Stainless pipe test advice

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Tomorrow morning I have a test on 6 inch schedule 80 stainless steel pipe. I've welded a lot of stainless but mainly thinwall like schedule 5 and 10. I've done a lot of tig on carbon too. I'm just asking if there is anything different from schedule 80 carbon to schedule 80 stainless besides having  a good purge and letting it cool between passes Also should I leave my purge on for the entire weld or can I shut it off after several passes Thanks
Reply:Originally Posted by Jde120Tomorrow morning I have a test on 6 inch schedule 80 stainless steel pipe. I've welded a lot of stainless but mainly thinwall like schedule 5 and 10. I've done a lot of tig on carbon too. I'm just asking if there is anything different from schedule 80 carbon to schedule 80 stainless besides having  a good purge and letting it cool between passes Also should I leave my purge on for the entire weld or can I shut it off after several passes Thanks
Reply:If I'm not paying for the argon by all means leave it on.It will not only reduce the chance of sugar coming through it also helps carry heat away from the coupon. Stainless is Imo by far the easiest material to make a nice slick weld.
Reply:If I'm not paying for the argon by all means leave it on.It will not only reduce the chance of sugar coming through it also helps carry heat away from the coupon. Stainless is Imo by far the easiest material to make a nice slick weld.Here is some reading if your interested. http://www.millerwelds.com/resources...t-I-do-at-work
Reply:I always leave my purge on until the weld reaches 1/4" thickness. It doesn't need to be a heavy purge after the root is in, i would set it at 15-20cfh after the root just to keep it pretty. I do like to let the material cool a little between passes too. Reputable sources say max interpass temp for austenitic and duplex stainless is 300 degrees fahrenheit.IAMAW Local 330Airco 300 AC/DC HeliwelderAirco Dip-Pak 200 with Profax spool gunPowr-Kraft AC225Everlast PowerArc 200stBuffalo Forge No.21 drill pressSpeedglas 9100xxAirco, Oxweld, Purox, Victor torchesLincoln Ranger 8
Reply:Thanks for all the help What would the starting amps be for the root? I like to run a 5/32in gap and backfeed the wire. My guess it would be similar to carbon? Sent from my HTC One using Tapatalk
Reply:Probably a little cooler than carbon pipe. Heavy wall 6" will take the heat I usually drop a range sch 40 and thinner.