Welding material grade AISI 4130 AS with A350 LF2

[Petropoulos Nick]

Hello,

i would like your help on a consumable selection issue.

We need to weld a hammer union (WECO) 4" mat. AISI 4130 AS (fig.1002) with a flange WN 4" RTJ sch.160 A350 LF2.
The joint will be butt connected with GTAW-SMAW method.
We are thinking to use the following:
AWS A5.28-96: ER80S-G (GTAW) and AWS A5.5-96: E8018-B2H4R (SMAW)
or
AWS A5.28: ER80S-Ni1 (GTAW) and AWS A5.5-96: E8018-C3H4R (SMAW)
The project's impact requirement is for -20 C.

Also, do you know if we have to pre-heat and/or heat-treat the joint?
About pre-heating and inter-pass temperature we are thinking of 205-315 C.

Thank in advance for your help.

Nick

 

[weldstan]

Your second filler metals would be recommended or use E7018-1 and ER70S-6, which would match the tensile properties of the A-350.LF2 flange, Preheat and inter-pass are fine.