Investigating the effect of the quench environment on the final microstructure and wear behavior of 1.2080 tool steel after deep cryogenic heat treatment

Deep cryogenic heat treatment is an add-on heat treatment which has been added to the conventional heat treatment to improve the wear behavior of cold worked tool steels in recent years. In this study, the effect of the different quench environments with different quench severities, including water, oil, air, −30 °C ethanol and −195 °C liquid nitrogen upon the final microstructure and wear behavior of the 1.2080 tool steel was investigated. Results showed that increasing the quench severity decreases the retained austenite before the deep cryogenic heat treatment, and the final microstructure shows a more homogenous carbide distribution with higher carbide percentages. Despite the low quench severity of liquid nitrogen, the samples quenched in this environment show the highest wear resistance and hardness after the ethanol-quenched samples. This behavior is a function of a very low quenching temperature and a long incubation time for the nucleation of other phases except the martensite. The wear rate and hardness of the ethanol-quenched samples shows the highest values due to the low temperature, higher thermal conductivity (as compared with the liquid nitrogen) and a less stable martensite structure. The formation of nano-sized carbide also shows an important role in the improving mechanical properties. The predominant wear mechanism is adhesive wear.

► Deep cryogenic increases the carbide percentage, makes a more homogenous distribution and eliminates the retained austenite.
► Quench environment affects carbide distribution and microstructure due to the severity of quench media and temperature.
► Virgin martensite does not show any significant potency in carbide formation during the deep cryogenic heat treatment.
► Wear behavior improves with increasing the thermal conductivity of quench media or decreasing its temperature.