[TheForge] cryogenics

Mon Apr 1 11:11:00 2002

To All,
Cyrogenic treatment for steels drives the martensitic transformation to completion.  It is a thermally activated process so the colder you get the more complete the reaction.  As you approach the nearly complete transformation point, usually slightly above room temperature, things get a little sluggish.  The very low temp provides the reaction with the energy differential to go all of the way.  The success or failure of the treatment all depends on the conditions used to austenitize and quench the work.  If you do it by the book, you should see a positive effect.  If you are sloopy with times and temperatures, you are on your own. The more complete the reaction, the more predictable will be the tempering response and final properties. 

Cryogenics are not a fix for bad procedures.

Hochewa

In a message dated Mon, 1 Apr 2002  9:21:06 AM Eastern Standard Time, "northwoods" <[email protected]> writes:

> I've heard a lot over the years on the subject of freezing knife blades, gun
> barrels, and other assorted parts in an attempt to make them...better in
> some way I guess. What is exactly going on at the molecular level in a piece
> of metal when this treatment is used? People have told me that they have
> done this to brake drums on vehicles and it has increased the wear
> resistance.
> Does freezing a piece relieve stress, also what else does it do and has
> anyone ever had any experience with the process?
> 
> T. Clark
> 
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