A cryogenic treatment is
the process of treating work pieces to cryogenic temperatures (i.e. below
−190 °C (−310 °F)) in order to remove residual stresses and improve wear resistance on steels. In addition to seeking enhanced stress relief and stabilization, or
wear resistance, cryogenic treatment is also sought for its ability to improve
corrosion resistance by precipitating micro-fine eta carbides, which can be
measured before and after in a part using a quantimet.
The process has a wide range of
applications from industrial tooling to the improvement of musical signal
transmission. Some of the benefits of cryogenic treatment include longer part
life, less failure due to cracking, improved thermal properties, better
electrical properties including less electrical resistance, reduced coefficient
of friction, less creep and walk, improved flatness, and easier machining.
Cryogenic machining is a
machining process where the traditional flood lubro-cooling liquid (an emulsion
of oil into water) is replaced by a jet of either liquid nitrogen (LN2) or
pre-compressed carbon dioxide (CO2). Cryogenic machining is useful in rough
machining operations, in order to increase the tool life. It can also be useful
to preserve the integrity and quality of the machined surfaces in finish
machining operations. Cryogenic machining tests have been performed by
researchers since several decades, but the actual commercial applications
are still limited to very few companies. Both cryogenic machining by
turningand milling are possible.
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