Investigating the effect of holding duration on the microstructure of 1.2080 tool steel during the deep cryogenic heat treatment

This study concerns the effect of the holding time at liquid nitrogen temperature during the deep cryogenic heat treatment on the microstructural changes, carbide distribution, carbide percentage, hardness and microhardness of 1.2080 tool steel. These analyses were performed via the scanning electron microscope (SEM), optical microscope (OM), transmission electron microscope (TEM) and X-ay diffraction (XRD). The obtained results showed that there is an optimum holding duration in which the carbides exhibit a maximum percentage and the most homogenous distribution as compared to the other soaking durations. It was also shown that by increasing the holding duration beyond the optimum holding duration, the hardness, microhardness, carbide percentage, carbide distribution homogeneity and particle size reach a constant value and do not change. (C) 2012 Elsevier Ltd. All rights reserved.