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

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CLAUSE 10. WELDABILITY TESTING AWS B4.0:2007

10.1.6 Apparatus

10.1.6.1 A simple fixture is required to hold the speci-

men so that the test welds can be made in the flat posi-

tion. Contact between the specimen and conductive

materials must be minimized throughout the test.

10.1.6.2 Metallographic equipment is required for

polishing and etching sections of the test weld.

10.1.6.3 Microhardness apparatus is required if hard-

ness tests are specified.

10.1.7 Specimens

10.1.7.1 Test specimen components are shown in Fig-

ure 10.1.2.

10.1.7.2 The cooling bath arrangement is shown in

Figure 10.1.3.

10.1.7.3 Minimum plate thickness is 1/4 in (6 mm).

10.1.7.4 The mating surfaces of the plates are to be

ground to provide intimate contact between these parts.

10.1.7.5 The surfaces of the top plate on which test

welds are to be deposited are to be machined.

10.1.7.6 Rolling direction shall be identified if

possible.

10.1.7.7 Plates are bolted together as shown in Figure

10.1.2 and anchor welds are deposited. The size of the

anchor welds should be as given below:

Plate Thickness in (mm) Weld Size in. (mm)

<5/8 (16)

≥5/8 (16)

1/4 (6)0

1/2 (13)

10.1.8 Procedure

10.1.8.1 Test welds are deposited in the flat position

using fixturing that minimizes contact between the speci-

men and thermally conductive surfaces. Between test

welds, the specimen shall be allowed to cool by placing

the specimen in the water bath as shown in Figure 10.1.3.

The test welds are to be single pass fillet welds extending

the full length of the top plate. Actual voltage, current,

and travel speed shall be recorded.

10.1.8.2 Any postweld heat treatment shall be accom-

plished immediately after deposition the test welds.

10.1.8.3 The test welds are sectioned as shown in Fig-

ure 10.1.4. These are examined metallographically for

cracks.

10.1.8.4 Hardness tests may be measured in the weld

metal and the HAZ (optional) as shown in Figure 10.1.5.

10.1.9 Report. An example of a suggested data sheet for

CTS test results is shown in Figure 10.1.6.

10.1.10 Commentary. A series of CTS tests may be

designed to evaluate the relationships between test

parameters such as TSN, heat input, filler metal, or pro-

cess. Commonly, all test parameters but one are held

constant. Examples of test series interpretation are:

(1) TSN at which cracking occurs for a given base

metal, heat input, and welding procedure;

(2) The heat input at which cracking occurs for a

given base metal, welding process, and TSN; and

(3) Base metal variable (chemistry, heat treatment,

etc.) at which cracking occurs for a given TSN, heat

input, and welding process.

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AWS B4.0:2007 CLAUSE 10. WELDABILITY TESTING

Figure 10.1.1—Fixture Used to Position CTS Specimen for Welding

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CLAUSE 10. WELDABILITY TESTING AWS B4.0:2007

Notes:

1. Welds are placed on sides opposite cooling bath.

2. Mating surfaces shall be no rougher than 125 microinches (3 micrometers) R

Figure 10.1.2—CTS Test Specimen

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AWS B4.0:2007 CLAUSE 10. WELDABILITY TESTING

Notes:

1. The specimen end that is immersed in the water cooling bath is always

opposite to the end containing the test weld being cooled.

2. Water depth (D) should be 2-1/2 in (63 mm).

Figure 10.1.3—Cooling Bath Arrangement for CTS Test

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CLAUSE 10. WELDABILITY TESTING AWS B4.0:2007

Figure 10.1.4—Sectioning of CTS Specimen

Figure 10.1.5—Typical Location of Microhardness Impressions

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AWS B4.0:2007 CLAUSE 10. WELDABILITY TESTING

CTS TEST RESULTS

Company Name _____________________________________________________________ Date _______________________

Job/Test No. ________________________________________________________________ Sheet _________ of __________

Description of Investigation ____________________________________________________________________________________

Base Metal Specification_______________________________ Thickness ___________________________________________

Base Metal Heat Treatment_____________________________ Heat No. ____________________________________________

Composition:

C__________ Si __________ Mn ________ P __________ S__________ Cr__________ Mo ________

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

Al _________ N __________ _________ __________ _________ __________ _________

Welding Procedure Spec. No. ___________________________ Welding Process ______________________________________

Test Weld Restraining Weld

Electrode/Wire Spec. No. ________________________ ________________________

Commercial Designation ________________________ ________________________

Diameter ________________________ ________________________

Baking Treatment ________________________ ________________________

Shielding Gas/Flux ________________________ ________________________

TEST WELD

Gas Flow Rate ______________________________________ Flux Size ____________________________________________

Current ____________________________________________ Preheat Temp.________________________________________

Voltage ____________________________________________ Postweld Heat Treatment _______________________________

Polarity ____________________________________________ Ambient Temp. _______________________________________

Travel Speed ________________________________________ Ambient Humidity _____________________________________

Heat Input __________________________________________ Water Bath Temp. _____________________________________

Hydrogen Determination Method ________________________________________________ Date _______________________

__________________________________________________ Result ______________________________________________

Results:

Remarks __________________________________________________________________________________________________

Tested By __________________________________________________________________

Signature___________________________________________________________________ Date _______________________

Figure 10.1.6—Suggested Data Sheet for CTS Test

Weld/Face/

Face No.

Mean Leg

Length

Crack

Length

Result

(C or NC)

Hardness, HV

HAZ WM BM

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CLAUSE 10. WELDABILITY TESTING AWS B4.0:2007

10.2 Cruciform Test

10.2.1 Scope

10.2.1.1 The cruciform test is used to measure the

susceptibility to hydrogen-assisted cracking of steel

weldments, primarily focusing on fillet welds. While pri-

mary application is to evaluate base-metal composition,

the test also may be used to evaluate the effects of weld-

ing consumables, welding heat input and preheating,

postheating, or both, on cracking susceptibility.

10.2.1.2 This standard is applicable to the following:

(1) Qualification of materials and welding proce-

dures where specific acceptance standards have been

specified;

(2) Information, basis of acceptance, or manufacturing

and quality control; and

(3) Research and development.

10.2.1.3 The use of this test is restricted as follows:

(1) The test shall not be used for base metal less than

3/8 in (10 mm) thick, and

(2) Close control of the welding parameters is re-

quired as the results of this test may be affected more by

differences in parameters than in cracking susceptibility.

10.2.1.4 The following information shall be furnished:

(1) Welding procedure (process and parameters);

(2) Base-metal specification/identification and actual

chemical composition;

(3) Filler metal specification/identification, size,

and any prewelding treatment, e.g., baking time and

temperature;

(4) Appropriate preheating postheating treatments

used;

(5) Acceptance criteria, if applicable; and

(6) The number of cross sections to be examined.

10.2.2 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 A4.3, Standard Methods for Determination of

the Diffusible Hydrogen Content of Martensitic, Bainitic,

and Ferritic Steel Weld Metal Produced by Arc Welding

10.2.3 Summary of Method. Figures applicable to this

test method are shown in Figures 10.2.1 through 10.2.7.

10.2.3.1 The test specimen consists of three plates

tack welded at their ends to form a double T-joint (Figure

10.2.1). A variation of this test called the slotted cruci-

form may also be evaluated. In this variation of the cruci-

form test, the attached plate (plate B or C) contains

longitudinal and transverse notches that are machined on

the edge of the plate as shown in Figure 10.2.3.

10.2.3.2 A single or multipass fillet weld is deposited

in succession in each of the four T-joints. Each test weld

is allowed to cool to ambient temperature prior to depos-

iting the subsequent weld. After the fourth weld is com-

pleted, the specimen is given any specified postweld

treatment.

10.2.3.3 The completed welds are examined visually

for any external cracks. The standard cruciform speci-

men is sectioned transversely for metallographic exami-

nation for hydrogen cracks. The slotted cruciform

specimen is sectioned longitudinally and transversely for

metallographic examination for hydrogen cracks as

shown in Figure 10.2.2.

10.2.3.4 Some additional longitudinal sectioning will

also be required for portions of the slotted cruciform as

discussed in 10.2.3.6.

10.2.3.5 The recommended base plate thickness for

the slotted cruciform test specimen is 3/4 in (19 mm).

Thicker plate may also be used (depending on the appli-

cation being simulated). The two surfaces of the continu-

ous plate are ground to bright metal prior to assembly.

The mating edges of the attached plates B and C are

machined flat prior to assembly. This is essential to

insure intimate contact and good heat transfer between

these surfaces during welding of the assembled speci-

men. For the slotted cruciform test, notches (or slots) are

machined on the edge of one of the attached plates as

shown in Figure 10.2.3. The assembly is tack welded

together prior to the test.

10.2.3.6 Sectioning for the slotted cruciform will

involve sectioning transverse to the direction of welding

for the longitudinal notches and parallel to the direction

of welding for the transverse notches. Schematic illustra-

tions of the sectioning for the longitudinal and transverse

notches are given in Figures 10.2.4 and 10.2.5. The cut

for the transverse notch is shown in Figure 10.2.5. The

cut for the longitudinal notch is shown in Figure 10.2.4.

10.2.3.7 For the standard cruciform specimen, sections

(Figure 10.2.2) are cut transversely from the test weldments.

For the slotted cruciform specimen, sections (Figure 10.2.6)

are cut longitudinally and transversely. Use of a water-

cooled cut-off wheel is recommended where practical.

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AWS B4.0:2007 CLAUSE 10. WELDABILITY TESTING

10.2.4 Significance. This test is relatively severe for

detecting hydrogen cracks. As a result, the test may be

more sensitive to variations in the welding conditions

than to any differences in the cracking susceptibility of

the base metals being examined. Therefore, the welding

conditions must be very closely controlled to avoid any

variations that may lead to incorrect results. Multiple

specimens are required to help assure reliable measure-

ment of the cracking susceptibility.

10.2.5 Apparatus. Evaluation for the presence of hydro-

gen cracks requires the use of metallographic equipment

to section and prepare the specimen for examination.

10.2.6 Specimens

10.2.6.1 The test specimen is shown in Figure 10.2.1.

The minimum base-plate thickness is 3/8 in (10 mm) The

two surfaces of Plate A and the mating edges of Plates B

and C are ground smooth prior to assembly. This finish is

essential to ensure intimate contact and good heat trans-

fer between these surfaces during welding of the assem-

bled specimen. The specimen is assembled and securely

clamped. The plates are tack welded, and then the clamps

are removed.

10.2.6.2 The suggested dimensions of the specimen

plates are as follows:

Plate A:

Length 12 in (305 mm)

Width 6 in (152 mm)

Plates B and C:

Length 12 in (305 mm)

Width 3 in (76 mm)

10.2.7 Procedure

10.2.7.1 Test welds are deposited in the sequence

shown in Figure 10.2.1. All welding shall be done in the

flat (1F) position using a mechanized process to maintain

close control of the welding parameters. If the shielded

metal arc process is used, it is recommended that the

covered electrodes be fed into the arc mechanically

rather than manually to maintain uniform parameters.

10.2.7.2 All test welds are deposited in the same

direction of travel. Each weld is made without any arc

interruptions, and the craters at the ends of the test welds

are filled before the arc is extinguished. The same weld-

ing parameters are used for each test weld, and each weld

shall be of the same size.

10.2.7.3 In some situations, a multipass test weld may

be desired. The sequence for depositing the individual

passes of multipass weld is indicated in Figure 10.2.1.

10.2.7.4 If weld metal cracking occurs in any of the

test welds, the test shall be discontinued and the location

and extent of cracking noted on the test record sheet.

10.2.7.5 If the welding procedure requires preheating,

the specimen shall be preheated before depositing each

test weld. If postweld heat treatment is required, this

treatment shall be applied to the test weldment immedi-

ately after completion of welding and before cooling to

ambient temperatures unless specifically required by the

weld procedure to cool the weldment prior to postweld

heat treatment. If no postweld heat treatment is required,

the as-welded specimen shall be aged at ambient temper-

atures for 48 h.

10.2.7.6 After postweld heat treatment or aging, the

test weldment is sectioned and examined for cracks. For

standard cruciform specimens, sections (Figure 10.2.2)

are cut transversely from the test weldment. For slotted

cruciform specimens, sections (Figure 10.2.6) are cut longi-

tudinally and transversely. Use of a water-cooled cut-off

wheel is recommended where practical. Each section

shall be identified as to its location in the test weldment.

The four quadrants corresponding to the fabrication

sequence shall be identified. No section shall be located

closer than 1 in (25 mm) from the end of the test weld.

10.2.7.7 One face of each section shall be prepared

with metallographic paper (240 grit or finer), etched and

examined at 50X. The presence and location of any

cracks shall be recorded.

10.2.7.8 When the test is used to evaluate susceptibil-

ity to hydrogen-assisted cracking, a diffusible hydrogen

determination shall be performed for each welding pro-

cess and consumable in accordance with AWS A4.3. The

diffusible hydrogen determination shall be performed

under the same conditions as the test weld.

10.2.8 Report. An example of a data sheet for cruciform

test results is shown on Figure 10.2.7.

10.2.8.1 The test results that shall be reported are the

following:

(1) Base metal and filler metal identification and

chemical composition,

(2) Base metal (specimen) thickness,

(3) Welding parameters,

(4) Any preheating and/or postweld heat treatment,

(5) Fillet weld size and weld bead size for multipass

welds,

(6) Identification of each section cut from the speci-

men and each test weld in the section,

(7) Presence and location of any cracks in each test

weld in each section, and

(8) Results of diffusible hydrogen test, if available.

10.2.8.2 Test data should be recorded on a Test

Results Sheet similar to Figure 10.2.7.

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CLAUSE 10. WELDABILITY TESTING AWS B4.0:2007

Figure 10.2.1—Cruciform Test Assembly

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AWS B4.0:2007 CLAUSE 10. WELDABILITY TESTING

Figure 10.2.2—Locations of Specimens for Examination of Cracks in Cruciform Test

Figure 10.2.3—Schematic Illustration of the Attached Plate

in the Slotted Cruciform Specimen

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