[TheForge] cryogenics

[northwoods]

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