The quenching hardness of cold work D2 die steel

     The quenching hardness of cold work D2 die steel is mainly related with temperature and heat preservation time. D2 steel transformed into austenite above 950 °C, the quenching hardness reaches above 52HRC. The hardness of D2 steel and transformed into austenite temperature after quenching has a great relationship with the heat preservation time. In 1010 ~ 1040 °C transformed into austenite, when the holding time is 20min, the hardness value is higher, which reached a maximum hardness 64HRC at 1010 °C. In the same austenitizing temperature, after heat preservation 40min, as the heat preservation time increases, D2 steel hardness declining, which is because the carbides dissolution, resulting in carbon content increased in austenite matrix, thereby reducing Ms point, residual austenite increases after quenching.

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