Alloy 17-4PH, TIG welding
Alloy 17-4PH, TIG welding
(OP)
On a test assembly for TIG welding alloy 17-4PH, fillet weld, single pass, I get fine cracking at weld toe. Anybody else experienced this?
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Alloy 17-4PH, TIG welding
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RE: Alloy 17-4PH, TIG welding
Are you using a filler?
If so what type?
RE: Alloy 17-4PH, TIG welding
The test assembly is made of a T joint, both members .125" thick, filler material is 17-4PH. Cracks are confirmed of intergranular type and shallow.
RE: Alloy 17-4PH, TIG welding
RE: Alloy 17-4PH, TIG welding
RE: Alloy 17-4PH, TIG welding
You need to have a metallurgical laboratory perform metallographic examination of the suspect locations to confirm the failure mechanism. The cracks need to be observed using an optical microscope to confirm their location (within grain boundaries or within grain interiors). Also, some work using the scanning electron microscope (SEM) may be required as part of the failure analysis. I would have a chemical analysis performed of the base metal, as well.
RE: Alloy 17-4PH, TIG welding
RE: Alloy 17-4PH, TIG welding
We normally used 308 electrodes or on some occasions we did use 630 electrodes. We welded to the 4140 with
Allstate 275 (312).
The cracking you describe sounds very similar to the shrinkage cracking experienced sometimes in the base metal when welding cast iron. My numbers for base metal and electrodes don't show this to be problem.
You state single pass welding, is this a full strength weld?
How is the heat input by the welder?
RE: Alloy 17-4PH, TIG welding
Not sure what you mean by "full strength" weld. Final application may be a butt joint with full penetration in one pass (thickness ranging from .040" to .080", or a Fillet weld, also single pass.
Heat input: for the Fillet weld test, current is approximately 80 amps for a fillet size of .100" to .125". I estimate the welding speed to 3-4 ipm.
RE: Alloy 17-4PH, TIG welding
RE: Alloy 17-4PH, TIG welding
RE: Alloy 17-4PH, TIG welding
One last thought, what shielding gas are you using for GTAW welding 17-4 PH?
RE: Alloy 17-4PH, TIG welding
RE: Alloy 17-4PH, TIG welding
RE: Alloy 17-4PH, TIG welding