Mig Welding A36 Steel

Date 07-14-2004 02:40

Technically you can use GMAW to weld this together. What I mean by this is the process is capable of making a sound weld low hydrogen weld, as long as you avoid short circuiting. The only reasons I can think of why you could not use GMAW are: the process is not permitted by the owner's specifications and you are located in a windy area that would disrupt shielding gas.

Peter Kinney

By jwright650 (*****)

Date 07-14-2004 12:09

I'm curious as to what size (GMAW) mig machine and the size wire you will be using. I ask that to say this, if you have a low amp/small GMAW machine, you may be better off going the low-hy stick(SMAW) route. Also note that GMAW is fussier about cleanliness of the materials at the joint than SMAW or FCAW. Fluxcore (FCAW) is more forgiving about the cleanliness and is deeper digging for more penetration than the solid wire of mig(GMAW). And FCAW offers a wire that is gasless(no external shielding gas needed), where as the GMAW wire does not. FCAW and SMAW can be run out of position is an other advantage over GMAW.
Just a few thoughts to ponder,
John Wright

Give a little more info about your situation, I'm sure other forum users will have more to add.

By rileyc85 Date 07-14-2004 14:04

I would like to use a 220v 200 amp mig to do the welding. probably a .030 solid wire. Would this be ok?

By swnorris (****)

Date 07-14-2004 14:18

Hi Rileyc85,

You could use mig wire. The beam is probably a tri cert beam, ASTM A36/A572/A992, which needs to be welded with a low hydrogen electrode. Mig wire is considered low hydrogen by its very nature. Low hydrogen rods are designated as such because of the flux coating. I'd definitely take into consideration what John and Peter mention, especially the short circuit transfer mode, which AWS D1.1 doesn't recognize as a prequalified process. Keep in mind that at least 80% argon is needed to get above the short circuit mode. For .030 ER70S-6 wire, your amp range should be between 150 and 200, and your volt range should be between 24 and 28. This would put you in the spray transfer mode.