really hard stainless steel

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new to the tig machine , ive gotten decent results with aluminum thus far so i guess im not totally lost.i got some stainless from a scrap bin a while back when i worked for a elevator fab company. not sure what kind it is .but its not magnetic and very hard. when i try to weld it it turns black no matter what. tried everything without asking for help/directions (typical male behavior) wire brushed till shiny with steel brush, used acetone,thought maybe the filler wasn't compatible so i tried not adding any... same mess.tried more shielding gas... that helped a little but as soon as i tried with filler it turned crusty black again. setup: 3/32 1% lanathated (black) modified point . 100% argon 8 liters/minute. (need to get a CFH one) , ~ 70 Amps , #6 cup ,  DCENFiller: 3/32 & 1/16 ER308L (cleaned w/ steel wool and acetone)oh and i was inside so there was no breezeany thoughts ?
Reply:Maybe 303 SS. It does not take a weld appreciably well.And then, after so much work...... you have it in your hand, and you look over to your side...... and the runner has run off. Leaving you holding the prize, wondering when the runner will return.
Reply:if it's a machineable grade it's considered non welded able. You could try grinding back the surface with a flapper disk to bright metal in case it was surface treated somehow.  Acetone and brush will only get you so far I prefer to tap everything with a flapper disk prior to welding.  Also make sure the brush isn't contaminated.Any reason you're not using a 2% thoriated?  Also a #6 cup seems kinda small for such a large electrode. the first test would be having the pre flow on and just making a spot on the plate without moving. If it's still getting nasty contamination it means it might be pulling it from the plate.
Reply:I'm new at sst TIG too.  You said you used a steel brush.  I think you're supposed to use a stainless steel brush (but I might be wrong...I know "clean" sst brushes are required on aluminum).Miller 211 w/ spool gunMiller Dynasty 200DXLongevity 60i IGBT plasmaO/A w/ crappy chinese torch/gaugesSouth Bend 10K latheGrizzly 4029 10x54 millGrizzly 7x12 hor bandsawangle grnders, bench grnder, bench belt sndr7.5 hp 80gal cmprsor
Reply:Originally Posted by RojodiabloMaybe 303 SS. It does not take a weld appreciably well.
Reply:The grade of stainess should have no effect on the weld color, if the shielding were perfect, the weld would be shiny with no color like the base metal.  Perfect shielding is impossible except in a chamber, so some gold and light blue is acceptable, even purple, but not black.  Either the base metal surface is contaminated or your shielding sucks.303 SS is a machinable grade, considered un-weldable because is has very high sulfur content to help the chips break easily, but this causes hot cracking, typically straight up the centerline of the weld while welding.Strange that you say you have had success with aluminum on the same machine.  If shielding was a problem you would think the aluminum would be rough looking with surface porosity.Lets see some pics.Good point about looking at the tungsten color as mentioned above.
Reply:303 isnt readily weldable but i've done it in a pinch and it shouldnt turn black. I vote for there being a coating on the parent metal.Last edited by i4sillypwr; 03-08-2010 at 07:54 PM.Reason: i'm a tard
Reply:i say try 2%... if not that, use 333 wire.. it works for all stainless...  304,309,316,cast,etc... if those two don't work, spark test.. it might be titanium... lol..if you're not livin on the edge, you're takin up too much room..
Reply:Originally Posted by ibanezed4yrsi say try 2%... if not that, use 333 wire.. it works for all stainless...  304,309,316,cast,etc... if those two don't work, spark test.. it might be titanium... lol..
Reply:Are you sure it's stainless? Stelite  is non-magnetic also, & extremely hard, almost to the point of being fragile. I did a little playing around this morning to see what ST- would look like if I laid a bead. 120 amps DCEN, 3/32 1.5% lan. tungsten, 1/16 ER308L filler, 18 cfh argon with 10 sec. post-flow. This is the result I got. Does it resemble what your getting? Attached Images"SOUTHPAW" A wise person learns from another persons mistakes;A smart person learns from their own mistakes;But, a stupid person.............never learns.
Reply:Oxidised Ti turns white not black. I'm with Pulser on this, from the description sounds like coked/sugared stainless but if gas coverage is that bad aluminium should be unweldable too. Need pics or at least more info, i'm thinking elevator company = very light gauge austenitic stainless + no mention of purge/solar flux = oxides pulled through from backside of joint and one big black crusty mess
Reply:Originally Posted by sn0border88None of that would be of any help to the OP.  Its not being caused by the tungsten, so switching to 2% isnt going to help.  333 Wire also isnt going to be of any help because if you read the post you would see that it becomes black with or w/o filler.  And a spark test isnt going to get you very far on stainless.
Reply:Originally Posted by hotrodderOxidised Ti turns white not black.
Reply:A picture would most deffinately help. A spark test could also be helpful in determining if it realy is stainless steel or not. I don't know much about the construction of elevators, but could it be some kind of cast iron or such for brake pads?
Reply:sorry for the delay . my camera got stuck between the scissor mech of a recliner a few months back had to barrow one . i fused to pieces together and it seemed strong.. didnt crack along the weld (maybe not machine ready ? ) maybe i will try a sulfur test on it with the photo paper?i put one pic of my aluminum. i know its sloppy ive only been tig welding for 2 weeks but it was to show the shielding is ok. i saw someone said there might be a coating on it so i ground some down on the grinder thats why its rough (dont die grinder yet) i raised the gas from 7 Liters/minute to 10 then 12did one spot each . then attempted to use filler at 10 L/min. then brushed the black crap on the end of each weld. pre-flow was 2 sec,post-flow was 10 sec .held it there till the air stopped to answer all the questions:the tungsten didnt change color and held its tipthe brush isnt magnetic and its shiny so i think its stainlessas far as heat goes. i would find it hard to be to hot because with the puddle i had i could barley keep 1/16 filler from cooling it down. i didnt have any larger cupswhy not 2% thoriated.. : almost everything i know about TIG i read from the web and there alot of mixed emotions it seems. i have no problem using it not worried about the radioactivity. im sure welding in general isnt the healthiest thing in the world. i think i will try those next.the reason i think its SS is because it was in the recycling bin for SS and everything in it looked the same. they must have taken some effort to seperate the metal because the SS was separate from brass and aluminum and mildi googled 333 filler and the spark test . nothing turned up i think that covers all of them Attached Images
Reply:Never saw anything like that before. My first thought is a bad bottle (possibly not even argon), or some kind of contamination inside the gas envelope. I could very well be wrong, but that is where I would start looking.  What kind of angle are you holding on the torch? Is the base metal free of moister? I'm sure others will have more ideas as to what may be causing it. Pulser is quite knowledgeable and may have some other suggestions.
Reply:Too much heat/ moving too slow. Low gas volume, or mixed gas/ bad gas. Papabear, there should be no appreciable moisture content in any steel not wet, and not outdoors.And then, after so much work...... you have it in your hand, and you look over to your side...... and the runner has run off. Leaving you holding the prize, wondering when the runner will return.
Reply:Originally Posted by RojodiabloPapabear, there should be no appreciable moisture content in any steel not wet, and not outdoors.
Reply:never had that kind of bad gass .. nuch nuch
Reply:Originally Posted by Fizzle6325never had that kind of bad gass .. nuch nuch
Reply:Your just getting it way to hot.  If it was a gas problem you would either see it on the tungsten or the aluminum so go ahead and rule that out.Also you can see one one of the spots where you just struck an arc in one spot you got some color bands that resemble what you should see on stainless.Learn how to control your heat and you should be good to be.I think I know the answer already, but what does the backside look like?Have we all gone mad?
Reply:first the gas now people want to know what my back side looks like . ok joking aside .its not sugared like you would expect. when i did those welds i tryed to keep the heat down as much as possibal. i had just gotten the puddle started before i killed the arc. and on top of that i was using a 3/32 tungsten with 1/16 filler. when i would add filler it stalls the heat. i thinking maybe trying a blunt tip ? the modified point is only about 1/4" . just went and tryed with the torch on a heavy angle to kinda pre-heat the filler and eaze the heat along but no good. hear are some pics of the back side. slightly raised in a few spots but no heavy sugar. oh and that edge on view is not a weld. thats just the edge from the plasma. i took that one to show that the burn though isnt raised at all. Attached ImagesLast edited by Fizzle6325; 03-09-2010 at 11:20 PM.
Reply:You're probably burning through to the other side. The contamination (sugar) then floats up to the top of the weld. Just look at some of your other welds. The edge weld you did looks good. Some of the spot welds look ok too. But notice how the spot welds with the pin holes are black like your bead? The pin hole indicate that you're burning through. I see the ends of some of your welds in the aluminum pic, again, pin holes indicating to much heat/burn through. Try some kind of backer, less heat, or higher travel speed.
Reply:ok. I take my last post back, just saw the back pics. You are burning through, but since your right on the table top, there's no air, and thus no sugaring on the back side. Hmmm. I'm stumped.
Reply:How thin is that scrap? I'm now leaning toward the too much heat theory, as in; moving the puddle (bead) too slow. And you shouldn't be burning through.You are just moving to slow and cooking the material.  I've seen the exact same thing before while making an attempt to teach a co worker to tig. Try a pass with no filler at your 70amp setting. hold as close of an arc as you can without dipping the tungsten. Just keep moving faster until you get some color. I can't really tell how thick that is from the picture. I'm guessing maybe 1/8th in? Going "colder" isnt always the answer with stainless. It doesnt dissipate heat very well so moving faster at a hotter setting can help you achieve the results you want. So just because we are saying its too "hot" doesnt always mean you should turn the amps down. Just practice without filler until you get some decent results color wise. Then add some filler, get frustrated again and keep practicing until you get that down too. You'll be just fine.
Reply:its 3/32" thick
Reply:Move the pool faster.
Reply:I did some more experimenting this morning trying to duplicate your weld bead. I think I found the answer to your problem;Way too much angle of the torch. Forcing you to travel slower than you should, while also giving insufficient gas coverage.I did use 303 reject castings with 1/16 ER308L filler at 70 amps 15 cfh gas flow.I will post pics this evening showing what I found.
Reply:I didn't think I had an open USB port on my work computer. But I do, so here goes.. Attached Images
Reply:i tried that angle papabear. same blackness . gonna pick up a gas lens later. see if that helps. i tried higher amps / fast travel, but it flared up so bright i couldn't look(shade 13). also gonna order some SS of a known type to practice on. is  304 good to learn ?thanx for all the help. my trade is electronics so if you have questions about that Email me, id be glad to help. if i ever get this figured out i will let u know. just trier AC and i made ther pool move much faster but still black.Last edited by Fizzle6325; 03-10-2010 at 12:59 PM.
Reply:I'm stumpedAre you keeping the filler inside the gas envelope?You are dipping the filler at the leading edge of the puddle, Yes?
Reply:yeah leading edge. and i keep the filler close enough that it dont ball but not to far. i just tryed AC and that enabled the weld to heat up and travel much faster but it still turned black. im gonna bring some down to the local welding supp. see if they have any insight . and im gonna try to find the weldig instructor in-between classes see what he says. i think i got some strange steel.  back in 2003 i took a Tig class and i didnt have nearly as much trouble with SS. im kinda tempted to offer sending you some of this material.
Reply:Sent you a PM.