"John R. Carroll" wrote in message
...

"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




But the poster thinks that cyro treating is going to make his piece harder,
sharper and tougher, ain't gonna' happen like he thinks. I'll refer to my
bud George Fisher of "Ion-vacuum Technologies" http://www.ivactech.com/
George knows cutting tools and materials and is probably one of the top 10
physicists on the planet. We've discussed cyro treating many times and I
relayed his opinion. It seems you'll get a different opinion from people
that do cyro for a living...kind of like global warming.