Carbide Precipitation During Tempering and the Mechanical Properties of Martensitic Wear Resistance Steel
摘要
The properties of martensitic steel are influenced by carbide precipitation from martensite. Here, two types of tempering were adopted to control the precipitation. One is one-step tempering at a temperature, which makes the precipitation at the interfaces of the martensite laths with 45% carbides by tempering the quenched steel at 200 °C. Another is two-step tempering first by tempering the steel at a lower temperature and then by doing at 200 °C, which makes the carbides fine and the precipitation mainly in martensite laths due to a larger nucleation rate of carbides with calculation value of 9.5 × 1022 s⁻1 m⁻3. The samples with the best properties have impact energy of 36 J and mass loss of 141 mg by two-step tempering. Compared with the samples tempered only at 200 °C, they show 20% increase in impact energy and 42% reduction in mass loss.