Cryogenics of parts Options

[lmcchesney]

I'v brought up this topic before, shoptalkforums, PP and I think here, but have never gotten a finished result/direction. I know that the topic is filled with proprietary beliefs, but there must be some good experience here or a source of reference to expand our knowledge.
Thanks,
L. McChesney

[ArtechnikA]

the research continues.

some people believe it's The Ultimate Solution.
some people believe it's The Ultimate Con.

some of each will never change their opinions in the face of any evidence.

the broad feeling is that for parts that are never heated to a major fraction of their interesting metalurgical-change temperature, it can do some good. (i.e. - any possible marginal benefit in brake rotors for track service is not worth the cost.)

especially for stressed parts that undergo flexure - springs - it seems to have quantifiable benefit. it may improve hardness and toughness without the usual increase in brittleness - which is the traditional non-cryo tradeoff in the search for high-Rockwell-number hardness.

mind you, this is all for steel. probably carbon (i.e. not 'stainless') steel, although that's a less-well documented area. some people claim great results with nonferrous materials such as aluminum alloy; i can understand how it works with ferrous materials - i have yet to see a plausible chemical explanation for how it can possibly work in aluminum. (not to say it doesn't, or it can't - but if it -does- it would involve some mechanism i simply don't know of. but i am not a metalurgist...)