SA335-P91 weld procedure

Date 02-16-2004 17:44

I have to develop a new weld procedure using SA335-P91 material. It's a P#5a group #2 material. It looks like a PWHT of 1350 deg. F. is in order, not sure about pre-heat? I was thinking of around 350 deg. F.? Does this sound adequate?
I'm still trying to figure out if SMAW (E9018-B3) or GTAW (ER90s-?) would be better.
Any suggestions or comments would be really appreciated. I really do not have any experience with this material.
Thanks a million!
Dagwood.

By G.S.Crisi (****)

Date 02-16-2004 19:32

Dagwood:
A-335 is piping material. Have you had a look into the applicable ASME B31 Code (B31.1, B31.3 etc.)? The information you're looking for must be there, unless you're using it as a vessel nozzle, in which case ASME VIII applies.
Giovanni S. Crisi
Sao Paulo - Brazil

By Dagwood (*)

Date 02-16-2004 21:50

As I look around sheepishly wondering exactly where my brain is/was...
Thank-you for pointing out where I should be looking. Not sure why I didn't go there myself. Should have known better...
Dagwood.

By GRoberts (***)

Date 02-16-2004 20:19

Unless you are welding P91 to a different material, the normal filler metal (matches creep strength and chemical analysis) is E9015-B9 or ER90S-B9. There are also a couple manufacturers who make a FCAW electrode for this material. I'm not at a place where I can review the temperatures at the moment, but there should be plenty of others that can help there.