Hardness Testing of Weld Cap in Field
Hardness Testing of Weld Cap in Field
(OP)
Dear and Respected,
We are performing hardness testing of field sour line piping joints. Is it possible to take hardness of weld cap? Our WPS got qualified with hardness of 225(Vicker). Our project requirement is 248max. Now the scenario is for weld joint hardness value come around 262 and in HAZ it comes around 195. I think this much difference is not possible. I read some where that in field weld cap hardness measurement is not possible due to irregular surface. Can you please guide? And what are the requirements in actual. To verify the PWHT and for other sour lines below 19mm do we need the hardness of HAZ and base metal or all three the weld metal , haz and base metal.
We are performing hardness testing of field sour line piping joints. Is it possible to take hardness of weld cap? Our WPS got qualified with hardness of 225(Vicker). Our project requirement is 248max. Now the scenario is for weld joint hardness value come around 262 and in HAZ it comes around 195. I think this much difference is not possible. I read some where that in field weld cap hardness measurement is not possible due to irregular surface. Can you please guide? And what are the requirements in actual. To verify the PWHT and for other sour lines below 19mm do we need the hardness of HAZ and base metal or all three the weld metal , haz and base metal.





RE: Hardness Testing of Weld Cap in Field
The hardness values you stated are rather large in comparison, 262 versus 195. What is the weld cap material you are testing and what type of portable hardness tester are you using for this work?
RE: Hardness Testing of Weld Cap in Field
RE: Hardness Testing of Weld Cap in Field
For your purposes, I would use the weld cap hardness and base material hardness only and forgo the HAZ hardness. My rationale is the weld cap hardness comes in under the max for PWHT, the surrounding region adjacent to the weld will be exposed to PWHT. Also, finding the exact location of the HAZ will be problematic in the field. Your objective is to confirm is PWHT was performed and hardness of the weld cap is what you need.
RE: Hardness Testing of Weld Cap in Field