Is it normal to have oxidation on a stianless weld after you weld with TIG? No matter what I try it is oxidized but comes right off with a wire brush. Also I dont get the neat colors just plain shiny. Is this right?
Stainless ???
Flux
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as said, the 'neat' colours are due to oxidation. they show the extent of oxidation that occured (how hot the weld was when shielding was lost as the torch moved).
http://www.bssa.org.uk/topics.php?article=140
it's normal but the acceptable 'colour' depends on application... http://www.bssa.org.uk/topics.php?article=2
if the welds are grey then somethings amiss. assuming good gas coverage (no leaks) then typically it could be to much heat input (welding too hot and/or slow) or the other favorite, not keeping the end of the filler within the gas shield (remove it and the hot end will oxidize and the next 'dip' will introduce oxides into the weld)
http://www.bssa.org.uk/topics.php?article=140
it's normal but the acceptable 'colour' depends on application... http://www.bssa.org.uk/topics.php?article=2
if the welds are grey then somethings amiss. assuming good gas coverage (no leaks) then typically it could be to much heat input (welding too hot and/or slow) or the other favorite, not keeping the end of the filler within the gas shield (remove it and the hot end will oxidize and the next 'dip' will introduce oxides into the weld)
pics of SS color versus oxygen content in purge gas.
http://www.intercononline.com/welding/ypurge.htm
http://www.intercononline.com/welding/ypurge.htm
did you properly read the previous posts and links? colour, any colour IS the result of surface oxidation at elevated temperature. brushing a weld/HAZ that is gold, purple or blue will result in a shiney colour free finish too- brushing removes this 'thickened' oxide layer
the colour indicates how much oxidation occured- grey is severly oxidized
contaminated argon could be the cause (never experienced it or for that matter even heard of the problem prior to reading about it on forums- cylinder filling is more heavily regulated in the UK). the most common causes are...
it's pretty easy to eliminate shield gas (bad gas, leaks) as the problem- strike an arc, form a puddle and then stop the arc without moving the torch until the post flow stops. the spot weld/tack should be colour free
if the weld is cleaner (better colour) when done without filler then that would point to oxidized filler being the problem
if you post details of machine settings and thickness of stainless used we'll be able to tell you if you're in the ballpark with regards to amperage, flow rates, post flow etc
the colour indicates how much oxidation occured- grey is severly oxidized
contaminated argon could be the cause (never experienced it or for that matter even heard of the problem prior to reading about it on forums- cylinder filling is more heavily regulated in the UK). the most common causes are...
- too much heat input (typically begin with 10% less than for carbon steel)
- not keeping the end of the filler within the gas shield, allowing it to oxidize
- arc length too long (heat is less focused as arc length increases meaning more is required thus increasing overall heat input). no longer than electrode diameter, preferably 1/16" or as short as possible
it's pretty easy to eliminate shield gas (bad gas, leaks) as the problem- strike an arc, form a puddle and then stop the arc without moving the torch until the post flow stops. the spot weld/tack should be colour free
if the weld is cleaner (better colour) when done without filler then that would point to oxidized filler being the problem
if you post details of machine settings and thickness of stainless used we'll be able to tell you if you're in the ballpark with regards to amperage, flow rates, post flow etc
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At work we have been delivered our usual big liquified tank that was marked argon but we found out later it had been mis-marked, it was nitrogen. We couldn't weld anything with it and sent it back to trade for another. The welds looked like we weren't using any gas at all.
not sure how familiar you are with TIG, but make sure you are pushing the torch, rather than pulling. also, the color, as everyone has said, is a direct result of oxidation. silver or the same color as the base metal is the best, but gold is very lightly oxidized, fucia/pink/red a little more, purple a bit more than that, and blue is the most. gray, from my understanding is severe oxidation and/or carbonizing of the base metal. in order to combat this, also as previously stated, either move your hand faster or turn down your heat. i tend to turn down my heat a bit so i have more control, do not feel like i am being rushed, and can ensure proper penetration and puddle shape/size.
Later,
Andy
Later,
Andy
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I have run nitrogen through a TIG torch as well. It kind of created a weak plasma ray. A lot of big white flashes. Similar to pure oxygen being run through actually.DesertRider33 said:
I had only done this for some kind of understanding of what each gas did. I was more then aware of how wrong it was.
Sincerely,
William McCormick
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Flux said:
No color, is best, shinny pristine metal is best. It is certainly attainable.
However for different jobs it can become very hard to maintain. With stainless steel it is usually ok to turn it a shallow purple.
Sincerely,
William McCormick
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Na, I push it and it does nothing. I wait. I press it again. And it blinks a couple times. I don't know.MicroZone said:Still haven't figured out that "post reply" button, eh Willy Mac?
Sincerely,
William McCormick
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