Stainless Steel Course Modules Compressed(2)

7/30/2019 Stainless Steel Course Modules Compressed(2)

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Course IIW: 141 - TIG WELDING OF STAINLESS STEEL

This project has been funded with support from the European Commission. This publication reflects the views

only of the authors, and the Commission cannot be held responsible for any use, which may be made of the

information contained therein.


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List of content

MODULE 1.......................................................................................................................................... 5

Activity Based Training ..................................................................................................................5

Normative references ...................................................................................................................... 8

MODULE 2........................................................................................................................................ 12

Welding symbols according ISO 2553 (A6) .................................................................................12

Types of butt welds .......................................................................................................................13Types of fillet welds......................................................................................................................13

Supplementary symbols ................................................................................................................14

Joint preparation for butt welds, welded from one side ................................................................14

Joint preparation for T - joints, welded from one side.................................................................21

Role of inspection and quality control (B9) ..................................................................................23

Introduction to ISO 3834 (B9) ......................................................................................................24

Summary comparison of ISO 3834, Parts 2, 3 and 4 .................................................................... 26Stainless steel compared to unalloyed steel and aluminium alloys (PSS1) ..................................30

Definition of stainless steel ...........................................................................................................30

Identification of stainless steel ......................................................................................................30The working environment of the fabrication shop, general hazards, dust, heavy and hot material,

cables (A4) ....................................................................................................................................33

Handling of stainless steel in the workshop and the use of tools for stainless steel (PSS2).........36MODULE 3........................................................................................................................................37

Personal protective equipment and clothing (A3).........................................................................37Noise hazards (A3)........................................................................................................................40

Suitable cutting processes for different types of steel to achieve a suitable cutting surface (A8) 41

Flame cutting, Principle and parameters, cutting blowpipes, cutting machines, quality of cutsurface ........................................................................................................................................... 42

Other cutting processes as: plasma, laser, mechanical cutting......................................................42

Safety precautions for cutting (PSS1) ........................................................................................... 44

Burns and fires, fire prevention, fire fighting (A3) ....................................................................... 44

MODULE 4........................................................................................................................................46Welding procedures and instructions. ........................................................................................... 46

Methods for joint preparations in stainless steel (PSS2)...............................................................50MODULE 5........................................................................................................................................52

Principle of welding consumables and functions of each type of welding consumable (A5) ......52

Shelding gases, backing gases.......................................................................................................54

Selection of Welding Gas .............................................................................................................54Classifications of welding consumables (A5)...............................................................................55

Storage drying and handling (A5) ................................................................................................57

Types of welds and joints, characteristics, size, surface finish (A6) ...........................................57

141 - TIG and 15 - PAW...............................................................................................................57131/135 MIG/MAG...................................................................................................................... 58

136 - FCAW..................................................................................................................................58121 SAW.......................................................................................................................................58

MODULE 6........................................................................................................................................60

Specific rules and regulations (A3) ...............................................................................................60

Electric shock (A3).......................................................................................................................61

Steps to Prevent Electrical Shock .................................................................................................63

Emergency Procedures:.................................................................................................................64

UV- and heat radiation (A3)..........................................................................................................64





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Eye hazards ...................................................................................................................................66

Welding fumes ..............................................................................................................................67Hazardous substances....................................................................................................................70

Removal of hazardous welding dust ............................................................................................. 72

Detectable of internal imperfections of welds (B8) ...................................................................... 75MODULE 7........................................................................................................................................ 78

Inspection and testing.................................................................................................................... 78

Survey of specific weld imperfections and their cause (B5)........................................................80

111 - SMAW troubleshooting .......................................................................................................80

141 - TIG welding .........................................................................................................................81Problems and corrections ..............................................................................................................81

131/135 MIG/MAG...................................................................................................................... 82Weld Discontinuities ..................................................................................................................... 83

Flux Cored Arc Welding (136 - FCAW) Troubleshooting ...........................................................86

111 - SMAW ................................................................................................................................88

Electroslag troubleshooting...........................................................................................................89Oxyfuel gas welding...................................................................................................................... 90

MODULE 8........................................................................................................................................ 92

Introduction to ISO 14731 Welding Coordination (B9) ...............................................................92

Welding related tasks of the welding coordinator.........................................................................93Welding personnel......................................................................................................................... 93

Quality records ..............................................................................................................................95Surface inspection on cracks and other surface imperfections by visual testing (B8) ..................95

Welders qualification and qualification standards ...................................................................... 110

Accredited and none-accredited certification..............................................................................110

Maintenance and prolongation of certificates .............................................................................110

Essential variables for the certificates .........................................................................................111MODULE 9......................................................................................................................................112

Delivery of the product. ..............................................................................................................112

The European Welded Product Directives. .................................................................................113The European Welded Product Standards...................................................................................114

The EN ISO 3834........................................................................................................................116Identification and traceability......................................................................................................118

Quality records ............................................................................................................................118





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MODULE 1

Activity Based Training

Instead of utilizing the traditional methodology whereby the student moves through a traditional

education with theoretical content from A to Z, followed by hands on training, this course will usean Activity Based Training (ATB). With ATB it is understood that the training follow the

production activities according the production path of a predefined structure or product. The course

will also exploit a blended approach whereby different delivery technologies for the content itself

will be used.

The course has been divided into 9 different modules and three of these are modules where the

major part of the hours will be utilized for practical work. This means that the students have toparticipate together in a workshop or laboratory.

This is an important aspect of the methology itself. When working in an industrial environment the

student has to work together with other personnel in order to meet the requirements in quality, time

schedules and so forth. The team building effort, its importance for the final product and itsimportance for the total quality of the production environment must be stressed during the

educational process.

In a welding environment today the students will work together with other persons from different

cultures, with different educational backgrounds and with different practical experience, which willrequire a profound focus on flexibility and open minded attitude towards other people. Few if any

other educational routes will demand such flexibility to the student itself and to the studentsbehaviour on a short and long term basis.

The course will consist of several job-elements. The figure shows how one job-package is built up

of different elements, some are pure theory elements and other is a mixture of theory and hands-ontraining. The training will be carried out in the workshop, shop, or in a laboratory. Video streaming

and/or videoconferencing will be used in Shop/Theory packages.





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Job Package.

A job package might contain several job elements. A job package is a complete documentation

package of specific activities that must be mastered in the welding industry in order to handle thewhole production process. It contains at least the following information:

i. Drawing of the structure to be fabricatedii. Work description with which methods shall be used in the productioniii. Work description with process description of the work process for reaching the target

and the knowledge required

iv. Quality assurance requirements for the ingoing elementsv. Quality assurance description of the outgoing elementsvi. Work package description for the work to be donevii. Reference to available resources for the work

viii. Reference to environmental resources or requirements or restrictionsix. Requirements for knowledge, prerequisite or knowledge that has to be obtainedx. Cooperation strategy with other in a defined group or to related groups

However, some basic prerequisite knowledge must be mastered by the production staff in order tofollow the knowledge requirements. The knowledge and competence requirements include:

Ability to work in a multicultural environment with the colleagues due to exchange of mobile

personnel across borders and among mechanical industry companies

Ability to understand and communicate the content in the job packages to the colleagues in a

multilingual working environment

Ability to understand his/her responsibility in the production chain and to communicate the needfor knowledge.

Ability to search for relevant learning and training material when needed.

To understand how a process plan might be visualized by utilizing a project plan.





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A general design of a learning element. This element consists of both theoretical content as well as

practical work. We can also see that the practical task, when completed shall be verified by the

student as well as by a 3-part. This will both ensure that the student feel responsible for the partitself, but also be aware of the quality assurance aspect which is very important withing the welding

activities. This is a simplified design where no loops are included in the process flow.

A central philosophy within fabrication is that the person who produce a product shall not be the

one carrying out the quality control of the same product. To establish the same methology ineducation one aims at introducing an alternative production flow whereby the product alternate

between students or student groups.

A product is alternating between students during the fabrication process. When produced by

student A at a certain stage then student B will carry out the quality control of the part. Student Bwill then use the part from A in his own production and then transfer it back to A for the following

quality control.

This means that the students shall be familiar with and use the definitions and actions that are

common in the industry. It will consequently be mandatory to switch the objects for this purpose in

order to avoid that a person verifies himself. If defects or non-conformance is found then the

necessary corrective actions have to be carried out by the student.

The use of objects should reflect the typical industry environment that is domination in the areawhere the course is held in order to create a more relevant training domain. But when this is done,then he other examples and references in the material should be selected from a similar industrial

background in order to make tis relevant fro the student .

Delivery.

The structure described here is a structure that can be used in different environments. The structure

has not been designed for a special delivery method. However, when that has been said, it is

possible to use a highly structured an d rigid structure whereby you may control an verify all steps

of the student,

If that is the correct way of carrying out the course is of course another question.





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The structure that follows is a an idea of which elements that a course should contain, if its running

as a web course or if its running as a face-to face course without having access to the web itself.

Normative referencesIn the following table is a list of some of the European (EN) standards within the welding sector.

This list is not complete.

Bold documents are of special importance

DokNo Name

Year

EN 287-1 Qualification test of welders - Fusion welding - Part 1:Steels3.2004

EN ISO 9606-2 Qualification test of welders - Fusion welding - Part 2:Aluminium 1.1999

EN ISO 9606-3Qualification test of welders - Fusion welding - Part 3; Copper and copperalloys

1.1999

EN ISO 9606-4Qualification test of welders - Fusion welding - Part 4: Nickel and nickel

alloys1.1999

EN ISO 9606-5Qualification test of welders - Fusion welding - Part 5: Titanium and

titanium alloys

1.

1999

EN ISO 15607 Specification and qualification of welding procedures for metallicmaterials - General rules (ISO 15607:2003)

2004

EN ISO 15609-1Specification and qualification of welding procedures for metallic

materials - Welding procedure specification - Part 1: Arc welding (ISO15609-1:2004)

2004

EN ISO 15614-1

Specification and qualification of welding procedures for metallic

materials - Welding procedure test - Part 1: Arc and gas welding of steelsand arc welding of nickel and nickel alloys (ISO 15614-1:2004)

2004

EN ISO 15610Specification and qualification of welding procedures for metallicmaterials - Qualification based on tested welding consumables (ISO15610:2003)

2004

EN ISO 15611Specification and qualification of welding procedures for metallicmaterials - Qualification based on previous welding experience (ISO15611:2003)

2004





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EN ISO 15612Specification and qualification of welding procedures for metallicmaterials - Qualification by adoption of a standard welding procedure(ISO 15612:2004)

2004

EN ISO 15613 Specification and qualification of welding procedures for metallicmaterials - Qualification based on pre-production welding test (ISO15613:2004)

2004

EN 288-9Part 9: Welding procedure test for pipeline welding on land and offshore

site butt welding of transmission pipelines1999

EN ISO 3834 Welding coordination - Tasks and responsibilities 2005

EN ISO 3834-1Quality requirements for welding - Fusing welding of metallic materials -Part 1: Guidelines for selection and use

2005

EN ISO 3834-2Quality requirements for welding - Fusing welding of metallic materials -Part 2: Comprehensive quality requirements

2005

EN ISO 3834-3Quality requirements for welding - Fusion welding of metallic materials -Part 3: Standard quality requirements

2005

EN ISO 3834-4 Quality requirements for welding - Fusion welding of metallic materials -Part 4: Elementary quality requirements 2005

EN 756Welding consumables - Solid wires, solid wireflux and tubular coredelectrode-flux combinations for submerged arc welding of non alloy andfine grain steels - Classification

22004

EN 970 Non-destructive examination of fusion welds - Visual examination 1998

EN 1011-1Welding - Recommendations for welding of metallic materials - Part 1:General guidance for arc welding

1998

EN 1011-1/A1Amendment A1 - Welding - Recommendations for welding of metallicmaterials - Part 1: General guidance for arc welding

2002

EN 1011-1/A2Amendment A2 - Welding - Recommendations for welding of metallicmaterials - Part 1: General guidance for arc welding

2004

EN 1011-2Welding - Recommendations for welding of metallic materials - Part 2:

Arc welding of ferritic steels2001





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EN 1011-2/A1Amendment A1 - Welding - Recommendations for welding of metallicmaterials - Part 2: Arc welding of ferritic steels

2004

NS-EN 1011-3Welding - Recommendations for welding of metallic materials - Part 3:

Arc welding of stainless steels2000

EN 1011-3/A1Amendment A1 - Welding - Recommendations for welding of metallicmaterials - Part 3: Arc welding of stainless steels

2004

EN 1011-5Welding - Recommendations for welding of metallic materials - Part 5:

Welding of clad steel2003

EN 1418Welding personnel - Approval testing of welding operators for fusionwelding and resistance weld setters for fully mechanized and automaticwelding of metallic materials

1998

EN ISO 4063Welding and allied processes - Nomenclature of processes andreference numbers (ISO 4063:1998)

2000

EN ISO 5817Welding - Fusion-welded joints in steel, nickel, titanium and their alloys(beam welding excluded) - Quality levels for imperfections (ISO5817:2003)

2003

EN ISO 6520-1Welding and allied processes - Classification of geometric imperfectionsin metallic materials - Part 1: Fusion welding (ISO 6520-1:1998)

1998

EN ISO 6520-2Welding and allied processes - Classification of geometric imperfections

in metallic materials - Part 2: Welding with pressure (ISO 6520-2:2001)2002

EN ISO 9692-1Welding and allied processes - Recommendations for joint preparation -

Part 1: Manual metal-arc welding, gas-shielded metal-arc welding, gaswelding, TIG welding and beam welding of steels (ISO 9692-1:2003)

2004

EN ISO 9692-2Welding and allied processes - Joint preparation - Part 2: Submerged arcwelding of steels (ISO 9692-2:1998) (Corrigendum AC:1999incorporated)

1998


Part 3: Metal inert gas welding and tungsten inert gas welding ofaluminium and its alloys (ISO 9692-3:2000)

2001





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EN ISO 9692-3/A1Amendment A1 - Welding and allied processes - Recommendations forjoint preparation - Part 3: Metal inert gas welding and tungsten inert gaswelding of aluminium and its alloys

2004


Part 4: Clad steels (ISO 9692-4:2003)2003

Page Title Comment

Table with reference literature to be read in addition to the course documentation for the individualmodules. This table to be compiled according to the national availability of reference literature.





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MODULE 2

Welding symbols according ISO 2553 (A6)

The weld joint is where two or more metal parts are joined by welding. The five basic types of

weld joints are the butt, corner, tee, lap, and edge.Special symbols are used on a drawing to specify where welds are to be located, the type of joint to

be used, as well as the size and amount of weld metal to be deposited in the joint.

A standard welding symbol consists of a reference line, an arrow, and a tail. The reference line

becomes the foundation of the welding symbol. It is used to apply weld symbols, dimensions, and

other data to the weld. The arrow simply connects the reference line to the joint or area to be

welded. The direction of the arrow has no bearing on the significance of the reference line. The tail

of the welding symbol is used only when necessary to include a specification, process, or other

reference information.

The term weld symbol refers to the symbol for a specific type of weld: fillet, groove, surfacing,

plug, and slot are all types of welds. Some of basic weld symbols are shown in the next figures.

Types of butt welds





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Single V preparation Double V preparation

Types of fillet welds

The leg length of a fillet weld is located in front of the weld symbol (triangle). The dimension is in

millimeters preceded with the letter Z or by the letter a.

In addition to basic weld symbols, a set of supplementary symbols may be added to a weldingsymbol.

Some of the most common supplementary symbols are shown in the following figure.

Supplementary symbols





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Weld this joint on site Inspect by NDT, Weld, Paint, etc.

Joint preparation for butt welds, welded from one side

Dimensions

R

ef

.

N

o.

Wor

kpiec

e

thick

ness

t

mm

Desi

gnati

on

Sym

bol

ISO

255

3

Cross

section

Angl

e

,

Gap

bmm

Thic

knes

s of

root

face

cmm

Dep

th

of

pre

par

a-

tion

h

mm

Wel

ding

proc

ess

ISO

4063

Illustrat

ion

Re

marks

1.

1 2

Butt

weld

betw

een

plate

s

with

raised

edge

s

- - - -

3

111

141

512

Usual

ly

witho

ut

filler

metal

-1.

2.

1

~ t

3

111

141

13

141

6

b

8

~ t

1

1.

2.

2

4

3 < t

8

15

Squa

re

buttweld

-

0

- -

52

With

temp

orary

backi

ng





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1.55 t

40

Singl

e V

Buttweld

with

broa

d

rootface

~

600

1

b 4

2 c

4-

111

13

141

-

1.6 > 12

Singl

e-Ubutt

weldwith

V

root

e

600

900

80

120

1

b 3

- ~ 4

111

13

141

6

R9

1.7 > 12

Singl

e V

butt

weld

with

V

root

e

60 0

900

100

150

2

b

4

> 2 -

111

13

141

-

1.8 > 12

Singl

e-U

butt

weld

(slop

ingsides

)

80

120

4 3 -

111

13

141

-

3 < t

10

400

600 4

3

111

13141

3 8 < t12

Single V

butt 60 8

0 - 2 -

52

4 > 16

Steep-

flanked

single-V

butt with

backing

50

200

5 b

15- -

111

13

With

perman

t backin





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1.9

.1

1.9

.2

3 < t

10

Singl

e-bevel

butt

weld

350

600

2 b

4

1 c 2

-

111

13

141

-

1116

b

12

1.1

0> 16

Steep

-flank

edsingl

e-

bevelbutt

weld

150

60

0~12

- -13

141

With

permanent

backi

ng

1.1

1> 16

Singl

e J

butt

weld

10 0

200

2

b

4

1 c

2-

111

13

141

-

Dimensions

R

ef

.N

o.

Wor

kpie

ce

thick

ness

t

mm

Desi

gnation

Sym

bol

ISO

255

3

Cross

section

Angl

e

,

Gap

bmm

Thic

knes

s ofroot

face

cmm

Dep

th

of

prepar

a-

tion

h

mm

Wel

ding

proc

essISO

4063

Illustrat

ion

Re

marks

8 ~t/2 111

141 t/213

2.

1 15

Squa

re

butt

weld

-

0

- -

52

111141

2.2

3 t 40

Single-V

~600

3 2 - -





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111

141~

6002.

2

3 t

40

prepa

ratio

n400

600

3 2 -

13

-

~

600

111

141

2.

3> 10

Single-V

buttweld

with

broa

d

root

face

andbacki

ng

run

400

600

1 b

3

2 c

4-

13

-

~

600111

141

2.

4> 10

Double

-V butt

weld

with

broadroot

face

400

600

1

b

4

2 c

6

h 1= h

2 =

13

-

~

600111

141

symme

trical

X

2.

5.

1

~

13

-400

600 111

1411~

600

2~600

2.

5.

2

> 10 asymmetrical

X 400

1

600

400

2

600

1

b 3 2

~

13

-





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1b

3

111

13

2.6 > 12

Singl

e-U

butt

weld

with

backi

ng

run

80

120

3

~ 5 -141

c

Root

runmay

be

necess

ary

2.7 30

Doub

le-U

butt

weld

80

120 3 ~ 3

~ 111

13

141

This

type of

joint

preparat

ion can

also be

produce

d

asymme

tri-cally

in a

similar

manner

to the

asymmetrical X

butt

weld

2.83 t

30

Singl

e-

bevel

butt

350

600

1b

4 2 -

111

13

141

Root

run may

be

necessar

y





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2.

9.

1

2.

9.

2

> 10

T-joint

both

sides

bevell

ed

prepar

ation

350

600

1b 4

2

=

sau

=

111

13

141

This

type of

joint

preparation

can

also be

produc

edasymm

etric-

ally in

a

similar

manne

r to the

asymm

etrical

X

2.

10> 16

Single

-J butt

weld

with

backing run

100

200

1b

32 -

111

13

141

Root

run

may be

necess

ary





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> 30

2

=

< 2

~

111

13

141

2.

11

170

Doub

le- J

buttweld

for

singl

e

pass

weldi

ng

process

100

200

3

51

This

type of

joint

preparation

can

also be

produc

edasymm

etric-

ally in

a

similar

manne

r to the

asymm

etrical

X

Joint preparation for T - joints, welded from one side

Dimensions

Ref

.

No.

Workpi

ecethickne

ss

t

mm

Designa

tion

Symbol

ISO

2553

Cross sectionAngle

,

Gap

b

mm

Welding

process

ISO

4063

Illustratio

n

3.1.

1

t 1 > 2

t 2 > 2

Single

fillet

weld

700

1000

2

3

111

13

141

3.1.

2

t 1 > 2

t 2 > 2

Single

fillet

weld

- 2

3

111

13

1413.1.

3

t 1 > 2

t 2 > 2

Single

fillet

weld 60 0

1200

2

3

111

13

141





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Dimensions

Ref.

No.

Workpi

ece

thickness

tmm

Design

ation

Symbol

ISO

2553

Cross sectionAngle

,

Gap

b

mm

Weldingprocess

ISO

4063

Illustratio

n

4.1.

1

t 1 > 3

t 2 > 3

Single

fillet

weld

70 0

1000

2

3

111

13

1414.1.

2

t 1 > 2

t 2 > 5

Single

fillet

weld2

t1 4

2

t2 4

60 0

120

0

-

3

111

13

141

2

4.1.

3

t 1 > 4

t 2 > 4

Singlefillet

weld

-

-

3

111

13

141

Role of inspection and quality control (B9)

To ensure that a product has the right level of quality, some form of inspection is often required.

This can involve such things as measuring the dimensions of a welded part. The measurement result

is then compared with the applicable requirement for the welded part in question. If the

requirements are fulfilled, the part can be approved. If the requirements are not fulfilled, the partwill not be approved. A standard definition of Inspection is: "Measurement, investigation, testing orother classification of one or more characteristics or properties of a product and the comparison of

the results with set requirements to determine whether they are fulfilled".

Accreditation

Within the European system, there are a number of standards (EN 45000 series) that include

regulations for testing the ability of inspection organs. Its aim is to ensure that inspection organs in

Europe carry out equivalent assessments so that the results can be approved by all the member

countries. The inspection organs that are approved according to these requirements become

accredited for a certain task.

The following bodies can be accredited:

1 Laboratories.





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2 Certification organs for products, quality systems, personnel.

3 First, second and third party inspection organs.

Welding is a special process, which requires the coordination of welding operation in order to

establish confidence in welding fabrication and reliable performance in service. The tasks andresponsibilities of personnel involved in welding related activities, e.g. planning, executing,

supervising and inspection, needing to be clearly defined. Welding coordination requirements can

be specified by a manufacturer, contract or an application standard.

Quality controlThe operations of a company are controlled to give products the right level of quality. This means

that the daily activities follow the company's quality system, applying the directions contained inthe quality manual and the instructions that are to be available at each workplace. One example of

quality control is the application of welding procedure specification (WPS) in order to obtain the

right level of quality in welds.

Quality control as applied to welded products includes those activities which monitor the quality ofthe product the operational techniques of checking materials, dimensional checks, inspection

before, during and after welding, non-destructive testing, hydraulic or leak testing in other words,

activities which take place after the event and which check that everything has been carried out

correctly.

Introduction to ISO 3834 (B9)

ISO 3834: Quality requirements for fusion welding of metallic materials

ISO 3834 consists of 5 parts, under the general title Quality requirements for fusion welding of

metallic materials:

-Part 1: Criteria for the selection of the appropriate level of quality requirements

-Part 2: Comprehensive quality requirements-Part 3: Standard quality requirements

-Part 4: Elementary quality requirements

-Part 5: Applicable documents

ISO 3834 is not a quality management system standard replacing ISO 9001:2000 but a useful toolwhen ISO 9001:2000 is applied by welding manufacturers.

ISO 3834 identifies measures that are applicable for different situations. They may be applied in the

following circumstances:

- in contractual situations: specification of welding quality requirements;

- by manufacturers: establishment and maintenance of welding quality requirements;

- by committees drafting manufacturing codes or application standards: specification of welding

quality requirements;

- by organizations assessing welding quality performance, e.g. third parties, customers, ormanufacturers.

ISO 3834 can be used by internal and external organizations, including certification bodies, to

assess the manufacturer's ability to meet customer, regulatory or the manufacturers own

requirements.

ISO 3834 therefore provides a method to demonstrate the capability of a manufacturer to produce

products of the specified quality.

It was prepared such that:

a) it is independent of the type of construction manufactured;





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b) it defines quality requirements for welding in workshops and/or on site;

c) it provides guidance for describing a manufacturer's capability to produce constructions to meetspecified requirements;

d) it provides a basis for assessing a manufacturers welding capability.

ISO 3834 is appropriate when demonstration of a manufacturer's capability to produce welded

constructions, fulfilling specified quality requirements, is specified in one or more of the following:

- a specification;

- a product standard;

- a regulatory requirement.The selection of the appropriate part of ISO 3834 should be in accordance with the product

standard, specification, regulation or contract.

The manufacturer selects one of the three parts specifying quality requirements based on the

following related to products:

- the extent and significance of safety-critical products;- the complexity of manufacture;

- the range of products manufactured;

- the range of different materials used;

- the extent to which metallurgical problems may occur;- the extent to which manufacturing imperfections, e.g. misalignment, distortion or weld

imperfection, affect product performance.

A manufacturer that demonstrates compliance to a level of this document is also considered to have

established compliance to all lower levels without further demonstration (e.g. a manufacturer

compliant to ISO 3834-2 demonstrates compliance with ISO 3834-3 and ISO 3834-4).





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Summary comparison of ISO 3834, Parts 2, 3 and 4

The manufacturer shall review the contractual requirements and any other requirements, together

with any technical data provided by the purchaser when the construction is designed by the

manufacturer. The manufacturer needs to establish that all information necessary to carry out the

manufacturing operations is complete and available prior to the commencement of the work.

The manufacturer shall affirm its capability to meet all requirements and shall ensure adequate

planning of all quality-related activities. A review of requirements shall be carried out by the

manufacturer to verify that the work content is within its capability to perform, that sufficient

resources are available to achieve delivery schedules and that documentation is clear and

unambiguous.

The manufacturer shall ensure that any variations between the contract and any previous quotationare identified and the purchaser notified of any programme, cost or engineering changes that may

result.

Items considered at or before the time of the review of requirements review:

a) The product standard to be used, together with any supplementary requirements;





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b) Statutory and regulatory requirements;

c) Any additional requirement determined by the manufacturer;d) The capability of the manufacturer to meet the prescribed requirements.

Sub-contractingWhen a manufacturer intends to use sub-contracted services or activities (e.g. welding, inspection,

NDT, heat treatment), information necessary to meet applicable requirements shall be supplied by

the manufacturer to the sub-contractor.

The sub-contractor shall provide such records and documentation of his work as may be specified

by the manufacturer.A sub-contractor shall work under the order and responsibility of the manufacturer.

The manufacturer shall ensure that the sub-contractor can comply with the quality requirements asspecified.

The information provided by the manufacturer to the sub-contractor shall include all relevant data

from requirements review and technical review. Additional requirements may be specified as

necessary to assure sub-contractor compliance with technical requirements.

Welding personnel

The manufacturer shall have at his disposal sufficient and competent personnel for the planning,

performing and supervising of the welding production according to specified requirements.Welders and welding operators shall be qualified by appropriate tests.

The manufacturer needs to have appropriate welding coordination personnel. The weldingcoordinator shall have sufficient authority to enable any necessary action to be taken.

Inspection and testing personnel

The manufacturer shall have at his disposal sufficient and competent personnel for planning,

performing, and supervising the inspection and testing of the welding production according tospecified requirements.

The non-destructive testing personnel shall be appropriate qualified/certified. When a qualification

test is not required, competence shall be verified by the manufacturer.

Inspection and testing

Applicable inspections and tests shall be implemented at appropriate points in the manufacturing

process to assure conformity with contract requirements. Location and frequency of such

inspections and/or tests will depend on the contract and/or product standard, the welding process

and the type of construction.

Inspection and testing before welding

Before the start of welding, the following shall be checked:

- suitability and validity of welders qualification certificates;

- suitability of welding-procedure specification;- identity of parent material;

- identity of welding consumables;- joint preparation (e.g. shape and dimensions);

- fit-up, jigging and tacking;

- any special requirements in the welding-procedure specification (e.g. prevention of distortion);

- arrangement for any production test;

- suitability of working conditions for welding, including environment.





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Inspection and testing during welding

During welding, the following shall be checked at suitable intervals or by continuous monitoring:- essential welding parameters (e.g. welding current, arc voltage and travel speed);

- preheating/interpass temperature;

- cleaning and shape of runs and layers of weld metal;- back gouging;

- welding sequence;

- correct use and handling of welding consumables;

- control of distortion;

- any intermediate examination (e.g. checking of dimensions).

Inspection and testing after weldingAfter welding, the compliance with relevant acceptance criteria shall be checked:

- by visual inspection;

- by non-destructive testing;

- by destructive testing;- form, shape and dimensions of the construction;

- results and records of post-weld operations (e.g. post-weld heat treatment, ageing).

Inspection and test statusMeasures shall be taken, as appropriate, to indicate, e.g. by marking of the item or a routing card,

the status of inspection and test of the welded construction.

Non-conformance and corrective actions

Measures shall be implemented to control items or activities, which do not conform to specified

requirements in order to prevent their inadvertent acceptance. When repair and/or rectification is

undertaken by the manufacturer, descriptions of appropriate procedures shall be available at allworkstations where repair or rectification is performed. When repair is carried out, the items shall

be re-inspected, tested and examined in accordance with the original requirements. Measures shall

also be implemented to avoid recurrence of non-conformances.

Calibration and validation of measuring, inspection and testing equipment

The manufacturer shall be responsible for the appropriate calibration or validation of measuring,

inspection and testing equipment. All equipment used to assess the quality of the construction shall

be suitably controlled and shall be calibrated or validated at specified intervals.

Identification and traceability

Identification and traceability shall be maintained throughout the manufacturing process, if

required.

Quality records

Quality records shall include, when applicable:- record of requirement/technical review;

- material certificates;

- welding consumable certificates;

- welding-procedure specifications;

- equipment maintenance records;

- welding-procedure qualification records (WPQR);- welder or welding-operator qualification certificates;

- production plan;





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- non-destructive testing personnel certificates;

- heat-treatment procedure specification and records;- non-destructive testing and destructive testing procedures and reports;

- dimensional reports;

- records of repairs and non-conformance reports;- other documents, if required.

Quality records shall be retained for a minimum period of five years in the absence of any other

specified requirements.

Application

Conformity to ISO 3834-2 to 4 shall be claimed by a manufacturer using the normative references

given in this part. Conformity to ISO 3834-2 to 4 may also be claimed by adopting other standardsthat provide equivalent technical conditions.

Where other standards are adopted, they should only be used when they are referenced in product

standards for constructions being made by the manufacturer.

It is the responsibility of the manufacturer to demonstrate technically equivalent conditions whennormative references other than those listed in this part are applied. Certificates issued following

assessment by independent certification organizations or claims of compliance by a manufacturer

with any part of ISO 3834 shall clearly identify the normative references or specifications used by

the manufacturer.

Stainless steel compared to unalloyed steel and aluminium alloys (PSS1)

The consumption of stainless steel is increasing and will continue to do so. The reason of growth is

increasingly demanding environment in the petrochemical industry and the process industry.

Demand for these materials is also growing in industrial sectors such as foodstuffs, electronics,

biochemistry and nuclear power.Stainless steel have also replaced other structural materials in many applications where it has been

realized that stainless steel is cheaper in the long term, if both capital outlay and maintenance costs

are taken into account.Two types of stainless steel have been more and more important: ferrite-austenitic (duplex) and

fully-austenitic steels.The advantages of duplex steel are as follows:

- good weldability- considerably higher yeld strength- good resistance to stress corrosion, above all, but also to general corrosion and

pitting.

Aluminum and aluminum alloys are structural materials with many good properties: with a proper

design they do not corrode, they conduct electricity and they combine strength with low weight.Aluminum is considered to be a very important construction material in the future, especially in the

automotive industry.

Definition of stainless steel

Stainless steels are defined as iron base alloys, which contain at least 11 % chromium.

There are fivetypes of stainless steels depending on the other alloying additions present, and they

range from fully austenitic to fully ferritic.

Identification of stainless steel

The most important property of the high-chromium stainless steels is their corrosion resistance,





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without which they would find little commercial use, as their general level of mechanical properties

and forming characteristics can be equaled or exceeded by many other types of steel at a muchlower cost. A chromium content above 12% also provides a considerable measure of oxidation

resistance.

Thus the stainless steels are used for both corrosion resisting and high-temperature creep resistingand heat resisting applications, the temperature of application usually increasing with increasing

chromium content.

The important factors, which must be considered in the design of the various types of stainless

steels, are:

- corrosion and oxidation resistance in the operating environment- mechanical and physical properties

- fabrication characteristics from the point of view of both hot and cold working- welding - many of the stainless steels are required to be readily weldable, and welding must not

impair the corrosion resistance, creep resistance or general mechanical properties.

There are many different stainless steels, see figure, and the main types are listed below.

a) Ferritic steels, containing 11,5 30% Cr, up to 0,20% carbon, no nickel and often some

molybdenum, niobium or titanium. They are ferritic at all temperatures and, therefore, do nottransform to austenite and are not hard enable by heat treatment.

Some of these can be highly corrosion resistance, and being fully ferritic are reasonably formable.

They can in the less severe applications, replace the more expensive austenitic stainless steels.They are characterized by weld and HAZ grain growth, which can result in low toughness of welds.

To weld the ferritic stainless steels, filler metals should be used which match or exceed the Cr levelof the base alloy.

To minimize grain growth, weld heat input should be minimized and preheat should be limited, and

used only if necessary.

b) Martensitic steels containing 11 18% Cr, 0 4% Ni, 0,1 1,2%C, and sometimes additions of

molybdenum, vanadium, niobium, aluminum and copper. These are often alloyed to produce therequired tempering resistance and strength. They are austenitic at temperatures of 950 1000 o C

but transform to martensite on cooling, and the high hardenability makes them martensitic air





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hardenable even in large section sizes.

This can lead to difficulty in softening for machining and fabrication, particularly as they frequentlyalloyed to produce a high degree of tempering resistance.

The steels are usually tempered to produce useful combinations of strength, ductility and toughness,

and may be precipitation hardened.They have a tendency toward weld cracking on cooling when hard brittle martensite is formed.

Chromium and carbon content of the filler metal should generally match these elements in the base

metal.

Preheating and interpass temperature in the 204 to 316 o C range is recommended for most

martensitic stainless steel.Steel with over 0,20 % C often require a post weld heat treatment to soften and toughen the weld.

c) Austenitic steels which contain 16 26% Cr, 8 20% Ni, up to 0,40% C. These steels also often

contain additions of molybdenum, niobium or titanium and are predominantly austenitic at all

temperatures, although depending o the composition and consequent constitution, some delta ferrite

may be present.The austenite may have a varying degree of stability with respect to the formation of martensite,

being transformed by cold work at room temperature in some compositions.

The balance between the Cr and Ni + Mn is normally adjusted to provide a microstructure of 90 -

100% austenite.These alloys are characterized by good strength and high toughness over a wide temperature range

and oxidation resistance to over 538oC.

Filler metal for these alloys should generally match the base metal but for most alloys, provide a

microstructure to avoid hot cracking.

Two problems are associated with welds in the austenitic stainless steels:

- sensitization of the weld heat affected zone

- hot cracking of weld metal.

d)Precipitation hardening stainless steel are martensitic, semiaustenitic and austenitic.

The martensitic stainless steel can be hardened by quenching from the austenitizing temperature(around 1038 o C) then aging between 482 to 621 o C. Since these steels contain less than 0,07% C,

the martensite is not very hard and the main hardening is obtained from the aging (precipitation)reaction.

The semiaustenitic stainless steel will not transform to martensite when cooled from the

austenitizing temperature because the martensite transformation temperature is below room

temperature. These steels must be given a conditioning treatment which consists heating in the

range of 732 to 954 o C to precipitate carbon and/or alloy elements as carbides or intermetallic

compounds.

The austenitic precipitation hardening stainless steel remains austenitic after quenching from the

solutioning temperature even after substantial amounts of cold work. They are hardened only by theaging reaction. This would include solution treating between 982 to 1121 o C, oil or water

quenching and aging at 704 to 732oC for up to 24 hours.

If maximum strength is required in martensitic precipitation hardening stainless steels, matching or

nearly matching filler metal should be used and the component, before welding, should be in the

annealed or solution annealed condition. After welding, a complete solution heat treatment plus an

aging treatment is preferred.

The austenitic precipitation hardening stainless steel are most difficult to weld because of hot

cracking. Welding should preferably be done with the parts in the solution treated condition, underminimum restraint and with minimum heat input.





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e) Duplex stainless steel are the most recently developed group of stainless steel and have a

microstructure of approximately equal amounts of ferrite and austenite.These steels have advantages over the conventional austenitic and ferritic steels in that they offer

higher strength and greater stress corrosion cracking resistance.

The duplex microstructure is attained in steels containing 21 - 25% Cr and 5 7 % Ni by hotworking at 1000 to 1050 o C followed by water quenching. Weld metal of this composition will tend

to be mainly ferritic because the deposit will solidify as ferrite and will transform only partly to

austenite without hot working or annealing.

The alloying elements which appear in stainless steels are classed as ferrite formers and austeniteformers:

Ferrite formers

Chromium - provides basic corrosion resistance Molybdenum - provides high temperature strength and increases corrosion

resistance

Columbium, Titanium - strong carbide formers Phosphorous, Sulfur, Selenium - improves machinability, causes hot cracking

in welds

Austenite formers

Nickel - provides high temperature strength and ductility Carbon - carbide former, strengthener Nitrogen - increases strength, reduces toughness

The working environment of the fabrication shop, general hazards, dust, heavy and hot

material, cables (A4)

The welding processes are characterized by high temperatures, extensive fumes, light and heatradiation and risks from electric power. All these phenomena can endanger welder health, and

potentially they are also dangerous for the environment.

The basic task for health and safety is to eliminate these dangerous aspects of welding.

General Hazards

The general hazards in welding and cutting are:

Fire from sparks and spatter

Explosion and fires from reaction with welding gases

Asphyxiation

Electric shock

Inhaling toxic fumes and gases

Eye injuries from heat rays

There are many regulations regarding safety in welding, which are derived from more general

safety regulations, like 'General rules for hygienic and technical safety measures at work' and'Regulations for personal safety means'. Every welder has the right and obligation to be protected

under these regulations.

The owner/operator is obliged to have a safety inspection performed on the welding equipments at

least once every 12 months.

A safety inspection, by a trained and certified electrician, is prescribed:- after any alterations

- after any modifications or installations of additional components





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- following repairs, care and maintenance

- at least every twelve months.

Measures - technical devices and equipment

When planning a workplace, the working height plays an important part in creating the correctworking position. In this context, positioners and lifting tables can be very useful. The working

position is partly determined by the welders need to have his/her eyes close to the workpiece to be

able to see the molten pool clearly while welding. If the working height is too low, the welder has to

bend to see properly. A chair or stool might then be very useful. Working with the hands in a high

position at or above shoulder level should be avoided whenever possible.In conjunction with heavier welding, the gun and hoses are also heavier and the load on the body is

more static. A balanced load-reduction arm is very useful in this situation. Lifting the hoses off thefloor also protects them from wear and tear, as well as facilitating wire feed.

It is also a good thing if the workpiece is placed in a positioner and is positioned to ensure the best

accessibility and height. A more comfortable working position can be created and, at the same time,

welding can be facilitated as the joint is in the best welding position.Roller beds can be used for welding tubes or other cylindrical items. A hook or some other device

on which the welding gun can be placed when it is not in use is another valuable piece of

equipment.

Hot work exposes workers to:- Molten metal

- Toxic gases- Fumes and vapors

- Harmful radiation

- Excessive noise

- Electrical shock- Fire hazards.

Appropriate personal protective equipment (PPE) must be selected to protect the worker from these

hazards. Fire watches in the area are required.

Hot work operations include:- Gas Welding and Cutting

- Electric Arc Welding

- Carbon Arcing or Plasma Arc Cutting

Each of these operations may present unique hazards.

Electro- magnetic effectsCurrent gives rise to a magnetic field around the conductor. The magnetic field is stronger closer to

the conductor and rapidly subsides as the distance increases. A magnetic field is created around thewelding cable and earth cable when welding is in process.

Studies have indicated that one should not be exposed to strong magnetic fields. However, there is

no evidence of any injuries. No limits have been yet set.

Recommendations: You should make sure that as little as possible of the welding cable is directly

adjacent to your body when welding. If you are right-handed, the welding machine should be placed

on your right-hand side to avoid laying the welding cable on your lap or around your body. It is not

a good idea to rest the welding cable around your body while erection welding (with the weldingmachine on the ground).

Do not forget that MAGNETIC FIELDS can affect pacemakers and hearing aids.





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Recommendations:- Pacemaker wearers keep away.

- Wearers should consult their doctor before going near arc welding, gouging, or spot welding

operations.

Ancillary measures for preventing EMC problems:

a) Mains supply

- If electromagnetic interference still occurs, despite the fact that the mains connection is in

accordance with the regulations, take additional measures (e.g. use a suitable mains filter).

b) Welding cables- Keep these as short as possible

- Arrange them so that they run close together (to prevent EMI problems as well)

- Lay them well away from other leads.

c) Equipotential bondingd) Workpiece grounding (earthing)

- where necessary, run the connection to ground (earth) via suitable capacitors.

e) Shielding, where necessary

- Shield other equipment in the vicinity

Shield the entire welding installation.

Handling of stainless steel in the workshop and the use of tools for stainless steel (PSS2)

For welding of stainless steels we have to respect following:- welding will be made in special arranged spaces, where no other type of steel or material or

alloys will be welded;

- the necessary tools and devices for welding and cleaning must be form stainless steel inorder to avoid surfaces pollution elements welded;

- an accentuate cleaning of the elements and equipments has to be maintained; touching of thecomponents will be made only with white cotton gloves in order to avoid surfaces

degradation through impurities, dust ,metallic powder, oils;

- components manipulation will be carefully realized to avoid the damaging of the surfaces;- in welding spaces air currents have to be avoid;- welding has to be stopped if the outside temperature is bellow than + 5 C.





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Example of stocking pipes and fittings, separating steel and stainless steel .





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MODULE 3

Personal protective equipment and clothing (A3)

Personal protective equipment especially designed for the task at hand must always be used when

arc welding. Protective clothing must not be heavily soiled or torn.

1.Head Protection

This provides protectiona) against falls (e.g. crash helmets, cycle helmets, climbing helmets)

b) against falling objects or against striking fixed objects

c) against striking fixed objects (e.g. objects in confined spaces).

2. Eye Protection

Welding helmet

A welding helmet must always be worn when welding to protect the eyes and face from radiation

and welding spatter.The welding helmet can be lowered in front of the face. The lens should be lowered using one hand

instead of the "chin-up" method as repeated nodding can cause neck injuries.

Welding lenses

Welding helmets and welding lenses both have dark glass, so-called welding lenses. The welding

lens is used to filter out UV and IR radiation. Only visible light is allowed to pass the lens.

Lens protector

Lens protectors are used in welding helmets and shields to protect the welding lens from spatter.

Automatic welding lenses

Automatic anti-dazzle welding lenses are also available. This type of welding lens darkens

automatically the moment the arc is ignited and becomes lighter again when the arc is extinguished.Automatic welding lens can be set to different densities.

Welding helmet with fresh-air supply

Equipment is available for supplying fresh and cool air to the welding helmet. The positive pressure

created inside the welding helmet prevents weld smoke from mixing with the air the welder inhales.

Comfort is also enhanced and mist is prevented from forming on the welding lens.

Relevant standards:

a) EN169 welding filters

b) EN175 welding eye protectors

Always choose eye protection appropriate to the hazard and ensure that fits properly and is

comfortable.Dirty lenses impair vision, causing eye fatigue and leading to accidents. The plastic lenses of eye

protectors should be wet cleaned to avoid scratching; scratched lenses should be replaced, as should

face shields if they become crazed or brittle with age.

Safety spectacles and goggles should be issued on a personal basis and should be thoroughly

cleaned before issue to someone else.

3. Foot Protection

Safety footwear should comply with EN 345 (with toe protection of 200 or 100 joules). Footwear

with anti-static or slip resistant properties should conform to EN 347.The choice of safety footwear should first be made on the basis of the protection required, but

comfort is a significant issue and should not be ignored. Care should be taken in the choice of anti-static and conductive footwear. Both give protection against the hazard of static electricity and anti-

static footwear also gives some protection against electric shock. However conductive footwear





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Welder equipped with personal protection equipment.

In addition to the general protective clothing for welding and cutting operations, arc welding

requires the following extra clothing: Wear clothes made of materials heavy enough to protect against ultraviolet rays.

Wear dry welders gloves to protect against shock and electrocution.

Noise hazards (A3)

Noise is usually defined as undesirable sound and is a health hazard. Noise can cause hearing

damage. Disturbing noise levels in combination with requisite ear defenders can make it difficult to

communicate, which may lower the level of enjoyment in the workplace. Psychological well-being

is also affected by noise.

Noise abatement

Sources of noise in a welding workshop are grinding, slagging and beating. This kind of work must

be minimized. When grinding or hammering must be performed the use of equipment and aids thatgive the lowest possible noise levels is requested.

Clang dampers

It is the workpiece that generates most noise during grinding, slagging and beating. Using clang

dampers will reduce the noise level considerably. Clang dampers are elastic dampers with a

magnetic layer for fastening on the workpiece.

Silenced machines

Quieter hand-held machines have been developed during the last few years. Pneumatic slag picks

and grinding machines are now fitted with silencers. Quieter grinding discs have been developed.

Using modern equipment will reduce the noise level considerably.Noise absorbing screens

Screens made of porous material such as mineral wool erected between the welding areas can limit

the noise in many cases. The screen must be high and wide and located as close as possible to the

source of the noise. By erecting absorbers above and beside the screen, noise can be reduced at





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longer distances.

Ear defendersIn many welding shops the noise level is so high that ear defenders must always be used. Wearing

ear defenders of down or earplugs will provide basic protection against background noise and

unexpected sound. The noise level when slagging and beating is so high that ear cups are required.It is essential to wear ear defenders all the time in extremely noisy environments. Even short

periods without protection can risk damaging your hearing. A hearing impairment cannot be cured.

Resume: Noise of 85 db (A) or higher might lead to hearing damage

Safety measures:

- noisy techniques to be substituted by quieter ones- protection from sound waves - isolation- spatial division

- marking noisy areas- personal safety equipment (ear phones)- medical prevention and ambulanceIf the 85 db (A) level is reached - one must posses personal hearing protection equipment

Above the level >90 db (A), standard noise protection is required for all employees.

Suitable cutting processes for different types of steel to achieve a suitable cutting surface (A8)

The three thermal cutting methods: flame cutting, plasma cutting and laser cutting are widespread

and well known to most people.

'

Flame cutting, Principle and parameters, cutting blowpipes, cutting machines, quality of cutsurface

Flame cutting is the traditional and clearly predominant method, but its use is slightly declining

because of the increase in laser cutting and plasma cutting. Flame cutting remains a very usefulcutting method, partly owing to its versatility. It covers the entire thicknesses range from 3 to 300

mm for unalloyed steels. By using special torches the field of application can be extended to

thicknesses of up to 1000 mm or even more. The quality of cut is excellent when the cutting

parameters are correctly set. In economic terms, flame cutting is clearly an alternative where

numerically-controlled machines are used in conjunction with several torches in order to increasethe productivity per employee.

Other cutting processes as: plasma, laser, mechanical cuttingLaser cutting give a high-quality cut, narrow kerfs and low heat transfer to the workpiece. The

economic thickness for unalloyed steel is 2 to 3 mm. The use of laser cutting will increase, mainly





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due to increased laser power output, which will enable thicker material thicknesses to be cut.

The economic material thickness range for plasma cutting is 3 to about 20 mm. In this range plasmais faster then laser, but the quality of cut is not comparable. In an effort to compete with laser

cutting, recent developments in plasma cutting have aimed to produce a system which is capable of

producing cuts with completely square edges and narrow kerf width to enable higher cuttingaccuracy to be achieved.

The resulting systems are commonly known as high tolerance plasma cutting and are characterized

by torches having high current density cutting arcs.

Smaller sets intended for manual cutting are usually air plasma, whilst larger mechanized

installation use oxygen, nitrogen or argon mixtures as the plasma gas. Plasma power sources above300 amps never use air.

In connection with subsequent welding of air-plasma cut edges, weldability problems like poreformation and lack of fusion have been noticed. Investigations have shown that high concentrations

of nitrogen in the cut edges are responsible for the problems. There are different ways to avoid the

problems. One is to grind off the thin layer of the cut surface that has a high nitrogen concentration.

This is an expensive method and it will reduce the productivity. Another way is to cut with oxygenplasma.

An alternative to the thermal cutting methods is water jet cutting. The method emerged during the

1970s, when it was used to cut composites. Since then it has been developed to cut metals. This wasmade possible by adding abrasives to the jet, a technique known as abrasive water jet cutting. Using

water jet cutting without abrasives it is possible to cut, in addition to composites, materials such asleather, rubber, textiles, wood, mineral wool and frozen foodstuffs. Abrasive water jet cutting can

be used to cut sheet metal in gouges up to 50 mm, concrete up to 200 mm, stone and ceramics.

Abrasive water jet cutting competes to some extent with the thermal methods, but as figure 1

shows, the cutting speed is very low, so the method is only competitive where some particular

technical advantage can be exploited. Examples of such advantages are that the quality of cut isvery good and that no heat is transferred into the workpiece the latter feature means that there are no

deformation of the workpiece. Abrasive water jet cutting is also a suitable method for cutting

surface treated materials like Zn, AlZn or polymer coated sheet metal, since this cutting method willminimize destruction of surface treatment.





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Safety precautions for cutting (PSS1)

In the table 1 are presented the representative cutting speed for different cutting methods.

Cutting speed (mm/min)

Materials

Plate

thicknesses

(mm)Flamecutting

Plasmacutting

Lasercutting

Abrasivewater jet

cutting

Steel

Steel

Stainless

steel

Stainless

steelAluminum

Aluminum

5

20

3

402

40

850

660

-

--

-

4500A

2000A

5000B

500B>6000B

1200B

2200 C

-

6500

-1000 C

-

200

50

200

10-20800

80

A - Nitrogen plasma with water injected, 500 A

B - Gas plasma (Ar/H2), 240 A

C - Carbon dioxide laser 1000W, with oxygen as cutting gas

Table 2 showsthe cutting methods for different materials.

Table 2

Material

Cutting method Mild steels Stainless

steels

Aluminum Titanium

Flame

Plasma

Laser

MechanicalWater jet

+++

+++

+++

++++

+++

+++

++++

+++

++

+++++

++

++

+++

++++

+++ well suited

++ suited

+ possible

Burns and fires, fire prevention, fire fighting (A3)

The basic precautions for fire prevention in welding or cutting work are:Cutting or welding must be permitted only in areas that are or have been made fire safe.

When work cannot be moved practically, as in most construction work, the area must be made safeby removing combustibles or protecting combustibles from ignition sources.

If the object to be welded or cut cannot readily be moved, all movable fire hazards in the vicinity

must be taken to a safe place.

If the object to be welded or cut cannot be moved and if all the fire hazards cannot be removed, then

guards must be used to confine the heat, sparks, and slag, and to protect the immovable fire hazards.

If these requirements cannot be followed then welding and cutting must not be performed.Suitable fire extinguishing equipment must be maintained in a state of readiness for instant use.

Such equipment may consist of pails of water, buckets of sand, hose or portable extinguishers





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2009.02.11 39 of 100

depending upon the nature and quantity of the combustible material exposed.

Fire watchers must have fire-extinguishing equi

Documents

Stainless Steel Course Modules Compressed(2)