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Hey folks,Came across a nice sheet of 347 SS, .020" thick today. I haven't tigged SS before - only plenty of mild (.06-.188 thk) and I'd like some advice from you experienced folks on where I might start when I go to practice on this stuff. I know it's not an ideal SS or thk to start with, but eventually I'd like to give it a go. Probably start with just running some beads, then butt, lap, corner & fillet joints.Electrode - Diameter and type?Cup Size?Filler - type and size?Gas Flow? (Argon)Amps?Setup - backing strips/plates/fixturing methods?Will I need to back purge on the joints?I have a Dynasty 200DX.....I know that a lot of the criteria I'm asking for varies with joint type, setup..etc, but looking for a good starting point and any general words of advice (besides "just don't do it! )Not sure what I'll use it for yet (maybe a nice birdhouse, box, somethign creative?..lol) - I'm sure I'll come up with something.PS - I've looked up some general info on tiggin SS, but theres not much on 347, hence the majority of reason for my post.MikeMiller Dynasty 200DXHypertherm PowerMax 45Victor OAIR CompressorLots of blacksmithing tools and other fun toys meant to creatively disfigure, reshape, manipulate and join metal.
Reply:The alloy, 347 SS will weld just like 304/316, no problem. In fact it is a special grade that is "stabilized" with niobium additions to prevent chromium carbide precipitation and loss of corrosion resistance due to welding.The tough part is that 0.020" is very thin, and SS warps extremely easily. The easiest joint to weld will be an outside corner weld, which would work well for some kind of box type project. If you can fit-up the corner joint very tight, with-out any gaps, and put very tiny tack welds every 1/2" or so, then you can simply fuse the weld joint without having to add filler metal. It will help a lot to securely clamp a tight fitting backup bar (copper ideally) on the inside of the joint to help prevent burning through. Without a good tight backup bar, you'll have to shield the backside with argon to prevent sugaring (severe oxidation).1/16 or 0.040" sharp, 2% Thoriated or anything but pure tungsten.whatever cup size that allows you to access the joint and clearly see the weld puddle.No filler needed on the outside corner joint, that's the beauty of it. A butt or fillet weld with filler on something this thin is a job for an expert/artist.Argon and 10 cfh, indoors with no breeze.Amps, probably 15 to 20 constant current, around 1 amp per 0.001". Experiment with some pulsed current, see this site for ideas on pulse settings.http://www.pro-fusiononline.com/welding/pulseparams.asphttp://www.pro-fusiononline.com/welding/pulserate.aspAlmost forgot, you'll need to hold an extremely tight arc length. Ideally for machine welding, I'd set the gap at no more than 0.035", for hand welding try to hold less that 1/16" for sure.Last edited by pulser; 04-15-2009 at 07:11 PM.
Reply:Thanks Pulser - Thats the kind of feedback/info I was looking for. I know its a little over my head at my current abilities, but I definitely want to work towards practicing in this realm of welding.I'll have to post some pics when decide to go for it! MikeMiller Dynasty 200DXHypertherm PowerMax 45Victor OAIR CompressorLots of blacksmithing tools and other fun toys meant to creatively disfigure, reshape, manipulate and join metal. |
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发表于 2021-8-31 23:49:11