TIG welding IN718

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I have a requirement to weld a IN718 part using IN82 weld filler. This i s in the age heat treat condition, which will make it more dificult.....any thoughts?
Reply:So, GTAW correct? Care to expand on the details a bit?  Thickness, joint, etc...
Reply:GTAW is the only way to go on this as far as I am concerned.I would use 718 filler wire. Inconel 82 was not listed as a filler wore for 718.#82 was listed for the 600 series and 330 only. You can Google that. Weld in the heat treated condition.The HAZ will be slightly softened but that is a good thing in this case.Cracking is what you do not want.This metal is usually used in the afterburner sections of jet engines.Some aircraft wheels are made of this metal because of its tolerence for heat.to re heat treat if you have the facilities here is the formula.But then you bring up the whole subject of RE heat treating and or just stress relieving. If it is nit on the plane you might go with ultra sound as a stress reliever.There are free aircraft welding consultants on the web.go to:http://www.eng-tips.com/viewthread.c...=207135&page=1Also any IA can give you the WPS's for this repair. If they are worth their salt.Although IA's are usually weak in this area.i got my info from a metalurgical engineer. I always like to go one step further...know what i mean? Cover your self because you are signing it off.Last edited by Donald Branscom; 03-03-2008 at 04:11 PM.
Reply:I found an old procedure for Alloy 718.  I agree with DB filler metal, use alloy 718 (AMS 5832) unless you are required to use IN82 by plan or engineer.  I would recommend double checking that even if they think they are right.GTAW of 0.10" total thickness, 3 layers [email protected]" [email protected]"Joint type: EdgeElectrode: 0.040" 2% ThoriatedFiller: 0.035" Alloy 718Shielding: Ar @ 20SCFHCurrent: 50A DCENArc Volts: 9.4Travel speed: 15IPM on a welding latheProbably not what you are doing, but this stuff is not too exotic.  Play around with it.
Reply:I believe inconel 82 is for dissimilar metals.  It has a good post weld hardness and is resistant to cracking.  I don't know if that makes it superior to 718 filler metal.  Probably not unless you are welding 718 to another material.   I consulted welding process setup people once and used inconel 82 to weld 718 inconel to 316L and that worked.  I did not age the 718 before or after welding, so I was welding annealed, as machined 718.  The parts had been machined from round bar.  I've been trying to figure out whether it is advisable to age thin 718 sheet stampings prior to welding them with inconel 82.  It seems people with knowledge on the subject are very rare.