Cryo

My products are all Cryo'd and have been for years. First to reduce possibility of metallurgic failure. Second to reduce surface porosity, reducing surface build up of crud. My products are combat weapons components, exposed to harsh treatment and brutal, 50,000 psi pressures at high cyclic rates. Not knives.

I had two stainless (prorietary composition) Sniper barrels back from Cryo. My Master Sniper printed these barrels and stated the improvement in accuracy over the previous Non-Cryo'd barrels was significant. I agreed. It is not my opinion as a manufacturer; it is the opinion of the Master Sniper who did the tests. He was not aware these barrels were cryo'd; until AFTER the questions were answered.

I never thought much about the claims that Cryo improves accuracy. I always did it for my peace of mind; I offer lifetime guarantees. Now, I know there is some truth to the accuracy improvement hype.

My GUESS is the enhanced accuracry results from the molecular re-structuring and stress relief. FYI: the Non-Cryo'd barrels, all custom made for my company, were "stress relieved" via heat tempering at the factory.

For what it is worth, a first hand perspective on Cryo.

p.s. I do NOT send my stag handled, R2 Damascus Itou's out for Cryo.
greg leaf
www.m16clinic.com
 
Some knives seem to improve with age. Could it be from being used and carried in cold weather, or just from wearing into better steel deeper into the knife from subsequent sharpenings and work hardening from use? Some interesting point in this thread.
 
gregleaf said:
My Master Sniper printed these barrels and stated the improvement in accuracy over the previous Non-Cryo'd barrels was significant.
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There are many claims like this, I would be interested to know if anyone has even done a larger scale study of similar issues.

Bufford said:
Some knives seem to improve with age. Could it be from being used and carried in cold weather, or just from wearing into better steel deeper into the knife from subsequent sharpenings and work hardening from use?
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I would say mostly it is user skill and comfort with the knife.

-Cliff
 
I believe bridge builders also discovered that applying ice to welded joints made the welds stronger.
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no, definatly NO! modren bridge and most other critical weld codes call for welds to be slowly cooled, never quenched, sometimes they are placed in an oven after welding or more commonly pre heated so that the weld cools more slowly. if your reffering to icing AFTER the weld is cooled, I cant see how this would help it. Anyway weldable steels are quite different from steels used in knives.
 
Post Script:

Cryo treatment, done properly, includes the critical, computer controlled time dscent of the temperature, holding at lowest, then time ascent back to room temp. Furthermore, some steels such as stainless need a post-cryo re-heat tempering; 400 series stainless. Re-heat treatment converts brittle Martinsite into hardened martinsite.

From what I understand.............certainly NOT an authority on the process.

greg leaf
www.m16clinic.com
 
gregleaf said:
Cryo treatment, done properly, includes the critical, computer controlled time dscent of the temperature, holding at lowest, then time ascent back to room temp. Furthermore, some steels such as stainless need a post-cryo re-heat tempering;
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I think most would advocate cryo be part of the quench ideally and thus tempering should be post cryo. For use on knives the use of slow decent vs plunge is of some debate. Some very experienced metallurgists who are also knifemakers say a plunge is ok, but they tend to just view cryo as martensite conversion.

-Cliff
 
Ninjajoe: Yes, after the weld cooled....

My understanding of slow cooling is to prevent cracking in thick/irregular sections. Camshafts, engine blocks, rifle barrels have a lot of mass and need to be slow cooled. Knife blades, being thin and of a shape that cools evenly, are OK with a dunk. I have never had one crack.

Tempering is mandatory after cryo. For cryo of already heat treated parts, a stress relief at 300F is generally prescribed.
 
rj martin said:
My understanding of slow cooling is to prevent cracking in thick/irregular sections. Camshafts, engine blocks, rifle barrels have a lot of mass and need to be slow cooled. Knife blades, being thin and of a shape that cools evenly, are OK with a dunk. I have never had one crack.
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R.J., there is some arguement that the long slow process is necessary for the non-martensite part of the process, the carbide precipiation and the rest of the benefits. This however as far as I can tell is of fairly vigerous debate.

-Cliff
 
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