PWHT and hardness testing
PWHT and hardness testing
(OP)
Hello.
I am working on the quality control for the installation of a steam header. The material is 2.25% Cr steel (P22).
The header was prefabricated in a shop, but will require several field welds. Regarding PWHT of the field welds, how relevant is hardness testing as a quality control step for checking stress relieving? What do we do with high readings? Is hardness testing typically used for this purpose?
Thank you.
I am working on the quality control for the installation of a steam header. The material is 2.25% Cr steel (P22).
The header was prefabricated in a shop, but will require several field welds. Regarding PWHT of the field welds, how relevant is hardness testing as a quality control step for checking stress relieving? What do we do with high readings? Is hardness testing typically used for this purpose?
Thank you.





RE: PWHT and hardness testing
RE: PWHT and hardness testing
Very relevant. Use this information along with the PWHT charts to ensure it was done correctly.
Usually a few extra readings are taken in the near vicinity as the high readings. If the extra readings are also high, check the entire circumference of the weld/HAZ to determine if another PWHT is required. Develop a repair plan if necessary.
Yes.
RE: PWHT and hardness testing
If the repair contractor is reputable and has dealt with these materials based on their track record, I would say most clients would not require hardness testing as an additional QA/QC step only because of schedule and cost.
RE: PWHT and hardness testing