Microstructure and mechanical properties of 20Si2CrNi3MoV steel treated by HDQP process

A combined process of hot-deformation plus two-step quenching and partitioning(HDQP)treatment was applied to a low-carbon 20 Si2CrNi3 MoV steel,and transmission electron microscopy(TEM),scanning electron microscopy(SEM),X-ray diffraction(XRD),Vickers hardness and tension test were used to characterize the microstructure and mechanical properties.More stable retained austenite due to fine microstructures and typical curved micromorphology is obtained,and the newly-treated steel obtains more retained austenite because of the effect of hot deformation.The retained austenite fraction increases and then decreases with the increasing quenching temperature from 200 to 350°C.The maximum retained austenite fraction(18.3%)and elongation(15%)are obtained to enhance the ductility.