Welding of 2.25Cr-1Mo to 316 SS

[engineermat]

I am preparing a Welding procedure for 2.25Cr-1Mo to 316SS.

From ASME VIII appendix R recommends 204C preheating temperature for 2.25Cr.

API 582 also recommends 175C Maximum of interpass temperature for 316 stainless steel.

1) I was wondering what temperature I can used for preheating and interpass for these two materials.

2) Can I use 1300F-1400F of PWHT temperature?

Thanks.

 

[GRoberts]

Assuming that this is a high temperature application, butter the 2 1/4 Cr-1Mo with inconel with the Cr-Mo preheats, such as Inco 82. PWHT the buttered piece, then weld to the 316 stainless with inconel also. Then the final joint can be preheated IAW the 316 and no PWHT is required.

However, if there is a lot of cyclic heating, you are actually better off with an inconel transition peice instead of welding the stainless direct to the Cr-Mo due to having a longer transition area for the thermal stresses generated by the different CTE of the materials.

 

[metengr]

Agree with the above. Also, you had posted this in another thread in another forum.

 

[engineermat]

GRoberts, metengr

Thanks for your advice.


I started another topic for these two materials in the corrosion engineering forum previously. That's the reason I asked the same questions in that post.