QW-466.1

[Agnewt]

I have some performance qualification test pieces which have come back as 'failed'. The welders are claiming that it is not their welding technique which caused them to fail, but rather the bend radius of the test pieces was too small. I am using SA-516 Grade 70 material with a thickness of 3/4". I see QW-466.1 gives dimensions for for the test jig, however this diagram and the general notes have me rather confused.

Can anyone give me a clue as to what the proper bend radius should be?

 

[grayseal]

Agnewt,
Assuming you are qualifying to ASME Section IX and SA-516 Grade 70 is a P1 material with greater than or equal to 20 % elongation. QW-452.1(a) requires two side bend tests which are cut from the test plate at 3/8" thick. Per QW-466.1, A = 1 1/2".

grayseal

 

[gtaw]

Did you look at the failed bend samples?

If there is evidence of slag, incomplete fusion, porosity, etc, then technique is most likely the problem.

In the absence of visible defects, I would check the preparation of the samples and check the direction of rolling. The direction of the roll should be transverse to the axis of the weld if face and side bends are performed. Also, check the direction of the "scratches" for the grinding operations. They too should be transverse to the weld. If they are parallel to the bend, they act as stress risers and can result in cracks in an otherwise sound weld.



Best regards - Al