welding 303 SS

from a quick google, it looks like you should be fine if you can get the proper rods...looks like the stuff is prone to cracking though...but so is cast iron, and I've had good results fixing that stuff with 0.035 and straight CO2 with no pre or post heat (yep, broke ALL the rules on that one) so there ya go...YMMV of course
give it a shot, let us know how it went...
-- Big Ben BS266 the "hell, ya never know until ya try it" Slug

It tends to crack like crazy. They do make a 303Si that has silicon added that makes it possible to weld. It can be welded using very low amps and 309L filler, but you have to be very careful to keep dissolution of the filler rod into the base metal to a minimum.

Most references I've seen is that it has poor weldability but if you have to do it use 308L electrode.
that implies, to me, that it can be welded. But if it is a work of art, perhaps you can use silver soldered :-)

For Art I would think about brazing. Might look really nice. I also did some googling, and found someone that recommended brazing with aluminum bronze.
Dan

Big Ben wrote in sci.engr.joining.welding on Thu, 10 Feb 2011 18:58:46 -0800 (PST):
If I go into work tomorrow(sat.) I will give it a shot. From what I found on the web, 308 filler rod, low heat, minimum penetration. I'll be using TIG so straight AR for gas.

Ernie Leimkuhler wrote in sci.engr.joining.welding on Thu, 10 Feb 2011 19:19:37 -0800:
Thanks Ernie, that confirms what I found on the web, except most said to use 308 filler. If I get into work tomorrow, I'll give it a try with the 308 I have.

john B. wrote in sci.engr.joining.welding on Fri, 11 Feb 2011 18:40:35 +0700:
I could solder, but I prefer the look of the base metal melted into a puddle/bead. On some pieces (steel, 304SS)I don't use filler, and make a lot of undercutting. Non metalworking folks think it looks cool when they can see that the metal has melted. They don't understand what a proper bead is. And the heat marks look cool too. If TIGing it doesn't work out, I think would use a metal colored epoxy.
And thanks.

snipped-for-privacy@krl.org wrote in sci.engr.joining.welding on Fri, 11 Feb 2011 05:06:10 -0800 (PST):
Thanks, but I wanted the melted metal look. I'll try TIGing it tomorrow with some 308 filler and see how it goes.

308L is a poor choice. It has a little too much shrinkage. 309L and 312 are the better choices for difficult stainless steels.
Even better are the high nickel alloys, such as Inconel 625, but they are also way expensive.
The most important thing is to keep the heat down.

Ernie Leimkuhler wrote in sci.engr.joining.welding on Fri, 11 Feb 2011 17:47:14 -0800:
All I have now is 308. I'll see if my LWS has any 309L or 312 on my way in to work.

If you are welding outside corners in sheet metal you could also consider an autogenous weld, with no filler. Very tight joint fit up is required (either fixtured or very well tacked, fixturing preferred) and one piece must project a bit beyond the corner to serve as the filler. Keep the puddle very small, about 2x material thickness or just enough for adequate penetration, use just enough projection to melt down to a nice square corner. I have seen a lot of really nice looking and structurally sound welds done this way making boxes from 16 gage 303. Inside corners require more heat input and butt welds are more rigidly restrained from thermal expansion and contraction, both of which increase risk of cracking, I have not seen either done in production welding of 303.
Glen

We used to do fusion welded butt welds by turning up a tiny (1/16" to 1/8") lip on one of the pieces. Exactly the right amount of filler material, just get the puddle started and go. Distortion is always a problem on flat stock though.

So I gave it a try today and it worked out better than I had hoped.
And I got some pics. Full directory: my welding cart: I grabbed some bad parts from the scrap bin and a piece of 308 filler rod. First, three parts that have a hexagon profile, three welds holding them together. Welds were polished with a red scotchbright wheel. Then one of the hex parts and another part: Then I tried some fillet welds on crossed pieces: Some similar parts and did a butt weld without filler: (sorry about the over exposure) Better pic: Then I took some larger pieces and ran a butt weld: side: about the size on this last one, don't know how that happened.
I had put my camera away, and then thought to use the larger chunks to make a fillet weld and see how it busts with a hammer.
It broke through the bead, and showed incomplete penetration at the root, as expected.
When making the welds, I was sort of brazing with the filler, trying not to dilute the puddle with base metal.
Not for anything structural for sure. But for "Objets d'art", works just fine.

(...)
That was my experience with SS as well. Stuff welds like a dream.
However!
A few days after I did my SS repair, I noticed corrosion that looked just like rust appearing within a couple mm either side of my autogenous weld.
Ed Huntress put me straight on that!
Apparently, I should have supplied a generous quantity of filler rod to replenish some of the kinds of metal I was boiling off.
From now on, I will use the proper filler rod on SS.
Lesson learned.
--Winston

try E 312-16 welds anything to anything (almost)