American Welding Society Forum
4340 is a AISI designation. We are joining the same alloys and engineering wanted like materials used as a filler to the part would respond to the heat treating process. The filler we are using is a tubular material made by Weld Mold. We believe that the problem is due to humidity either being sucked in or there from the start. Welding does not seem to be a problem, as we have done this many times and results seem to be consistant with the amount of "fireworks" emitted from the molten tig puddle. As a note, we just found solid vacume melted material at Universal Wire, for a mere $67.00 /lb. Any advice would be appreciated.
I know what AISI 4340 is I weld it almost every day I just never heard of trying to use it as a filler.
All I can tell you is that filler material is designed with chemistry that aid in the joining of materials. 4340 is not a filler of that sort it is the exact same as the base material and unless you duplicate the process at the steel mill that produced it how do you figure to achive the same results.
The fire works you mentioned is from the carbon reacting to the atmosphere. 4340 has plenty of carbon but you are takeing it out of solution with your welding process. The way I understand it you are doing more harm than good.What kind of process are you useing? GTAW? GMAW? do you have a trailing gas? are you purgeing. You mentioned that you found wire that has been "vacume melted" dosent that give you a hint as to what might be the problem.
Thanks for the return. Yes, we trail and back gas, and would like to here if your welds with Er100 (I believe that is what you said) will have the same/similar mechanicals as the parent metal. Our choice is mandated by the government boys and unless I can offer good reason to change it, my request will be denied. The fireworks I refered to is from the tube filler that we have, Vacume melted material has nevere caused any problems in the past. We have hesitated to use it due to cost and long deliverys. The joint is a butt joint single "u" groove configuration. Preheat (700 Deg. F) is used to reduce cracking followed imeadiatly by an anneal. Any hints/ your method would be appreciated. If you like phone calls My toll free number is 888-808-9353
Thanks again Jerry Cotter
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