Yes it is for aerospace, the thickness of the casting is about 0.250", the 718 is annealed prior to welding. The reason that I think we need to preheat the casting is past experience with inspection of castings, granted those castings were not inco but I was thinking what's good is good for the gander.
I'm new to this company and they have been building this part for about a year, with little to no success. With my NDT, fab shop and field experience I'm trying to figure out their problem without stepping on too many peoples toes ( a lot of seniority here ).
I did find out that they are using ams5537 to weld up the entire part, even when they are joining 718 to 718. I was told about a filler wire called
"filler 82" but I have never heard of this one and I'm not sure where to find info about it.
With everything I have learned since I first posted the question, at this time I just need advice on the preheat and the "filler 82".
And thank you Lawrence, for taking the time to answer me back and for teaching me how to properly use this forum.
Inco 718 is a precipitation strengthened superalloy
Inco 625 is a solid-solution strengthened Nikel-base superalloy
There are several choices for fillers to join them. But those are high level engineering decisions that greatly depend on the service of the parts.
Is this a flange on a compressor? TMF? LPT? Stator? Blade? Vane?... Rotating componant?
As Ringo mentioned, cobalt alloys like Haynes 25 (L605) have been used since the 60's for crack repair and wear abrasion build ups.. Newer alloys like GE's propriatary Nozzaloy has proven itself superior to Haynes 25 in a number of applications. But I love Haynes 25..... Welds like buttah!
Over the years I've Inco joined 718 to dissimalar metals with everything from 347 stainless to Rene 41 to Haynes to 718 or 625....... Every time somebody else made the filler decision.
The general rule of thumb with Inco 718 is to keep heat input to a minimum to minimize grain growth... So preheat with inco 718 is uncommon in the repair world...... In fact I've never encountered a procedure that required it.
Service temps, vibration, rotation, wear, airflow, cycle types all must be considered when making this selection high level decision. This is a call far beyond the scope of this forum. But it's still fun to talk a bit about it :)
Is your project a repair of an engine part or a new fabrication?
All this engineering has been done before by somebody. There are standard practice manuals for every major engine vendor for both fabrication and repair....... If your working on GE equipment or Pratt or CFM or any other vendor, you should have access to those standard practices. These will help inform your engineering staff.
Finally... Those repairs should be driven by class 1 doccumentation if were talking about jet engines... Those repair docs should provide specific filler metal requirements specific not only to the part but the part # of the componant itself since manufacturers make alloy changes in production from time to time. This should not be guess work.
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