Hello all, I have a question regarding the qualification of 316 stainless to ASTM A 500. I have looked at both  AWS D1.1 and D1.6 and do not see that there are any listings in the group base metals where they overlap. Meaning D1.1 is for various carbon steel and no stainless steel and vise versa. I am trying to convince myself that I am able to use prequalified joints from D1.6 because we are going to use 308L filler material on carbon steel to stainless steel joints. 309L filler for stainless to stainless joints are prequalified and welders have qualified 3G ss to ss, no problem. Where I do have the problem is a PJP on 6.625 O.D. 1/2" wall pipe(A 500), to an end cap(316L) 1/2' thick 1/4" bevel, 1/4" land. If they were both carbon, or both stainless I would be ok with prequalified joints, but they aren't. I think I need to have a PQR? We will be doing CJP,PJP, and Fillets welds. For any carbon to stainless joint do I need PQR? and then a WPS for the welders to qualify? I think I can write the WPS for the CJP to cover fillets? All welders have qualified fro 3g Carbon to carbon, 3g stainless to stainless, and 1g rotated carbon to carbon. Simplified is they anywhere a carbon to stainless prequalified joint exists?
Thanks, I going a bit crazy over this one.