"Buerste" wrote in message
...

"JoanD'arcRoast" wrote in message
. ..
I shape my wood lathe tools by hand, and then heat treat in a campfire
and quench in used motor oil.

I have access to LN2, but wonder if it would make a noticeable
improvement of the O-1.

I know I will encounter inefficiencies due to Leidenfrost effect, even
if I pre-chill the steel to minus 80 C. (Perhaps I can roto-vac to make
slush, I'll have to explore that.)

Opinions?

Do you think my methods are too primitive and hit-or-miss to achieve
better sharpness and edge retention on the lathe tool?

Am I barking up the wrong tree? Would the little extra hardness gained
not be desirable for this application?

Pointers? Links?

Thanks for taking the trouble to read this mess,
-j

I've heard from experts that cyro is smoke and mirrors.



Cryogenics Process
ASM International, the Materials Information Society, acknowledges cryogenic
processing as a valuable heat treating process - and one that is distinctly
different from "cold" treatments (-120 degrees Fahrenheit). Cryogenic
temperatures are those below - 244 degrees Fahrenheit.

A typical cryogenic cycle includes slowly lowering the temperature, holding
at -300 degrees Fahrenheit and then slowly returning to room temperature. In
many instances, a short heat tempering cycle is used to complete the
process. The cryogenic process can take up to seventy hours to complete,
depending on the composition and amount of the material being treated.

U. S. Cryogenics' state of the art equipment is capable of achieving
temperatures between -315 degrees Fahrenheit and +315 degrees Fahrenheit
according to specified profiles. The unique ability to reach these limits in
the same machine allows for a more controlled process, eliminating
unnecessary handling and exposure of the payload to the environment prior to
the completion of the profile/run.

U. S. Cryogenics is a leading provider of cryogenic treatment.


The best thing said is cyro provides superb stress relief.

Cryogenic treatment: 1) converts retained austenite to martensite in
hardened steels; 2) relieves residual stresses; 3) precipitates fine eta-
carbides in appropriate steels; and 4) is suspected of refining the
crystalline structure of the metal. These metallurgical changes result in
reduced residual stresses and increased abrasion resistance, fatigue life,
and ductility.

Your application and your level of correct heat treatment limits what you
can do.

True but it might be worth fooling with if he were so inclined.

A little research would seem in order.
http://www.uscryogenics.com/index.html
http://www.cryogenicsinternational.com/
http://www.nitrofreeze.com/cryogenic_treatment.html

JC