has anyone tried welding stainless steel pipings with flux-core? mig welding stainless to mild steel??? someone has done it right?? how does it hold? any info and pics would be great. thanks in advance.

 

I had it done by a friend in an emergency pinch. Its still holding (2 months later), but I cant say it looks great.

 

i have done it at work
instead of straight flux-core, use flux-core with gas

straight co2 shielding gas is recommended
although 25 or 20% co2 w/ argon would give
less spatter, slag that peels off easier, & weld appearance is better

i actually like flux-core with gas when welding steel
imo, it makes the smoothest weld bead out of all the processes including tig
its a hell of lot faster and you can weld in a breeze where mig/tig would be affected
i do get more buggers tho with flux-core

 

So it's "the smoothest weld bead but you get more buggers"?

Are you serious? BTW, it's still MIG even if it is flux-core.

On a realistic note, there is no proper method for using a flux core wire on stainless steel. PERIOD.

 

well , i meant smooth as in "no apparent bead/ripples."
in an industrial setting you don't want separate beads/ripples...
although pretty, they are prone to cracking & failure.
i should have mentioned it is only really recommended in an industrial.
yes, more buggers because of using gas & the flux that burns off the wire.

the majority of the work i do is industrial plate & pipe using stick & tig.
in an industrial setting (where it should be used since its for thicknesses > 1/8")
yes, there are true welding procedures for using it on stainless.

flux-core with gas (fcaw-g) is often overlooked.
it has deeper penetration than mig, but deposition rate just as fast.
the base metal distorts less; produces uniform bead
and u can use it harsh environments.
i was amazed by my first fcaw-g bead that i ran
after learning stick, mig, & tig yrs ago.

if you've ever run it on steel w/ correct settings,
the finished bead looks like it was forged in the steel!
it looks exactly like the base material & smooth as butter
with no apparent scale or oxide around it in the HAZ.
thats a acceptable finished weld bead in structural.
no stacked coins/ripples.. that can cause fatigue
leading to stress fractures.

 

ive welded mild steel to stainless with flux core. its still holding fine, but its not showroom looking material