Welded SA-335-P22 tube by mistake using ER90S-B9 followed the welding parameters for P15E. Is there any risk in conducting the 1350F PWHT & leaving as-welded.
Do you have a procedure so qualified? If not, cut it out and reweld using the proper WPS.
Fatigue life could be adversely affected with the higher strength filler metal versus the lower strength of the tube.
If this is a repair, it is a nonconformance that requires some level of action for disposition. I agree with weldstan, otherwise you will need to qualify a WPS to at least leave the B9 filler metal with PWHT. Seems like a lot of effort rather than remove the B9 filler metal, NDT and re-weld.
