heat treating 440c

[W.B. Cameron]

It's time I used this new Heat Treating oven.
So here's my question.
I have a standard recipe for 440c.
What I'm wondering about, is will it benefit from a cyro between
tempering cycles?
Any ideas???
Bill

[tmickley]

yes it will, do the cryo after heat treat or if are worried about to much stress, do a low temp snap temper at 250 for an hour, then cryo, then at least a couple tempers.

[W.B. Cameron]

Thanks for the information.
Btw Why do they call it a "snap temper"??
Bill

[RJ Martin]

Bill: You can snap temper first, but, it's not necessary for 440C. You can freeze right after quench. Then, double temper. the Crucible data sheet that you can access at the sticky at the top of this forum will steel you right for 440C.