Continuous cooling transformation behaviour of 30CrMo steel simulated by CSP process

The continuous cooling transformation (CCT) diagram of 30CrMo steel simulated by compact strip production process was constructed. And the effect of austenite deformation on the CCT behaviour was investigated. The results showed that the microstructure gradually transformed from proeutectoid ferrite and pearlite to bainite and martensite with the increase of cooling rate, accompanying a refined microstructure and an increasing hardness. When the cooling rate was lower than 0.1°C s−1, the desired microstructure of ferrite and pearlite could be obtained. And the austenite deformation strongly promoted the formation of proeutectoid ferrite, which led to a decreasing hardness of deformed steel. When the cooling rate was larger than 10°C s−1, the fully martensite microstructure was obtained. And the austenite deformation inhibited martensite transformation, resulting in a decrease of the martensite transformation starting (Ms) temperature from 391°C to 368°C.