welding dissimilar materials

[sajid8768]

Anybody please give me the information about the welding consumeble and heat treatement method of welding with two dissimilar materials like sa335 p91 with sa 312 304

 

[stanweld]

A nickel base alloy, weld filler metal is required; e.g., ERNiCr-3/ENiCrFe-3, etc. Preheat at 400F minimum, PWHT at 1300F minimum per ASME I and ASME B31.1 (1325 F recommended by me). Buttering of the P91 side of the joint is recommended followed by PWHT. The strength joint may be made without subsequent PWHT.

Other nickel base fillers may be required when service conditions dictate; e.g., sulpfur containing hydrocarbon streams. If you are contemplating using P91 in services where P9 is normally used in refinery applications, reconsider the substitution!!!

 

[jtseng123]

also check API 582 "welding guidelines for the chemical, oil, and gas industries", that defines what type of Inconel to use for dissimilar weld, based on temperature and sulfur environment. It also has interpass temp and PWHT.