Microstructure Evolution and Tempering Transformation Kinetics in a Secondary Hardened M50 Steel Subjected to Cold Ring Rolling

The microstructure evolution and tempering transformation kinetics of the M50 steel subjected to cold ring rolling (CRR) have been investigated. results indicate that brass R{110}<110> texture is weakened with enhancement <111>//ND during CRR. Due increased low angle boundaries by CRR, Ac1 temperature decreases while carbon content volume fraction RA increase. During tempering, activation energy atoms segregation transition carbide precipitation decrease, retained austenite (RA) decomposition increases after kinetic analysis shows CRR beneficial beginning tempering. Then, leads delay onset precipitation, but whole reaction time, which has verified transmission electron microscopy (TEM) hardness results. lagging in early stage caused trapping atoms, higher nucleation rate responsible for enhanced later stage. For cementite formation, there are no significant changes predictive applied However, inhibited attributed smaller grain size RA. Additionally, alloy carbides also process secondary hardening.