Hello everybody. I'm new user and I hope that you'll help me to find informations about welding of Inconel 718. I have problem with FPI indications on welds and I suppose it's related to coagulation process during welding. I'd like to read more about it but google didn't help to much. Maybe some of you could provide any links? Thanks in advance
Hello pandox, first off welcome to the forum, I believe you will find that this is a great resource for this and other questions like it. If you are able to familiarize yourself with the search portion of the forum that is the first place that I would turn to for some information. Click on the "Search" at the top of the page and enter a topic such as "Inconel 718", I believe you will find a number of discussions that will be of use to you. If you don't feel that it is covered by using that search keyword or phrase then try some others or word them differently such as possibly: "Inconel 718 welding challenges" or something along that line. Best of luck and regards, Allan
Ok I'll try to give more details. Material its a sheet metal, about 0,04'' (1mm) thick. Annealing after welding. Shape of the part is flattened pipe. New fabrication, GTAW. Here are some pictures taken from Scanning Electron Microscope: http://img230.imageshack.us/img230/3002/rybi4.jpg
Wow... Nice pictures.. You must have an excellent facillity.
It looks like the third image is of a Tee joint fillet... If I'm wrong about this than disregard the rest of my response :)
The first thing I noticed is that at least on the last picture the fillet size appears to be about three times the material thickness.. A weld that big might be cause for liquation cracking in the HAZ. I would hazard to guess that distortion may also be an issue.
Is the required weld size actually that big?
Also I see no ripple in the weld deposit... It looks very hot and wide, like a lay wire technique with a large diameter filler or even GMAW.
0.040 thick inconel plate with GTAW would require between 30-50 amps and a 0.045 diameter filler wire is optimal for manual and if your welds are semi-automatic than you could run 0.020 diameter filler and get a fillet leg size about equal to the material thickness. 1/16 tungsten electrode max.. 0.040 optimal
Torch is traveling in one way, then goes back around 5mm and more filler material is being added to avoid concavity of the root which is unacceptable.
I don't remember parameters because I'm dealing with this issue very short and I still have problems to check everything what is nessesary. But tommorow I'll be ready :)
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