Hi, i`m writting a procedure for a groove weld on 4" pipe Sch XXS (17 mm wall thickness). The joint is SA-106 Gr.B with AISI 4130. Root must be welded with SMAW, fill can be GMAW/FCAW/SMAW.

What do you think about the following?:
-Root pass: SMAW 7010-A1
-Fill: FCAW - E410NiMoT0-4

Preheat: 250 ˙C
Interpass: 300 ˙C

Postweld:
650 ˙C - 1 hr / in - min. 2 hs.
Cooling rate: Air.

Before offering any suggestions, I think it is in order to ask a few questions:

What welding standard is invoked?

What is the application?

What is the nature of the loads?

Are the loads cyclic or static?

If the loads are cyclic, what is the anticipated load cycles and what is the range of the cyclic stress?

Are there any requirements for notch toughness?

What are the post weld heat treat requirements, i.e., stress relief, normalize, or anneal?

Are there any coating requirements, i.e., hot dip galvanizing for instance?

Last; what is the thickness of the two members being joined? I know you mentioned the thickness of one member, but what of the other?

Best regards - Al