughness requirements, while Table 5.2.9 details exemption for weld metal impact testing for various materials as a function of temperature, otherwise Fig.2.6.2(A) and (B) apply. The number, orientation and location of test specimens are described, as well as retest procedures. The following requirements apply:

| Parent material

1 C, C-Mn steels, as welded

1 Alloy steel

1 3V4%Ni steel

1 9%Ni steel

1 High alloy steels

Impact requirements |

47J for MMA welds. 35J (or 40J) for yield strength s 450MPa (or > 450MPa) at 20°C 1 above parent material test temperatures 1

27J at DMT

20J at DMT

0.38mm lateral expansion at DMT 1

20 or 27J, depending on constituents 1

PWHT C and C-Mn steels and quenched and tempered steels require toughness levels determined as follows:

Cv = 6.5 x 10"6 oy2B

where B is the section thickness and oy is the yield strength. An alternative requirement of 0.38mm lateral expansion is permitted for quenched and tempered

49

steels. Charpy energies of less than 14J are not permitted, and toughness need not exceed 68J. Permissible retest conditions are presented in Table 5.2.18 of AS1210.

A-8.2. AS1228-1984: Boilers - Water-Tube (1984, (9))

This Standard requires the following minimum weld metal Charpy impact levels (3 specimens, at a test temperature less than 50°C or 30°C above the lowest permissible hydrostatic test temperature):

1 Material tensile strength, N/rara2

1 *450 >450

Impact energy, J |

27 1 40

If one test value is less than these requirements, by not greater than 10%, then a retest is permitted. Section 5 of this standard describes the location and orientation of Charpy test specimens.

A.8.3. AS1548-1981: Steel Plates for Boilers and Pressure Vessels (1981, (9))

This standard requires the following Charpy impact toughness levels (3 specimens, parallel to RD)

1 Grade Π

1 5-490N, A

1 7-430N, A

1 8-490N, A

Sub-grade \

LO L20 L20 L50

LO L20 L40

LO L20 L40

Test temperature, °C

0 -20 -40 -50

0 -20 -40

0 -20 -40

Impact energy, J 1

Average

55 47 31 27

55 47 31

| 55 47

! 31

Minimum 1

41 1 35 1 23 1 20 1

41 1 35 1 23 1

41 1 35

[23

Section 3 of this standard describes the number, orientation and location of Charpy test specimens, as well as retest procedures and requirements for sub-size specimens.

A.8.4. AS1797-1981: Fire-Tube, Shell and Miscellaneous Boilers (1981, (9))

This standard requires that a minimum weld metal Charpy impact toughness of 27J be achieved when the test temperature is not greater than 50°C. Section 5 of this

50

standard describes the number, location and orientation of test specimens for Class 1, 2 and 3 boilers.

A.9. AUSTRIAN FEDERAL STATUTE: MATERIALS AND CONSTRUCTION REGULATIONS FOR STEAM BOILERS (1949, AMENDED 1979 (10))

A.9.1. Material Requirements for Steam Boilers, Chapter Π: Mild Steel, A: Plates, 1: Grades (10)

Four grades of steel are specified with a required yield strength at room temperature (RT) of 186, 235, 255 and 275MPa for thicknesses up to 40mm and 186, 216, 235 and 255MPa for thicknesses above 40mm. The Charpy requirements at RT are, for plate thicknesses above 16mm: 118, 98, 79 and 69 J/cm2, and for thickness below 16mm: 88, 59, 49 and 39 J/cm2.

A.9.2. Construction regulations for steam boilers, Chapter III: Weldments, E: Quality testing, 3: Impact tests (10)

Weld metal Charpy impact energy requirements at RT are, for grades I and II 79 J/cm2, and for grades III and IV 59 J/cm2.

A.10. FRENCH CODE FOR THE CONSTRUCTION OF UNFIRED PRESSURE VESSELS CODAP (1980, REVISED 1984, (11))

A.10.1. Part M: Materials, Appendix MA.2: Prevention of the Risk of Brittle Fracture (11)

The recommendations are applicable to unalloyed steels and alloyed non-austenitic steels and concern the parts and units and welded parts subjected to pressure as well as the welding procedure approval tests.

The criteria adopted are defined as follows:

the minimum design temperature Tmc, i.e. the lowest temperature that can be reached at mid-thickness of the shell of the vessel.

permissible minimum temperature Tma, the minimum temperature which the vessel can reach without risking brittle fracture. For welded joints made of different grades, the component with the highest Tma is to be considered.

Reference temperature Tr, this is the temperature at which the impact tests are carried out according to the standard for the product under consideration to obtain minimum impact strength values. Guidance for impact test temperatures complying with the French Standard are given in Table 4.1.c of the code.

Reference thickness Er, where Er depends on the dimensions of the welding carried out and on the thickness of the parts involved. The rules are given in Table 4.1.d of the code.

51

The selection of a steel grade, by reference to the vessel's conditions, entails a value Tr for the impact test. The permissible minimum temperature T^ is then determined from Tr and the reference thickness Er using relations between Tr, E and T^ depicted in Graphs 4.2.1 of the code for 9 different steel strengths and for the as-welded and PWHT condition (see Fig.9a to 9r). The value of ΤΜ shall not be greater than the minimum design temperature Tme otherwise another steel grade must be chosen. At the reference temperature, the average guaranteed impact strength of three test pieces shall be at least 35 J/cm2 with no single value below 26 J/cm2.

For products with thicknesses < 5mm and in cases where the level of stresses is reduced, the permissible minimum temperature can be somewhat reduced as specified in the code.

A.11. GERMAN PRESSURE VESSEL CODE (12)

A.11.1. AD Merkblatt W10, Materials for Pressure Vessels (1987, (12))

This standard specifies toughness requirements for ferrous materials. The lowest permissible operating temperature depends on the classification in stress categories which are specified in the code. The toughness is verified for different steel grades at a temperature corresponding to the lowest permissible operating temperature for the highest stress category. The toughness requirements are specified in separate materials specifications as a function of steel grade, orientation, material thickness and impact test temperature, (see DIN 17102, 17173, 17174, 17178, 17179 and 17280, for different types of steel).

As an example, the basic grade of weldable normalized fine grain structural steel specified in DIN. 17102, requires a Charpy impact energy of 21J in transverse and of 39J in longitudinal orientation at -20°C.

A.11.2. AD Merkblatt HP512, Manufacture and Testing of Pressure Vessels (1982, (12))

This code covers the testing of the quality of welded joints of pressure vessels. The number of test specimens for Charpy impact testing of weld metal and HAZ depends on material thickness, heat treatment and grade of steel and is specified in Table 1 of the code. The test temperature shall be the same as for the base material. The requirements for the Charpy impact energy of weld metal are the same as required in Merkblatt W10 for base material in transverse orientation. For HAZ specimens, the stipulated requirement is half the value for the base material in the transverse direction at room temperature but at least 35 J/cm2 for temperatures below -10°C.

A.12. ICI E354C, SPECIFICATION FOR PRESSURE VESSELS (1979, (13))

Each material must conform with the requirements of the corresponding British Standards. For plate steel, the specification BS1501, Steel for pressure purposes: plates1 is appropriate. For tubing and forgings, the materials must comply with BS3602, BS3059 and BS1503.

52

A.13. BS5500, SPECIFICATION FOR UNFIRED FUSION WELDED PRESSURE VESSELS (1991, (14))

A.13.1. Appendix D, Requirements for Ferritic Steels in Bands MO to M4 Inclusive for Vessels Required to Operate Below 0°C (14)

The requirements for all pressure parts of pressure vessels and attachments welded thereto are specified in these standards. The following definitions apply:

The design reference temperature 0R is the temperature which is used to determine impact test temperatures by means of Figure D.3(l) for as-welded components and of Figure D.3(2) for post weld heat treated components (see Fig. 10a and b).

The design reference temperature 0R shall not be smaller than the minimum design temperature 0D (the minimum temperature experienced by the component) which is adjusted, as appropriate, by (i) a membrane stress correction 0S which is 0,10 or 50°C depending on the membrane stress, (ii) a construction category adjustment Oc which is 0, -10 and -20°C for category 1, 2 and 3 vessels and (iii) a post weld heat treatment adjustment ΘΗ of 15°C, if applicable. Thus,

ÖR * ®D + ®s + Öc + ©H

The reference thickness used in Fig.D.3(l) and (2) is given for different weld geometries in Fig.D.3(3) and (4) (see Fig. 11 and 12).

Once the impact test temperature is determined, the material impact test require-ments are defined as follows:

For minimum tensile strengths of less than 450MPa, the average Charpy impact energy of three test pieces shall be at least 27J with no single value smaller than 70 percent of that value. For tensile strengths equal to or greater than 450MPa, the required average value is 40J.

For weld metal and HAZ, the same Charpy energy value is required as for the base material specified above (except for heat input in the range 1 to 5 kJ/mm for HAZ where no toughness requirement applies).

If the specified value is not attained, or if one specimen only shows a value less than the specified minimum, then three additional specimens shall be tested, taken from a position similar to that from which the first set of specimens were taken. The average value of the six specimens shall not be less than the specified minimum average value, not more than two specimens shall show values below the specified minimum average value, and only one is permitted to be below the specified individual value.

53

A.14. JAPANESE INDUSTRIAL STANDARD, JIS B 8243-1981, CONSTRUCTION OF PRESSURE VESSELS (1981, (15))

For pressure vessels with a minimum design temperature of less than -70°C, the materials shall be impact tested. The impact test temperature shall be at or below the minimum operating temperature of the pressure vessel. The required average Charpy energy of three test pieces shall be:

For steels with a minimum tensile strength of less than 490MPa, at least 20.6J with no single value smaller than 13J;

For tensile strengths between 490 and 588MPa exclusive, average 27.5, minimum 20.6J;

For tensile strengths equal to or greater than 588MPa, average 27.5, minimum 27.5J.

If the base metal thickness is thinner than 11mm the average values of three test shall be 27.5, 20.6 and 13.7J for material with a minimum tensile strength of cTC < 490, 490 * a ß < 588 and σ^ * 588MPa, respectively.

A.15. DUTCH RULES FOR PRESSURE VESSELS: SHEET NO. 110 (1975, REVISED 1983, (16))

A.15.1. Notch Ductility Testing (16)

Two types of Charpy testing are specified in these rules: 'quality testing1 and 'extra testing1. Quality tests are carried out at +20°C while the test temperature for extra tests is determined from reference temperature, reference thickness and test temperature diagrams.

There are four diagrams applicable to ferritic steels with a nickel content of less than 1.5%. The choice of diagram depends on tensile strength (greater or less than 450N/mm2) and on heat treatment (as-welded or PWHT). The reference temperature to be used with these diagrams is based on the minimum metal temperature, with corrections for pressure reductions and for the case of vessels of simple design with partial heat treatment. The reference thicknesses for different components are defined in the rules.

The need for quality tests and/or extra tests is determined by working through flow charts given in Appendices 2 and 3 of (16). The criteria for quality testing are dependent on steel type and thickness. For extra tests, the criteria are based on the reference temperature, the material type and strength level, the thickness, the hazard category and whether the vessel is to be pressure tested. The temperature for extra testing is given by the flow charts and may be at a set temperature, the reference temperature or the temperature determined from the diagrams.

The required absorbed Charpy energy is an average of 27J from three specimens. For sub-size test pieces the Charpy energy is decreased in proportion to the thickness.

54

The rules also give guidance for material selection using reference temperature versus thickness diagrams for different grades of steel.

A.16. THE NORWEGIAN PRESSURE VESSEL COMMITTEE, GENERAL RULES FOR PRESSURE VESSELS (1978, (17))

A.16.1. Chapter 25.6, Requirements of Test Results (17)

The impact tests shall be performed at a temperature corresponding to the lowest design metal temperature (but less than 20°C). The results are acceptable if the mean value of three specimens is at least 27.4J and no single value smaller than 19.6J. These requirements apply for base material and weldment.

If the required mean value is not attained, or if only one specimen shows a value below 19.6J, three supplementary test specimens shall be taken. The results are acceptable if the mean value of the six tests meets the requirements, and if only two specimens show values below this value and only one of these has a value below 19.6J.

A.17. THE SWEDISH PRESSURE VESSEL CODE (SUPERSEDED) (1977, (18))

A.17.1. Chapter 4: Materials, Section 4.2: Pressure Vessel Steels (18)

Minimum temperatures (-40 £ T £ -20°C) are listed for different grades of steel for which an average Charpy energy of three tests of 27J is required.

A.17.2. Section 4.3 Structural Steels (18)

Minimum temperatures (-20 xT * 0°C) are listed for different grades of steel for which an average Charpy energy of three tests of 27J is required.

A.18. ECISSfTC22 N52, FRACTURE TOUGHNESS CONCEPT OF THE SWEDISH PRESSURE VESSELS CODE (1989, (19))

A.18.1. Chapter 4.14: Choice of Material with regard to the Risk of Brittle Fracture (19)

Maximum wall thickness and lowest temperature during operation are stipulated to prevent brittle fracture.

The design minimum temperature TM is the lowest temperature during normal operation, starting up or stopping, exceptional conditions, pressure or leak testing, temporary rapid cooling, or the lowest environmental mean temperature according to the Swedish Meteorological Service. However, TM is at most 0°C.

TM may be increased by 10°C if the pressure vessel structure or parts thereof have been stress relieved and are not exposed to more than half the allowable stresses. TM may be increased by 30°C if the structure or parts are not exposed to more than 20 percent of the allowable stress. However, the increased temperature must not be higher than 0°C.

55

The reference thickness Sß is defined as follows: for shells etc. SB = wall thickness; for welded joints Sj, is defined as in the British Standard BS5500:1991 (see Fig.ll and 12).

A.18.2. Un-alloyed and Low Alloy Pressure Vessel Steels (19)

For steel grades having impact strengths of 27J at 20, 0, -20 and -40°C. Figures 4.18 and 4.21 of the code determine the design minimum temperature as a function of reference thickness with distinction between as-welded and PWHT conditions.

Figures 4.22 to 4.25 of the code determine the design minimum temperature as a function of reference thickness for steel grades with an impact strength of 40J at 20, 0, -20 and -40°C with distinction between as-welded and PWHT conditions.

A.18.3. General Structural Steels (19)

For general structural steels with a minimum impact strength of 27J at 20°C, the maximum reference thickness is 18, 13 and 10mm for a design minimum temperature of DMT * 0, -10 and -20°C. For general structural steels with a minimum impact strength of 27 J at -20°C, the maximum reference thickness is 20mm for all design minimum temperatures.

56

Tab

le A

.1 A

SME

ΠΙ D

ivisi

on 1

-Sub

sect

ion

NC

(see

Sec

tion

A.1

.2)

1 N

omin

al w

all

I thi

ckne

ss t,

1

in.

1 t

* 5/

8 5/

8 <

t s 1

1

< t s

1.5

1.5

< t

s 2.

5 |

2.5

< t

Later

al e

xpan

sion,

m

ils

Ave

rage

20

25

35

45

Min

imum

15

20

30

40

Impa

ct e

nerg

y, ft

.lb

1

Ave

rage

20

25

35

45

55ks

i

Min

imum

15

20

30

40

55 <

ay

* 75

ksi

Ave

rage

25

30

40

50

Min

imum

20

25

35

[45

75 <

Oy :

Ave

rage

30

35

45

55

s 10

5ksi

1

Min

imum

D

25

30

40

[50

Not

e:

The

read

er is

refe

rred

to ta

bles

NC

-233

2.1-

1 an

d N

C-2

332.

1-2

Tab

le A

.2 A

SME

III D

ivisi

on 1

-Sub

sect

ion

ND

(see

Sec

tion

A.1

.3)

I N

omin

al w

all

| th

ickn

ess

t, 1

in.

I t s

5/8

I

5/8

< t x

3/4

1

3/4

< t *

1

I 1

< t s

1.5

I

1.5 <

t *

2.5

1 2.

5 <

t

Later

al e

xpan

sion,

m

ils

Ave

rage

—

13

15

20

25

30

Min

imum

—

10

10

15

20

25

i^ÊÊÊ

ÊÊÊÊ

ÊÊÊÊ

m^^Ê

ÊÊÊÊ

mÊmm

Oy

£

Ave

rage

—

13

15

20

25

30

40ks

i

Min

imum

—

10

10

15

20

25

Impa

ct e

nerg

y, ft

.lb

40 <

oy

* 55

ksi

Ave

rage

—

15

20

25

35

40

Min

imum

—

10

15

20

30

35

55 <

oy :

Ave

rage

—

20

25

30

40

45

s 10

5ksi

1

Min

imum

1

_ 15

I 20

25

I

35

| 40

Tabl

e A

3 A

SME

III D

ivisi

on 1

-Sub

sect

ion

NF

(see

Secti

on A

.1.5

)

1 N

omin

al w

all

I th

ickn

ess

t, 1

in.

It *

5/8

1 5/

8 <

t « 1

|

l<t

p^

sBso

sosa

na

Late

ral e

xpan

sion,

m

ils

15

25

Impa

ct e

nerg

y, ft

.lb

1

<h*

Ave

rage

15

25

55ks

i

Min

imum

10

20

55 <

oy

s 75

ksi

Ave

rage

20

30

Min

imum

15

25

75 <

oy

s

Ave

rage

25

35

s 10

5ksi

1

Min

imum

I

20

1 30

1

SECTION B:

PIPELINE AND TUBE TOUGHNESS REQUIREMENTS

SECTION B:

PIPELINE AND TUBE TOUGHNESS REQUIREMENTS

B.l. AMOCO (1990, (20))

All pipe manufactured for Amoco must meet the requirements of API 5L (reviewed in Section B.3), plus additional requirements listed in the Amoco specification (20). The following Amoco requirements apply to Charpy V-notch impact testing (3 specimens, 32°F):

I Specimen | size

I full size 1 3/4 size 1 2/3 size 1 1/2 size

—————————^ ^ —^———— - ^^^^^—^^^^^^ -* Absorbed energy, ft.lb 1

Transverse

Average

69 52 46 34

Minimum

52 39 35 26

Longitudinal 1

Average

87 65 58 43

Minimum 1

65 1 49 43 32

Amoco require that impact tests on each lot of 100 lengths of pipe or fewer, with the additional restriction that the minimum acceptable shear fracture area is 75% for an average of three specimens, with no single value below 60%.

B2. BRITISH GAS, AISI, BATTELLE (1990 (21))

Jones and Noklebye (21) have reviewed the pipeline toughness requirements of British Gas, American Iron and Steel Institute (AISI) and Battelle, applied to the Statoil Zeepipe system (711-918mm ID, 18-29mm thickness, 157-172bar, 1300km long, from the North Sea Sleipner and Troll gas fields to Zeebrugge in Belgium). These requirements are based on onshore experience, and owing to the hydrostatic pressure of the seawater surrounding the offshore pipeline, Jones and Noklebye consider the toughness requirements to be conservative when applied to offshore pipelines (by up to 50%).

Brittle cracks propagate at speeds up to 600m/s, which is slower than the decom-pression speeds of liquids. However the decompression speed of natural gas is typically 400m/s, and so brittle fractures can propagate virtually indefinitely, since the gas pressure is continuously maintained at the crack tip. To guard against brittle fracture the drop weight tear test (DWTT) requirement for the Zeepipe system is 85% shear fracture area at -10°C (the minimum design temperature).

Shear fractures travel at speeds (typically 60 - 250m/s) lower than the initial gas decompression speed. However, the expanding gas near the crack tip can cause the crack to continue to propagate unless the pipeline material has sufficient ductile toughness (fractures in pipelines have propagated in the fully shear mode for distances up to 300m).

61

British Gas employs the following Charpy V-notch toughness predictions for shear fracture arrest:

Cy = i

c K = <

r

2.08

1.85 . 0 «

- 0.001 V0

- 0.001 V0

Rl* jO.75

Rl* . 0 7 5

10"3 (95% confidence level)

ah . 10"3 (50% confidence level)

These predictions are restricted to pipelines of less than 42" diameter and 20mm wall thickness.

The AISI prediction is (for pipelines < 56" diameter, 19mm wall thickness):

Cv= 2.38 x 10-4 oh 2R (95% confidence level)

The Battelle prediction is (for pipelines < 48" diameter, 17mm wall thickness):

Cv= 2.38 x 10"5 ofc2(Rt)1/3(50% confidence level)

where

Cv = 2/3 (10mm x 6.7mm) Charpy V notch impact toughness, J t = wall thickness, mm R = pipe radius, mm oh = hoop stress, N/mm2

V0 = acoustic velocity of gas, m/s

The Charpy specification for the Zeepipe system was set at 150J (the maximum arrest impact toughness predicted by the above equations was 102J). These requirements are for the parent material only. Weld regions do not need to meet these requirements, although typical impact energies in the weld metal and HAZ were in the range 112 to 191J (at -30°C).

B.2.1. BGC/PS/LXl: British Gas Specification for Submerged Arc Welded Line Pipe (supplementary to API 5LX) (22)

This specification describes drop weight tear test and Charpy upper shelf energy requirements for submerged arc welded line pipe. Drop weight tear tests must be performed at the following temperatures:

62

I Nominal 1 size, 1 mm

1 600 750

1 900

Outer diameter, (OD), mm

609.6 762 914.4

Thickness, mm

17.48 19.05 19.05

Grade

X60 X60 X60

Test | temperature, 1 °C

20 | 15 10

The reader is referred to the British Gas document BGC/PS/CP/TMl where the selection, location and test requirements of the drop weight tear tests are specified.

Each set of two specimens is required to show at least 75% shear fracture appearance at 0°C except for the sizes and grades tabulated above.

For upper shelf Charpy impact testing of welds, the specification requires testing of three 2/3 size Charpy specimens, tested at 0°C with a minimum average toughness of 31J (minimum single value of 27J).

Impact toughness requirements for the parent material are as follows (three 2/3 size Charpy specimens, tested at 0°C).

Carrier pipe:

1 Nominal 1 size, | mm

| 600

| 750

| 900

1050

\_J

Outside diameter (OD), mm

609.6

762

914.4

1066.8

SSSBBSSSSSSSSaBBBSSS

Wall thickness, mm

9.52 14.27 17.48

11.91 15.88 19.05

12.70 19.05 15.88

14.27 19.05 17.48

Material grade

X52 ! X52 X60

X52 X52 X60

X60 X60 X65

X60 X60 X65

——'————

Impact energy, J 1

Average

24 24 24

26 26 26

27 27 27

30 30 30

Minimum 1

22 | 22 22 1

23 23 23

24

24 I

27 | 27 I 27 |

63

Sleeving pipe:

| Nominal I size, 1 mm

1200 I 1400

Outside diameter (OD), mm

1219.2 1422.4

SaBBBRBOHHBBaaHBBBBDB

Wall thickness, mm

12.70 14.27

S S S B 8 B B S B B S : S

Material grade

X65 X65

Impact energy, J 1

Average

27 27

Minimum 1

24 1 25 1

TTie number, location, orientation, preparation and testing of specimens are described in Section 4 of this specification, as well as retest procedures.

B.2.2. BGC/PS/LX4: British Gas Specification for Seamless Line Pipe 150mm -450mm Nominal Pipe Size (supplementary to API 5LX) (23)

For pipe sizes of OD £ 323.8mm, this supplementary specification requires that each of a set of three 2/3 size Charpy V-notch specimens shows not less than 50% shear area fracture when tested at -15°C. The specimens are required to be heated to 100°C for one hour, and allowed to cool to ambient temperature before testing. For pipe sizes of OD > 323.8mm the requirement is 75% shear area fracture when tested at 0°C. Retest procedures are described in Section 4 of this specification, as well as number, location and orientation of test specimens.

B3. AMERICAN PETROLEUM INSTITUTE (7)

B3.1. API 2B: Specification for Fabricated Structural Steel Pipe (1977, (7))

This specification requires 20ft.lb impact energy at 0°F if the relevant welded consumable specifications do not specify a toughness requirement, for deposited weld metal in the as-welded condition.

B3.2. API 5CT: Specification for casing and tubing (1989, (7))

This specification requires that three transverse Charpy V-notch impact tests be performed at 75 ± 5°F, from three tubes of each lot. A minimum impact energy of 20ft.lb is required, or as calculated by the following equation, whichever is greater:

cv = σπι«(π ac+ 0.23)/3.6 [ft.ib, rounded to the next higher whole number]

where

σιη« = maximum specified yield strength, ksi ac = 12Vi% of nominal wail thickness, in.

The number, location and orientation of test specimens are described in Sections 4.3 and 5.18 of API 5CT, as well as retest procedures and requirements for sub-size Charpy testing.

64

The impact requirements for various wall thicknesses of grade Q125 pipe vary from 20 to 43ft.lb, for thicknesses up to 2.042".

In addition, electric welded (ERW) pipes must satisfy the following flattening requirements:

| Grade

H40

J-55, K-55

N-80

L75, L-80

L-95

Q-125

D/t ratio

* 16 <16

*16 3.93 - 16 <3.93

9 - 2 8

9 - 2 8

9 - 2 9

All

Distance between plates, in. or mm |

0.5 D 1 D (0.83 - 0.0206 D/t)

0.65 D D (0.98 - 0.0206 D/t) D (1.104 - 0.0518 D/t)

D (1.074 - 0.0194 D/t)

D (1.074 - 0.0194 D/t)

D (1.080 - 0.0178 D/t)

D (1.092 - 0.014 D/t)

B3.3. API 5L: Specification for Line Pipe (1990, (7))

This specification covers seamless and welded steel line pipe, and includes weld ductility requirements for electric welded pipe. No cracks or breaks exceeding 1/8H

in any direction in the weld or parent metal are permitted until the distance between the flattening plates, S (in mm), is less than:

S = 3.07 t / (0.07 + 3t/D) for Grades < X52 S = 3.05 t / (0.05 + 3t/D) for Grades * X52

where t and D are the wall thickness and OD of the pipe in mm. TTie following Charpy impact requirements apply to Grade X80 (3 specimens, tested at 32°F):

1 Minimum fracture shear area, %

1 All heat average

1 70

One heat

40

= = = = = ^ ■ ■

Minimum impact energy, ft.lb | All heat average

50

One heat |

20 1

Alternatively, drop weight tear tests can be carried out with a required shear fracture area of 60% for all heats, and 40% for one heat. Sections 4.18 to 4.20 of API 5L describe the number, location and orientation of test specimens, as well as retest procedures.

Appendix E of API 5L describes supplementary toughness requirements. For pipe diameters greater than 4.5", transverse Charpy specimens are required to be tested at 50°F or less, with a requirement of 60% shear fracture appearance (average of 3

65

specimens) and 80% all heat average. Retesting procedures are described, as well as the number, location and orientation of test specimens, and sub-size Charpy testing. Impact energies are required, as specified by the purchaser. For welded pipe 20" OD or larger, Grade X52 or higher, drop weight tear testing is required (transverse specimens), tested at 50°F or lower. At least 80% of the heats are required to exhibit 40% shear fracture appearance.

B J.4. API 6A: Specification for Wellhead and Christmas Tree Equipment (1989, (7))

This specification requires the following Charpy impact toughness levels (3 specimens):

| Temp. | Class.

1κ

| L | p 1R

| s 1T

lu

Test temperature, op

-75 -50 -20

0 0

1 o 0

Impact energy, ft.lb

PSL1

15 15

PSL2

15 15 15

PSL3

15 15 15

Lateral 1 expansion, 1 in. |

0.015 1 0.015 | 0.015 | 0.015 | 0.015 0.015 |

j 0.015

The production specification levels (PSL1 to 3), defined in Section 103 and Appendix A of API 6A, refer to increasing levels of quality and service ratings. Temperature classifications K, L, P, R, S, T and U refer to the following temperature ranges, respectively: -70 to 180°F, -50 to 180°F, -20 to 180°F, room temperature, 0 to 150°F, 0 to 180°F and 0 to 250°F. The number, location and orientation of test specimens are described in Sections 403 and 404 of API 6A, as well as retest procedures and sub-size Charpy requirements.

B3.5. API 6D: Specification for Pipeline Valves (Steel Gate, Plug Ball, and Check Valves) (1988, (7))

The following Charpy impact toughness requirements apply (3 specimens, tested at temperatures specified on purchase order):

B B B B B B n a S B S S a S B B S n a B S B E S S B S S B B S S S a S S S S B S S S B S S B S S S ^ ^ S

| Actual ultimate strength of the material, ksi

I s85 86 - 100 >100

Impact energy, ft.lb |

15 1 20

_25

The number, location and orientation of test specimens are described in Section 3 of API6D.

66

B3.6. API 14D: Specification for Wellhead Surface Safety Valves and Underwater Safety Valves for Offshore Service (1983, (7))

This specification requires that the impact toughness for metals intended for low temperature service (< -20°F) be considered. For valve materials, excluding inherently ductile metals such as austenitic steels, the following requirements apply:

I Specified 1 minimum tensile 1 strength, | ksi

1 <90

1 < 90 (API Type 2)

Test temperature,

! °F

-50 -75

-50 -75

Impact energy, ft.lb 1

Average

15 13

20 [_15

Minimum 1

12 1 10

15 10

For materials with tensile strength equal to or greater than 90ksi, a lateral expansion of 0.015" is required. The number, location and orientation of test specimens are described in Section 3.5 of API 14D, as well as sub-size Charpy impact test requirements.

B.4. AUSTRALIAN STANDARDS (9)

B.4.1. AS1697 - 1981: Gas Transmission and Distribution Systems (1981, (9))

Section 2 and Appendix R (Fracture toughness for steel transmission pipelines and mains) of this standard describe when fracture toughness testing is required, including the influence of the type of fluid being transported, wall thickness, operating stress and temperature. Pipelines intended for gas and mixed gas/liquid transmission should be designed to prevent both brittle and ductile fracture propagation. Pipelines intended for liquid transmission require an assessment of brittle fracture only, and less stringent toughness requirements are appropriate.

Components in steel pipelines or mains intended to operate at a hoop stress greater than 0.3 SMYS, or with an operating stress greater than 85MPa require fracture toughness testing. The fracture face appearance may be determined by either the drop weight tear test (DWTT), or Charpy impact testing. The average percentage shear fracture appearance of two transverse DWTT specimens must exceed 75% at the test temperature. Retests are permitted if this requirement is not met.

The Charpy fracture toughness requirement is determined by correlation with the DWTT requirement of 75% shear. Sufficient drop weight tear tests are required to establish the temperature transition curve from 20% to 100% shear. Three Charpy specimens are then tested at the temperatures corresponding to 75% in a DWTT, with the average Charpy shear percentage area defining the Charpy requirement for future tests. The average and minimum impact energy from three transverse Charpy specimens are also required to meet the relevant code acceptance levels.

67

Appendix K of AS1697 describes the factors which influence brittle and ductile fracture, including type of fluid, wall thickness, operating stress and temperature. The reader is referred to Appendix C of AS2885 (9), reviewed in Section B.4.2, where these issues are also discussed.

B.4.2. AS2885 - 1987: Pipelines - Gas and Liquid Petroleum (9)

This standard (including advisory Appendix C: "Fracture toughness for steel pipelines") requires that the fracture toughness of the pipe is established if the pipeline fluid is a gas or high vapour pressure liquid, and where the pipe is stressed to either 30% SMYS or 85MPa. Brittle fracture requirements are described in Clause 2.6.4, ductile fracture requirements in Clauses 2.6.4 and 2.6.5.

To establish the fracture face appearance, tested at a temperature equal to or less than the minimum design temperature either the drop weight tear test (DWTT, 75% shear area for two specimens) or the Charpy V-notch test, (correlated to DWTT temperature at which 75% shear area occurs), is required, as described in AS1697 (see Section B.4.1). The number, orientation and location of test specimens are described in Section 2 of this standard, including retest procedures.

Appendix C of AS2885 describes factors which influence fracture of steel gas pipelines, including brittle and ductile fracture considerations. These factors include fluid type, wall thickness, operating pressure and temperature. Propagating fracture failure is considered unlikely in pipe less than 300mm diameter, and for wall thickness less than 5mm. Fracture toughness requirements are not needed for pipelines intended to carry only liquids, because decompression wave speeds in liquids are faster than crack propagation velocities, permitting unloading of a propagating crack tip. Figure 13 (Fig.C2 of AS2885) sets out in graphical form typical shelf energies which arrest ductile fracture in pipe at 72% SMYS for various grades and diameters, at two typical design pressures. Propagation of brittle fracture is prevented by using pipes which generally have a transition temperature below the service temperature (hence the 75% shear area requirement).

It is difficult to measure the percentage shear fracture appearance for HAZ Charpy specimens, therefore, to avoid propagation of fracture in longitudinal seam welds, it is required that pipe Sections be offset (rotated) at butt welds. The required frequency of testing (Section 2.6.4.2 of AS2885) is intended to ensure that propagating cracks are arrested within two pipe lengths.

Transverse energy requirements are based on upper shelf (100% shear) requirements. Equations for predicting upper shelf Charpy requirements to ensure crack arrest are currently being investigated. These equations are of the form:

CV = KDX C akz

where Cv is the shelf energy (J), K is a constant, D is outside diameter (mm), ^ is wall thickness (mm), oh is hoop stress (MPa) and x, y and z are constants.

Requirements for avoiding fracture initiation, in terms of tolerable flaw sizes (evaluated using fracture mechanics assessment principles) are permitted, although

68

these approaches generally result in greater impact energy requirements. Thus these approaches are not recommended except for large pipelines having a high SMYS and operating at high stress.

B.4.3. ASCB18, Part 1 - 1967: Design, Fabrication, Installation and Inspection of Pressure Piping. Part 1 - Ferrous Piping (1967, (9))

This standard requires the following Charpy impact toughness levels (3 specimens, weld metal, fusion line and parent metal):

^■■■■aassssxsssssaBBBSs^saEssEEss

1 Steel type

C, C-Mn 1 Low alloy

Impact energy, ft.ib 1

Average

20 15

Minimum 1

15 1 10

Section 2 of this standard describes the number, location and orientation of test specimens.

B.5. BS4515: SPECIFICATION FOR WELDING OF STEEL PIPELINES ON LAND AND OFFSHORE (1984 (24))

BS4515 (24) applies to arc welding of butt joints, branch connections, fillet welds and socket joints in C, C-Mn and low alloy steel pipelines. The standard applies to pipes with outside diameter OD £ 21.3mm and thickness t * 3.2mm.

The following Charpy impact energy is required:

Cv = SMYS/F

where SMYS is the specified minimum yield stress (MPa) and F (mm3) is given below:

I Thickness 1 t, mm

1 6.3 to 10 1 10 to 12.5 1 12.5 to 16 1 16 to 20

20 to 25 1 More than 1 25

Charpy specimen size, mm

10x5 10 x 7.5 10x10 10 x 10 10 x 10 10 x 10

Test temperature, °C

0 0 0 -10 -20 To be specified by employer

F, mm3 |

Minimum average value

14 12 10 10 10 To be specified by employer

Minimum 1 individual 1 value 1

18 1 15 1 12 1 12 1 12 1 To be specified 1 by employer 1

69

The employer may specify other requirements to those above, or alternatively specify requirements in terms of the CTOD values given in Fig.14 (described in Appendix H of BS4515). Figure 14 specifies the minimum value of CTOD (3 specimens), as a function of pipe thickness and yield strength.

B.6. CANADIAN STANDARDS (25)

B.6.1. CSA Z183 - M1982: Oil Pipeline Transportation Systems (1982, (25))

This Canadian standard requires that steel pipe and associated steel components in HVP pipeline systems 60.3mm and larger in diameter with wall thickness greater than 5mm are impact tested. The impact requirements are presented in Table B.l.

Category I requires no impact testing. Category II fittings, flanges, valves, and category III pipe are required to have a minimum absorbed energy of 20J at the lowest operating temperature. A zone 1 location is an area extending 200m on either side of any continuous 1km length of pipeline that contains 5 or fewer dwelling units intended for human occupancy. A zone 2 location contains more than 5 dwellings or 20 or more persons during normal use.

B.6.2. CSA Z245.1 - M1982: Steel Line Pipe (1982, (25))

This standard specifies the following Charpy impact toughness requirements (average of 3 specimens, tested at a temperature specified by the purchaser):

| Outside diameter, mm

1 <457

1 *457

Grade

All grades

< 359MPa * 359MPa

Impact energy, J |

20 1

20 27

One specimen is permitted to have a toughness less than the average requirement, but not less than 2/3 of this requirement. Section 6 of this standard describes the number, orientation and location of Charpy impact specimens, as well as retest procedures. For pipe 406.4mm OD and larger, drop weight tear tests are required, with both the drop weight tear and Charpy specimens required to exhibit 50% or greater shear area, with no specimens less than 40%.

B.7. DET NORSKE VERITAS: RULES FOR SUBMARINE PIPELINE SYSTEMS, NORWAY (1981, (26))

Section 5: Material Requirements for Pipes and Piping Components; Section 5.2, Steel for Line-Pipes; Section 5.2.7 Brittle Fracture Resistance (26)

Base material and welded joints must meet the average Charpy V-notch energy requirements of Re/10 Joules, where Re is the minimum yield strength in MPa. For Re < 275MPa a constant requirement of 27J is required. Individual values must be at least 75% of the specified average value. The impact testing temperature depends

70

on wall thickness and minimum design temperature and is given in the table below. The maximum impact testing temperature is 20°C.

■ ■ ■ ■ ■ ■ S i B B B B a a B B B E B

Wall 1 thickness t, 1 mm

1 ts20

20 < t * 30

t > 3 0

Risers Gas + Liquid

T = TD - 10

T = TD - 20

T to be decided in each case

Pipeline 1

Gas

T = T D - 10

T = T D - 10

Liquid 1

T = TD 1

T = TD

where T = Charpy V-notch impact testing temperature [°C] and TD = minimum design temperature [°C].

71

Tab

le B

.l CS

A 7

183

- M

1982

(see

Sec

tion

B.6.

1)

| Zo

ne

1 2

Des

ign

oper

atin

g str

ess,

MPa

<225

>2

25

<180

>1

80

Pipe

not

ch to

ughn

ess

cate

gory

(d

efin

ed in

CSA

Z24

5.1)

I Π

I III

Fitti

ngs

and

flang

e no

tch

toug

h-ne

ss c

atego

ry (d

efin

ed i

n CS

A

Z245

.10)

I II I II

Val

ve n

otch

toug

hnes

s 1

categ

ory

loss

def

ined

in

| CS

A Z

245.

15)

I II I 1

π I

SECTION C:

FIXED OFFSHORE TOUGHNESS REQUIREMENTS

SECTION C:

FIXED OFFSHORE TOUGHNESS REQUIREMENTS

Cl . AMERICAN BUREAU OF SHIPPING (27)

C.l.l. ABS: Rules for Building and Classing Offshore Installations, Part 1 -Structures (1983, (27))

This specification requires the following impact requirements for longitudinal Charpy specimens (3 specimens):

Steel group Section size, in. Impact energy, ft.lb

I

II, III

0.25 - 0.75 i0.75

i0.25

15 20

25

where Group I, II and III steels have yield strengths in the ranges < 40ksi, 40 -60ksi and 60 - lOOksi respectively. The following test temperatures apply:

For critical components subject to severe stresses:

1 Steel group

lui ni

Minimum service temperature (MST), °F

32 14 -4

-22

Test temperature, °F |

MST - 54 1

-40 -58 -58 -76

For important components, subject to significant stresses:

1 Steel group

1ι

II

MST, °F

32 14 -4

-22

■ — — — — — — — — ■ ■ ■ — ^ ^ — ^ ^ ^ — τ ι

Test temperature, °F |

MST - 18 I

-22 1 -40 | -40 | -58 |

For less critical components Group I steels may be tested at the MST. Impact testing is not required for sections less than 0.25" in thickness. Testing of sub-size Charpy specimens is described in Table 10.3 of this specification. The following

75

alternative toughness requirements may be applied. Transverse specimens require 2/3 the impact energy requirements for longitudinal specimens. The T^y^ as determined by drop weight tests should be 10°F below the Charpy test temperature. Lateral expansion *:0.5mm for longitudinal specimens or *0.38mm for transverse specimens.

For steel Grades A, B, D, E, DS, CS, AH32/36, DH32/36 and EH32/36 similar impact energy requirements apply as for the ABS rules for building and classing steel vessels (reviewed in Section D).

C.1.2. ABS: Guide for Building and Classing Fixed Offshore Structures (1978, (27))

This guide refers to API RP2A (Planning, designing and constructing fixed offshore platforms), which is included in Appendix A of this guide. Impact energies of 20ft.lb at 0°F are required for welds in tubular joints constructed from high strength steels.

C2. AMERICAN PETROLEUM INSTITUTE (7)

C.2.1. API 2A: Recommended Practice for Planning, Designing and Constructing Fixed Offshore Platforms (1989, (7))

API 2A requires the following weld metal Charpy impact toughness levels (3 specimens):

| Steel group

1u

1 III

Steel class

C B A

C B A

A

sassBsasssssssaso^sssm

Test temperature, °F

0 0

-20

0 -20 -40

-40

Impact energy, 1 ft.lb 1

20 1 20 1 20 1

20 1 20 1 25 1 30

ssssssssssaaBaamaKmaaÊÊÊBÊÊmm

The minimum single specimen result may not be less than 5ft.lb below these average requirements.

For structures which operate in moderate temperature environments (e.g. 40°F seawater and 14°F air exposure), the following alternative HAZ impact require-ments apply:

76

I

1 Steel group

1 I

11

1 III

Steel class

C B A

C B A

A

Test temperature, °F

50 40 14

50 40 14

14

Impact energy, ft.lb |

For information only 1 15 15

For information only 1 15 2 5

30

For critical welded connections CTOD toughness requirements are appropriate, with tests performed at realistic temperatures and strain rates. Engineering fracture mechanics techniques may be employed for defect assessments.

C .2.2. API 2H: Specification for Carbon Manganese Steel Plate for Offshore Tubular Joints (1988, (7))

This specification requires that either Pellini drop weight or Charpy impact toughness tests are performed. These requirements are similar to those in API 2W, described in Section C.2.4. Requirements for sub-size Charpy impact tests are also presented in Table 6.1 of API 2H.

C.2.3. API 2T: Recommended Practice for Planning, Designing, and Constructing Tension Leg Platforms (1987, (7))

API 2T (7) recommends that for Class B steels Charpy V-notch toughness of 15ft.lb is required for Group I steels, and 20ft.lb for Group II, tested at the lowest anticipated service temperature. Class B steels can generally meet these require-ments in the temperature range 32 to 50°F. Class A steels can generally meet the Class B requirements in the temperature range -40 to -4°F. Class C steels do not require impact testing, as they are intended for service above 32°F. High levels of Charpy energy are required for high strength steels in Groups III and IV, although alternative fracture mechanics assessment based on CTOD requirements may be employed.

Group I steels are mild steels, oy * 40ksi Group II steels, 40 < oy < 52ksi Group III steels, 52 < oy < 70ksi Group IV steels, oy > 70ksi

C.2.4· API 2W: Specification for Steel Plates for Offshore Structures, Produced by Thermo-Mechanical Control Processing (TMCP) (1989, (7))

Section 6 of API 2W requires that drop weight tests are performed, unless Charpy tests are specified by the purchaser or the nominal thickness is less than 5/8w. Two specimens must be tested at -40°F, with both giving "no-break" results.

77

Alternatively, Charpy impact toughness requirements are as follows (3 transverse specimens):

| Grade

142

I 50, 50 T 1 60

SBBBSBESBEBESXSSSBSaGBSSSSSSSSS

Test temperature, °F

-40 -40 -40

Impact energy, ft.lb 1

Average

25 30 35

Minimum 1

20 1 25 30

Retest procedures are described in Section 6.1 of API 2W.

C.2.5. API 2Y: Specification for Steel Plates, Quenched and Tempered, for Offshore Structures (1987, (7))

The toughness requirements presented in this specification, in terms of drop weight tests and Charpy impact tests are similar to those in API 2W, reviewed in Section C.2.4.

C.2.6. API 2Z: Recommended Practice for Pre-Production Qualification for Steel Plates for Offshore Structures (1987, (7))

Section 3 of API 2Z presents detailed specifications of crack tip opening displacement (CTOD) testing requirements for steel structural plate intended for offshore service. Pre-qualification welded specimens must be prepared and tested to BS5762 procedures (28), ensuring a reasonable lower bound CTOD fracture toughness is measured.

The effect of variability of welding procedures is accounted for by requiring that three welded test plates be produced: one made with the lowest intended preheat, interpass temperature and heat input; another at the highest; and a third at the most likely preheat and interpass temperature at 3kJ/mm heat input.

Details are presented of permissible welding conditions, as well as CTOD test specimen extraction preparation (including fatigue notching) and testing. Welding consumables must be chosen to give the weld metal a CTOD toughness 0.13mm greater than that required for the HAZ, at -10°C (or at an alternative selected temperature). Metallographic examination of the fracture faces is required, to ensure that the fatigue crack for three specimens sample 75% of the etched HAZ microstructure (maximizing sampling of coarse-grain regions, to achieve 15%). A further two specimens are required to sample the fusion boundary. In total, five valid specimens are required from each of the three welded test plates.

For each test weld, 0.25mm CTOD is required (except for material with a specified minimum yield strength greater than 50ksi). 0.38mm CTOD is required for as-welded steel thicker than 3". For materials where oy > 50ksi the acceptance requirements must be agreed upon between the manufacturer and purchaser. Retests are permitted, with only one of the ten test results not meeting the CTOD toughness requirements.

78

In addition, at least eight Charpy impact specimens are required to be tested to establish the impact toughness temperature transition curve, for the coarse-grained and unaltered sub-critical HAZ at both the root and quarter thickness locations. The test temperatures should bracket the 50% shear fracture appearance temperature.

CJ. BS7191, WELDABLE STRUCTURAL STEELS FOR FIXED OFFSHORE STRUCTURES (1989(29))

BS7191 (29) is applicable to plates (t * 150mm), sections complying with BS4848 and BS4, and seamless tubulars (t £ 40mm), for steels with yield strengths oy < 450N/mm2 with impact properties specified down to -40°C

The following Charpy impact energy requirements apply to plate material (minimum of 3):

| Grade 1 275D

275E 275EX 355D 355E 355EM 355EMZ 450EM 450EMZ

iflBE9CESSn=aS=B==DE=S

Tensile strength, N/mm2

430/580 430/580 430/580 490/640 490/640 460/620 460/620 550/700 550/700

sasHaassasBssBsssss

p s a E s s s s s s s s s s s s s

Test temp, oC

-20 -40 -40 -20 -40 -40 -40 -40 -40

Thickness t> mm 20 40 40 20 40

150 150 75 75

\ Impact 1 energy, 1 j 1

40 1 40 1 40 50 1 50 1 50 1 50 60 1 60 1

The following Charpy impact energy requirements apply to sections (minimum of 3):

| Grade

1 275D 275E 275EZ 355D 355EM

| 355EMZ

Tensile strength, N/mm2

430/580 430/580 430/580 490/640 460/620 460/620

BBEaBSSSZSSSaBSESSSSSSSSS

= = = = = Test temperature, °C -20 -40 -40 -20 -40 -40

Impact 1 energy, 1 j 1

40 1 40 40 1 50 1 50 1 50 1

79

The following Charpy impact energy requirements apply to seamless tubulars (minimum of 3):

| Grade 275D 275E 355D 355EM 450EM

strength, N/mm2

430/580 430/580 490/640 460/620 550/700

sasssass i l e g s o s s m :

Test temperature, °C -20 -40 -20 -40 -40

III 1 1 I M ^ B ^ — t ^ ^ B — B

Impact 1 energy, 1 J 40 1 40 50 50

_60

C.4. BUREAU VERITAS, FRANCE, RULES AND REGULATIONS FOR OFFSHORE PLATFORMS (1975, (30))

C.4.1. Section 5-2: Non-Alloy and Micro-Alloy Steel Rolled Flat Products: Plates and Large Flats; Section 5-24: Guaranteed Mechanical Properties of Plates (30)

Steels are divided into 4 grades defined by the minimum guaranteed impact energy at a given temperature of 20, 0, -20, and -40°C, respectively.

A second rating is achieved via three classes of safety. For a minimum yield of ayg

* 275MPa and 275 < oys * 355MPa, the required impact energies (in J) are listed in the table below:

1 Steel 1 grade

I II III IV

B s s a s s s s s

SSSSSESBBBBj

Test temp.

+20°C 0°C

-20°C -40°C

ays * 275N/mm2

1st Class

20 (T) 20 (T) 20 (T)

2nd Class

27 (L) 27 (L) 27 (L) 27 (L)

3rd Class

27 (L) 27 (L) 27 (L)

275 < ayi s 355N/mm2 |

1st Class

24 (T) 24 (T) 24 CO

2nd Class

34 (L) 34 (L) 34 (L) 34 (L)

3rd 1 Class 1

34 (L) 34(L) 34 (L)

where (L) stands for longitudinal and (T) stands for transversal orientation, respectively

These requirements are average values of three impact tests with no single value smaller than 80% of the required value.

The grade of steel to be used in terms of the minimum design temperature and the thickness of the plate can be taken from Chart 5-1 to 3 in the Code for 1st, 2nd and 3rd Class elements, respectively.

80

Tensile

C.5. LLOYD'S REGISTER, RULES AND REGULATIONS FOR OFFSHORE PLATFORMS (1989, (31))

C5.1. Part 2, Materials and Manufacturing Procedures, Chapter 2, Section 2: Structural Steels for Design Temperature 5°C and above (31)

Steels are classified in two categories: special and primary. Charpy energy requirements are shown in the two tables below, as a function of plate thicknesses and specified minimum yield stress.

(a) Elements categorized as Special

1 Plate I thickness, I mm

1 Up to 15 16-25

26-35 36-60

| 61-80

Specified minimum yield stress, N/mm2

Any Up to 235 236-355 Up to 355 Up to 355 Up to 355

Charpy impact test requirement 1

Temperature, °C

0 -10 -10 -20 -40 -60

Impact energy, J 1

27 1 27 34 34 34 34

(b) Elements categorized as Primary

1 Plate 1 thickness, 1 mm

1 Up to 15 16-25

26-35

36-50 | 51-80

p — a a ^ ^ ^ ^ a ι n n ι n .

Specified minimum yield stress, N/mm2

Any Up to 235 236-355 Up to 235 236-255 Up to 355 Up to 355

Charpy impact test requirement 1

Temperature, °C

0 0 0 -10 -10 -20 -40

Impact energy, J 1

27 1 27 34 27 34 34 34

C.5.2. Chapter 2, Section 3: Structural Steels for Design Temperature 0°C and Below (31)

These steels are classified in three categories: special, primary and secondary. The test temperature for each category is obtained from the design temperature and the material thickness by the use of Fig. 15a to c. The impact energy requirements at the determined test temperature is 21, 27, 31, 34 and 41J for minimum yield strength of 215, 235, 315, 345 and 415MPa, respectively.

81

C.6. DEPARTMENT OF ENERGY: OFFSHORE INSTALLATIONS: GUIDANCE ON DESIGN, CONSTRUCTION AND CERTIFICATION (1990 (32))

C.6.L Appendix A21.4.2 Charpy Impact Requirements (for Parent Materials) (32)

The minimum Charpy energy shall be Oy/10 Joules, where oy is the specified minimum yield stress (MPa) for the steel grade in question, with no individual value less than 70% of the specified minimum average energy, and not more than one individual value less than the specified minimum average.

The required energies shall be achieved at test temperatures which depend on plate thicknesses, on whether the plates are in the as-welded (AW) or PWHT condition and whether the constructions are to be used in regions where the stresses, calculated for the maximum design loading, exceed 0.8 times the specified yield stress (high stress regions). The test temperature are given in the table below (parent material):

I Thickness, t,

1 mm

| t s 2 0 1 20 < t s 100

40 < t s 100

| t > 100

Charpy specimen locations

Sub-Surface Sub-Surface Mid-thickness

Charpy test temperature, °C |

As welded

High stress region

-20 -40 -30

Other

-20 -30 -20

PWHT |

High stress region

-20 -30 -20

Other 1

-10 1 -20 -20 |

To be agreed with the Certifying Authority 1

Transverse Charpy specimens shall be used for plate, longitudinal specimens for rolled bars, sections and structural hollow sections. If the achieved average value is less than the specified minimum average, or if one individual is less than 70% of the specified minimum average, three additional test pieces, taken from the same position, can be tested and a new average calculated. The new average shall not be less than the specified minimum average; not more than two individual values shall be less than the specified minimum average; and only one individual value is permitted to be less than 70% of the specified average value.

C.6.2. Appendix A21.8.9: Avoidance of Brittle Fracture, Charpy V-notch Require-ments (for Welded Joints) (32)

The minimum Charpy energy required for weld metal and HAZ is σ/ΙΟ Joules where oy is the minimum yield stress (MPa) for the plate to be welded. The required energies must be achieved at temperatures which depend on plate thickness, on whether the plates are in the AW or the PWHT condition and whether the constructions are to be used is high stress regions, as defined above. Hie test temperatures are given in the table below. CTOD testing is required for welded joints in high stress regions of thicknesses greater than 40mm, and for all welded joints of thicknesses greater than 50mm.

82

Heat affected zone and weld metal Charpy requirements:

1 Max. 1 structural 1 Thickness t, 1 mm

1 t s 2 0

1 20 < t s 100

1 t < 40 It > 50

| t > 100

locations

HAZ

Sub-surface Sub-surface

WM

Sub-sur-face Sub-sur-face

Charpy test temperature, °C and 1 CTOD requirements |

As welded

High stress region

-20

-40

CTOD CTOD

| Other

-20

-30

-30 CTOD

PWHT |

High stress region

-20

-30

-30 -30

Other 1

-20 1

-20 1

-20 1 -20 |

To be agreed with the Certifying Authority 1

C.7. EEMUA PUBL. No. 150: STEEL SPECIFICATION FOR FIXED OFFSHORE STRUCTURES (1987, (33))

C.7.1. Chapter 25: Impact Tests and Chapter 28: Retests (33)

The test temperatures and the average impact requirements from three tests for different steels are listed in Tables 7, 9 and 11 of this specification. It is permitted for one value to be less than the specified average but not less than 70% of the average value.

If the average value of the three impact tests is less than the specified minimum value or if one value is less than 70% of the specified average, three additional tests can be conducted and a new average calculated. The new average value shall not be less than the specified minimum average, not more than two of the individual values shall be less than the specified minimum average and only one individual value shall be less than 70% of the specified minimum value.

C.7.2. Appendix F5: Test Requirements (33)

Specimens must be taken in the transverse orientation; the Charpy energy shall be 36J average, 26J individual at -40°C for Grade 355 steel, and 45J average, 32J individual at -40°C for Grade 450 steel.

83

Charpy specimen

C&. DET NORSKE VERITAS: RULES FOR THE DESIGN, CONSTRUCTION AND INSPECTION OF OFFSHORE STRUCTURES, NORWAY (1981, (34))

C.8.1. Section 6: Steel Structures, Section 6.1 Materials, Section 6.1.5 Mechanical Properties (34)

Three types of structural steel are defined: special, primary and secondary structural steel. TTie impact energy requirement, as a function of the specified minimum yield strength, are given in Figure 16 of these Appendices, where KVTand KVL stands for the Charpy energy in transverse and in longitudinal orientation respectively.

Steel castings and weld metal shall fulfil the longitudinal requirements. One test sample consists of three specimens. No single value is to be less than 75% of the specified minimum average.

The impact test temperature is defined using the design temperature, which is to be taken as 5°C below the most probable lowest monthly mean environmental temperature, with a maximum of +10°C. The impact test temperature is then determined as a function of thickness and steel type using the table below.

| Material thickness | t, mm

I t s 12.5 1 12.5 < t s 25.5 I 25.5 < t s 50 | t > 5 0

Special structural steel

T = TD T = TD - 20 T = TD - 40 T = TD - 40

Primary structural steel

T = TD T = TD

T = TD - 20 T = TD - 40

Secondary 1 structural steel |

T = TD

T = TD - 20 |

where T is the impact testing temperature (°C) and TD is the design temperature (°C).

C.9. DET NORSKE VERITAS TECHNICAL NOTE; FIXED OFFSHORE INSTALLATIONS FRACTURE TOUGHNESS PROPERTIES AND POST WELD HEAT TREATMENT (35)

C.9.1. Chapter 3, Fracture Toughness (35)

The Charpy impact requirements are specified as a function of minimum specified yield strength for transverse and longitudinal orientated specimens. For longitudinal orientation and a yield strength of 270 £ oy & 420MPa, the requirement is σ/ΙΟ Joules; for oy < 270MPa the requirement is 27J; and for oy > 415MPa the requirement is 42J. For transverse orientation 2/3 of the requirement for longitudi-nal orientation is stipulated. The individual values shall be at least 75% of the specified average.

The impact testing temperature is determined from graphs for as-welded and PWHT conditions, relating the minimum design temperature and the reference thickness to the impact testing temperature. For unwelded components, the impact testing temperature is to be taken as for PWHT components.

84

The reference thickness is the wall thickness for parent plate; for flanges, tube sheets and flat covers the thickness shall be the greater of VA of the flange or the neck/shell thickness to which it is attached.

The combination of reference thickness and minimum design temperature requiring impact testing or/and normalising or other equivalent heat treatment is specified in Figure 1 of the Technical Note.

85

SECTION D:

MOBILE OFFSHORE UNITS AND SHIPPING TOUGHNESS REQUIREMENTS

SECTION D:

MOBILE OFFSHORE UNITS AND SHIPPING TOUGHNESS REQUIRE-MENTS

D.I. REGISTER OF SHIPPING OF THE PEOPLE'S REPUBLIC OF CHINA: RULES FOR THE CONSTRUCTION OF SEA-GOING STEEL SHIPS (1978, (36))

The Chinese rules for welded joints in carbon steel hulls of ships (36) require that for Classes II, III and IV steels (tensile strength 42 - 52kg/mm2, yield strength * 24kg/mm2, see Reference 36 for chemical composition) and weldments which are to be subjected to a low temperature impact test, either V-notch or U-notch specimens may be adopted, and the impact energy values must meet the following average requirements (3 specimens):

1 Class of 1 steel

1 Π

III | rv

U-notch

Test temp., °C

-20 -40 -40

Impact energy, kg.m/cm2

3 3 5

V-notch |

Test temp., °C

0 0

-10

Impact ductility, 1 kg.m/cm2 |

2.8 1 4.8 6.2

For U-notch specimens only one result is permitted to be lower than the average requirement. For V-notch specimens a re-test is permitted if the average is not less than 85% of the requirement. The average results from all six specimens must then be used.

Low alloy (killed) steel for hull structures must comply to the impact energy requirements presented in Table D.I. The reader is referred to the document (36) where the chemical composition and tensile properties of these steels are presented.

For boiler and pressure vessel constructions, V-notch impact toughness values (average of 3, room temperature) of 6.0kg.m/cm2 for 20g, 22g, 12Mng, 16Mng and 15Mn Vg Grades of steel and 7.0kg.m/cm2 for 18Mn Mo Nbg. After strain aging, 3.0kg.m/cm2 is required for 22g, 12Mng, 16Mng, 15Mn Vg and 18Mn Mo Nbg and 3.5kg.m/cm2 for 20g. One specimen per set of three is permitted to have toughness less than 1.0kg.m/cm2 below the average requirement (0.5kg.m/cm2 for strain aged steels). Steel forgings must comply to the following requirements (average of two specimens):

1 Grade of 1 steel

115 ■■■■aaaaaB&SBBBaBssss

Section thickness or diameter, mm

s 100 101 - 300

~———~———————————

Impact energy, kg.m/cm2 |

6.5 1 6.0 1

89

Table continued,

1 Grade of 1 steel

1 20

125

130

1 35

1 40

145

■■■■■■■■■■■■■■■■■■■I

■■■■■■■EBBBBBBBaBBaBasBasBBBBESBBBBBBsna

Section thickness or diameter, mm

s 100 101 - 300

s 100 101 - 300

s 100 101 - 300

s 100 101 - 300 301 - 500 501 - 750

s 100 101 - 300 301 - 500 501 - 750

s 100 101 - 300 301 - 500 501 - 750

Impact energy, kg.m/cm2 |

5.5 1 5.0 1

5.5 1 5.0 1

5.0 (6.0) 1 4.0 (5.0) 1

4.5 (6.0) 1 4.0 (5.0) 1 4.0 (5.0) 1 3.5 (4.5) 1

4.0 (5.0) 1 4.0 (5.0) 3.5 (4.5) 3.0 (4.5) 1

4.0 (5.0) 1 3.5 (4.5) 1 3.5 (4.0) 3.0 (4.0)

The impact energies in brackets apply to important forgings (crankshafts, propeller shafts, etc). The lower toughness value is not permitted to be less than 75% of the required average value.

Steel castings must comply to the following requirements (average of two specimens):

P H ^ H i ^ H i ^ w a

1 Grade of steel 1 ZG15 1 ZG25 1 ZG35

ZG45 1 ZG55

ZG25Mo 1 ZG20CrMo 1 ZG35CrMo

Tensile strength, kg/mm2

40 45 50 58 65 50 47

1 60 BBBBBBSSSSSSmEBBBBSSSSS

Yield strength, kg/mm2

20 24 28 32

! 35 27 25 40

Impact energy, 1 kg.m/cm2 | 6.0 1 4.5 1 3.5 1 3.0 1 2.0 1 4.5 1 3.0 1 3.0 1

90

Nodular iron castings must comply with the following requirements (3 specimens):

| Grade of steel

1 QT40-17 QT42-10

| QT42- 1

Tensile strength, kg/mm2

40 42

120

Yield strength, kg/mm2

25 27 84

Impact energy, 1 kg.m/cm2 |

6.0 1 6.0 1 3.0 1

Grades QT50-5, QT60-2, QT70-2 and QT80-2 do not require impact testing. Retests are permitted if two specimens meet these requirements.

Boiler tubes and steam pipes constructed from steel Grades 12Cr 1 Mo V and 15Cr Mo must have 6.0kg.m/cm2 impact toughness for longitudinal specimens and 5.0kg.m/cm2 for transverse specimens (tensile strength 45 - 48kg/mm2, yield strength 24 - 26kg/mm2). Three specimens must be tested, with the lowest result not less than lkg.m/cm2 lower than the average requirement.

Ό2. U.S. COAST GUARD (1970, (37))

The U.S. Coast Guard Marine Engineering Regulations, sub-chapter F, requires that pressure vessel steels meet the following Charpy V-notch impact requirements (3 specimens, parent material and weldments, tested at 10°F below the minimum service temperature):

| Test temperature, °F

0 to -70 1 * - 7 0

Impact energy, ft.lb 1

Average

30 35

Minimum 1

20 1 16.7

Section 54.05 of the document (37) describes the number, orientation and location of the test specimens, as well as sub-size Charpy specimen requirements and retest procedures. Longitudinal specimens are preferred, although if only transverse specimens can be extracted then the required energy levels must not be less than 2/3 the above values.

Retests are permitted if the average of 3 specimens is not less than 15% lower than the average requirement, or if the value from a single specimen result is less than the minimum requirement by less than 15%. The three retest specimen results must be combined with the initial three, and the average of the six must meet the average requirements presented in the Table above.

When required, drop weight tests must be conducted in accordance with ASTM Specification E-208, with a "no break" result.

91

DJ. AMERICAN BUREAU OF SHIPPING (27)

D3.1. ABS: Rules for Building and Classing Steel Vessels (1986, (27))

This specification requires the following impact energy levels (3 specimens):

| Grade

1 A

B

1D

E

DS, CS, E

AH32, 36

DH32, 36

EH32, 36 1

Thickness, in.

> 2

1 - 2 > 2

All

< 2

> 2

All

All

All

Test temp., °F

68

32 32

14

-40

14

32

-4

-40

Impact energy, ft.lb 1

Longitudinal

20

20 20

20

20

20

25

25

25

Transverse 1

14 1

14 1 14 1

14 1

14 1

14 1

17

17

17 1

The number, orientation and location of Charpy impact specimens are described in Section 43.3.5 and Tables 43.1 and 43.2 of this specification, as well as retest procedures.

For materials intended for low temperature service, Charpy requirements are 0.38mm lateral expansion for transverse specimens (0.50mm for longitudinal specimens) and impact energies of 20ft.lb for transverse specimens (30ft.lb for longitudinal specimens) tested at -38, -60 and -76°F for Grades V/VH-039, V/VH-051 and V/VH-060 respectively. These are average requirements for 3 specimens. The minimum single specimen requirements are 13.5ft.lb (transverse specimens) and 20ft.lb (longitudinal specimens). Sub-size specimen requirements and retest procedures are described in Table 43.6 of this specification. If the Charpy requirements are not met on re-testing then "no-break" results are sufficient from two drop weight tests, for thicknesses of greater than 0.5".

D3.2. ABS: Rules for Building and Classing Mobile Offshore Drilling Units (1985, (27))

This specification requires the following impact energy levels for steels in the 34-58ksi yield strength range, tested at 0, 18 or 54°F below service temperature (see Table 11.4 of this specification) for secondary, primary and special application structures, respectively:

92

1 Yield strength, ksi

1 34-44 1 44-58

Impact energy, ft.lb

20 1 25 1

High strength steels (60 *oy* lOOksi) require 25ft.lb at the following test tempera-tures:

I Service I temperature 1 °F

1 32 1 14 1 -4 1 -22 1 -40 | -58

Primary and secondary application test temperature, °F

-22 -40 -40 -58 -75 -94

Special application test 1 temperature, 1 °F 1

-40 1 -58 1 -58 1 -75 1 -94 1

-112 1

The following alternative requirements may be used:

Transverse specimens require 2/3 of the energy levels required for longitudinal specimens. Lateral expansion requirements are 0.38mm for transverse specimens and 0.50mm for longitudinal specimens. The nil-ductility temperature (TNOT)> as determined by drop weight tests, must be 9°F below the Charpy impact test temperature.

Grades B, D and E require 20ft.lb impact energy for longitudinal specimens and 14ft.lb for transverse specimens, tested at 32, 14 and -40°F respectively. Grades AH32/36, DH32/36 and EH32/36 require 25ft.ib for longitudinal specimens and 17ft.lb for transverse specimens tested at 32, -4 , -40°F respectively.

High strength steels (61 * oy * lOOksi) require 30ft.lb (longitudinal specimens) and 20ft.lb (transverse specimens) at the following test temperatures:

1 Grade

1 AQ43, 47, 51, 56, 63, 70 DQ43, 47, 51, 56, 63, 70 EQ43, 47, 51, 56, 63, 70

1 PQ43, 47, 51, 56, 63, 70

Test temperature, °F |

32 H -4 1

-40 1 -76 1

sssssgsssssssssBsssBBsssBSKBM^ammmÊÊÊÊÊÊmÊmam

93

D.4. GERMANISCHER LLOYD: RULES FOR THE CLASSIFICATION AND CONSTRUCTION OF SEAGOING STEEL SHIPS, VOL. HI MATERIALS AND WELDING (1976 (38))

D.4.1. Chapter 6: Materials, Section 2: Steel (38)

The Charpy V-notch energy requirements are listed for different grades of ordinary hull structural steels. Impact energies of 2.8kg.m are required for Grade B to E at test temperatures of 0, -20 and -40°C, respectively.

Impact requirements for higher tensile strength hull structural steels are as follows: For a minimum yield strength of 32kg/mm2 (313MPa), an impact energy of 3.2kg.m is required (longitudinal orientation) for Grade A32, D32 and E32 at a test temperature of 0, -20 and -40°C. 2.2kg.m is required (transverse orientation) for Grade A32 and D32 at 0 and -20°C, respectively; 2.4kg.m is required for Grade E32 at -40°C

For a minimum yield stress of 36kg/mm2 (353MPa), an impact energies of 3.5kg.m is required at 0, -20 and -40°C for Grade A36, D96 and E36 for the longitudinal orientation; 2.4kg.m is required at 0 and -20°C for Grade A36 and D36 and 2.2kg.m at -40°C for Grade E36 for the transverse orientation.

D.4.2. Chapter 7: Rules for Welding; Section 1.D5: Requirements (38)

For butt weldments of Grade 4 steels (A, A32, A36) the impact energy requirement of the weld metal are 6kg.m/cm2 for manual and semi-automatic welds at 20°C and 4.4kg.m/cm2 for fully automatic welds at 20°C. For Grade D and E structural steels, the same energy requirements apply at test temperatures of 0 and -20°C, respective-iy.

DJ. LLOYD'S REGISTER: RULES FOR THE MANUFACTURE, TESTING AND CERTIFICATION OF MATERIALS (1984 (39))

D.5.1. Chapter 3: Rolled Steel Plates, Strip, Sections and Bars; Section 2: Normal Strength Steels (39)

The steels are divided in 4 grades (A,B»D,E) with a average energy requirement of 27J at a test temperature of 0, -10 and -40°C (no requirements for Grade A steel). Only one individual value is permitted to be less than 70% of the specified average.

D.5.2. Section 3: High tensile steels (39)

Three types of steel with a required minimum yield strength of 315, 340 and 355MPa are classified as Grades A, D and E with a required impact energy of 31J at 0, -20 and -40°C for steel types AH32, DH32 and EH32 and of 34J at 0°C for AH34S and AH36S, at -20°C for DH34S and DH36S, and at -40°C for EH34S and E36S.

94

D.53. Chapter 11: Approval of Welding Consumables; Section 3: Electrodes for Manual Welding (39)

The impact requirements for weld metal tests (covered electrodes) are 47J at 20°C (Grade 1), 47J at 0°C (Grade 2 and 2Y) and 47J at -20°C (Grade 3 and 3Y). Grade 1 electrodes are to be used with steel Grade A, Grade 2 with A, B or D Grade, Grade 3 with A, B, D or E, Grade 2Y and 3Y with AH, DH or EH Grade.

D.5.4. Section 4, Wire-flux combinations for submerged-arc automatic welding (39)

The requirements for weld metal testing (wire-flux combinations) are 34J at 20°C (Grade 1 and 1Y) 34J at 0°C (Grade 2 and 2Y) and 34J at -20°C (Grade 3 and 3Y).

Ό.6. REGISTRO ITAUANO NAVALE (MNA): RULES FOR THE CONSTRUC-TION AND CLASSIFICATION OF SHIPS (1990, (40))

D.6.1. Section 6, Rules for quality of materials and testing, Chapter 3.2, Hull structural steels (40)

Steel classifications in the RINA designation correspond to the International Association of Classification Societies (IACS) designation of A, B, D and E, with a minimum yield strength of 235MPa and a required impact strength of 27J for longitudinal and 20J for transverse orientation at a test temperature of 20, 0, -20, -40°C, respectively.

High strength structural steels, IACS designation A32, D32 and E32, with a minimum yield stress of 315MPa, have a required impact energy of 31J in longitudinal and 22J in transverse orientation at 0, -20 and -40°C, respectively. High strength structural steels, IACS designation A36, D36 and E36, with a minimum yield stress of 355MPa have a required impact energy of 34J for the longitudinal orientation and 24J for the transverse orientation at a test temperature of 0, -20 and -40°C, respectively.

D.6.2. Section H: Rules for Welding, Chapter 2, Welding Processes and Procedures for Approval and Qualification (40)

The requirements for electrodes for welding C and C-Mn steel are as follows. Electrodes are divided in three classes of approval with a required Charpy V-notch energy of 47J at 20, 0 and -20°C for joints welded in flat and horizontal positions and 34J at 20, 0 and -20°C for joints welded in vertical and overhead positions.

The requirements for fluxes for submerged-arc welding processes are as follows. Fluxes are divided in three classes with a required Charpy V-notch energy of 34J at 20, 0 and -20°C, respectively.

The requirements for welding consumables for semi-automatic welding processes with or without shielding gas are as follows. Welding consumables are divided in three classes of approval with a required Charpy V-notch energy of 47J at 20,0 and -20°C for joints welded in flat and horizontal positions and 34J at 20,0 and -20°C for joints welded in vertical and overhead positions.

95

The requirements for welding consumables for automatic welding processes with or without shielding gas or for welding consumables for electrogas and electroslag welding processes are as follows: Welding consumables are divided in three classes of approval with a minimum Charpy V-notch energy of 34J at 20, 0 and -20°C, respectively.

D.7. DET NORSKE VERITAS: RULES FOR CLASSIFICATION OF STEEL SHIPS, MATERIALS AND WELDING (1984, (41))

D.7.1. Part 2, Chapter 1, Steel and Iron (41)

D.7.1.1. Section 2: Rolled steel for structural application (41)

Normal strength steel is classified in 4 grades, NVA, NVB, NVD and NVE with a minimum yield strength of 235MPa and a required impact energy of 27J for longitudinal and 20J for the transverse orientation at 0, -20 and -40°C, respectively (no requirement for NVA Grade steel).

Four types of high strength steel are specified with a minimum required yield strength of 265, 315, 355 and 390MPa. Each steel type is sub-divided in 3 grades (A, D and E) with a required impact energy at a temperature of 0, -20 and -40°C. The required impact energy values for the four steel types at the above mentioned temperatures are 27, 31, 34 and 39J for specimens in longitudinal orientation and 20, 22, 24 and 26J for transverse orientation.

The required values are mean values of three tests with no single value smaller than 70% of the specified average. If one specimen falls below this criterion or if the average value is not achieved, another three specimens may be tested and a new average can be calculated. This new average shall comply with the required average with not more than two specimens falling below that value and not more than one falling below the 70% limit.

D.7.1.2. Section 3: Rolled steels for boilers, pressure vessels and special applications (41)

Five carbon and carbon/manganese steel grades are specified in the code (0 - 4) with the following Charpy requirements. No requirements for Grade 0 steel, 27J for steel plates and 41J for sections at test temperatures of 0, -20, -40 and -55°C for Grade 1 - 4 , respectively.

The same requirements as specified for steels for structural applications see Section D.7.1.1 apply for average values and re-testing.

D.7.2. Part 2, Chapter 2: Welding (41)

Electrodes for manual metal-arc welding are classified in five categories (1, 2, 2Y, 3 and 3Y) with a required impact energy of 47J at 20, 0 and -20°C for category 1, 2 and 3, respectively.

96

For wire-flux combinations for submerged arc welding, the following Charpy impact energy requirements apply 34J at 20, 0 and -20°C for Grade I(IY), II(IIY) and III(IHY), respectively.

For wire-gas combinations and wires for automatic and semi-automatic welding the requirements are as follows. For semi-automatic welding, the requirements for manual metal-arc welding. For automatic welding, the requirements are the same as for submerged-arc welding.

ΌΛ. JAPAN: RULES AND REGULATIONS FOR THE CONSTRUCTION AND CLASSIFICATION OF SHIPS (1978, (42))

D.8.1. Section K: Materials, Chapter 3.1 Rolled Steel for Hull (42)

Four types of steel are classified, with minimum yield strengths of 24 (235), 32 (314), 36 (353) and 46kg/mm2 (451MPa), respectively. Each type is divided in to 3 grades.

For the first steel type, a Charpy V-notch energy of 2.8kgm (27J) for longitudinal and 2.1kgm (21J) for transverse orientation at temperatures of 0, -10 and -40°C for Grade KB, KD and KE, respectively, is required.

For the steel types with minimum yield strengths of more than 32kg/mm2, an energy of 3.2 (31J) (longitudinal) and 2.3kg.m (22J) (transverse) at 0, -20 and -40°C are required for Grade KA32, KD32 and KE32, respectively. 3.5 (34J) (longitudinal) and 2.5kg.m (24J) (transverse) at 0, -20 and -40°C are required for Grade KA36, KD36 and KE36, respectively 4.8 (47J) (longitudinal) and 3.5kg.m (34J) (transverse) at 0, -20 and -40°C are required for Grade UA46, UD46 and UE46, respectively.

Chapter 3.3 Rolled Steel Plates for Pressure Vessels (42)

For all grades, an average (of three tests) minimum energy value of 4.8kg.m (47J) is required with no single value less than 2.8kg.m (27J). If the required value is not met by one specimen (at most), and the average value is at least 85% of the required value, three additional test specimens may be tested and a new average calculated. If the new average and each individual value of the additional tests fulfil the requirements, the material may be accepted.

97

Tab

le D

.l Ch

ines

e Re

giste

r of

Shi

ppin

g (se

e Se

ction

D.l)

H C

lass o

f 1

steel

I I III

III

IV

1 iv

aaB

aaaB

BB

Boi

BB

Categ

ory

of

steel

I II I II I II

U-n

otch

Test

tem

p., °

C

-20

-20

-40

-40

-40

-40

Impa

ct d

uctil

ity, k

g.m

/cm2

3.0

3.0

3.4

3.6

5.6 6.0

V-n

otch

1

Test

tem

p., °

C

0 0 0 0 -10

-10

Impa

ct d

uctil

ity, k

g.m

/cm2

1

2,8

1 2.

8 1

5.4

5.8 6.9

7.4

1

SECTION E:

PETROCHEMICAL PLANT TOUGHNESS REQUIREMENTS

SECTION E:

PETROCHEMICAL PLANT TOUGHNESS REQUIREMENTS

E.l. ASME B313 CHEMICAL PLANT AND PETROLEUM REFINERY PIPING REQUIREMENTS (1990 (43))

This ASME publication (43) requires the following impact test acceptance criteria to be met for parent material and weldments (3 specimens tested at minimum design temperature):

1 Specified 1 Minimum 1 tensile 1 strength, 1 ksi

1 s 65 6 5 - 7 5 7 5 - 9 5

* 9 5

B — — i — — —

Impact energy, ft.lb 1

Fully deoxidized steels

Average

13 15 20 (1)

Minimum

10 12 15

1(1)

Other steels 1

Average

10 13

Minimum 1

7 1 10

[ω 1 Note:

(1) These steels (including bolting and high alloy steels) have a lateral expansion requirement of 0.015". The number, orientation and location of impact test specimens are described in Section 323.3 and Table 323.3.1 of (43), as well as retest procedures and sub-size Charpy specimens.

Section K323 of Chapter IX of (43) and Tables K323.3.1 and K323.3.5 describe impact test procedures and impact toughness acceptance criteria (3 specimens tested at lowest metal temperature at which a piping component or weldment is subjected to a stress greater than 6ksi):

1 Pipe wall

1or

I component 1 thickness, 1 in.

^ 1

1 - 2

> 2

Specified minimum yield strength, ksi

s 135 > 135

s 135 >135

£135 >135

Impact energy, ft.lb 1

Transverse

Average

20 25

25 30

30 35

Minimum

15 20

20 24

24 28

Longitudinal 1

Average

40 50

50 60

60 70

Minimum 1

^50 40 1

40 1 48 1

48 1 56 1

101

[ω

E-2. AMERICAN PETROLEUM INSTITUTE (7)

EJL1. API 620: Recommended Rules for Design and Construction of Large, Welded, Low-Pressure Storage Tanks (1985, (7))

Appendix Q of API 620 requires Charpy impact testing of materials (other than austenitic stainless steels or aluminium alloys) in low-pressure storage tanks for liquified hydrocarbon gases. For plates in primary components of 9% and 5% nickel steel, an average (of 3 specimens) transverse impact energy of 20ft.lb (16ft.lb minimum single specimen) is required; tested at -320°F for A353 and A553 steel, and -275°F for A645 steel. Longitudinal orientation requirements are 25ft.lb (20ft.lb minimum single specimen). In addition, a lateral expansion of 0.015" is required. Weld metal and HAZ also have to be tested.

Structural members, as well as forgings, piping and tubing, are required to achieve transverse energies of 25ft.lb (20ft.lb minimum single specimen). The number, location and orientation of test specimens, as well as retest procedures and sub-size Charpy requirements are described in Sections Q.2 to Q.6 of API 620.

Appendix R of API 620 presents impact toughness requirements for low-pressure storage tanks for refrigerated products. Between 13 and 20ft.lb (9-15ft.lb minimum single specimen) impact energy is required for Group I (semi-killed), Group II (fully killed) and Group III (fully killed, high strength), tested at the applicable minimum permissible design metal temperature. The reader is referred to Tables R.2.1, R.2.2 and R.2.3 of API 620 where the test temperatures and impact requirements are presented in detail for materials of various grades and thicknesses.

E2.2. API 650: Welded Steel Tanks for Oil Storage (1988, (7))

This specification requires that the design metal temperature (DMT) be calculated for all shell plates, shell reinforcing plates, shell insert plates, bottom plates welded to the shell, shell manhole and nozzle neck plates, and plate-ring shell-nozzle flanges (with the exceptions presented in Sections 2.2.7 and 2.2.9 of API 650). The DTM must be evaluated from Fig.2.1 of API 650, reproduced as Fig.17 of this Compendium, where the DMT is defined graphically as a function of Section thickness and steel Group, defined below:

Group I - as rolled, semi-killed (e.g. A283C, A285C, A131A) Group II - as rolled, killed or semi-killed (e.g. A131B, A36, Fe 42C) Group III - as rolled, killed, fine grain practice (e.g. A573-58, A516-55) Group III A - normalized, killed, fine grain practice (e.g. A131 LS) Group IV - as rolled, killed, fine grain practice (e.g. Grade 44, A662 B) Group IV A - as rolled, killed, fine grain practice (e.g. A662C, A573-70) Group V - normalized, killed, fine grain practice (e.g. A573-70, A516-70) Group VI - normalized or quenched and tempered, killed, fine grain practice,

reduced carbon (e.g. A131 EH 36, A633 D)

The reader is referred to Table 2.3 of API 650 where a full list of materials is given for each material group. The following Charpy V-notch impact requirements apply (3 specimens, tested at a temperature less than the DMT):

102

1 Group

1 I, II, III, III A

1 IV, IV A, V, VI 1 (except quenched and 1 tempered)

1vi 1 (quenched and tempered)

Thickness, in.

See Sections 2.2.2 to 2.2.5 of API 650

ssl.5 1.5 - 1.75

1.75 - 2 2 - 4

3:1.5 1.5 - 1.75 1.75 - 2 2 - 4

Impact energy, ft.lb 1

Longitudinal

15

30 35

40 50

35 40 45 50

Transverse 1

30 1

20 1 25 1

30 40

25 30 35

_40 1

The number, orientation and location of Charpy test specimens are described in Section 2.2 of API 650, as well as retest procedures and sub-size Charpy requirements. For impact toughness requirements of piping and forgings, flanges, bolting and welding electrodes API 650 refers to relevant API and ASTM specifications.

Section 7 of API 650 presents the following impact requirements for HAZ and WM (if DMT < 50°F) of welds produced with consumables not covered by ASME K , but listed in Section 2 of API 650:

1 Group □ Tensile strength, ksi

*60 6 0 - 7 5 >75

Impact energy, ft.lb |

15 1 20

J5

E.2.3. API 660: Shell and Tube Heat Exchangers for General Refinery Services (1982, (7))

This standard requires that impact toughness levels specified in ASME Section VIII, Division I (reviewed in Appendix A) are met. More stringent requirements may be specified by the purchaser to minimize the possibility of brittle fracture.

E3. BRITISH STANDARDS

E3.1. BS2654: Manufacture of vertical steel welded non-refrigerated storage tanks with butt-welded shells for the petroleum industry (1989, (44)).

BS2654 (44) is applicable to non-refrigerated storage tanks with maximum design pressures of 56mbar, and with design metal temperatures above or equal -10°C.

103

The following Charpy impact energy requirements apply to the parent material (average value, with the minimum result from three tests not less than 70% of the average value):

| o-re, N/mm2

1 s 430

1 430-490

1 >490

Thickness t, mm

s 13 >13 s 13 >13 Allt

Test temp., °C (1)

20

-5 -15

Impact energy, J |

27

41 1 41

Note:

(1) The lower of the test temperature given in this table and in Fig. 18 applies.

The Charpy impact energy requirement for the weld metal is 27J at the test temperatures given in the above table (or Fig. 18), for vertical shell butt welds and MMA welded shell butt welds, including the connections between nozzles and mountings and the shell. For girth seams welded by an automatic process, the test temperature is -10°C, or Fig.18 (using scale A), whichever is the less onerous.

E3.2. BS4741: Specification for vertical cylindrical welded steel storage tanks for low temperature service: single-wall tanks for temperatures down to -50°C (1971, (45)).

BS4741 (45) is applicable to tanks for above ground storage of products with specific gravity * 0.8, for temperatures down to -50°C, and for the following material grades: BS1501, BS4360, ISO/R 630, BS1503, BS1506 and BS3603 (plates, bars, forgings, bolting materials and piping).

The following impact requirements apply (average of three specimens, with no individual result less than 75% of average):

| Specimen size, 1 mm II

I 10 x 10 10 x 7.5 10x5

! 10 x 2.5 1 « = = = = = ^ = =

Impact energy, J |

oy s 450N/mm2

27 22 19 10

oy > 450N/mm2

41 33 29 15

Weld metal j

27 22 19

The specimens are to be tested at the following temperatures (°C):

104

I Material thickness, 1 mm

t s 2 0 1 20 < t s 30 | 30 < t s 40

Minimum design metal temperature, °C 1

* -10°C

-10 -20 -30

* -35°C

-35 -45 -55

* -50°C |

-50 | -60

E3.3. BS7122: welded steel tanks for liquéfiable gases transported by road (1989, (46)).

BS7122 (46) requires that impact testing be performed on plates and forgings used for pressure containing parts and attachments directly welded to them which have a specified thickness of 5mm or greater.

The following minimum Charpy impact energies are required, tested at 0°C:

1 Specified tensile 1 strength, N/mm2

I Minimum

1 <450

*450

Maximum

<560

<610

Size of test piece, mm

10x10 10 x 7.5 10x5

10x10 10 x 7.5 10x5

Impact energy, J |

Average (of 3)

27 22 19

40 32 28

Minimum (of 3) 1

19 | 15 13

28 22 20

105

SECTION F:

BRIDGE TOUGHNESS REQUIREMENTS

SECTION F:

BRIDGE TOUGHNESS REQUIREMENTS

F.l. AASHTO REQUIREMENTS

F.1.1. AASHTO: Standard specifications for highway bridges (1983, (47))

This standard requires the following impact toughness acceptance levels:

For base metals:

I Thickness, 1 inch

1 s 4" Mechanically 1 fastened

1 s 2W welded

1 2Yi - 4" welded

Impact energy, ft.lb 1

Zone 1

20

25

25

Zone 2

20

20

25

Zone 3 1

20 1

20 1

25

where zones 1, 2 and 3 have minimum service temperatures of * 0°F, - 1 to -30°F and -31 to -60°F, respectively, with impact tests performed at 50°F, 20°F and -10°F. If the yield strength exceeds 85ksi, the test temperature must be reduced by 15°F for each increment of lOksi above 85ksi.

For weld metal an impact value of 25ft.lb is required for Zone 1, 2 and 3 materials, tested at -10°F, -10°F and -25°F, respectively.

F.1-2. AASHTO: Guide Specifications for Fracture Critical Non-Redundant Steel Bridge Members (1978, (47))

This specification defines a fracture control plan for fracture critical steel bridge members. The impact toughness requirements include the following weld metal acceptance criteria (5 specimens, with the lowest and highest test result discarded):

| Parent material

1 M183, M222, M223 (ASTM A36, A588, A572)

M244 (ASTM A514), ASTM | A517

Test temperature, °F

-20

-30

Impact energy, ft.lb |

25 1

35

The locations and orientations of test specimens are detailed in Section 8 of this Guide for fillet welds made with filler material normally used for welding M183, M223, and

109

M222 steels (25ft.lb at -20°F). A single specimen may have a toughness less than the average requirement, but not less than 2/3 of the average value. Retests are permitted, with all three specimens meeting the average requirement.

For the base metal the following requirements apply:

1 AASHTO

1 M183

1 M233

1 M222

1 M244

SSSSSSSBSSSSSS

ASTM

A36

A572

A588

A514

Thickness, in.

s VA l'A-4 4

*VA-2 (M,W) 1*4-2 (M,W) 2 - 4 (M)

s VA (M,W) VA-2 (M,W) 2 - 4 ( M ) 2 - 4 (W)

VA (M, W) VA - 2XA (M,W) 2V4 - 4 (M) 2Vi - 4 (W)

Impact energy, ft.lb (at test temp., 1 °F) 1 Zone 1

25 (70) 25 (50)

25 (70) 25 (50) 25 (50)

25 (70) 25 (50) 25 (50) 30 (50)

35 (0) 35 (-20) 35 (-20) 45 (-20)

Zone 2

25 (40) 25 (20)

25 (40) 25 (20) 25 (20)

25 (40) 25 (20) 25 (20) 30 (20)

35(0) 35 (-20) 35 (-20) 45 (-20)

Zone 3 1

25 (10) 1 25 (-10) 1

25 (10) 1 25 (-10) 1 25 (-10) 1

25 (10) 1 25 (-10) 1 25 (-10) 30 (-10)

35 (-30) 1 35 (-40) 35 (-50) 1 Not per- 1 mitted 1

where (M) indicates mechanically fastened, (W) welded. Zones 1, 2 and 3 indicate minimum service temperatures of * 0°F, -1 to -30°F, and -31 to -60°F, respectively. If the yield strength of ASTME Grade A572 and A588 steels exceeds 65ksi, then the test temperature must be reduced by 15°F for every lOksi above 65ksi.

F-2. BS5400: PART 6: SPECIFICATION FOR MATERIALS AND WORKMANSHIP, STEEL (1980, (48))

F.2.1. Section 5: Inspection and Testing (48)

All parent steel shall comply with the requirements of BS4360. Weld metal and HAZ Charpy V-notch impact test requirements for areas subject to tension are:

Butt welds: for regions with a design tensile stress above 75MPa, the requirement shall be 0/355.1/2 J or 10J, whichever is greater, ay is the yield strength in MPa, t is the relevant thickness in mm.

For regions with a design tensile stress less than or equal to 75MPa the requirement is Oy/355.t/4 J or 10J, whichever is greater.

110

For butt welds carrying tension stress, for which the procedure test tensile test show the weld metal to overmatch the parent material strength, the Charpy V-notch requirements may be reduced to 27J at -20°C.

The fusion boundary region of the HAZ of butt welds shall have the following requirements:

1 Welding heat input |

I * 5kJ/mm 1 > 5kJ/mm

Minimum yield strength, oy |

oy < 400MPa No requirements As above, when specified

oy > 400MPa As above, when specified 1 As above 1

The minimum average value is specified for three specimens. If the minimum average value is not achieved, or if one single value is less than 70% of the specified average, or if two results are less than the specified average, then three additional test pieces from the same sample may be tested. The new average, including the former three tests, shall not be less than the specified minimum value, not more than three of the total six results shall be less than the specified average, nor more than two results less than 70% of the specified value and no single value less than 50% of the specified minimum.

F.2.2. Section 6: Properties of Materials; Section 6.5: Notch Toughness (48)

The energy absorption requirements are:

Cv * a/355.t/2 J for Type 1 [J, MPa, mm] Cv * σ/355.ί/4 J for Type 2 [J, MPa, mm]

at the minimum design temperature U (°C): U = Uc -5°C for parts to resist thermal movements where Ue is the effective bridge temperature, and U = Uc for all other parts. Type 1 materials are parts which are subjected to applied principal tensile stresses greater than lOOMPa (ignoring stress concentrations) and which have any welded connections, attachments or repairs. Type 2 materials are all other parts subjected to tensile stresses.

For parts where severe stress concentrations occur, the impact requirements is:

Cv * σ/355 [0.35 t (1 + 0.67k)] [J, MPa, mm]

where k is the stress concentration factor.

I l l

SECTION G:

MATERIAL TOUGHNESS REQUIREMENTS

SECTION G:

MATERIAL TOUGHNESS REQUIREMENTS

G.I. ASME II MATERIAL SPECIFICATION, PART A - FERROUS (1989 (49))

G.l.l. Pressure Vessel Materials (49)

G.l.1.1. SA-20/SA-20M: Specification for general requirements for steel plates for pressure vessels (49)

This specification, which is virtually identical to ASTM A20/A20M-88, covers rolled steel plates for pressure vessels. The reader is referred to specification SA-20/SA-20M (49) for an extensive list of ASTM materials covered.

Section 12 describes the number, orientation and location of impact specimens, as well as the test method. Sub-size specimens may be used for materials which normally have absorbed energy values in excess of 180ft.lb. For full size specimens the following impact results are required (average of 3 specimens):

R Material | Class

. II, III IV V

| VI

Impact energy, ft.lb

Average

10 13 15 20 1 " ——————

Minimum

7 10 12 15 -

Lateral expansion, mils 1

Average

—

-

--

-

Minimum 1

— I

- 1 - 1

É Where Classes III to VI are fully killed steels with specified minimum tensile strengths in the following ranges: III (ay <: 65ksi), IV (65 < oy * 75ksi), V (75 < oy < 95ksi) and VI (95ksi £ oy). Classes I and II correspond to steels which are not fully killed: I (oy * 65ksi), II (65 < oy z 75ksi). The ASTM material specifications which correspond to these Classes are listed in Table A1.15 of ASME II, as well as the test temperature to be used if none is specified for plate thicknesses up to 5". These temperatures range from -320°F for some Class VI materials with thicknesses less than 1", to -80°F for some Class I materials with thicknesses between 1 and 2". Table A1.16 of ASME II gives the corresponding impact energy acceptance requirements for sub-size Charpy specimens (full to VA size).

If drop weight testing is specified, then two specimens are required, with the "no break" acceptance criterion applying to both specimens. Section 16 of ASME II describes permissible retest procedures of impact requirements are not met.

115

G.I.1.2. SA-352/SA-352 M: Specification for steel castings, ferritic and martensitic, for pressure containing parts, suitable for low temperature service (49)

This specification is virtually identical to ASTM A352/A352M-88. The following impact requirements apply (3 specimens):

1 Matenal | Grade

1 LCA LCB LCC LCI LC2 LC2-1 LC3 LC4 LC9 LA6NM

Material type

C steel C steel C-Mn steel C-Mo steel 2Vi% Ni steel Ni-Cr-Mo steel 3Vi% Ni steel 4Vi% Ni steel 9% Ni steel 12V4% Cr, Ni-Mo steel

Usual mini-mum test temp., °F

-25 -50 -50 -75

-100 -100 -150 -175 -320 -100

Impact energy, ft.lb 1

Average

13 13 15 13 15 30 15 15 20 20

Minimum |

! 10 1 10 12 10 12 25 12 12 15 15

G.I.13. SA-508/SA-508M: Specification for quenched and tempered vacuum treated carbon and alloy steel forgings for pressure vessels (49)

This specification is virtually identical to ASTM A508/A508M-88. Section 6.2 describes the number, orientation and location of Charpy impact specimens. The following impact energy acceptance criteria apply (3 specimens):

| Material class

1 l> la 2,3

I 2a, 3a 4, 4a, 4b, 5, 5b

1 22B, F3V « ■ Β Μ Β 1 SSSSSSBSSSSSSSSSt

Test temperature, °F

+40 +40 +70 -20

0

Average

15 30 35 35 40

Minimum |

10 I 25 30 30 35

sasassasasBBBaiaam

The reader is referred to specification SA-508/SA-508M for the definitions of material Classes and chemical composition. Alternatively, when specified by the purchaser, Charpy impact temperature transition curves may be established, and drop weight tests performed to establish TNDT, or two "no break" test results.

G.I. 1.4. SA-541/SA-541M: Specification for steel forgings, carbon and alloy quenched and tempered for pressure vessel components (49)

This specification as virtually identical to ASTM A541/A541M~87a. Section 6 describes the number, orientation and location of Charpy impact specimens. The following impact energy requirements apply (3 specimens):

116

Impact energy, ft.lb

1 Material class

1 1, 1A 2A, 3A 2, 3, 4 22D 22C, 7, 7A, 7B, 8, 8A

| F3V, 22B

Test temperature, °F

+40 +70 +40 +40 +40

0

Impact energy, ft.lb 1

Average

15 35 30 25 35 40

Minimum 1

10 1 30 25 1 20 30 35

The reader is referred to specification SA-541/SA-541M for definitions of material Classes and chemical compositions.

G.I.1.5. SA-564/SA-564M: Specification for hot-rolled and cold-finished age-hardened stainless and heat-resisting steel bars and shapes (49)

This specification is virtually identical to ASTM A564/A564M-876. Sections 9 and 10 describe the number, orientation and location of Charpy V-notch specimens. The following impact energy requirements apply (3 specimens tested at room temperature, between 70 and 80°F):

| Material type and condition

1 630 - H900 I - H925 I - H1025 1 - H1075 1 - HllOO 1 - H1150 1 - H1150M

1 XM - 12 - H900 I - H925

- H1025 - H1075 - HllOO - HI 150 - H1150M

Minimum impact energy, ft.lb 1

Longitudinal

5 15 20 25 30 55

5 15 20 25 30 55

Transverse 1

10 1 5

15 20 1

J5 1

The reader is referred to specification SA-564/SA-564M where the material types and heat treatments are defined, as well as chemical compositions. Other material types (631, 632, 634, XM-9, XM-13, XM-16, SA45503, XM-25) do not require impact testing.

117

G.l.1.6. SA-645/SA-645M: Specification for pressure vessel plates, 5% Ni alloy steel, specially heat treated (49)

This specification, which is identical to ASTM AÖ45/A645-87, covers austenised, quenched, tempered and reversion-annealed 5%Ni alloy steel plates intended primarily for welded vessels for service at low or cryogenic temperatures.

This specification requires that Charpy V-notch tests be conducted at -275°F, with a lateral expansion requirement of 0.015". Impact energies must be recorded and reported for information.

Supplementary acceptance criteria for impact energies are presented, which apply if specified by the purchaser (3 transverse specimens).

1 Specimens

1 Longitudinal specimens 1 Transverse specimens

Impact energy, ft.lb 1

Average

25 20

as

Minimum 1

20 1 16

===========s3=EBEBaaBEaaEsanJ

Requirements for sub-size Charpy specimens are also presented.

G.l.1.7. SA-662/SA-662M: Specification for pressure vessel plates, carbon-manganese, for moderate- and lower-temperature service (49)

This specification is identical to ASTM A662/A662M-86, and covers C-Mn steel plates where improved low temperature notch toughness is important. The following non-mandatory impact requirements are presented (3 specimens):

1 Test 1 temperature,

op

I ~75

-60 -50 -40 -25

M

0 32 75

Average

Grade A

Longitudinal

20 30 35 40 45 55 70 75

Transverse

15 18 19 20 25 30 35 40

Grade B and C 1

Longitudinal

15 20 22 25 30 35 40 50

Transverse 1

15 20 20 25 25 30

Grade A: 58 ί oy s 78ksi Grade B: 65 s σ, s 85ksi Grade C: 70 s σ, s 90ksi

118

Impact energy, ft.lb

Impact energy, ft.lb

G.I.1.8. SA-693: Specification for precipitation-hardening stainless and heat-resisting steel plate, sheet, and strip (49)

This specification is identical to ASTM A693-88, and covers low temperature heat treated materials used for parts which require corrosion resistance and high strength at temperatures from ambient up to 600°F. The following impact requirements apply (3 specimens):

i \ Material grade

630, XM - 12 - 1025 | - 1075 | - 1100 1 " 1150 | - 1400

Impact Charpy energy,

0.1875 - 0.625" thick

10 15

1 15 25

[55

0.626 - 4.0" thick 1

15 1 20 | 20 | 30 | 55 |

The reader is referred to specification SA-93 for definitions of material types and heat treatments. The impact test procedures and temperatures are not presented.

G.I.1.9. SA-705/SA 705M: Specification for age-hardening stainless and heat resisting steel forgings (49)

This specification is virtually identical to ASTM A705/A705M-87a. The following impact requirements apply (3 specimens, tested at room temperature, 70 to 80°F):

| Material type and condition

| 630 - H925 - H1025

| - H1075 - H1100 - HI 150 - H1150M

XM - 12 - H925 - H1025 - H1075 - HI 100 - HI 150 - H1150M

Minimum impact energy, ft.lb I

Longitudinal

5 15 20 25 30 55

5 15 20 25 30 55

Transverse 1

:

10 15 15 20 | 35

The reader is referred to specification SA705/SA705M for details of material type and heat treatment.

119

Impact energy, ft.lb

G.I.1.10. SA-723/SA-723M: Specification for alloy steel forgings for high-strength pressure component application (49)

This specification is identical to ASTM A723M-86a, and covers high-strength quenched and tempered alloy steel forgings for pressure vessels, isostatic presses, shock tubes and similar components not intended for welded construction. Three grades of Ni-Cr-Mo steels of six classes of increasing tensile strength are included. Section 6 describes the number, orientation and location of Charpy impact specimens. The following impact requirements apply (3 specimens tested at 40°F):

| Material class

1i

2 2a 3 4

15

Impact energy, ft.lb 1

Average

35 30 28 25 20 12

Minimum |

30 I 25 23 1 20 I 15 10

— — — — — — — — — ι ^ — — J l

The reader is referred to specification SA-723/SA-723M for details of material types. If requested by the purchaser, impact energy transition curves must be established. Also, the temperature at which 50% fibrous fracture occurs may be required. For Class 2a forgings a minimum impact energy of 45ft.lb and 25mils lateral expansion may be required at a test temperature specified by the purchaser.

G.I.1.11. SA-765/SA-765M: Specification for carbon steel and low-alloy steel pressure vessel component forgings with mandatory toughness requirements (49)

This specification is identical to ASTM A765/A765M-85. Section 7 describes the number, orientation and location of impact test specimens, while Section 8 describes retest procedures. The following impact energy requirements apply (3 specimens):

| Material grade

1 I II

| in

Test temperature, °F

-20 -50

-150

Impact energy, ft.lb |

Average

13 13 15

Minimum |

10 1 12 12

120

G.1.2. Pipes and Tubes (49)

G.l.2.1. SA-333/SA-333M: Specification for seamless and welded steel pipe for low-temperature service (49)

This specification is identical to ASTM A333/A333M-88a. The following impact energy requirements apply (3 specimens, parent material and weldments):

I Material grade

1 1 13

I 4

6 1 7

8 9

| io

Test temperature,

-50 -150 -150 -50

-100 -320 -100 -75

Average

13 13 13 13 13

13 13

Minimum 1

10 1 10 10 10 10

10 1 10

For Grade 8 each Charpy specimen must display a lateral expansion of not less than 0.015". The reader is referred to specification SA-333/SA-333M for details of material Grades (tensile strengths in the range 55 to lOOksi, yield strengths 30 to 75ksi). Retests are permitted, as well as sub-size specimens. Sections 12 to 14 describe the number, location and orientation of Charpy test specimens.

G.l.2.2. SA-334/SA-334M: Specification for seamless and welded carbon and alloy-steel tubes for low-temperature service (49)

This specification is identical to ASTM A334/A334M-88. Similar impact toughness requirements for Grades 1, 3, 6, 7, 8 and 9 are presented to ASME specification SA-333/SA-333M described in Section G.l.2.1. The reader is referred to specification SA-334/SA-334M for details of material Grades. Retests and sub-size Charpy specimens are permitted. Sections 14,15 and 15 describe the number, orientation and location of Charpy test specimens.

G.1.23. SA-350/SA350M: Specification for forgings, carbon and low-alloy steel, requiring notch toughness testing for piping components (49)

This specification is identical to ASTM A350/A350M-87, and covers several grades of carbon and low-alloy steel forged or ring-rolled flanges, forged fittings and valves intended primarily for low-temperature service. Section 6 describes the number, orientation and location of Charpy test specimens. The following impact toughness requirements apply (3 specimens):

121

Impact energy, ft.lb

1 Material grade

| LFl | LF2 | LF3 | LF5, Class 1, 2 | LF6, Class l 1 LF6, Class 2 1 LF9 1 LF787, Class 2 1 LF787, Class 3 nOBBEBSSSSSSSSSSSBaSSSSBBSSSi

= = = = = = = = = = = = Test temperature, °F -20 -50

-150 -75 -60 -60

-100 -75

-100

Impact energy, ft.lb |

Average

13 15 15 15 15 20 13 15 15

Minimum |

10 | 12 | 12 | 12 | 12 | 15 | 10 | 12 | 12

Tables 6 and 7 of specification SA-350/SA-350M present impact toughness requirements and test temperatures for sub-size Charpy specimens.

G.1.2.4. SA-420/SA-420M: Specification for piping fittings of wrought carbon steel and alloy steel for low-temperature service (49)

This specification is virtually identical to ASTM A420/A420M-85a, and covers wrought carbon steel and alloy steel fittings of seamless and welded construction. Section 9 describes the number, orientation and location of Charpy impact specimens, as well as retest procedures. The following impact toughness requirements apply (3 specimens, parent material and weld metal):

| Material grade

| WPL-3 | WPL-6 | WPL-8 | WPL-9

Test temperature, °F

-150 -50

-320 -100

Impact energy, ft.lb |

Average

13 13 25 13

Minimum |

10 | io | 20 W

Tables 3 and 4 of specification SA-420/SA-420M present details of heat treatment and sub-size Charpy specimen toughness requirements.

G.1.3. Bolting Materials (49)

G.1.3.1. SA-320/SA-320M: Specification for alloy steel bolting materials for low-temperature service (49)

The specification is virtually identical to ASTM A320/A320M-85a, and covers rolled, forged and strain hardened bars, bolts, screws, studs and stud bolts. Several grades are covered, including both ferritic and austenitic steels. Section 6 describes the number, orientation and location of Charpy impact test specimens, while Section 7 describes retest procedures. The following impact toughness requirements apply (3 specimens):

122

1 Material grade

L7M, L70, L71, L72, L73

L7, L7A, L7B, L7C

L43

Li m

Test temperature,

-100

-150

-150

-100

Impact energy, ft.lb |

Average

20

20

20

40

Minimum |

15 1

15 1

15 1

30 1

Impact tests are not required for strain hardened Grades B8, B8F, B8M, B8P, B8T, B8LN and B8MLN for temperatures above -325°F; for carbide solution treated Grades, B8, B8P, B8C and B8LN above -425°F; and all ferritic and austenitic steel grades of bolting Vi" and smaller in diameter. Testing of sub-size Charpy specimens is described.

G.l.3.2. SA-437/SA-437M: Specification for alloy steel turbine-type bolting material specially heat treated for high-temperature service (49)

This specification is identical to ASTM A437/A437M-846. The following impact energy requirements apply:

1 Material grade

I B4B I B46 | B4D (t > 5")

Minimum impact energy, ft.lb |

10 1 25 25

The material chemical and tensile properties are described in Tables 1 and 2 of specification SA-437/SA437M (tensile strength 100 to 145ksi, yield strength 85 to 105ksi).

G.1.33. SA-540/SA-540M: Specification for alloy steel bolting materials for special applications (49)

This specification is virtually identical to ASTM A540/A540M-85a, and covers regular and special-quality alloy steel bolting materials which may be used for nuclear and other special applications. Sections 12,13 and 14 describe the number, orientation and location of Charpy impact test specimens, as well as retest procedures.

The reader is referred to Table 2 of specification SA-540/SA-540M where impact acceptance requirements are presented. Grades B21 (Cr-Mo-V), B22 (4142-H), B23 (E-4340-H), B24 (4340 Mod.) and B24V (4340V Mod.) are represented, and acceptance criteria fall into four categories (3 specimens): no requirements (tests

123

performed for information only); average impact energies of 35, 30 and 25ft.lb, minimum impact energy of 30, 25 and 20ft.lb, depending on the material diameter and material Grade and Class.

G.2. AUSTRALIAN STANDARDS (9)

G2.1. AS 1204-1980: Structural Steels - Ordinary Weldable Grades (1980, (9))

This standard requires the following impact toughness levels (3 specimens):

I Material grade

I 250L0, 250L0 | 250L15, 350L15

Test temperature, °F

0 -15

Average

27 27

Minimum 1

20 1 20

Sections 6 to 8 of this standard describes the number, orientation and location of Charpy test specimens, as well as retest procedures and requirements for sub-size Charpy specimens.

G2.2. AS 1205-1980: Structural Steels, Weather-Resistant Weldable Grades (1980,(9))

This standard requires the following impact toughness requirements for low alloy hot-rolled steel in the form of plate, strip, structural sections and bar (3 speci-mens);

| Material grade

I WR350/1L0, 2L0 | WR350/2LI5

Test temperature, °F

0 -15

Impact energy, ft.lb 1

Average

27 27

Minimum 1

20 1 _20

Section 6 to 8 of the standard describes the number, orientation and location of test specimens, as well as retest procedures and requirements for sub-size Charpy specimens.

G3. INTERNATIONAL STANDARDS ORGANISATION

G3.1. ISO 630: Structural Steels (1980, (50))

This standard requires the following Charpy V-notch impact energy levels (3 longitudinal specimens):

124

Impact energy, ft.lb

1 Grade

I Fc 310

Fe 360

Fe 430

Fc 510

Quality

0

A B C D

A B C D

B C D

Test temperature, °C

-

_

+20 0

-20

—

+20 0

-20

+20 0

-20

Impact energy, J |

- 1

— I

27 1 27 1 27 1

— I

27 1 27 1 27 1

27 1 27 1 27 1

The minimum single specimen requirement is 70% of the average requirement. The mechanical property requirements of sections greater than 63mm in thickness are subject to agreement between the interested parties. The number, orientation and location of test specimens are described in Section 6 of ISO 630, as well as retest procedures and requirements for sub-size Charpy specimens.

G.4. NORME BELGE: STRUCTURAL STEELS, (1976, (51))

G.4.1. NBN AZA-101: Steel Plate (51)

Steels are specified in different types according to their yield strengths. Each type comprises different grades (A, C, D and DD). The Charpy V-notch energy requirement is 35 J/cm2 at a temperature of 0°C for Grade C (no requirements for Grade A). For Grade D steel with a yield strength up to 255MPa the requirements is 35 J/cm2 at -20°C. For Grades D and DD steels with yield strengths * 295MPa the requirement is 50 J/cm2 at -20°C.

G.4.2. NBN F31-001: Covered Electrodes for Manual Arc Assembly (51)

Two types of electrodes (Class 43 and Class 51) are specified according to their yield strength; each type is divided into five classes with a required Charpy V-notch energy of 28J at 20, 0, -20, -30 and -40°C, respectively.

G.5. BRITISH STANDARDS

G.5.1. BS970: WROUGHT STEELS FOR MECHANICAL AND ALLIED ENGIN-EERING PURPOSES1 (1991 (52))

BS970 divides steels in categories 'Α' and 'Μ'. Only for category 'Μ' steels Charpy toughness is stipulated. The average impact energy of three Charpy tests is

125

specified. One single value may be below the requirement but not lower than 70 percent of it. If the required average is not met or if one single value lies below 70 percent the stipulated value, three additional tests can be carried out. The average of ail six specimens must meet the requirement with only two single values allowed to be lower than the requirement and only one value allowed to be lower than 70 percent the specified value.

Part 1: General Inspection and Testing Procedures and Specific Requirements for Carbon, Carbon Manganese, Alloy and Stainless Steels' (52)

The specific room temperature requirements for Part 1 steels are given in the tables below.

i. Micro alloyed carbon manganese steels

| Steel grade

1 280 M01

Minimum yield strength, MPa

530 560 600

Minimum average impact 1 energy, J 1

10 1 8

[8

ii. Case hardening steels carbon and carbon-manganese steels

1 Steel grade 1 045 M10

080 M15 1 130 M15

1 210 M15 1 214 M15

Minimum tensile strength, MPa 430 430, 460, 490

| 590 650 740

! 430, 460, 490 ! 590 650 740

Minimum average impact 1 energy, J 1 42 1 35 1 42 1 35 1 28 1

35 1 42 35 28

126

ni. Case hardening steel, alloy steels

1 Steel grade

1 523 M15 527 M17

| 590 M17 | 708 M20 1 805 M17 | 805 M20 I 805 M22 1 808 M17 1 815 M17 I 820 M17 I 822 M13 1 822 M17 1 835 M15 Κ ^ ^ B B O B B S

Minimum tensile strength, MPa

620 720 930 930

| 770 850 930 930

! 1080 1160 1080 1310 1310

Minimum average impact 1 energy, J 1

28 1 16 1 16 | 16 | 22 | 16 1 11 | 22 1 22 | 22 1 28 | 22 1

js 1

Part 3: Bright Bars for General Engineering Purposes (52)

The specific room temperature requirements for Part 3 steel bars are given in the tables below.

i. Free cutting steels

| Steel grade and conditions

1 216 M36 (hardened and tempered 1 (HT) and turned or ground (TG))

226 M44 (HT and TG)

1 1

Minimum yield strength, MPa

340, 400, 480

450 525, 600

Minimum average 1 impact energy, J |

28 1

22 16

ίί. Carbon and carbon manganese steels

| Steel grade and conditions

1 080 M30 (HT and TG)

080 M40 (Normalised (N) and TG)

080 M40 (HT and TG)

Minimum yield strength, MPa

340, 415

280

385, 465

Minimum average 1 impact energy, J |

28 1

16

28

127

Table continued...

1 Steel grade and conditions

150 M19 (N and TG)

150 M19 (HT and TG)

150 M36 (HT and TG)

Minimum yield strength, MPa

325

340, 430 510

400 480, 555 635

Minimum average 1 impact energy, J |

35 1

50 1 35 1

42 1 35 1 28

Hi. Alloy steels

j Steel grade and conditions

1 530 M40 (HT and TG)

605 M36 (HT and TG)

1

1 606 M36 (HT and TG)

1 708 M40 (HT and TG)

n

H 709 M4 (HT and TG)

R

1 722 M24 (HT and TG)

M — ^ S 1 I II III II ^ B ^ ^ S S S = ^ ^ = ^ = ^ ^ ^ =

Minimum yield strength, MPa

525, 585, 680

495 525, 585, 680 755, 850

525 585 680

495 525, 585, 680 755, 850 940

495 555 585, 680 755, 850 940

650 680 755

Minimum average impact energy, J

50

28 50 42

50 42 35

28 50 42 35

28 22 50 42 35

35 50 42

1 a a ^ s s a a a a a — —

Ί H

H

128

Table continued...

I 1 Steel grade and conditions 1 817 M4 (HT and TG)

I 826 M31 (HT and GT)

1 826 M40 (HT and TG)

1 945 M38 (HT and GT)

945 M38 (HT and cold 1 drawn or HT and cold ■ drawn and ground)

Minimum yield strength, MPa 650 680 755, 850 940

1020 1235

650 680 740 755, 850 940

1020 1235

740 755 835 850 925 940

1020, 1095 1235

495 525, 585, 680 755, 850

540, 600, 700 770, 865

Minimum average 1 impact energy, J 1 35 50 42 35 1 28 1 9 1

35 1 50 1 28 1 42 35 28 9 1

28 42 I 28 1 42 1 22 1 35 1 28 1 11

28 50 42

50 42

G.5.2. BS1113 SPECIFICATION FOR THE DESIGN AND MANUFACTURE OF WATER TUBE STEAM GENERATING PLANT (1989, (53))

Section 5 Inspection and Testing; Section 5.5: Details of Destructive Tests for Boiler Drum Production Control Test Plates (53)

The Charpy V-notch energy requirement for specimens orientated transverse to the weld axis, taken parallel to the surface, and so that one face is within 3mm of the original plate surface, is 40J at a maximum test temperature of 37°C. This requirement is an average of three tests with no single value less than 36J. Provided that not more than one of the specimens results in less than 40J but not

129

less than 36J, a re-test of three additional specimens shall be made. If all these re-tested specimens comply with 40J the values shall be accepted.

GS3. BS1501: STEELS FOR UNFIRED AND FÏRED PRESSURE VESSELS: PLATES (1980 (54))

Three Charpy specimens shall be taken with their longitudinal axis lying in the principal rolling direction. The specimens shall be notched perpendicular to the original plate surface (through-thickness notch). For plate thicknesses smaller than 40mm, the specimens shall be taken with one specimen surface close to the original plate surface. For plate thicknesses greater than 40mm» the axis of the specimens shall be lA thickness from the original plate surface. For plate thicknesses between 6mm and 11mm sub-size Charpy specimens shall be used with the following reduced Charpy impact energy requirements.

| Specimen size, mm

| 10 x 10

1 27 1 31

1 41

1 54

10 x 7.5

22 25 33 44

10x5

19 22 29 38

Average energy 1 requirement, J 1

The values are specified for the average of three specimens. One value may be below the specified value but not smaller than 70 percent thereof.

Part 1: Carbon and Carbon Manganese Steels

The specific Charpy requirement for the different steel grades are summarised in the table below:

1 Steel grade 1 164-360, -400

223-460, -490

1 224-A11 grades

IfenanEasassssssBcsBSEEa

Qualification class —

LT0 LT20

—

LT0 LT15 LT30

—

LT0 LT20 LT30 LT40 LT50

Test tem-peratures, °C RT (1) 0 -20

RT 0 -15 -30

RT 0 -20 -30 -40 -50

Average impact 1 energy, J | 41 1 31 1 27 1

61 1 55 1 41 1 27 1

61 1 55 1 47 1 41 1 31 1 27 1

130

Table continued...

1 Steel grade

1 225-460, -490

:Bssaass^ssssssssssssss=ssss=

Qualification class

LT20 LT30 LT50 LT60 (Grade 460 only)

■aaHEBRESBSSESSBBEBSSSSSSSSSSSS

Test tem-peratures, °C

-20 -30 -50 -60

Average impact 1 energy, J 1

61 1 47 1 27 1 27 1

Note:

(1) RT - room temperature (approximately 20°C).

Part 2: Alloy Steels

The specific requirements are given in the table below. The Charpy specimens are to be taken transverse to the rolling direction. Re-tests are permitted as specified in BS970 (see Section G.6).

1 Steel grade

| 243

1 271 1 281

1 620, 621, 622-I 515, 622-690

1 503

1 5 1 ° | 828

Thickness range, mm

Up to 60 Up to 100

Up to 150

Up to 100

Up to 50 j

Up to 100

Test temperature, °C

20 20

0 -40

20

-100 -196

-85

Average impact energy, J

31 27

54

Minimum | single value, | j |

22 1 19

38 1

G.5.4. BS1502: STEELS FOR FIRED AND UNFIRED PRESSURE VESSELS: SECTIONS AND BARS (1982 (55))

Three impact pieces shall be taken from specific locations in sections and flat bars specified in this standard. For thinner sections sub-size specimens shall be tested with reduced toughness requirements as specified in BS1501 (Section G.7.). The specific impact requirements are given in the table below:

131

1 Steel grade 1211

1 221

1 224

1 620 440 1 (normalised and 1 tempered (NT))

1 620 - 440 I (quenched and 1 tempered (QT)) j

I 620 - 470 NT i

1 620 - 470 QT

I 620 - 540

1622

I 625 - 590 I 629 !

1 509 (NT)

1 509 (QT) DMBBHHBESSSXSS=SSSSESSS=BSSSS=

Qualification class —

LTO

—

LTO

—

LTO LT20 LT30 LT40 LT50

_

-

-

_

_

-

-

Test temperature, °C RT(1) 0

RT 0

RT 0 -20 -30 -40 1 -50

RT

RT

RT

RT !

RT RT '

RT RT

-196

-196

Average impact 1 energy, J 1 41 27

41 27

55 55 1 47 1 41 1 31 1 27 I

27 1

41 I I

27 I

41 1

41 1 41 1

41 1 27 1

27 1

70 1

Note:

(1) RT - Room temperature (approximately 20°C)

G.5.5. BS1503: STEEL FORGINGS FOR PRESSURE PURPOSES (1989 (56))

Three impact test pieces shall be taken and orientated such that the axis of the notch shall be perpendicular to the nearest surface of the forging. One value may be below the specified average but not smaller than 70 percent thereof.

The specific requirements for different steel grades are given in the tables below.

132

i. Carbon Manganese steels

1 Steel grade

1 164 - 490

221 - 410, 430 - 460, 490

223 - 410 -430

1 -460 -490 -510

224 - 410 1 -430 1 -460 1 -490

1 "510

| 225 - 490

Test temperature, °C

RT(1)

RT RT

RT, -10, -20, -50 (2) RT, -10, -15, -40 (2) RT, 0, -10, -20 (2) RT, 0, -10 (2) RT, 0 (2)

RT, -10, -20, -50 (2) RT, -10, -15, -40 (2) RT, 0, -10, -20 (2) RT, 0, -10 (2) RT, 0 (2)

RT

Average impact energy, J |

41 1

27 41

27 27 1 41 41 41

27 27 41 41 1 41 1

_41

Notes:

(1) RT room temperature (approximately 20°C) (2) As required by purchaser

ii. Low alloy, ferritic stainless, martensitic stainless, 2.5% Ni and 9% Ni steels.

1 Steel grade

1 243 - 430

1 620 - 440 1 -540

621 - 460

271 - 560

622 - 490 1 - 560

625 - 520 | -590

Test temperature, °C

RT

RT RT

RT

RT

RT RT

RT RT

Minimum impact energy, J |

27

27 1 41 1

41

41

41 1 41 1

27 1 41 1

133

Table continued...

1 Steel grade

1 410 - 521 1 -529

1 503 - 490

| 509 - 690

Test temperature, °C

RT RT

-80

-196

Minimum impact energy, J |

27 1 27

27

[34

G.5.6. BS1504: STEEL CASTINGS FOR PRESSURE PURPOSES (1976 (57))

Three Charpy test pieces are to be tested. One value may be below the required average but not lower than 70 percent thereof. The specific requirements for different steel grades are given below.

1 Steel type

| Carbon steel casting 430L T40

| Carbon-| molybdenum casting

| 3&%Ni casting

Test temperature, °C

-40

-50

-60

Average impact energy, J |

20 1

20

20 1

For austenitic steels the required impact energies at -196°C lie between 20 and 41J.

G.5.7. BS1506: CARBON, LOW ALLOY AND STAINLESS STEEL BARS AND BILLETS FOR BOLTING MATERIAL TO BE USED IN PRESSURE RETAINING APPLICATIONS (1990 (58))

Three full size Charpy test pieces to be taken longitudinally from bars. Number of test and retest procedures as specified in BS970 (see Section G.6). The specific requirements for different steel types are given in the table below.

1 Steel type

1 253

1 509 - 650 - 6 9 0

630 - 790 - 8 6 0

| - 6 9 0

Test temperature, °C

-100

-196 -196

-100, -75 -100 -100

Average impact energy, J |

27 1

40 1 40 1

20,27 1 27 | 27 |

134

G.5.8. BS4360: SPECIFICATION FOR WELDABLE STRUCTURAL STEELS (1990 (59))

Section 3,5,7: Mechanical Properties of Plates, Strip and Wide Flats; Section; Flats and Round and Square Bars; Hollow Sections (59)

The Charpy V-notch energy requirements are defined by the letters added to the numbers in the specific grade (e.g. 40E or 50EE), independent of the strength of the steel. The requirements are an average of 27J (three tests) at a test temperature defined in the table below. One value may be below the specific value but not smaller than 70 percent thereof. Re-test procedure as in BS970 (see Section G.6.).

1 Steel grade

ic 1 D 1 DD

1 E 1 EE

IF

Test temperature, °C |

0 1 -20 1 -30 1 -40 1 -50 -60

Section 8: Mechanical Properties for Plates; Strip; Wide Flats; Flats; Sections and Round and Square Bars; Weather Resistant Grades (59)

The Charpy V-notch requirements for specified weather-resistant grades are 27J at a test temperature given below:

B B B s a B s s a a s s B s s s a B s s s s s s

1 Steel grade

1 WR 50A WR 50B WR 50C

Test temperature, °C |

0 1 0

-15

G.5.9. BS EN10025: Hot rolled Products of Non-Alloy Structural Steels: Technical Delivery Conditions (1990 (60))

Parts of BS4360 (59) have now been superseded by this European standard. The following specific requirements apply.

| Steel grade

I Fe 'χχχ' Β (1) C

1 Dl, D2 1 DPI, DD2

Test temperature, °C

20 0

-20 -20

Average impact energy, J | — 1

27 1 27 1 27 40

Note:

(1) !xxxf stands for a three digit number indicating the strength of the steel.

135

G.6. JAPANESE WELDING ENGINEERING SOCIETY STANDARD (61)

G.6.1. WES 3001-1983: Weldable High Strength Steel Plates (1983 (61))

Average (3 specimens) Charpy V-notch energy of steel plate shall either conform to the requirements specified in the table below. Alternatively, the average energy determined at a temperature given in the table plus 7°C, shall be greater than half of the Charpy V-notch energy determined at a temperature where the fracture mode is 100% shear.

_ e t _ _ _ _ = _ = !

| Steel grade

HW36

HW40

HW46

I HW50

|

1 HW56

1 HW63 1 1

I HW70

1

Thickness, mm

Up to 13 Over 13 to 20 Over 20 to 32 Over 32

Up to 13 Over 13 to 20 Over 20 to 32 Over 32

Up to 13 Over 13 to 20 Over 20 to 32 Over 32

Up to 13 Over 13 to 20 Over 20 to 32 Over 32

Up to 13 Over 13 to 20 Over 20 to 32 Over 32

Up to 13 Over 13 to 20 Over 20 to 32 Over 32

Up to 13 Over 13 to 20 Over 20 to 32 Over 32

Test temperature, °C —

15 0

-5

—

15 0

-5

—

10 -5

-10

—

5 -10 -15

—

5 -10 -15

—

0 -15 -20

"""

5 -15 -20

Average impact energy, 1 Jf

47.1

47.1 1

47.1 1

47.1 1

47.1

39.2 1

35.5

136

Table continued...

1 Steel grade

1 HW80

1 HW90

Thickness, mm

Up to 13 Over 13 to 20 Over 20 to 32 Over 32

Up to 13 Over 13 to 20 Over 20 to 32 Over 32

Test temperature, °C

5 -20 -25

10 -25 -30

Average impact energy, 1 j |

27.5 1

27.5

WES 3005-1977: Pressure Vessel Plates, High Strength Steel, for Intermediate and Moderate Temperature Service (1977 (61))

Impact toughness requirements shall be 31.4J (average of 3 specimens), with no single value less than 25.5J, at a temperature of 0°C.

G.7· EUROPEAN COAL AND STEEL COMMUNITY EURONORM (62)

G.7.1. Euronorm 28-69: Non-alloyed Steel for Pressure Vessels (1969, (62))

Steels are classified according to their yield strength and sub-divided according to their Charpy V-notch energy requirements. The requirements are 3.5kgm/cm2 at 0°C for Grades 1KP and 3.5kgm/cm2 at -20°C for Grades 2KW and 2KP, independent of yield strength.

G.7.2. Euronorm 113-72: Weldable Structural Steel (1972, (62))

Steels are classified according to their yield strength and sub-divided according to their Charpy V-notch energy requirements. The requirements for Grade KG, KW and KT (for a steel type/yield strength up to 420MPa for t ^ 16mm) are given in the table below.

I Grade

KG, KW

KT

Orientation

Longitudinal Transverse

Longitudinal Transverse

Impact energy requirement in J at a temperature, 1 °c |

20

56 32

10

52 32

0

48 28

56 32

-10

44 24

52 32

-20

40 16

48 28

-30

40 24

-40

32 20

-50 1

28 1 16 j

137

G.6.2.

For steel Type Fe E40 with a yield strength of 460MPa at a thickness * 16mm, the requirements are:

1 Grade

I KG, KW

Orientation

Longitudinal Transverse

Longitudinal Transverse

Impact energy requirement in J at a temperature, 1 °c |

20

52 32

10

48 32

0

44 28

48 32

-10

40 24

44 32

as

-20

40 16

40 28

-30

36 24

SSSSSBEHB

-40

32 30

-50 |

28 16 |

G.73. Euronorm 149-80: Flat Products in High Strength Steels for Cold Forming (1980, (62))

Part 2: Specific requirements for thermo-mechanically treated hot rolled products, Part 3: Specific requirements for normalised hot rolled products. For all steel grades in this specification, a minimum impact strength of 27J at 20°C is required.

G.7.4. Euronorm 155-80: Weathering Steels for Structural Purposes Quality Standard (1980, (62))

Steels are classified according to their strength and sub-divided according to their Charpy V-notch energy requirements. The requirements are 27J at 20, 0 and -20°C, respectively, for sub-grades B, C and D, respectively.

138

KT

SECTION H:

WELDING CONSUMABLE TOUGHNESS REQUIREMENTS

SECTION H:

WELDING CONSUMABLE TOUGHNESS REQUIREMENTS

H.l. ASME II PART C: WELDING RODS, ELECTRODES AND FILLER METALS (49)

In the following specifications, impact testing is required if the weld metal is produced using the specified consumables. In general, five specimens must be tested, with the maximum and minimum values discarded.

H.1.1. SEA-5.1: Specification for Covered Carbon Steel Arc Welding Electrodes (49)

This specification is identical to AWS A5.1-81. The following Charpy V-notch impact toughness requirements apply:

1 AWS Classification

E6010, E6011, E6027 E7015, E7016, E7018 E7027, E7048

E7024, E7028

E6012, E6013, E6020 E6022, E7014, E7024

Test temperature, °F

-20

0

—

Average impact energy, ft.lb |

20 1

20

_ 1

H.1.2. SEA-5.5: Specification for Low Alloy Steel Covered Arc Welding Electrodes (49)

This specification is identical to AWS A5.5-81. The following Charpy V-notch impact toughness requirements apply:

r — L-uM—■ 1 AWS Classification

1 E8018-NM/C3, E8016-C3

1 E8015-D1/D2, E8016-D2/D3 E8018-D1/D2/S3, E9018-M

1 E10018-M, E11018-M, E12018-M

| E12018-M1

Test temperature, °F

-40

-60

0

Impact energy, 1 ft.lb 1 20 1

-20

20

141

Table continued...

1 AWS Classification

1 E7018-N, E8018-W

E8016-C1M E8018-C1

1 E7015-C1L, E7016-C1L 1 E8016-C2, C7018-C1 1 E8018-C2

1 E7015-C2L, E7016-C2L | E7018-C2L

Test temperature, °F

0

-75

-100

-100

-150

Impact energy,

20

20

20

20

f Ü b 1

H.1.3. SEA-5.17: Specification for Carbon Steel Electrodes and Fluxes for Submerged Arc Welding (49)

This specification is identical to AWS A5.17-80. A requirement of 20ft.lb impact energy must be met, with the flux classification dependant on the temperature at which this level of toughness is attained. Thus, the flux incorporates a digit which corresponds to the level of toughness (0, 2, 4, 5, 6 and 8 correspond to 20ft.lb at 0, -20, -40, -50, -60 and -80°F, respectively). If there is no impact requirement, then this digit is "Z".

H.1.4. SEA-5.18: Specification for Carbon Steel Filler Metal for Gas Shielded Arc Welding (49)

This specification is identical to AWS A5.18-79, and covers gas metal arc, gas tungsten arc and plasma arc welding processes. The following impact toughness requirements must be met:

| AWS Classification

1 ER70S-2 1 ER70S-3 | ER70S-6 | ER70S-7

Test temperature, °F

-20 0

-20 -20

Impact energy, ft.lb 1

20 1 20 20

JO

H.1.5. SEA-5.20: Specification for Carbon Steel Electrodes for Flux Cored Arc Welding (49)

The specification is identical to AWS A5.20-79, and covers flux cored arc welding of carbon and low-alloy steels. The following impact toughness requirements apply:

1 AWS Classification

I E6XT-1 1 E6XT-5 1 E6XT-6

Test temperature, °F

1 ° -20 -20

Impact energy, ft.lb |

20 1 20 1 20 1

142

Table continued...

| AWS Classification

E6XT-8 1 E7XT-1 1 E7XT-5 1 E7XT-6 1 E7XT-8

Test temperature, °F

-20 0

-20 -20 -20

Impact energy, ft.lb J

20 1 20 1 20 1 20 1

^ 1

H.1.6. SEA-5.23: Specification for Low Alloy Steel Electrodes and Fluxes for Submerged Arc Welding (49)

This specification is identical to AWS A5.23-80, and incorporates a system similar to specification SEA-5.17 (reviewed in Section H.1.3 for classification of fluxes according to the temperature at which 20ft.lb impact energy is achieved. Digits in the flux specification of 0, 2, 4, 6, 8,10 and 12 correspond to 20ft.lb at 0, 20, -40, -60, -80, -100, -120°F, respectively. In addition, weld metals with the "N" suffix are required to have a Charpy V-notch energy level of at least 75ft.lb at 70°C.

H.1.7. SEA-5.25: Specification for Consumables for Electro Slag Welding of Carbon and High Strength Low Alloy Steels (49)

This specification is identical to AWS A.25-78. The following impact energy requirements must be met:

1 AWS Flux classification

I FE56Z-xxxx 1 FE560-XXXX 1 FE562-XXXX 1 FE57Z-XXXX 1 FE570-XXXX 1 FE572-xxxx

Test temperature, °F

—

0 -20

-

0 -20

Impact energy, ft.lb |

— 1 15 1 5

- 1 15

_15

where "xxxx" stands for the electrode designation.

H.1.8. SEA-5.26: Specification for Consumables used for Electrogas Welding of Carbon and High Strength Low Alloy Steels (49)

This specification is identical to AWS 5.26-78. The following impact toughness requirements must be met:

1 AWS Classification

1 EG6Z-xxxx 1 EG60-XXXX | EG62-xxxx

Test temperature, °F

0 -20

Impact energy, ft.lb |

20 1 20 1

143

Table continued...

1 AWS Classification

1 EG7Z-xxxx 1 EG70-xxxx 1 EG72-xxxx

Test temperature, °F

0 -20

Impact energy, ft.lb |

20 20

where "xxxxM stands for the electrode designation.

H.1.9. SEA-5.28: Specification for Low Alloy Steel Filler Metals for Gas Shielded Arc Welding (49)

This specification is identical to AWS 5.28-79, and covers gas shielded welding processes. The following impact toughness requirements apply:

| AWS Classification

ER80S-NÎ1 ER80S-NÎ2 ER80S-NÎ3 ER80S-D2

1 ER1005-1, 2; ER1105-1; ER1205-1 1 ER80C-NÎ1

ER80C-NÎ2 ER80C-NÏ3

Test temperature, °F

-50 -80

-100 -20 -60 -50 -80

-100

Impact energy, 1 ft.lb |

20 1 20 20 20 50 20 20 20

H.1.10. SEA-5.29: Specification for Low Alloy Electrodes for Flux Cored Arc Welding (49)

This specification is identical to AWS A5.29-80, and covers carbon and low alloy steels. 20ft.lb impact toughness is required at the following temperatures:

| AWS Classification

1 E70T5-A1 1 E71T8-NÜ 1 E80T1-NÜ 1 E81T1-NÜ 1 E80T5-NÜ 1 E71T8-NÎ2 1 E80T1-NÎ2 1 E81T1-NÎ2 1 E80T5-NJ2

Condition

PWHT AW AW AW PWHT AW AW AW PWHT

Test temperature,

-20 -20 -20 -20 -60 -20 -40 -40 -75

op 1

144

Table continued...

| AWS Classification

E90T1-NÎ2 E91T1-NÏ2 E805T-NÎ3 E90T5-NÏ3 E91T1-D1 E90T5-D2 E100T5-D2 E90T1-D3 E80T5-K1 E70T4-K2 E71T8-K2 E80T1-K2 E90T1-K2 E91T1-K2 E80T5-K2 E90T5-K2 E100T1-K3 E110T1-K3 E100T5-K3 E110T5-K3 E110T5-K4 E111T1-K4 E120T5-K4 E61T8-K6 E71T8-K6 E101T1-K7

| E80T1-W

Condition

AW AW PWHT PWHT AW PWHT PWHT AW AW AW AW AW AW AW AW AW AW AW AW AW AW AW AW AW AW AW AW

Test temperature, °F [

-40 ] -40

- loo 1 - loo I -40 1 -60 1 -40 -20 -40

0 1 -20 -20

0 0

-20 -60

0 0

-60 -60 -60 -60 -60 -20 -20 -60 -20

H2. AMERICAN BUREAU OF SHIPPING

H.2.1. ABS: Provisional Rules for the Approval of Filler Metals for Welding High Strength Steels (1968, (27))

The following impact energy requirements apply for high strength steels (oy i 55.5ksi, σ„ * 71 - 95ksi):

Manual and semi-automatic welding:

| Grade |

HI H2

| H3

Test temperature, °F

68 32 -4 (or 14)

Impact energy, ft.lb |

40 1 40 40 (or 50)

145

Machine automatic welding:

1 Grade

1Hi

H2 | H3

Test temperature, °F

68 (or 50) 32 (or 14) -4 (or 14, or -22)

30 (or 20) 1 30 (or 20) 30 (or 38, or 20) |

H2.2. ABS: Rules for the Approval of Wire-Flux Combinations for Submerged Arc Welding (1965, (27))

This specification requires the following Charpy V-notch impact energy levels (3 weld metal specimens, oy * 44.1ksi, ou * 58.3 - 81.1ksi):

1 Grade Test temperature, °F

68 32 -4 (or 14)

25 | 25 25 (or 33)

The number, orientation and location of impact test specimens are described in sections 10 to 18 of the specification.

H-2.3. ABS: Rules for the Approval of Electrodes for Manual Arc Welding in Hull Construction (1965, (27))

This specification requires the following weld metal Charpy V-notch impact requirements (3 specimens, oy * 44.1ksi, au * 58.3 - 81.1ksi):

1 Grade

| 1 2

[3

Test temperature, °F

68 32 -4 (or 14)

35 | 35 35 (or 45)

Sections 7 to 18 of this specification describe the number, location and orientation of impact specimens, as well as retest procedures.

HJ. AMERICAN WELDING SOCIETY (AWS) (63)

The AWS specification for consumables which are applicable to pressure vessel materials have been adopted by the ASME Pressure Vessel and Piping Code, which is extensively reviewed elsewhere in this report. The reader is referred to Section H.l where the ASME II Part C consumable toughness requirements are described.

146

Impact energy, ft.lb

Impact energy, ft.lb

Impact energy, ft.lb

H.4. AUSTRALIAN STANDARDS (9)

H.4.1. AS1553 - 1983: Covered Electrodes for Welding

H.4.1.1. Part 1 - low carbon steel electrodes for manual metal-arc welding of carbon steels and carbon-manganese steels (1983, (9))

This standard requires the following average impact energy values for deposited weld metal (3 specimens):

1 Grade

1 ° 1 2 3

4

5

L· 1

BSBSaM^aSBBSZSaSSSSSSS^SSSSSSSSSSBSS

Test temperature, °C —

20 0

-20 -30 -40 -50

aaasaaaaaaaasaaaaaaaa a s a a a a a a a s a

Impact energy, J | — 1

47 1 47 47 47 47

J7 1 The minimum requirement for three Charpy specimens is 31J, although retests are permitted (see section 2 of this standard). For butt welds the following requirements apply:

1 1 Grade

1 ° 1 2 3, 4, 5, 6

IsasBassssaaaaasaa

Test Temp., °C

20 0

-20

Impact energy, J 1

Vertical up

Average

34 34 34

Minimum

23 23 23

All other

Average

47 47 47

positions 1

Minimum 1

31 31 I 31 1

H.4.2. AS1586-1980: Low Alloy Steel Covered Electrodes for Manual Metal-Arc Welding (1980, (9))

This standard requires the following Charpy impact toughness levels (3 specimens):

| Classification

1 E516-C3, E518-C3

E6215-D1, E6218-D1 E6915-D2, E6916-D2

1 E69118-D2 ■BaaaaB8BB8aBaaaaaaaas8B8B888BaaaaBaa

Test temperature, °C

-40

-50

Impact energy, J |

27 1

27

147

Table continued...

1 Classification

1 E6218-M, E6918-M, E7618-M, E8318-M

E5516-C1, E5518-C1

1 E5516-C2, E5518-C2

Test temperature, °C

-50

-60

-75

Impact energy, J J

27 1

27

27

One value may be less than these average requirements, but not less than 20J.

H.4.3. AS1858-1976: Electrodes and Fluxes for Submerged-Arc Welding of Carbon and Low Alloy Steels (1976, (9))

This standard requires the following weld metal Charpy impact levels (3 specimens):

Weld I metal | classification

W400 W401 W402 W403 W404

1 W405

W500 W501 W502

1 W503 1 W504 | W505

Test temperature, °C

20 0

-10 (or -20) -40 -60

20 0

-10 (or -20) -40 -60

Impact energy, J |

Average

35 35 45 (or 35) 35 35

40 40 52 (or 40) 40 40

Minimum J

23 23 30 (or 23) 23 23

36 36 34 (or 26) 26 26

where the W40X and W50X series weld metals have minimum yield strengths of 310 and 360N/mm2 and tensile strengths of 410 - 550 and 500 - 650N/mm2, respectively. The number, orientation and location of Charpy test specimens are described in Section 5 of this standard.

H.4.4. AS2203-1981: Carbon Steel Electrodes, Cored (for Arc Welding) (1981, (9))

This standard requires 47J (average of 3 specimens) and 31J minimum for the following weld metals:

148

1 Weld metal classification

W400 W401 W402 W403 W404 W405

W500 W501 W502 W503 W504 W505

ί — Β = = = = =

Test temperature, °C | — 1

20 0

-20 -40 -60

— 1 20 0

-20 -40 -60

— — — — — — » — J

Section 2.4 of this standard describes retest procedures.

KL4.5. AS2717.1-1984: Welding-Electrodes for Gas Metal Arc Welding (9)

H.4.5.1. Part 1 - ferritic steel electrodes (1984, (9))

This standard requires the following average Charpy impact toughness values (3 specimens):

1 Weld metal classification

1 W500H-X I W501H-X 1 W502H-X I W503H-X 1 W504H-X 1 W505H-X

1 W419H-5Q, 7Cr, 9Cr 1 W559H-B2, B2L 1 W629H-B3, B3L

1 W559H-NU W559H-NÏ2 W559H-NÎ3 W559H-D2

W699-M2, M5 | W769-M3, W839-M4

Test temperature, °C _

20 0

-20 -40 -60

20

-45 -60 -73 -30

-50

Impact energy, J | _ 1

47 47 47 47 47

20

27 27 27 27

68

149

Section 2.4 of this standard describes retest procedures (required if the minimum value of the three specimens is less than 13, 18, 31 or 45J for the average requirements of 20, 27, 47 and 68J, respectively).

H.5. BRITISH STANDARDS

Η·5.1. BS639: SPECIFICATION FOR COVERED CARBON AND CARBON MANGANESE STEEL ELECTRODES FOR MANUAL ARC WELDING (1986 (64))

The electrode grades specified in this code contain two digits which define the temperature at which the toughness requirements must be met.

The test temperatures for the different toughness digits are given in the tables below.

| Toughness digit (1)

1 ° 1 2 3 4 5 6(2) 7(2)

| 8(2)

Test temperature, °C |

20 0

-20 -30 -40 -50 -60 -70

Notes:

(1) The first toughness digit appears at the last but one position of the electrode grad code, E— 'D1-, where fD! stands for the toughness digit given above. The second toughness digit appears at the last position of the electrode grade code, E 'D\

(2) Digits 6, 7 and 8 apply to the second toughness digit only.

For the first toughness digit, 4mm diameter are to be used to prepare test panel from which six Charpy test pieces are taken transverse to the weld in a 20mm thick plate at mid-thickness and through thickness notched in the weld metal centreline. The required average of six values at the specified test temperature is 35J. If the average is smaller than the required 35J (but not smaller than 16J), twelve additional tests are to be carried out and the overall average (of eighteen specimens) is to be 28J.

If the average of the first six specimens is smaller than 16J, two new welds can be prepared using electrodes from the same batch. Six test pieces are to be tested from each new weld and have to exhibit average Charpy impact energies exceeding 35J.

For the second toughness digit, three Charpy specimens are to be prepared using 4mm diameter, and three using the largest diameter electrode submitted for classification. The required average value of each weld is 47J. If the average is

150

smaller than 47J (but not smaller than 40J and no single value below 20J), two additional sets of three specimens can be tested and the overall average of six specimens is to be 47J for both electrode diameters.

If requirements are not met, two new welds can be prepared and tested. The average of three tests shall be 47J for both welds.

H.5.2. BS2493: LOW ALLOY STEEL ELECTRODES FOR MANUAL METAL ARC WELDING (1985 (65))

Three Charpy specimens shall be prepared transverse to the weld at mid-thickness position and through-thickness notched in the weld metal centreline. The average impact value shall be 30J at the test temperature given below.

I Electrode code

1 INi LB 2NiLB 3 Ni LB I N i B 2 N i B 3 N i B I N i C 2 N i C MnMoB

1 2Mn Mo B 1 MnNiB 1 Ni Mo B

1 Ni Mo C 2 Ni Mo B

| 2 Ni Cr Mo B

Charpy test temperature, °C 1

^ 5 0 -70 -80 -40 -60 -75 -40 -60 -50 1 -50 I -50 1 -50 1 -50 1 -50 1 -50 I

H.5.3. BS4165: ELECTRODE WIRES AND FLUXES FOR THE SUBMERGED ARC WELDING OF CARBON STEEL AND MEDIUM TENSILE STEEL (1984 (66))

Six Charpy specimens, three using 3.2mm (or less) diameter wire, and three using the largest wire size submitted for approval, shall be prepared and tested. Specimen and notch orientation as in BS2493 (see Section H.6.).

If the average of three specimens of either set fails to reach the requirement by not more than 15% the required value, a further three shall be tested and the results added to form a new average of six. If the requirements are not fulfilled, two further test plates shall be prepared as above and tested.

The required average impact energies and the test temperatures are given in the table below.

151

1 Electrode code

I 1 M300 1 2M300 1 3 M300 1 4 M300 1 5 M300 1 5 M300

I 1 M350 1 2 M350 1 3 M350

4 M350 5 M350 6 M350

1 1 M450 2 M450 3 M450 4 M450 5 M450 6 M450

1 1T300 1 2T300

3T300 4T300 5T300 6T300

1T350 2T350 3T350 4T350

I 5T350 1 6T350

1 T450 2 T450 3 T450 4 T450 5 T450 6 T450

Test temperature, °C

RT(1) 0

-20 -40 -50 -60

RT 0

-20 -40 -50 -60

RT(1) 0

-20 -40 -50 -60

RT(1) 0

-20 -40 -50 -60

RT(1) 0

-20 -40 -50 -60

RT(1) 0

-20 -40 -50 -60

Average impact energy, J |

3 5 1 35 1 35 35 35 35

40 40 40 40 40 40

45 4 5

45 45 45 45

35 35 35 35 35 35

40 40 1 40 1 40 1 40 1 40 1

45 1 45 1 45 1 45 1 45 1

J5 1

Note:

(1) RT - room temperature (approximately 20°C)

152

H.5.4. BS7084: CARBON AND CARBON MANGANESE STEEL TUBULAR CORED WELDING ELECTRODES (1989 (67))

TTie tubular cored electrodes are classified by different digits regarding strength, toughness and welding position.

For the different toughness digits, a minimum average of three test pieces impact energy of 47J is required at the test temperature given in the table below.

1 Digit

1 0 2 3 4 5 6

[7

Test temperature, °C |

0 -20 -30 -40 -50 -60 -70

aaaHBHBKaaaoaaBBBBaaJ

Six Charpy specimens, three using the smallest, three using the largest diameter electrode submitted for approval shall be prepared transverse to the weld at mid-thickness position and through-thickness notched in the weld centreline.

If the average of either weld is below 47J but not below 40J, three additional specimens for each set concerned can be taken for the same weld piece and tested.

The overall average shall be at least 47J. If either average is below 40J or any single value below 30J, two new welds shall be made as above using the same number of layers with electrodes from the same batch. Three specimens shall be tested of each weld with a stipulated average of 47J (with no single value below 30J).

H.6. CANADIAN STANDARDS

H.6.1. CSA W48.1-M1980: Mild Steel Covered Arc Welding Electrodes (1980, (25))

This standard requires that the weld metal be tested, to meet the following impact toughness requirements (5 specimens, lowest and highest values discarded):

| Electrode classification

E4X011, E4X010, E4X011, E4X027, E48015, E48016, E48018, E48048

1 E48028

Test temperature, °C

-30

-20

Impact energy, J |

27

_27

One of the three remaining specimens may have a toughness less than the average requirement, but not less than 20J.

153

H.6.2. CSA W48.3-1976: Low-Alloy Steel Arc-Welding Electrodes (1976, (25))

This standard requires an average of 20ft.lb impact toughness for welded joints fabricated with the following electrodes (5 specimens, with the lowest and highest values discarded):

1 Electrode classification

1 E8016-C3, E8018-C3

1 E9015-D1, E9018-D1, E10015-D2, E10016-D2, E10018-D2

I E9018-M, E10018-M, 1 E11018-M, E12018-M

1 E8016-C1, E8018-C1

1 E8016-C2, E8018-C2

Test temperature, °C

-40

-60

-60

-75

-100

Test condition |

As-welded 1

Stress-relieved 1

As-welded 1

Stress-relieved 1

Stress-relieved 1

One specimen of the three may have a value less than the average requirement, but not less than 15ft.lb.

H.6.3. CSA W48.4-M1980: Solid Mild Steel Filler Metals for Gas Shielded Arc Welding (1980, (25))

This standard requires that the weld metal be tested, to meet the following impact toughness requirements (5 specimens, lowest and highest values discarded):

| Classification

1 ER4805-2 1 ER485-3

ER4085-6 | ER480-7

Test temperature, °C

-30 -20 -30 -30

Impact energy, J |

27 1 27 1 27 27

One of the three remaining specimens may have a toughness less than the average requirement, but not less than 20J.

H.6.4. CSA W48.5-M1980: Carbon Steel Electrodes for Flux- and Metal-Cored Arc Welding (1980, (25))

This standard requires the following impact toughness levels (5 specimens, with the lowest and highest values discarded):

154

1 Electrode classification

1 Metric

1 E480XT-1 E480XT-5B E480XT-6

1 E480XT-8 E480XT-9 E480XT-12 E480XC-3

1 E480XC-6

Imperial

E7XT-1 E7XT-5B E7XT-6 E7XT-8 E7XT-9 E7XT-12 E7XC-3 E7XC-6

Test temperature, °C

-20 -40 -30 -30 -30 -30 -20 -30

Impact 1 energy, 1 J

27 1 27 27 27 27 27 1 27 1 27 1

The minimum impact toughness (of 3 specimens) may be lower than these average requirements, but not less than 20J.

H.6.5. CSA W48.6-M1980: Bare Mild Steel Electrodes and Fluxes for Submerged-Arc Welding (1980, (25))

Ulis standard requires the following weld metal impact toughness values (5 specimens, with the lowest and highest results discarded):

| Flux/electrode classification

1 F410Z-xxxx 1 F4102-xxxx 1 F4103-xxxx 1 F4104-xxxx 1 F4105-XXXX

1 F480Z-xxxx 1 F4802-xxxx I F4803-xxxx I F4804-xxxx | F4805-XXXX

Test temperature, °C —

-20 -30 -40 -50

—

-20 -30 -40 -50

Impact energy, J |

— 1 27 27 1 27 1 27 1

_ 1

27 1 27 1 27 1 27 1

where "xxxx" is the electrode designation. Of the three remaining specimens, one may have a toughness less than the average requirement, but not less than 20J.

H.7. NAVAL ENGINEERING STANDARD 769: WELD CONSUMABLES FOR STRUCTURAL STEELS. APPROVAL SYSTEM, (1979, (68))

Annex 1: Weld Metal Mechanical Properties and Test Panel Requirements (68)

The requirements for different grades of all weld metal joints, or melt run panels are listed in the table below:

155

1 Weld metal designation

1 MS I B and BX up to 12mm thickness 1 B and BX above 12mm thickness vxw WT28 WIN

1 HY80

Impact energy, J

47 61 41 41 55 55 55

1 Test temperature, °C |

20 -10 -30 -30 -20 -20 -20

If the average of three specimens fails to comply with these specifications, three additional specimens may be tested and a new average calculated which must comply with the minimum value specified.

ΗΛ. SWEDISH STANDARD MNC 970E: WELDING ELECTRODES - COVERED ELECTRODES FOR MANUAL METAL ARC WELDING AND GRAVITY WELDING OF CARBON STEELS, CARBON MANGANESE STEELS AND FINE GRAINED STEELS WITH INCREASED YIELD STRESS, (1979, (69))

The required impact energy for different electrode grades is 27J at the test temperature given below.

1 Electrode grade

1 Swedish

1 3201 3202 3203 3204-H15/H10 3205-H15/H10 3206-H15/H10 3207-H15/H10

1 3208-H15/H10 1 3209-H15/H10 1 3210-H15/H10 1 3211-H15/H10 1 3211-H15/H10 1 3230 1 3231

ISO

E43 3 E51 0 E51 2 E51 3-H15/H10 E51 4-H15/H10 E51 5-H15/H10 E51 6-H15/H10

1

Test temperature, °C 1

-20 1

0 -20 -30 -40 -50

0 -20 -30 -40 -50 1

0 1 -20 1

a s a a s a n g a B W a a e a — M

156

REFERENCES

1 ASME III: 'Rules for construction of nuclear power plant components', American Society of Mechanical Engineers, New York, 1989.

2 ASME VIII: 'Rules for construction of pressure vessels', American Society of Mechanical Engineers, New York, 1989.

3 ASME III Appendix G: 'Protection against non-ductile failure', American Society of Mechanical Engineers, New York, 1989.

4 WRCB 175: 'PVRC recommendations on toughness requirements for ferritic materials', Welding Research Council, New York, 1972.

5 ASME XI Appendix A: 'Analysis of flaws', American Society of Mechanical Engineers, New York, 1989.

6 ASME XI Appendix G: 'Fracture toughness criteria for protection against failure', American Society of Mechanical Engineers, New York, 1989.

7 API Standards, Specification and Recommendations (see text for details of specific documents), American Petroleum Institute, Washington D.C.

8 Pressure Vessel Research Council (PVRC) recommendations on toughness requirements for ferritic materials, WRC Bulletin 175, 1972.

9 AS Standards, Specifications and Recommendations (see text for details of specific documents), Standards Association of Australia, Sydney.

10 Austrian Federal Statute: 'Materials & Construction regulations for steam boilers'. Bauvorschriften (WBV) Verordnung 264,1949. Amendment: Verordnung 67, 1979.

11 CODAP-1980, Revision October 1984: 'French Code for the construction of unfired pressure vessels', Part M, Appendix MA2, 1984.

12 AD-Merkblätter; W10: 'Materials for pressure vessels', DIN, November 1987 and HP5/2: 'Manufacture and Testing of Pressure Vessels', July 1984.

13 ICI Ltd: 'Specification for pressure vessels', E354C, September 1971.

14 BS5500: 'Specification for unfired fusion welded pressure vessels', Appendix D, 'Requirements for ferritic steels in bands MO to M4 inclusive for vessels required to operate below 0°C, January 1991.

15 JIS B 8243-1981: 'Construction of Pressure Vessels', Japanese Industrial Standards, 1981.

16 Dutch Rules for Pressure Vessels, Sheet No.110, The Netherlands, 1983.

157

17 The Norwegian Pressure Vessel Committee: 'General Rules for Pressure Vessels', 1978.

18 The Swedish Pressure Vessel Commission, 'Swedish Pressure Vessel Code', 1974, 1st Amendment September, 1977.

19 ECISS/TC22 N74: 'Fracture toughness concept of the Swedish pressure vessel code', February 1989.

20 Mucek M W: 'Amoco's line pipe specs exceed industry standards', Oil & Gas Journal, 88 (24), 1990, 45-47.

21 Jones D G, Noklebye A: 'Zeepipe fracture toughness requirements', Proc. Pipeline Technology Conference, Ed. R Denys, 15-18 October 1990, Oostende, Royal Flemish Society of Engineers, 1990, 10.17 - 10.23.

22 BGC/PS/LXl: 'British Gas specification for submerged arc welded line pipe (supplementary to API 5LX)'.

23 BGC/PS/LX4: 'British Gas specification for seamless line pipe (supplementary to API 5LX)'.

24 BS4515: 'Specification for welding of steel pipelines on land and offshore', British Standards Institution, London, 1984

25 CSA Standards, Specifications and Recommendations (see text for details of specific documents), Canadian Standards Association, Rexdale, Ontario.

26 Det Norske Veritas: 'Rules for submarine pipeline systems', Norway 1981.

27 ABS Standards, Specifications and Recommendations (see text for details of specific documents), American Bureau of Shipping, New York.

28 BS5762: 'Methods for crack opening displacement (COD) testing1, British Standards Institution, London, 1979.

29 BS7191: 'Specification for weldable structural steels for fixed offshore structures', British Standards Institution, London, 1989.

30 Bureau Veritas: 'Rules and Regulations for the Construction and Classification of Offshore Platforms', France, 1975.

31 Lloyd's Register: 'Rules and Regulations for the classification of fixed offshore installations, Part 2: Materials and Manufacturing Procedures', December 1989.

32 DOE: 'Offshore Installations: Guidance on design, construction and certifi-cation', UK Department of Energy, 1990.

158

33 EEMUA Publication No.150: 'Steel specifications for fixed offshore structures' (adapted for offshore from BS4360:1986), Engineering Equipment Manufacturers and Users Association, 1987.

34 Det Norske Veritas: 'Rules for the design, construction and inspection of offshore structures', Norway, 1981.

35 Det Norske Veritas: Technical Note fixed offshore installations: Fracture toughness properties and post weld heat treatment', Norway 1981.

36 Register of Shipping of the People's Republic of China: 'Rules for the construction of sea-going ships', The People's Communication Publishing House, Peking, 1978.

37 U.S. Coast Guard Marine Engineering Regulations, Subchapter F: 'Materials, construction, installation, inspection and maintenance of boilers, piping, welding and brazing', Department of Transportation, Washington, D.C., 1970.

38 Germanischer Lloyd: 'Rules for the Classification and Construction of Seagoing Steel Ships', 1973, Supplement, May 1976.

39 Lloyd's Register: 'Rules for the Manufacture, Testing and Certification of Materials', January 1984'. Rules and Regulations for the Classification of mobile offshore units, Part 2, June 1989.

40 Registre Italiano Navale: 'Rules for the construction and classification of ships', Italy, February 1990.

41 Det Norske Veritas: 'Rules for classification of steel ships, materials and welding', Norway, 1984.

42 Nippon Haiji Kyokai: 'Rules and regulations for the construction and classification of ships', Japan, 1978.

43 ASME B31.3: 'Chemical Plant and Petroleum Refinery Piping', American Society of Mechanical Engineers, New York, 1990.

44 BS2654: 'Specification for manufacture of vertical steel welded non-refrigerated storage tanks, with butt-welded shells for the petroleum industry', British Standards Institution, London, 1989.

45 BS4741: 'Specification for vertical cylindrical welded steel storage tanks for low temperature service: single-wall tanks for temperatures down to -50°C, British Standards Institution, London, 1971.

46 BS7122: 'Specification for welded steel tanks for liquéfiable gases transported by road', British Standards Institution, London, 1989.

159

47 AASHTO Standards, Specifications and Recommendations (see text for details of specific documents), American Association of State Highway and Transportation Officials, Washington D.C.

48 BS5400: Part 6: 'Specification for materials and workmanship, steel·, British Standards Institution, London, 1980.

49 ASMEII: 'Material specification1, American Society of Mechanical Engineers, New York, 1989.

50 ISO Standards, Specifications and Recommendations (see text for details of specific documents), International Organisation for Standardization.

51 Norme Belge: 'Structural Steels', February 1976. 'Covered electrodes for manual arc welding', May 1976.

52 BS970: 'Wrought steels for mechanical and allied engineering purposes', British Standard Institution, London, 1991.

53 BS1113: 'Specification for design and manufacture of water tube steam generating plant'. British Standard Institution, London, 1989.

54 BS1501: 'Steels for fired and unfired pressure vessels: plates'. British Standard Institution, London 1980.

55 BS1502: 'Steels for fired and unfired pressure vessels: sections and bars'. British Standard Institution, London 1982.

56 BS1503: 'Steel forgings for pressure purposes'. British Standard Institution, London, 1989.

57 BS1504: 'Steel castings for pressure purposes'. British Standard Institution, London, 1976.

58 BS1506: 'Carbon, low alloy and stainless steel bars and billets for bolting material to be used in pressure retaining applications'. British Standard Institution, London, 1990.

59 BS4360: 'Specification for weldable structural steels', British Standard Institution, London, 1990.

60 BS EN10025: 'Hot rolled products of non-alloy structural steels: Technical delivery conditions'. British Standard Institution, 1990.

61 JWES (see text for details of specific documents) (Japanese Welding Engineering Society).

62 Euronorm, European Coal and Steel Community, Commission of the European Communities, Iron and Steel Nomenclature Coordination Committee (see text for details of specific documents).

160

63 AWS Specifications, (see test for details of specific documents). American Welding Society, Miami.

64 BS639: 'Specification for covered carbon and carbon manganese steel electrodes for manual metal arc welding1. British Standard Institution, London, 1986

65 BS2493: fLow alloy steel electrodes for manual metal arc welding1. British Standard Institution, London, 1985.

66 BS4165: 'Electrode wires and fluxes for the sub-merged arc welding of carbon steel and medium tensile steel'. British Standard Institution, London, 1984.

67 BS7084: 'Carbon and carbon-manganese steel tubular cored welding electrodes'. British Standard Institution, London, 1989.

68 MOD Naval Engineering Standard 769: 'Welding consumables for structural steels approval system', Ministry of Defence, UK Ship Department, May 1979.

69 Swedish Standard MNC 970E: 'Welding electrodes', Swedish Standard Institution, 1979.

161

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General notes (a) Interpolation between yield strengths shown is permitted. (b) The minimum impact energy for one specimen shall not be less than 2/3 of the average energy

required for three specimens. (c) Materials produced and impact tested in accordance with SA-320, SA-334, SA-350 and SA-352

(see Table UG-84.3) do not have to satisfy these energy values. They are acceptable for use at minimum design metal temperature not colder than the test temperature when the energy values required by the applicable specification are satisfied.

163

Fig.3 ASME HI Appendix G reference toughness, Km, temperature transition curve (3).

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180

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164

Impact testing required

Nominal thickness, In. (limited to tin. for welded construction)

Fig.5 API 920 design metal temperature evaluation (7).

165

Fig.6 PVRC assumed flaw depth (8).

166

Wall thickness, T Inches

20 1 \ 1 Design minimum temperature for wrought carbon and carbon-manganese steels-as-welded- for stresses up to maximum allowable design stress

Material reference thickness, mm

Fig.7 AS 1210 unfired pressure vessel code: design minimum temperature (9).

Explanatory table for curves on Fig.7 and 8

Curve

A

B

C

D

E

Standard impact test temperature, •c No test

0 No test

-20

-40

-50

Standard impact test value, J

RM < 450MPa RJO > 450MPa

—

27

27

27

27

—

40

40

40

40

Type of steel (permitted by this standard)

All

All Fine grained C-Mn steel

Fine grained C-Mn steel

Fine grained C-Mn steel

Fine grained C-Mn steel

167

Special requirements for thicknesses over 32mm to 50mm Inclusive

40 60 80 Material reference thickness, mm

120 and over

Fig.8 AS 1210 un fired pressure vessel code: design minimum temperature (9).

168

Notes to Fig.7 and 8 1. Tested by steelmaker or manufacturer. 2. Steels produced to fine grained practice, i.e.

(a) normalised steel where the specified minimum %Mn divided by specified maximum %C > 4; or

(b) controlled rolled; or (c) grain refining elements added. e.g. AS 1548 Types 5 and 7.

3. For steel with impact test values > 27 J and < 40J, design minimum temperatures 10°C above the curve will apply.

4. Applicable only to steel with specified minimum tensile strength < 4 50 M Pa. 5. (a) Impact tests are not required for material thinner than 3mm. (See Note 1,

Clause 2.6.5.1.) (b) Material specifications may not require impact tests on Charpy specimens smaller

than 10 X 5mm without special negotiation and thus impact tested material thinner than 6mm may not be readily available.

6. Values at intermediate test temperatures may be obtained by linear interpolation. 7. See Clause 2.6.5. for impact testing. 8. R20 ~ specified minimum tensile strength at room temperature.

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ruct

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of p

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ves

sels

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). R

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46

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05

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173

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9 C

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174

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9 C

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Fig.

9 C

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(11)

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100

80

60

40

20

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ctio

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ssur

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ssel

s (1

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ngth

) in

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ts o

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imm

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Tm

a(°C

>

100

80

60

40

20

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0

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III

1

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110

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m)

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on

td

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DA

P c

od

e fo

r th

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nst

ruct

ion

of p

ress

ure

ves

se/s

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0002 (0

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nit

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0 -2

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Mat

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l Im

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eria

l Im

pac

t te

st

tem

per

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re,

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Fig

. 10

BS

550

0 sp

ecifi

catio

n fo

r un

fired

fusi

on w

elde

d pr

essu

re v

esse

ls (

14).

»

\λ w ^

a I

Shell

I — r I L

£

Fixed tubeplate or fiat end

V. Υ//////Λ Δ

ZZZZZ=CZZ23 _L. T

5Λβ//

\

c 7"

/I I Fixed tubeplate U or flat end *t

^ ;

Note For as-welded and post-welded heat-treated conditions, use the greater of e / 4 or e2 in Fig. 10a and 10b.

Reference thickness: slip-on and plate flanges, tubeplates and flat ends.

Fig. 11 BS 5500 reference thickness I (14) :

a) Slip-on and plate flanges; b) Fixed tubeplates and flat ends.

179

(a)

Weld neck flange

Ï:

lb)

Fixed tubeplate or tlar end

WZ7Z/

uzzux N

As-weldedL < 4e2 Use greatest of e,/4, e2 or e3 in Fig.lOa. L> 4e2 Use greater of e2 or e3 in Fig.lOa or use e,/4 in Fig.lOb whichever is more

onerous Post-weld heat-treated Use greatest of e,/4, e2 or e3 in Fig.lOb

Fixed tubeplate or flat end

J_ Fixed tubeplate or flat end

S3

! f 1 | i Utzfif- *♦ i

f / 1 5/θρβ

« ;

As-welded Use greater of e2/4 or e3 in Fig.lOa or use e,/4 in Fig.lOb, whichever is more onerous

Post-weld heat-treated Use greater of e,/4 or e3 in Fig.lOb

Fig. 12 BS 5500 reference thickness II (14).

180

! c «I

Wj

200 (a)

300 400 500 600 Outside diameter, mm

700 800

(b)

200 300 400 500 600

Outside diameter, mm 700 800

Fig. 13 AS 2885 Charpy impact requirements (9) :

a) Pressure — 7MPa; b) Pressure — lOMPa.

181

a) 200 < OD < 299mm b)300< OD< 399mm

C) 400 < OD < 499mm d) 500 < OD < 599mm

Fig.14 BS 4515 Appendix H minimum CTOD requirements

182

Yield stress(N/mm2) Yield stress (N/mm2)

Yield stress(N/mm2) Yield stress(N/mm2)

Pip

e th

ickn

ess(

mm

) _

* Is

J is

* U

\ O

U

l

Pip

e

thic

kn

ess

(mm

)

Pip

e th

ickn

ess

(mm

) _

* r

o

K»

8 Ï § I

Pip

e th

ickn

ess(

mm

) 250 312.5 375 437.5

Yield stress (N/mm )

500 250 312.5 375 437.5 Yield stress(N/mm2)

500

9) 600 < OD < 699mm f) 700< 0D< 799mm

10 250 312.5 375 437.5

Yield stress(N/mm^)

ε

1 I 20

d i î 15

500 250 312.5 375 437.5

Yield stresslNimro^)

g) 800< 0D< 899mm \\)900< 0D< 999mm

Fig. 14 Contd BS 4SI S Appendix H minimum CTOD requirements

183

>»F

£-20

c -&-J0

-40

h"

u

ΞΓ, -20 /

-40

1 1 1

—71

-50

■ Λ

/

/-80 |

— i 1

Post-weld J heat Ί treat-ment

1 1 » 20

(a) 30 40 50 Thickness, mm

60 70 80

lb) 10 20 30 40

Thickness, mm 50

10 F

J. -30

-40

f~

u

"-> T~ -70 /

-20 /

-40 >

'

7 '

-60

I / - l —

~~7 '—

-80

I L_.

— i 1

Post-weld J heat Ί treat-ment

1 10 20

(d 30 U0 50 Thickness, mm

60 70 80

Temperatures written on the graph are those at which Charpy impact specimens are to be tested. (Boundary lines form part of the lower grade, i.e. with the higher test temperature.) Do not extrapolate.

Fig. 15 Lloyd's Register, Charpy impact test temperatures as a function of wall thickness for different safety classes (29):

a) 'Primary' applications; b) 'Secondary' applications; c) 'Special'applications.

184

τ τ 39

Average minimum Charpy V-notch energy absorption

-\ 35

31

ΓSpecimen cross-section,

I mm*

10 x 10

10 x 73

10 x S

Fraction for minimum energy \

1

5/6

2/3

H 27

_L _L J_ - U 23 195 235 275 315

R*, MPa 355 390

Fig. 16 Det norske Veritas: minimum impact energy as a function of yield strength (32).

185

0.25 0.50 0.75 1.0 1.25 Plate thickness, including corrosion allowance, in.

1.50

Fig. 17 API 650 design metal temperature evaluation (7).

186

Charpy V test temperature,°C

NOTE: Scale A on the ordinate is to be used in determining minimum Charpy V requirements for the thickness and minimum design temperature concerned. Conversion of the measured impact value to the 27J (or 41J for steels with specified minimum tensile strength greater than 430 N/mm2) value may be made on the basis of 1.35J per °C, such extrapolation being limited to a maximum range of 20°C.

The requirements derived from scale A take into account an improvement in safety which may be anticipated as a result of the hydrostatic test. During the first hydrostatic test the degree of security against brittle fracture may be rather less than on subsequent loading. Attention is drawn to the more conservative requirements of scale B when consideration is to be given to the use of this scale during hydrostatic testing of tank shells constructed of steels with specified minimum tensile strength greater than 430 N/mm2.

Fig. 18 BS 2654 Charpy V requirements.

187

-50 -40 -30 -20 -10 10 20