Influence of Quench and Tempering Temperature on the Microstructure and Properties of 20SiMn2MoVA Steel

Using optical microscopy、impact and tensile test,Study the effects of different quenching and tempering temperature on the microstructure and mechanical properties of the steel 20SiMn2MoVA.The results showed that, at the test temperature range,with the rise of quenching temperature the tensile strength of steel 20SiMn2MoVA declining, Low-temperature impact energy along with the quenching temperature rise was increasing. After quenching at 920°Cand tempering at different temperatures, with increasing tempering temperature, the tensile strength of the material showed a declining trend, impact toughness values were rising trend has decreased, 220°Ctempered impact toughness appear peak. Below 300°C tempering is tempered martensite and a small amount of residual austenite; More than 300°C tempering, residual austenite begins to decompose, carbide separeated out, 400°Ctempering is tempered flexor s body. Test material at 920°Cafter quenching and tempering 220°C, has good strength and toughness, specific properties: tensile strength 1506 MPa and temperature impact toughness A_kv 35.6J.