I thought that others might benefit from this Q&A on pulse GMAW welding.
I have a cell that I am working on that has a pulse capable power supply. It currently runs .035″ solid lincoln wire.
If I was to experiment with pulse, somewhere in the back of my mind I thought you always taught us to go up to .045″. Is that correct or am I getting confused with some other application?
Thanks for the question. You are correct. This is the reason why various welding “experts” say that going to pulse causes a reduction in penetration that is often a problem. Going up one wire size is the “trick” that puts you back in the same ballpark on penetration, while gaining the benefits that pulse can bring – such as a longer arc length for lower spatter, spatter that is cooler and much less tenacious in adhering, and a different bead profile that often brings advantages.
Now, once you’re in pulse, then the window of opportunity opens in terms of waveform selection/alteration to optimize your weld characteristics for most advantage. Some say that “a factory waveform is already optimized and pulse is pulse”. That’s the voice of ignorance. The Pulse-GMAW process is the waveform, which produces specific results. Repeatability of the results hinges on the consistency of that waveform’s reproduction and stability. Each and every waveform produces a unique balance in target criteria such as travel speed, deposition rate, resistance to burn-through, spatter production, out of position capability, fit-up gap variations, sidewall penetration, bead width/depth, etc. Sure, the “factory waveform” was optimized, but probably not for your factory or specific application. Odds are that the “canned” waveform does not have the target balance you need to get highly optimized results like fast cycle times, zero rework, and no quality concerns. Read the rest of this entry »