Abstract:
The cryogenic treatment of tool steels has transformed
over centuries from black art to science, but the
metallurgical principles responsible for increase in wear
resistance, tensile strength, toughness, and stability are still
disputed. Metallurgists comprehend how tool steels respond
to cryogenic treatment, but they also understand that for
many years, the cryogenic treatment of tool steels had the
reputation of being a quick fix for poor heat treatment
practice. During the cryogenic treatment of tool steels, the
process modifies the carbon present in the tool steels.
However, cryogenic treatment has not been widely adopted
by the cutting tools industry due to lack of understanding of
the fundamental metallurgical mechanisms and due to the
wide variation in reported research findings. In the present
paper, an attempt has been made to review the literature on
metallurgical changes that occurred during the cryogenic
treatment of tool steels to benefit the cutting tools industry.
The prominent reasons found to be responsible for
improving the mechanical properties of tool steels are
transformation of retained austenite to martensite and
precipitation of fine carbides.
