pulse?

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Im a little embarresed to say that I dont know how to use the pulse on my welder.I have been using this welder for ten years and just tried the pulse today and Im not sure what the advantage is for this feature.I am a micro welder for the plastics industry and have been tig welding for ten years but this is the only tig I have ever welded with.There is pulse width,pulse rate,upslope,and downslope.This is a weldlogic welder,and I am using .062 lanthanated tungsten.I also use filler rod ranging from .003 to .020 dia.Mostly 420 stainless and a variety of tool steels.Is there any pointers that you guys could give me on this or should I just not use this feature.Nobody in my shop has any formal training so were kind of winging it.   Thanks
Reply:If you're welding on dies for the injection molding industry, then there's limited use for pulsing(in my opinion).  Pulsing is used to reduce the average heat input.  This reduces distortion and burn through on thin metal.  I think this is the main area that pulsed TIG is meant to help.  It should also make it easier to weld out of position.  In the type of work I think you're doing, it might be good for limiting shrinkage when you fill in pits in the die surface.  Anything that would benefit from lower heat input would benefit from pulsed TIG.  It would be good for shrinking the heat affected zone around the weld bead.  Mold repair might see some benefit from this if you're trying to avoid doing any post weld heat treatment...Pulse width would be the duration of the peak amperage, or how long the arc is at high tempPulse rate is how often the arc switches from high current to low currentUpslope is how long the arc takes to transition from low current to high currentDownslope is how long the arc takes to transition from high current to low currentI've never met anybody who had a general guideline for how to adjust all the parameters in pulsed TIG.  Everyone seems to just expereiment until they either find a set of parameters that works better, or they give up and go back to using a pedal or constant current settings...Benson's Mobile Welding - Dayton, OH metro area - AWS Certified Welding Inspector
Reply:I am a micro welder for the plastics industry ..., using .062 lanthanated tungsten.I also use filler rod ranging from .003 to .020 dia. Mostly 420 stainless and a variety of tool steels...
Reply:I'd also love to see some pics of the types of things you work on.  Sounds neat.
Reply:http://www.pro-fusiononline.com/welding/pulseparams.aspEd Conleyhttp://www.screamingbroccoli.com/MM252MM211 (Sold)Passport Plus & Spool gunLincoln SP135 Plus- (Gone to a good home)Klutch 120v Plasma cutterSO 2020 benderBeer in the fridge
Reply:A_DAB, that is a very good explanation.I could see that high speed pulsing may help with arc stability and puddle wetting while maintaining a continuous puddle similar to constant current.Low speed pulsing may not be desirable, since at its extreme, each spot weld is solidifying very rapidly and then is partially overlapped and remelted, a much different heat cycle than constant current.  Not sure what the effect might be metallurgically with highly hardenable mold steels.But in general a pulsed weld can achieve the same penetration at a lower average current. which as mentioned will reduce the size of the HAZ, which is generally a good thing.
Reply:Thanks a dab.That was a great explanation.I will try to post some pics of my work.
Reply:http://www.millerwelds.com/resources...-Productivity/Ed Conleyhttp://www.screamingbroccoli.com/MM252MM211 (Sold)Passport Plus & Spool gunLincoln SP135 Plus- (Gone to a good home)Klutch 120v Plasma cutterSO 2020 benderBeer in the fridge