shaggy56

I have access to a cryogenic freezer thats capable of freezing down to -1000f and has a digitally timed control to lower and raise the temperature at 1 degree increments. The freezer is large enough to temper a whole engine. I have access and know the owner of a major chemical developmental lab. I have found detailed information on how it is done.

The material is slowly cooled to -
320F (-196C) and "soaked" at that deep cryogenic temperature for
20-40 hours. The material is then allowed to return very slowly
to ambient temperature. The complete cryogenic cycle can take up
to 72 hours to complete. This procedure of precisely controlled
temperature profiles avoids any possibility of thermal shock and
thermal stress that is experienced when a tool or part is
subjected to abrupt or extreme temperature changes.

Do you think it can be done and would anyone have any added info?

Sonix

iTrader: (1)

yea, you're basically heat treating it. It's the cooling that develops your microstructure, so even after cooling past room temp you still get changes.
I thought you'd want to bring it up to temp first, then cool it right down to that cold.
Holding at a cold temp for a while... Isn't that spheroidizing? We're going over heat treatments in class today...

I think it mostly improves wear resistance, according to posts here on TGO, althought that doesn't match up logically with the process you described...

shaggy56

I actually copied and pasted that from a cryogenic tempering website that does all kinds of cryogenics. I can link you if you would like. They never actually mention heating the parts till after the freezing process.

Stage-II&III Cryogenically Treated Materials