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Highlights: [•] Deep cryogenic treatment increases the hardness and war resistance. [•] Increasing he cooling rate of quench environment, improves the hardness and wear resistance. [•] Increasing the β precipitates, improve the hardness and wear behavior. [•] Predominate wear mechanism is abrasive. [Copyright &y& Elsevier]

Abstract: 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. [Copyright &y& Elsevier]

Abstract: Deep cryogenic heat treatment is a supplementary process, which is performed in tool steels after quench and before temper regularly. In this study, the effect of the electric current flow through the deep cryogenically treated samples was investigated via the X-ray diffraction (XRD), scanning electron microscope (SEM), energy dispersive spectroscope (EDX), hardness test, and pin-on-disk wear testing machine. Results showed that the deep cryogenic heat treatment improves the carbide percentage, distribution, hardness and wear resistance of the 1.2080 tool steel, as compared with those of the conventionally treated. Further improvement in the wear resistance and hardness were also observed due to the formation of some newly formed nano-sized carbides in the structure. It was also observed that the electric current flow leads to a decrease in this improvement due to its effect on the as-quench vacancies, which were ignored as powerful places for carbide nucleation during the deep cryogenic heat treatment. It was also shown that the predominant wear mechanism is a combination of adhesive and tribo-chemical wear. [Copyright &y& Elsevier]

Abstract: This work concerns with the effect of applying an external magnetic field on the corrosion behavior, wear resistance and microstructure of 1.2080 (D2) tool steel during the deep cryogenic heat treatment. These analyses were performed via scanning electron microscope (SEM), optical microscope (OM), transmission electron microscope (TEM) and X-ay diffraction (XRD) to study the microstructure, a pin-on-disk wear testing machine to study the wear behavior, and linear sweep voltammetry to study the corrosion behavior of the samples. It was shown that the deep cryogenic heat treatment eliminates retained austenite and makes a more uniform carbide distribution with higher percentage. It was also observed that the deep cryogenic heat treatment improves the wear behavior and corrosion resistance of 1.2080 tool steel. In comparison between the magnetized and non-magnetized samples, the carbide percentage decreases and the carbide distribution weakened in the magnetized samples; subsequently, the wear behavior and corrosion resistance attenuated compared in the magnetized samples. [Copyright &y& Elsevier]

Abstract: 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. [Copyright &y& Elsevier]

Abstract: In this paper, the effect of magnetic field on the structure and hardness of deep cryogenically heat treated 1.2080 tool steel was investigated, via scanning electron microscope (SEM), Rockwell C, and microhardness evaluations. Testing at two different holding durations showed that as a result of the deep cryogenic treatment, the homogeneity of carbides distribution and the carbides percentage in the structure is increased; in contrast, retained austenite vanishes. Furthermore, the results showed that by applying the magnetic filed during the deep cryogenic treatment the start and finish martensite temperatures (M s and M f) increase; subsequently, the carbides distribution in the magnetized samples are less homogeneous than that in the non-magnetized samples. Also, in the magnetized deep cryogenically treated samples, the retained austenite completely vanishes; however, the final structure showed a lower carbides percentage compared to the deep cryogenically treated specimens. [Copyright &y& Elsevier]