Tips for Tig Welding Stainless Steel using Pulse Settings

Tips for Tig Welding Stainless Steel using Pulse Settings







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http://www.weldingtipsandtricks.com/tig-welding-stainless-steel-parts.html

Pulse tig works good but I like to pulse at 1 pulse per second or over 30 pps.


TIG welding stainless steel perfect
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Question:


I have a question on tig welding steel, basically sheet metal. Everytime I try to do it I get what looks to be carbon boils, the material looks like it boiled and gets porous. I'm using a steel filler, not sure of the composition but can look. I've asked the local welding shop what they do about it and they say they just use a stainless filler rod and they have no problems but, that can't seem to be the right answer, can it?

Machine is an old Lincoln Ideal Arc (I believe) it's old and huge but works great on stainless and aluminum.

Answer:


Cleaning the joint is very very critical. Some alloys will do that no matter what you do. One thing that does help is to use a gas shield. Its a cup and collet body for the torch that diffuses the gas flow so it doesn't swirl in the cone and cause air to get into the joint. If you are doing general welding of softer alloys ER70S2 is a good filler.

Most people talked about the cleanliness. GTAW wire tends to have less deoxiders than other types of welding wire (and you wouldn't want them) so the material needs to be more clean. What fluxes are there will generally form silica slag that will spin around at the top of the puddle. Get too much of that slag and it will start sucking into the weld and generally make it a pain. Same goes with trying to weld on Hot rolled parts with out removing the mill scale or cold rolled parts that still have the protective oil on them.




Now Stainless steel wire does work, 308 would be the preferred grade. Long story short the grain structure of 308 can handle more impurities and oxidation so you can get away with more crap by using stainless steel filler. Not an excuse to weld on dirty material but it helps if you've tried everything else. Often times at our shop I'll specify 308 for repairs or new construction if we are having issues with oxidation or slag inclusions and I use it all the time for personal work because I like the way it welds compared to 70S2


If you getting really bad boiling then it sounds like either your welding very hot, Or you have a shielding issue such as running the gas too high, or a hole in your liner or torch that's sucking in air. That would be my first bet, but it's hard to tell without looking at the weld.