I found some scrap stainless the other day and thought it was about time i gave it a try. I am using an Everlast 140st lift arc on 240v with 3/32 lanthinated tungsten. 1/16 308L filler, #8 cup with a gas lense on a 17 torch and 15cfh of argon.
So I started out on the top left at 40amps. It took a few moments to puddle and was very slow travel. I bumped it up to 60amps then progressed all the way to 140 amps on the last row. I see it progressively lost its coloration. Was this due to the faster travel and losing gas shielding? Or does stainless not change color at higher temps?
After a little wire brushing.
Any input is apreciated as I am just learning TIG.
There is allot to this subject. One big factor will be your cup setup, use a gas lense(sorry just saw that you did use a #8 lense). It makes a HUGE difference. Second, coverage and travel speed somewhat go hand in hand. The reason you get colours is when the steel is over a certain temperature and is not being shielded it will oxidize. The temperature and contents of the air will decide the colours of the weld. If your travel speed is too slow you will put too much overall heat into the workpiece and it will stay really hot after you have welded it. If you travel too fast you are not giving the steel enough time to cool before it is no longer in the shielding gas. Stainless will always use less amps then carbon steel. My best advice to you is to keep a really sharp tungsten, if there is any imperfections in the tungsten the arc will fan out causing more overal heat input into the material and less heat into the actual weld where it counts. Also, I have found it really helpful to use lower amps and get a puddle started, dab at it quickly and very steadily move the torch while keeping the arc at the leading edge of the puddle. The arc seems to be more concentrated when it is on the puddle.
Hello Brad, welcome to the forums
If you continued to weld without letting the base material cool down, then that is the reason the last set of beads turned gray, the metal was too hot and the air caused the contamination
LtBadd wrote:Hello Brad, welcome to the forums
If you continued to weld without letting the base material cool down, then that is the reason the last set of beads turned gray, the metal was too hot and the air caused the contamination
Correct, I see this as your main issue for the "gray" color.
I weld stainless, stainless and more stainless...Food Industry, sanitary process piping, vessels, whatever is needed, I like to make stuff.
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