PWHT for type 321 stainless steel

[kwaliteitshenk]

Can anyone give advise about pwht for welds in 24 mm A516-60 and A240 type 321.

 

[btrueblood]

Generally PWHT is not required for 321, as it is a stabilized grade.

 

[stanweld]

Are you welding the dissimilar materials together? To what Code are you welding? If you are welding either of the materials to ASME VIII, no PWHT is required for welding these materials whether similar or dissimilar joints are made.

 

[kwaliteitshenk]

Stanweld, the welding is between A516-60 and A240 type 321 22 mm thickness acc. ASME B31.3

 

[stanweld]

B31.3 permits discretionary latitude of the Owner (to be demonstrated by the desiner) whether to PWHT or not in this case (ref 331.2.2). If B31.3 is strictly folowed, PWHT for the P1 material (1100 F min)is required per Table 331.1.1.

Assuming that PWHT will be required, butter the carbon steel with nikel base alloy filler metal, PWHT buttered carbon steel and then make the joint between the nickel base butter and the 321 SS without further PWHT.