Welding Tips and Tricks

can one weld stainless ( gas or electric ) with regular steel rods if if one accepts that the weld wont have stainless properties??
or is it true that regular steel wont mix/alloy with iron/chrome/nickel of the stainless during the melting?

thanks,

bill in nc

I have done it with Mig.

I suppose it would depend on the alloy and the amount of chromium and nickel in it.

You can weld stainless with mild steel filler but you can't weld mild steel with stainless. Like you said, when you weld stainless with mild steel filler, you won't have the stainless characteristics. And never do this for anything that is structural. Do it only for a temporary fix.

This turned up today while I was searching for something else, you might find it useful-
http://www.articlesnatch.com/Article/We ... ipe/941542

I asked a very similar question when I was determining the best filler rod for 5052-H32 to 6061-T6 aluminum. The answer was to use 5356 filler but it had to be thoroughly merged with both alloys in the puddle. When I asked how that was achieved I was told as long as I kept a good flowing puddle with good even penetration I'd be fine.

From what I've read, the technique comes from doing what you're asking about.

Sschefer-My tig instructor passed us out a niffty little chart he got from ALCOA, and it had -every- alloy of aluminum on it, shown welding to any other alloy, with any kind of filler metal, and the properties you would get using what filler, etc... I'll look it up and see (unfortunately mine was in my snappack that was stolen out of my car) if I cant post it on here.

edit:http://www.alcotec.com/us/en/support/up ... hart-2.pdfIll post this in the tig forums too.

kermdawg wrote:Sschefer-My tig instructor passed us out a niffty little chart he got from ALCOA, and it had -every- alloy of aluminum on it, shown welding to any other alloy, with any kind of filler metal, and the properties you would get using what filler, etc... I'll look it up and see (unfortunately mine was in my snappack that was stolen out of my car) if I cant post it on here.

edit:http://www.alcotec.com/us/en/support/up ... hart-2.pdfIll post this in the tig forums too.

Thanks Kerndawg, I use that chart quite a bit. If I could get my danged camera to synch up I'd show you what I'm working on.

thanks for the good feedback. today i tried to weld 2 stainless steel spoons together with a-fluxcore wire and b-oxy/acy ( reducing flame ) with mild steel electrode.

i could tell the process went better where i ran the electric wire brush over the spoons to knock off the metal oxides. the gas welding went best ( good solid weld ) when the penetration got below the surface zone, as if welding 1/4" would be easier. i believe ill buy some of the stainless welding flux and try again.

Thanks Kerm! This will be valuable to me as well. I printed it and posted it by my desk...lol.

Ya its posted here on the site already. :p That chart is so incredibly handy, everyone should have a copy of that if their welding any aluminum.

How did we go from welding stainless & mild steel to welding aluminum???

jpence38 wrote:You can weld stainless with mild steel filler but you can't weld mild steel with stainless.

Whom ever told you this lied to you.
You can certainly weld mild steel with stainless.
In the boilermaker field, doing xray welds all the time, stainless is known as "magic wire" when tigging in roots.
If you have a nasty, infected tube, that keeps getting porosity in the root pass, a filler of stainless makes all the troubles go away, and I have yet to ever fail an xray with this technique.
I have done repairs here around home, and welded mild with stainless, and have yet to ever have a failure.
I fabbed up a set of long handle wrenches, made from two sets of Craftsman end wrenches, they were welded with stainless tig, and I have been using them for several years now, with no problems.

Well, you won't fail an x-ray because the x-ray cant tell the pass was made with stainless. Because of the dilution of the stainless root from the mild steel, you are getting by with it. We are talking about plate. Also, I can guarantee that your hand tools aren't mild steel either which makes a big difference. Perform two identical welds with the combinations of mild and stainless and then bend test them and guess which one fails first. You can practically get any two ferrous metals to mix together, but that doesn't mean you should.

A carbon steel bead on stainless will have, say, about 30% stainless (18% chromium 8% nickel) dissolved into that carbon steel.
Turns the bead into a nice air hardening tool steel.
An OK weld, just don't use that Widgit for anything practical, lest it snap.

Sorry, guys, I am a metallurgist not a welder.

I use 309 stainless rod pretty commonly at the sheet metal shop I work at when I am have porosity issues from laser slag. But that obviously non critical stuff, just saves time so it doesn;t have to get re welded after it gets ground because of porostiy.

Hi all, you should be able to do that with a Tig.......I say this because I use a Plasma welder, the Multiplaz 3500, that has been discussed at length elswhere on the forum, and one of the jobs I did was to coat a mild steel surface with a layer of stainless steel, mainly for appearance, but it flowed on like you would get if you were tinning steel with soft solder, so I would expect the opposite also if you were adding mild steel to stainless.

Once you have the weld pool formed the added metal just forms another alloy mix in the weld pool, less than stainless quality, but it will mix.....for whatever reason you want to go down this path.

I can't say the same for Mig with plain steel wire, as you are bound by the melt requirements of the steel wire, and you might not get the base metal to melt before the wire which means you just end up with blobs of steel on the surface of the base metal and no mixing.

A stick electrode would probably fare better as it has more body to get the stainless base metal up to melting point before the mixing occurs.

The last job I worked on before I retired in 2001 was to add a stainless steel layer 30mm thick to a steel surface on a steel wheel for a rock wool machine.

The wheel was undercut to a depth of 30mm, and the 319 stainless steel was welded on in layers with submerged arc........this was stainless on plain steel......never did the reverse.
Ian.