Annealing 17-4PH
Annealing 17-4PH
(OP)
Would anyone care to speculate on what dew point level would need to be specified to avoid embrittlement of 17-4 in a hydrogen (bright) furnace @ 1950°F?
I have found some incredibly helpful information here in other threads as I have researched this project, hopefully I haven't missed a reference where the question is already answered.
Thanks,
-------Jason





RE: Annealing 17-4PH
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Plymouth Tube
RE: Annealing 17-4PH
Thanks for the response. I had found the text below in the Allegheny Ludlum data sheet for 17-4, and am concerned that the "bright" requirement might not be good enough. I've got some parts that became brittle with an H2 exit DP of -40. It sounds like my furnace might not be too far away from being able to do this, if I can get it tightened up a bit.
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Material in the annealed condition should not generally be put into service. In this condition, the material has an untempered martensite structure and is less ductile than aged material. The untempered martensite may be subject to unpredictable brittle fractures. In corrosive environments, the untempered martensite is more sensitive to embrittling phenomena such as hydrogen embrittlement than material which has had one of the precipitation hardening heat treatments.
Jason
RE: Annealing 17-4PH
The bigger issue is that if your surface isn't truly bright the oxide skin can trap hydrogen in the alloy and make it very difficult to remove.
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Plymouth Tube
RE: Annealing 17-4PH
RE: Annealing 17-4PH