Investigating the effect of as-quenched vacancies in the final microstructure of 1.2080 tool steel during the deep cryogenic heat treatment

In this study, the effect of the as-quenched vacancies on the formation of nano- and micron-sized carbides during the deep cryogenic heat treatment of 1.2080 tool steel was investigated. For this purpose, an electric current with the voltage of 650 V and the current densities of 4.5–2 A was used to clarify the effect of the vacancies as potential sites for carbon atoms jumping during the cryogenic treatment. These atoms produced some appropriate places for carbide nucleation during the tempering. This paper also showed that the common theories in the deep cryogenic heat treatment, which are based upon the dislocation mobility and formation, are not comprehensive and should be reviewed for empowerment.

► As-quenched vacancies are preferential sites for carbon atoms jumping during the deep cryogenic heat treatment. ► Electric current reduced the as-quenched vacancies near the prior austenite grain boundaries. ► Electric current reduced the carbide percentage and its homogenous distribution in the deep cryogenically treated samples as compared to the ordinary cryogenically treated samples.