Forging of SS304L and grain boundary carbides
Forging of SS304L and grain boundary carbides
(OP)
We have ben forging SS 304L grade steel in the temperature range 1150 - 1000 C and water quenching. Further it is Solution annealed and water quenched (soaking at 1060 C - 1 hour per inch thickness). we are getting grain boundary carbides despite the solutionizing treatment. can anybody what could be the reason for this? Sometimes the finish forging temperature goes as low as 900 C.





RE: Forging of SS304L and grain boundary carbides
RE: Forging of SS304L and grain boundary carbides
What is your C and N level? Is it low enough?
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P.E. Metallurgy, Plymouth Tube
RE: Forging of SS304L and grain boundary carbides
RE: Forging of SS304L and grain boundary carbides
The only other option is to check the condition of the in-coming material, for any possible macro-segregation issues.
RE: Forging of SS304L and grain boundary carbides
It should not sensitize at that C level, unless there is a lot of segregation.
How are you cooling? You will need something faster than a natural cooling rate, such as fans with water spray.
1150C should be fine for solution anneal.
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P.E. Metallurgy, Plymouth Tube
RE: Forging of SS304L and grain boundary carbides
"Even,if you are a minority of one, truth is the truth."
Mahatma Gandhi.
RE: Forging of SS304L and grain boundary carbides
RE: Forging of SS304L and grain boundary carbides
If they really are carbides then either the material have some significant segregation which accelerates the process,
Or they are not carbides.....
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P.E. Metallurgy, Plymouth Tube
RE: Forging of SS304L and grain boundary carbides
I'd think keep the 1140 F degrees because he is so thick, but soak much longer, then try to quench faster. ?? But that's an opinion, not based on the metals he has.
What we don't know is if the problematic crystals are appearing at the surface, or deep within the 4 inch thick mass of his casting.
RE: Forging of SS304L and grain boundary carbides
RE: Forging of SS304L and grain boundary carbides
Finally, I agree with the suspicion of Ed Stainless: are really Carbides ?
Or Boron precipitates ?
RE: Forging of SS304L and grain boundary carbides