When tools and other heat treated metals are cooled to very cold temperatures, -120°F or below, unstable phases are transformed, making the part very stable at normal use temperatures. This treatment is performed by slowly cooling the parts in a controlled bath of liquid nitrogen or other refrigerant, and holding the parts until the temperature has reached the target temperature, then returning the part to room temperature. The resulting part will have low distortion tendency, and often is significantly stronger and tougher.
- Increases resistance to abrasive wear
- Improves the microstructure of the metal, not just the surface
- Parts may be subsequently reground or machined without affecting the results of the cryogenic process.
- Decreases residual stresses, while increasing toughness and dimensional stability
- Improves resistance to impact