Asme section ix

04/10/23 ASME Section-IX 1

ASME Section IX

By

Joseph Davis


WELDING QUALIFICATIONS AND WELDING QUALIFICATIONS AND ESTABLISHING WPS.ESTABLISHING WPS.

• ASME Section IX relates to qualification of welders, welding operators, brazers and brazing operators and the procedures that they employ in welding and brazing.

• It is divided in two parts, part QW gives requirements for welding and part QB contains requirements for brazing. We shall deal only with part QW.


WPS & PQRWPS & PQR

• The purpose of welding procedure specification (WPS) and procedure qualification records (PQR) is to determine that the weldment proposed for construction is capable of providing the required properties for its intended application.

• WPS is intended to provide direction for the welder and lists the variables, both essential and non essential and the acceptable ranges of these variables when using the WPS.


WPS & PQRWPS & PQR

• It is presumed that welder or welding operator performing the welding procedure qualification test is skilled workman so that welding procedure qualification test establishes the properties of weldment and not the skill of the welder.

• The purpose of performance qualification is to determine if the welder is able to deposit sound metal or the welding operator is able to operate welding equipment properly.


Part QWPart QW

Part QW is divided into 4 articles.• Article I -Welding general requirements• Article II-Welding procedure qualifications• Article III-Welding performance qualifications• Article IV-Welding data


Test PositionTest Position

Before we proceed let us first understand various

test position in groove welds in plates, groove welds

in pipes and fillet weld in plates etc.

In general,• 1G or 1F is called flat positions• 2G or 2F is called horizontal and circumferential• 3G or 3F is called vertical position • 4G or4F is called overhead position



Test PositionTest Position

• Position 5G is only in welds in pipes. It is a position when pipe axis is held horizontal and circumferential seam is welded without rotating. In a way it is combination of 1G, 3G & 4G.

• Position 6G is also for the pipes when pipe axis is at 45 deg. to horizontal plane and circumferential seam is welded without rotating the pipe. It is combination of all positions.


Position for groove & fillet weldPosition for groove & fillet weld

• Fig. 461.1- is the diagram defining the position for groove welds depending on the inclination of the axis of the weld and the angle of rotation of the face of the weld.

• There is similar fig. 461.2 giving position for fillet welds.




• Fig. 451.1 gives the thickness limits and the type and number of the test specimen required for procedure qualification of groove


• In case of weld between dissimilar materials where it is difficult to carry out bending so that weld is at the center of convex position, transverse bends are replaced by longitudinal bends and the fig. look like (Refer fig. 463.1 c)


• Fig.451.3 & 451.4 Give the test required to fillet test and fig.462.4 a,d (it is similar except that instead of bend there is macro examination of 2 section of ¼ section)


Cont.Cont.




• Refer fig.452.1,that gives performance qualification limits and type and number of the test specimen required table. Fig 452.3 gives the diameter limits. It is worth noting that one, two or more welders can be qualified on just one test coupon. Each may be using even different processes.




• Refer fig. 462.4 B & C that gives the requirements for performance qualification of fillet welds.



• Refer fig. 461.9 that gives performance qualification position and diameter limits.



Radiographic acceptance standards


Cont-


Welding VariablesWelding Variables

• Article (IV) gives data about various types of welding variables. It also gives tables for various welding processes showing essential variables, supplementary essential variables and non essential variables for procedures qualification; and essential variables for performance qualification.


Cont.Cont.

• Essential variables for procedure are those welding variables whose change will affect the mechanical properties (other than notch-toughness) of the weldment (ex. Change in P-number, filler metal, electrode type, preheat post heat etc.)


Cont.Cont.

• Supplementary essential variables for procedure are those welding variables whose change will affect the notch toughness properties of weldment (ex. Uphill or down hill vertical welding, heat input, preheat or PWHT)


Cont.Cont.

• Non essential variables for performance are those welding variables which will not affect the mechanical properties of weldment (ex. Joint design, method of back gauging or cleaning etc.)


Cont.Cont.

• Essential variables for performance are those welding variables which will affect the ability of welder to deposit sound weld (e.g. position, deletion of backing F-number etc.

• Change in process is essential variable for procedure as well as performance.


Have look on some essential variables tables.


Welding variables WPQWelding variables WPQ


Let us understand the term P-number A-number and F-number.

• All those materials are divided into various P-numbers depending on their nominal composition and further divided into groups depending on the type of refinement / min. specified UTS etc. QW-422 gives the full details.


Cont.

• Plain carbon steels, C-Si, Cr-Mn & C-Mn-Si are grouped as P-1 materials and austenitic stainless steel as P-8 material. Ferrous welding consumable are classified under various A-numbers based on their weld metal chemical composition (table 442) and all welding electrodes and welding rods are grouped in different F-number depending on their AWS classification which is based on type of flux and chemical composition (table 432)


QW-120 - TEST POSITIONS FOR GROOVE QW-120 - TEST POSITIONS FOR GROOVE WELDSWELDS

• Angular deviation of ±15 deg from the specified horizontal and vertical planes, and an angular deviation of ±5 deg from the specified inclined plane are permitted during welding.


QW-140 – TYPES AND PURPOSES OF TESTS QW-140 – TYPES AND PURPOSES OF TESTS AND EXAMINATIONSAND EXAMINATIONS

• Tension tests are used to determine the ultimate strength of groove-weld joints.

• Guided-bend tests are used to determine the degree of soundness and ductility of groove-weld joints.

• Toughness Tests are used to determine the notch toughness of the weldment.


QW-144 – VISUAL EXAMINATION

Visual examination is used to determine that the final weld surfaces meet specified quality conditions.


QW-150 – TENSION TESTSQW-150 – TENSION TESTS

• Thicknesses up to and including 1 in. (25 mm), a full thickness specimen shall be used for each required tension test.

• Cold straightening of the test coupon is permitted prior to removal of weld reinforcement


QW-153 – ACCEPTANCE CRITERIA, QW-153 – ACCEPTANCE CRITERIA, TENSION TESTTENSION TEST

• If the specimen breaks in the base metal outside of the weld or weld interface, the test shall be accepted as meeting the requirements, provided the strength is not more than 5% below the minimum specified tensile strength of the base metal.


QW-163 – ACCEPTANCE CRITERIA, BEND TEST

• Open discontinuity in the weld or heat-affected zone exceeding 1/8 in. (3 mm), measured in any direction on the convex surface of the specimen after bending. Open discontinuities occurring on the corners of the specimen during testing shall not be considered unless there is definite evidence that they result from lack of fusion, slag inclusions, or other internal discontinuities. For corrosion-resistant weld overlay cladding, no open discontinuity exceeding 1/16 in. (1.5 mm), measured in any direction, shall be permitted in the cladding, and no open discontinuity exceeding 1/8 in. (3 mm) shall be permitted along the approximate weld interface.


QW-184 MACRO-EXAMINATION, QW-184 MACRO-EXAMINATION, PERFORMANCE SPECIMENS PERFORMANCE SPECIMENS

• Visual examination of the cross section of the weld metal and heat-affected zone shall show complete fusion and freedom from cracks, except that linear indications at the root not exceeding 1/32 in. (0.8 mm) shall be acceptable.

• The weld shall not have a concavity or convexity greater than 1/16 in. (1.5 mm)

• There shall be not more than 1/8 in. (3 mm) difference in the lengths of the legs of the fillet


QW-201 MANUFACTURER’S OR QW-201 MANUFACTURER’S OR CONTRACTOR’S RESPONSIBILITYCONTRACTOR’S RESPONSIBILITY

• Each manufacturer shall qualify the WPS by the welding of test coupons and the testing of specimens (as required in this Code), and the recording of the welding data and test results in a document known as a Procedure Qualification Record (PQR).


QW-251.2 Essential Variables

• Essential variables are those in which a change, as described in the specific variables, is considered to affect the mechanical properties of the weldment, and shall require requalification of the WPS.

• Supplementary essential variables are required for metals for which other Sections specify notch-toughness tests and are in addition to the essential variables for each welding process.


QW-251.3 Nonessential VariablesQW-251.3 Nonessential Variables

Nonessential variables are those in which a change, as described in the specific variables, may be made in the WPS without requalification.


Tables to be referredTables to be referred

1 QW461.3 Groove welds in test position

2 QW461.4 Fillet welds in plates test position

3 QW461.5 Fillet welds in pipe test position

4 QW462.1

A,b,c,d & e

Method of taking out test specimen

5 QW463.1

A,b,c,d,e,f

Method of taking out test specimen

6 QW451 Procedure qualification thk.limits

7 QW452 Performance qualification & test specimen

8 QW461.9 Performance qualification & diameter limits


Acceptance criteria, Procedure qualification

• QW153 Tension test

• QW163 Bend test

• QW183 Macro-Examination procedure

specimen

• QW184 Macro-Examination performance

specimen

• QW191 Radiographic Examination

Engineering

Asme section ix