E70 S6 mig stainless?

[wagin]

Learned something new the other day. I built an aerator framed with carbon angle but used stainless plate for drop down shaft supports. when fitting up, I had mig cooking and didn't want to fire up tig so I tried tacking up the stainless with mig, E70 S6, it worked great. I've never tried this in the past due to being tout that stainless filler can weld carbon base but not the opposite. Of course when welding out, I stick welded the stainless/carbon with 309L.

[DesertRider33]

Stainless can be welded with carbon filler for general use purposes. The weld won't retain the rust resistant properties of the stainless though. I'm sure the other metal properties of the stainless are adversely affected as well, but for a non-critical application, that may be of no importance.

I'm sure one of the other guys here with alot more knowlege about it will post up the details of the properties changed/lost by welding stainless with carbon filler and I'm sure it differs depending on what stainless alloy is in question.

May the 'schooling' begin!

[pulser]

As pointed out many times before, mixing SS and CS can lead to a very hardenable chemistry mix, and result in a brittle weld and cracking. You could now have brittle areas in your weld due to tacking with CS, and in any critical application these stress risers would be a liability. I suppose this application of your's is not critical, but this may be a good thing to keep in mind.

The other day I was messing around and welded a copper sheet to 304 SS, and it looked beautiful with no cracks. In theory, melting copper into SS with cause intergranular cracking, and maybe it did in this case to, but I couldn't see it on the surface by eye. I may use this on a sculpture, but nothing structural.

[wagin]

Originally Posted by pulser

As pointed out many times before, mixing SS and CS can lead to a very hardenable chemistry mix, and result in a brittle weld and cracking. You could now have brittle areas in your weld due to tacking with CS, and in any critical application these stress risers would be a liability. I suppose this application of your's is not critical, but this may be a good thing to keep in mind.

The other day I was messing around and welded a copper sheet to 304 SS, and it looked beautiful with no cracks. In theory, melting copper into SS with cause intergranular cracking, and maybe it did in this case to, but I couldn't see it on the surface by eye. I may use this on a sculpture, but nothing structural.

Agreed. Is this process, the stainless plate was attached to carbon angle. I located tacks at corners and welded with 309L.

[pulser]

OK. I guess you're aware of the issues and are comfortable with the tacking situation.