Professional welding advice?

[slomove]

I am not a master welder, well maybe not even apprentice level but I do use my MIG welder with good results. Sometimes it just takes a grinder to make the welds look nice :jester:

 

Anyway, usually I take the mild steel wire to weld normal steel and the 308 stainless wire to weld stainless parts. Today I was too lazy to swap the spools and welded some regular steel (actually a cheap wrench) with the stainless wire and the weld looked really good, I guess better than welded with the mild steel wire.

 

So, a question....besides the more expensive wire, is a stainless weld wire strength-wise comparable to a mild steel wire when used with non-stainless parts? Just curious....

[KiwiBirkin]

It will be fine Gert probably even stronger i'm a sheet-metal worker/welder by trade and if we don't have any mild steel wire for tig welding we will use AMS 317 which is a S/S wire for general use and will be fine welding mild steel.

[JohnK]

From my build files: 300 series stainless in not heat treatable, therefore it is immune to mass quench effect. The weld metal will not be embrittled by cooling, and since stainless is very ductile it also reduces the stresses in the joint due to contraction of the adjacent metal. That makes it a good choice for welding 4130 chassis tubing, particularly heavy cluster joints. Also it's good for welding dissimilar steels since it suppresses outgassing of sulfur, lead, etc, which makes it a good choice for welding free-machining steels used in some steering spline weld-on ends (free-machining steels contain lead for ease of machining).

 

A note on MIG: When faced with building a steering column which required welding spline ends to (plug fit) a hollow shaft, I found out my TIG machine left me in the lurch. Because TIG is slow, building such a shaft will result in unacceptable warpage. The solution is MIG because can do the weld before things move out of line. I wound up taking it to a driveshaft place where they have a MIG (with stainless wire) plus a lathe to handle such problems.

Edited September 24, 2010 by JohnK

[slomove]

Thanks guys, that simplifies life!