welding 304 with 316
welding 304 with 316
(OP)
I walked into a project today where they were socket welding 2" pipe. They were tig welding the sockets which is a little odd in it's self but they were also welding the 304L pipe with ER 316L filler rod. I advised them that you would normally stick weld the sockets and that if you were going to tig the socket that the apropriate filler metal would be ER 308 or ER 309. Do you think there will be cracking at the root of the welds made with the 316L due to filler/base metal differences?
Thanks
StoneCold
Thanks
StoneCold





RE: welding 304 with 316
GTAW welding of stainless steel socket welds is very common. The filler metal selection is fine, ER308L is typically used. The key to avoid cracking in the weld root is to assure you have an adequate gap on fit-up (1/16" min).
RE: welding 304 with 316
The only real problem is that they are using filler that costs a lot more than they need.
= = = = = = = = = = = = = = = = = = = =
Rust never sleeps
Neither should your protection
http://www.trent-tube.com/contact/Tech_Assist.cfm
RE: welding 304 with 316
In my understanding, GTAW is "better" for welding stainless because the heat input can be better controlled. Thing is, where I work, it's our "common wisdom" to be suspect on welder GTAW technique with respect to root penetration and sidewall fusion, and will radiograph greater than minimum % of GTAW'd weld. In the case of SW's, we look both for minimum gap and for tell tail LOF.
Cheers
Rob
RE: welding 304 with 316
It is also true that with improper welding techniques, it can be difficult to get complete penetration to the root of a fillet weld, but in my experience, GTAW welds should have less defects per inch of weld than most other processes if done properly.
RE: welding 304 with 316
We almost exclusively weld stainless steel sockets with the GTAW process. The leak incidence using SMAW was simply too high due to poor welding technique at the tie-in locations.
RE: welding 304 with 316
RE: welding 304 with 316