AWS WPS Question!!
AWS WPS Question!!
(OP)
I have been given a weld plate that is 1"x15"x36" long. its a CJP with a backing plate. Its a "internal" WPS qualification test. During UT a 2 inch section of lack of fusion was found in the test plate. A report was issued for the rejected plate. A few hours later the plate was back in our possession, with the rejected section cut out. Can this be possible? If a plate fails UT, even if its a small section, doesn't this need to be repaired? Can they just cut the bad section out and say the plate is good??
RE: AWS WPS Question!!
Best regards - Al
RE: AWS WPS Question!!
You have posted in the AWS section - is this regarding D1.1 as Al has noted ?
With some codes UT / RT is not a requirement so you can perform internal" NDT, remove defective areas and then submit for mechanical testing.
With a PQR qualification coupon you are examining the tensile strength, yield strength and ductility of the welded coupon - not the ability of the welder who performed the test.
Cheers,
DD
RE: AWS WPS Question!!
Possibly did not explain very well.
Where it is clear that the defects are attributable to the welder and not the welding parameters then the below can be applied (excerpt from ASME IX)
"When it can be determined that the cause of failure is not related to welding parameters, another test coupon may be welded using identical welding parameters.
Alternatively, if adequate material of the original test coupon exists, additional test specimens may be removed as close as practicable to the original specimen location to replace the failed test specimens."
Cheers,
DD
RE: AWS WPS Question!!
As I stated earlier, if the standard is AWS D1.1 the test assembly has to pass both visual and volumetric NDE before any mechanical testing is performed. The purpose of NDE is not to "cherry pick" to good spots for mechanical testing. The entire assembly must pass or the entire assembly is failed and a new assembly must be welded.
Once the test assembly passes NDE, the assembly is sliced and diced for the destructive mechanical tests. There is a provision in D1.1 where it is permitted to test two additional specimens if one fails the mechanical test. The details can be found in AWS D1.1 clause 4.9.5.
Different requirements for different welding standards.
Best regards - Al
RE: AWS WPS Question!!
So, if the testing group wants to, they can cut out a sample out of any sample they want to, then machine it down to run an "internal" (informal) destructive test to find out if the actual test coupon will work. It won't be the final result, but there is nothing wrong with doing a preliminary test before the final certification.
RE: AWS WPS Question!!
If needing a clear cut answer as to whether the test plate may be repaired for a D1.1 qualification, the answer above as stated was no, and this is clarified in AWS interpretion D1-2.71.