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Old 08-25-2004, 10:15 AM
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Ed Caffrey Ed Caffrey is offline
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My short answer to doing cryo without liquid nitrogen is no. Dry Ice and Acetone can be a hazardous mixture to use. The other drawback is that it will only achieve about -70F, which would take an extraorinary amount of time to achieve any conversion. There are several schools of thought concerning this, and this is just mine, but I have experiemented with the process and found little benifit from trying to cryo with dry ice/acetone.

Cryo treatment will often times cause an Rc hardeness test to read a couple of points higher but you have to remember that your converting austinite to martensite. If you worried about the extra hardness, my suggestion is to temper the blade after the cryo treatment at 25F higher than the previous temper cycle(s).


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