Another Sub-Arc Girter question
Another Sub-Arc Girter question
(OP)
We are using a single wire SAW tractor with L-61, 5/32" wire, Lincolnweld 980 Flux to weld up some 1.5"-2" thick girters. We're using a double-bevel groove weld (TC-U5-S) but the customers want us to do this without backgouging, so this becomes a procedure we need to prequalify, correct?? Any tips on settings or procedure for doing this and has anyone done this before? Any help is greatly appreciated.





RE: Another Sub-Arc Girter question
If they really need a full pen. weld, then backgouging is more than likely needed. This might be the case on a flange plate splice which is highly loaded, perpendicular to the potential defects. But, then you have the wrong weld joint designation. And, I would most likely UT this weld after completion.
RE: Another Sub-Arc Girter question
Since you're using Lincoln products I'd suggest you get with their technical department for suggestions on welding parameters. Once you have those, things like joint geometry, land thickness, fit up and wire placement are critical.
Two methods I've used are, 1. a flux backup which typically requires some additional equipment, and 2. careful choice of joint details, fit up and welding technique.
You have to consider that with the latter method wire placement is absolutely critical. If the wire is off one diameter, which isn't much, you may lose the required penetration and with a tractor,it's easy to move off the mark.