Effect of Austenitic Deformation on Microstructure and Microhardness of 45 Steel

The quenching of 45 steel at different temperatures,deformation and strain-rate deformation were carried out.The relationships between austenite deformation,grain refinement and the martensitic forms were discussed.The results show that: 45 steel is heated to 830 ℃,and then deformated and quenched at 800 ℃,the hardness decreases compared with unstrain hardening.Cooled to 760℃ to quenching with two strain-rate deformation,austenite deformation induced ferrite transformation occurs,the microhardness is lower than those without strain quenching.The results show that the martensitic morphology has effects on the austenite deformation and grain refinement.