welding AL6XN STAINLESS

By fbrieden (***)

Date 12-17-2008 03:58

Shielding gas and wire specification?

By js55

Date 12-17-2008 13:43

Really.
The wire classification is important info in order to troubleshoot.
The usual recommended wire for AL6XN is NiCrMo-3 which contains Cb in large enough quantities to be crack sensitive.
Some have gone to NiCrMo-4 to eliminate the Cb but being a nickel base alloy it will still be crack sensitive (not to mention removing the possiblity of Columbium nitride precipitation-though this, to my knowledge has never proven to be related t failures).
Also, what kind of cracking are you seeing?

By defaced (**)

Date 12-17-2008 21:02

The GMAW-P stuff we've done used ERNiCrMo-10.

By js55

Date 12-17-2008 22:18 Edited 12-17-2008 22:27

10's a good choice. Perhaps a little more alloy than you need, though maybe not in strong oxidizing service. The 4 will still out perform AL6XN in the 10% FeCl3 test. 4 and 10 will handle Mo segregation better than 3, and far better than the AL6XN HAZ. Though 3, like 10 matches the Cr better. But the main thing is 4 and 10 use W instead of Cb/Nb (depending upon what side of the ocean your on) so the perceived problem with N goes away, and they are less prone to hot cracking, at least in my experience.
As for cracking you still haven't said what it is your seeing.
I would gather centerline hot cracking. Though neither of these fillers are exessively prone to hot cracking, as long as parameters are within reason.
What parameters are you running?
Do you have good convexity on your beads?
Are they narrow?