Study on CCT Curve and Microstructure Evolution of a Vanadium-Containing Steel Rebar

Abstract

The microstructure evolution and hardness change were studied for a vanadium-containing steel rebar at different cooling rates. The experimental results show that bainite and martensite gradual emerged with the increasing cooling rate and resulted in an increasing micro-hardness. Bainite or ferrite and peartite should gradually disappear when the cooling rate increased to a certain value. The cooling rate should be controlled below 10°C/s to ensure good performances. The CCT curve of HRB400E measured with the inflation method and metallographic-Hardness method could provide the theoretical basis for controlled cooling process.