Welding Martensitic ss to Austenitic ss

By korety_k Date 01-04-2003 08:32

I want to carry out welding of A-487 CA6NM grade pump casing to SS 316 SS 3/4" size pipe.
What are the options do I have to carry out the welding to avoid PWHT.
Operating temp in 320 Deg.C.

Regards,

Kiran

By Tim Buyle (**)

Date 01-06-2003 07:02

Use an Inconel 600 type welding filler material.

By GRoberts (***)

Date 01-06-2003 15:42

It is not recommended to weld CA6NM without PWHT. There will be untempered (brittle) martensite in the HAZ of the weld no matter what filler metal you use. If pipe is subsequently welded to a CA6NM casting, often the casting is overlayed with 309L and then gets a PWHT. Later, the pipe can be welded to the overlayed portion of the casting without further PWHT. Another option is to use local PWHT with resitance heating pads.