welding Stainless to A36

By jon20013 (*****)

Date 06-25-2008 08:28

Generally speaking we try to avoid ss contact with carbon steels. In such case it is likely on minor consequence but your stainless anchor tabs ARE going to rust and corrode (time and amount of corrosion depends on environmental conditions). When welding ss to carbon steel, the general rule of thumb is to use a 309 type filler metal also. Likely there is nothing "wrong" with the welds but a galvanic couplant has been established that will facilitate accelerated corrosion.

Incidentally, you won't find any guidance in D1.1 because it ONLY addresses carbon steels.

By Kix

Date 06-25-2008 14:38

We do it all the time using GMAW and a ER309L stainless wire. The weld will rust after time though like said above, but you should have a good strong joint if your parameters where correct and you established good penn and fusion.

By jrw159

Date 06-25-2008 16:15

As stated, there is no problem with welding SS to CS. We always used 309L or 309LS.

jrw159

By swnorris (****)

Date 06-25-2008 16:54

Consider adding a post weld surface coating repair to the carbon steel to restore complete corrosion protection to the joint. If this recoating or painting is allowed to lap over onto the weld bead, the joint should not be at risk to bimetallic corrosion in any environment as long as the coating is sound. Ideally the weld bead should be covered so that only the parent stainless steel is ultimately exposed. This ensures that galvanic corrosion cells cannot be set up across the joint, where there is a composition variable.

By Jeffrey Grady (***)

Date 06-25-2008 18:46

Thank You Guys,
This is going to be sprayed with an epoxy coating, but a 309 filler was not used. We used ER-70S. OOOPS!
Jeffrey.

By jrw159

Date 06-25-2008 23:14

It may still hold but it is not code. CS to SS falls under Structural SS and needs to be joined with 309L or equivelant. There are more options but for the most part 309L or 309LS is what is generally used.

jrw159

By Jeffrey Grady (***)

Date 06-26-2008 15:44

John,
Thank You for the reply. I knew it wasn't right, but the Man i was welding under said it wasn't a problem. I should have insisted but he is a 22yr veteran in this field and always stressed that as a point.
Oh well, I guess it doesn't matter now...I had to drag up from that shop already. it wasn't the work or the pay...it was the cost of fuel to commute 100 miles a day to work. I couldn't get a place to live anywhere near the shop, because of the flooding in Iowa. Every one from Iowa City and Cedar Rapids converged on Tipton Iowa because it's high ground. They took up all the rental units the week before i was hired. can't even get a Motel anywhere in the area as there are so many displaced people who's homes were destroyed by the floods. Ah, Just my luck...I find a really good place to work and improve my skills, and i have to resign because of high fuel costs. I do have an open invite to return when things get better. I also have an interview next Tuesday at a union shop here in my home town. I was turned down for a position at the U.S. Army Arsenal yesterday, because they could not place me on a shift that would allow me finish my college Education. Man, That job started out at $20.88hr! I only hope that next week I am not shot down for the same reason. I really want to finish my education. Thanks again,
Respectfully, Jeffrey

By jrw159

Date 06-26-2008 15:56

Jeffrey,
Yeah the price of fuel is really starting to hurt alot of us, but with your drive and willingness to excel, I know something will fall into place for you. Just hang in there, you are not alone. :-)

John

By swnorris (****)

Date 06-26-2008 16:24

Jeffrey,

"I should have insisted but he is a 22yr veteran in this field and always stressed that as a point". Just because someone has been at it for a long time doesn't necessarily mean that he knows what he's doing. You have to be sharp enough to know the difference between somebody who really knows his stuff and somebody who's been doing it wrong for 22 years. I've always taken the "show me" stance, when someone tells me something, and I'm a bit leery about what they're telling me, I ask them to show me a code reference. If they can, fine. I've learned something, I know which code it's in, and I know where to look for it. If they can't, then it can most likely be dismissed as b.s. and poppycock.

By Jeffrey Grady (***)

Date 06-26-2008 18:57

Scott,
Thank You. I really should have listened to the alarm going off in my head and insisted on seeing the WPS, or if that was not available, I should have gone to the shop supervisor and had him place a call to the EOR. The scary part of this is, this is an out-doors multi-story stair and landing. If the coating is not proprly maintained, corrosion may cause weld failure in the future. I have learned a valuable lesson. I will not just simply take the word of another fabricator based on yrs in the Biz.
Respectfully, Jeffrey

By Pipeslayer (**)

Date 06-27-2008 14:25

I'd really have to question his 22 years in this case. Somtimes working for MOMS AND POPS this is what you get. It is ashame that people do questionable things when they just dont want to spend the money to do right. In my 3rd party inspection adventures I would see this almost daily and I always heard ( I've been doing this forever and a day like this ) well you sir are doing it wrong. Then to try and argue the point they do not even have a code book and have never even read one. You would think if you're in the steel erecting business one would at least know the codes that govern that business. It's small time hustlers like this that keep good craft peoples wages down!!

By ibeweldingsum (***)

Date 06-27-2008 00:24 Edited 06-27-2008 00:30

In most WPS's i've seen preheating of the carbon steel is a must for proper adhesion and a 309 alloy for filler I am by no means an expert. Just my 2 cents