AWS B4.0: 2007 Standard Methods for Mechanical Testing of Welds

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CLAUSE 10. WELDABILITY TESTING AWS B4.0:2007

(1) Base metal specification;

(2) Filler metal specification, size, and chemical

composition;

(3) Trough test specimen dimensions and thickness;

(4) Welding procedure (process and parameters);

(5) Shielding gas identification;

(6) Location of weld starts and stops;

(7) Preheat, interpass, and postweld thermal treatments

used;

(8) Description of thermal treatment found to elimi-

nate delayed cracking and/or reduced tensile ductility;

(9) Time delay and description for presence of

cracks;

(10) Method of examination for presence of cracks;

(11) Tension test ductility, if required; and

(12) Results of diffusible hydrogen test, if required.

Test data should be recorded on a Test Results Sheet

similar to Figure 10.8.3.

10.8.9 Commentary. There are other U.S. and ISO test

methods available whose objectives are to evaluate the

susceptibility of weld metal and consumables to hydro-

gen-assisted cracking. This test method is unique in that

it is intended to determine welding parameters and ther-

mal treatments to eliminate hydrogen-assisted cracking

in repair welds in thick section medium and high strength

alloy steel structures and components.

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AWS B4.0:2007 CLAUSE 10. WELDABILITY TESTING

Figure 10.8.1—Trough Test Specimen

Figure 10.8.2—Location of Weld Starts, Stops, and Tension Test Specimens (Side View)

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CLAUSE 10. WELDABILITY TESTING AWS B4.0:2007

TROUGH TEST RESULTS

Company Name _____________________________________________________________ Date _______________________

Job/Test No. ________________________________________________________________ Sheet _________ of __________

Description of Investigation ____________________________________________________________________________________

Base Metal Identification and Thickness__________________________________________________________________________

Base Metal Heat Treatment_____________________________________________________ Heat No. ____________________

Base Metal Composition:

C__________ Si __________ Mn ________ P __________ S__________ Cr__________ Mo ________

Ni _________ V __________ Cu_________ Nb _________ Ca_________ B __________ Ti _________

Al _________ N __________ _________ __________ _________ __________ _________

Weld Metal Composition ______________________________________________________________________________________

C__________ Si __________ Mn ________ P __________ S__________ Cr__________ Mo ________

Ni _________ V __________ Cu_________ Nb _________ Ca_________ B __________ Ti _________

Al _________ N __________ _________ __________ _________ __________ _________

Welding Process Procedure Spec. No. ___________________________________________________________________________

Electrode/Wire Spec. No. ______________________________ Commercial Name ____________________________________

Diameter ___________________________________________ Baking Treatment _____________________________________

Shielding Gas/Flux ___________________________________ Flow Rate/Flux Size ___________________________________

Current ____________________________________________ Ambient Temp. _______________________________________

Travel Speed ________________________________________ Ambient Humidity _____________________________________

Current ____________________________________________ Voltage _____________________________________________

Heat Input __________________________________________

Hydrogen Determination Method ________________________________________________ Date _______________________

Result ____________________________________________________________________________________________________

Results:

Results (cracking free welding and thermal treatment)_______________________________________________________________

Tested By __________________________________________________________________

Signature___________________________________________________________________ Date _______________________

Figure 10.8.3—Suggested Data Sheet for Trough Test

Specimen No. Welding and Thermal Treatment

Cracking Time Lapse (Days) Red. in Tensile Ductility (Y/N)

See 10.8.7.3 for suggested welding and thermal treatment (number of weld layers, preheat and interpass temperature, postweld

thermal treatment).

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AWS B4.0:2007 CLAUSE 10. WELDABILITY TESTING

10.9 Gapped Bead On Plate (GBOP)

Test

10.9.1 Scope

10.9.1.1 This subclause covers the Gapped Bead On

Plate (GBOP) test for susceptibility of as-welded metal

to hydrogen-assisted cracking. The standard gives the

requirements for test specimen preparation, test parame-

ters and testing procedures, but does not specify the

requirements or acceptance criteria.

10.9.1.2 Where specified, this standard is applicable

to the following:

(1) Information, specifications of acceptance, manu-

facturing quality control; and

(2) Research and development.

10.9.1.3 When this standard is used, the following

information shall be furnished:

(1) Weld procedure (process and parameters);

(2) The specific criteria used for distinguishing

cracked verses not cracked samples. For example, 50%

cracked may be used as the distinguishing level of crack-

ing to be considered “cracked”; and

(3) The specific test temperature [for example, test-

ing may start at 212°F (100°C)].

10.9.2 Normative References. The following standards

contain provisions which, through reference in this text,

constitute mandatory provisions of this test. For undated

references, the latest edition of the referenced standard

shall apply. For dated references, subsequent amend-

ments to, or revisions of, any of these publications do not

apply.

ASME Documents:

ASME B46.1, Surface Texture, Surface Roughness,

Waviness and Lay

10.9.3 Summary of Method. This test assesses the sus-

ceptibility of weld metal to hydrogen-assisted cracking.

A preheat temperature at which the weld metal shows

acceptable resistance to hydrogen-assisted cracking is

determined. At low temperatures hydrogen can’t easily

escape, causing a weld metal condition that is susceptible

to cracking. Conversely, at higher preheat temperatures,

there is more opportunity for the hydrogen to diffuse out,

and susceptibility to hydrogen-assisted cracking is reduced.

10.9.4 Significance. Hydrogen-assisted cracking is a

major cause for concern in weldments. Understanding of

appropriate preheat temperatures to reduce the suscepti-

bility of a weldment to such cracking can be beneficial

for both electrode comparison and determination of

appropriate welding procedures.

10.9.5 Apparatus. The apparatus consists of 2 machined

blocks that are clamped together. One of the blocks has a

machined recess though the thickness. This is illustrated

in Figure 10.9.1.

10.9.6 Specimens

10.9.6.1 Butter plates, if necessary. If plate buttering

is employed the details of the buttering procedure shall

be described in the test report. Three (3) layers is suffi-

cient to minimize the effects of base plate dilution.

10.9.6.2 Machine the test block to 4 in by 5 in by 2 in

(101 mm by 126 mm by 50 mm) thick, with a maximum

average roughness of 125 microinches (3 micrometers),

and final dimensions as shown in Figure 10.9.1.

10.9.6.3 Bake the samples at least 5 h at a minimum

of 550°F (288°C) for hydrogen removal. If there is an

oxide coating, it should be cleaned with a power brush or

equivalent prior to testing.

10.9.7 Procedure

10.9.7.1 A minimum of three samples should be

welded for each test. Preheat samples for at least 4 h to

25°F (–4°C) above the anticipated test temperature. The

sample block should be removed from the oven, then

placed in a test fixture or simply clamped together. The

samples are then tightened together and welding can be

done once the test temperature is reached. Either temper-

ature crayons or digital temperature probes are permissi-

ble for temperature measurement.

10.9.7.2 Weld across the gap a minimum of 4 in

(101 mm) total weld length. Welding parameters should

follow manufacturer’s suggested welding procedures.

10.9.7.3 After welding, the test assembly must sit a

minimum of 24 h in the test fixture or clamp.

10.9.7.4 Examination for Cracks. Penetrant testing,

heat tinting or other methods may be used to determine

the extent of cracking. One other method is to break the

test assembly and note whether it did not crack or the

degree to which it cracked based on the predetermined

testing criteria.

10.9.7.5 The samples can be re-used indefinitely, pro-

vided that they are baked out between successive tests.

This is to remove the hydrogen introduced during the

testing. This normally entails grinding away some weld

metal or machining after grinding.

10.9.7.6 If a sample cracks at a certain test tempera-

ture, the next test should be run at a higher temperature.

If the sample doesn’t show cracks at a given preheat tem-

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CLAUSE 10. WELDABILITY TESTING AWS B4.0:2007

perature, the next temperature should be done with a

lower preheat.

10.9.7.7 As soon as the “cut-off” point is known

between cracking and noncracking samples, the test is

complete for that particular electrode.

10.9.8 Report

10.9.8.1 In addition to the requirements of the norma-

tive references, the report shall include the following:

(1) Weld procedure (process and parameters);

(2) Materials identification including base metal

specification and filler metal specification;

(3) Specimen thickness and width;

(4) Specific test temperatures performed;

(5) Number of tests per condition or lot;

(6) The number, type, size, and location of defects (if

any); and

(7) Observations of unusual characteristics of the

specimens or procedure.

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AWS B4.0:2007 CLAUSE 10. WELDABILITY TESTING

Note: Surface finish to be 125 microinches (3 micrometers) R

maximum.

Figure 10.9.1—Specimen Dimensions and Test Set-Up

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CLAUSE 11. PROCESS SPECIFIC TESTS AWS B4.0:2007

100

11. Process Specific Tests

11.1 Stud Weld Test

11.1.1 Scope

11.1.1.1 This subclause covers mechanical testing of

stud welds. When testing of stud welds is required, the

procedure shall conform to this standard. This standard

does not specify requirements or acceptance criteria.

11.1.1.2 When specified, this standard is applicable to

the following:

(1) Qualification of materials, welding operators, and

welding procedure;

(2) Information, basis of inspection and fabrication

quality control (when acceptance criteria have been

established); and

(3) Research and development.

11.1.1.3 When these tests are specified, the following

information shall be furnished:

(1) Weld procedure (process and parameters);

(2) The specific tests and number of specimens that

are required;

(3) Base metal specification/identification;

(4) Position of welding;

(5) Stud analyses or specification (part number), or

both;

(6) Type of testing;

(7) Acceptance criteria; and

(8) For bend testing, the maximum angle of bend

must be specified, and for torque testing, the torque to be

used must be specified.

11.1.2 Normative References. The following standards

contain provisions which, through reference in this text,

constitute mandatory provisions of this test. For undated

references, the latest edition of the referenced standard

shall apply. For dated references, subsequent amend-

ments to, or revisions of, any of these publications do not

apply.

AWS Documents:

AWS C5.4, Recommended Practices for Stud

Welding

AWS D1.1, Structural Welding Code—Steel

11.1.3 Summary of Method. The specimen is tested by

one of two methods:

(1) The stud is bent by striking with a hammer or

bending it using a length of tube or pipe, or

(2) A tensile load is applied to the stud using an

appropriate fixture. This commonly is accomplished by

use of a torque wrench and a stand-off sleeve.

11.1.4 Significance

11.1.4.1 Mechanical testing of arc welded studs is

used to evaluate weld soundness, tensile properties, and

ductility of the stud weld.

11.1.4.2 These tests are primarily used as a welding

procedure qualification method to evaluate welding

parameters and surface preparation.

11.1.5 Apparatus. Apparatus used shall be capable of

firmly holding the test assembly and applying the bend-

ing force or torque as needed.

11.1.6 Specimens

11.1.6.1 Test specimens shall be prepared by welding

the studs being tested (qualified) to specimen plates of

the appropriate base metal as specified in 11.1.1.3.

11.1.6.2 Test specimens shall be made using the

appropriate automatic timing, voltage, current, and gun

settings for lift and plunge as recorded in 11.1.1.3.

11.1.7 Procedure. The following are two test procedures

as specified in Part 11.1.3:

(1) Bend Testing. The required number of welded

specimens shall be tested by bending the required num-

ber of degrees from their original axis. Bending may be

done by striking the stud with a hammer or by bending it

using a length of tube or pipe as shown in Figure 11.1.1;

and

(2) Torque Testing. The required number of stud

welded specimens shall be tested by applying a torque

using equipment as shown in Figure 11.1.2. A steel

sleeve or washers, of appropriate size are placed over the

stud. A nut of the same material as the stud is tightened

against the washer bearing on the sleeve, using a torque

wrench. Tightening the nut applies the tensile load to the

weld. Torque is applied until the specified level is

reached or the weld fails. The results of this test may be

significantly affected by friction. Care should be taken to

minimize this effect.

11.1.8 Report. In addition to the requirements of appli-

cable documents, the report shall include the following:

(1) Test results and observations,

(2) The information listed in Part 11.1.1.3, and

(3) Drawings showing shapes and dimensions of studs

and arc shields.

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AWS B4.0:2007 CLAUSE 11. PROCESS SPECIFIC TESTS

101

Figure 11.1.1—Equipment for Bend Tests for Welded Studs

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CLAUSE 11. PROCESS SPECIFIC TESTS AWS B4.0:2007

102

Figure 11.1.2—Equipment for Applying a Tensile Load to a Welded Stud Using Torque

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AWS B4.0:2007 CLAUSE 11. PROCESS SPECIFIC TESTS

103

11.2 Resistance Welding Test

11.2.1 Scope

11.2.1.1 This subclause covers the destructive testing

used to determine the weld quality and mechanical prop-

erties of resistance spot, seam, and projection welds.

When testing of resistance welds is required, the test

specimens and procedure shall conform to this standard.

This standard does not specify requirements or accep-

tance criteria.

11.2.1.1 This standard is applicable to the following,

where specified:

(1) Qualification of materials, welding personnel,

welding procedures;

(2) Information, specification of acceptance, manu-

facturing quality control; and

(3) Research and development.

11.2.1.2 When this standard is used the following

information shall be furnished:

(1) Weld procedure (process and parameters);

(2) The specific types and number of specimens

required;

(3) Base metal specification and thickness;

(4) Electrode material, diameter, and shape;

(5) Base metal surface condition; and

(6) Postweld temper time.

11.2.2 Normative References. The following standards

contain provisions which, through reference in this text,

constitute mandatory provisions of this test. For undated

references, the latest edition of the referenced standard

shall apply. For dated references, subsequent amend-

ments to, or revisions of, any of these publications do not

apply.

AWS Documents:

AWS C1.4M/C1.4, Specification for Resistance

Welding of Carbon and Low-Alloy Steels

11.2.3 Summary of Method

11.2.3.1 Weld Quality Tests. Three tests used to

determine the quality of resistance welds are:

Test procedure adopted from AWS C1.1M/C1.1:2000,

Recommended Practices for Resistance Welding.

(1) Peel Test. The peel test is used to determine the

weld button diameter and fracture mode of spot and pro-

jection welds;

(2) Bend Test. This test, which was developed for

aluminum and its alloys, is used for a quick check of pro-

duction spot weld soundness, particularly for freedom

from cracks or micro fissures. The bend test is not pre-

cise enough to calibrate equipment, evaluate machine

performance, or to set-up and qualify welding schedules.

It is intended as a supplement to the shear or peel tests. It

can be performed with equipment which is readily avail-

able in most shops and requires only visual examination

of the specimen; and

(3) Chisel Test. The test consists of forcing a tool

into the lap on each side of the weld until the lap joint

separates.

11.2.3.2 Mechanical Property Tests. The following

tests are used to assess the mechanical properties for

spot, seam, and projection welds:

(1) Tension-Shear Test. This test consists of pulling a

test specimen in tension to destruction on a standard ten-

sile testing machine and determining its tension-shear

characteristics;

(2) Tension Test. The purpose of the tension test is to

provide a method to determine the spot weld strength

under tensile loading;

(3) Cross-Joint Tension Test. This form of tension

test is designed to stress the weld in a direction normal to

the surface of the material so that tension at right angles

to the plane of the joint is produced;

(4) U-Specimen Tension Test. The purpose of this test

is to also determine the tension strength of spot weld but

is limited to base metal thicknesses and material that can

be readily bent into a U-shape;

(5) Pull Test. The pull test determines the resistance

of the welded joint to the opening mode of fracture. This

test may also be referred to as a “90° peel test”;

(6) Torsion Shear Test. The torsion-shear test may be

used where the strength and ductility of a spot weld is

required;

(7) Impact Test. The impact test differentiates

between degrees of weld resistance to fracture under

impact load. Five types of spot weld impact tests are

described in this standard;

(8) Fatigue Test. This test is used to evaluate the

fatigue performance of spot and projection welds for cer-

tain applications; and

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