Does pulse tig make any difference on 4130 chromoly tubing?
I think it does. But not a huge difference.
Some welders, especially in the motorsports industry, actually pulse the welding current with the foot pedal...and that is usually about like one pulse per second give or take. The reason for manual pulsing with foot pedal is the moving the torch around a small round tube joint works better when you can control exactly when the pulse happens.
Personally, I see the benefit in using higher pulse speeds.
Like 30-50 pulses per second.
On a metal like 4130 chromoly that hardens by quick cooling, it does not make sense to me to use a slow pulse speed with low background current.
see more videos on tig welding 4130
But high speed pulse using over 30 pps can really help with gaps.
And gaps are something everyone deals with. When you are welding .030" thick tubing and you have a .060" gap, you can have a hole happen real quick.
using a pulse rate of 30-50 pps helps. It seems to make the puddle more stable and heat does not build up as quickly.
You really notice this when you are near an edge. the puddle just does not wander over to the edge as easily.
Pulsing the foot pedal like that is one way that some welders control heat input. I have seen also seen really good results without pulsing.
Some Old schoolers out there are still under the impression that 4130 chromoly tubing can only be welded with a gas welding oxy acetylene torch.
Well thats the old way to do it, and it definitely works, but
There is a whole bunch of Engineering data available on the web that endorses tig welding chromoly with no preheat or post heat stress relieve treatment. As long as the tubing is under a certain thickness (.120" thick) , it can be tig welded with E70S2 filler without problems.
I know one thing....I would rather tig weld 4130 chromoly tubing than gas weld it anyday of the week.
Keep in mind, I am strictly talking about thin wall tubing under .120".
4130 also comes in thicker tube as well as plate.