关键词: 55NiCrMoV7钢, 微观组织, 力学性能, 模型

Abstract: Change rule the microstructure evolution and mechanical properties of 55NiCrMoV7 die steel under different quenching temperature (790~910°C) , and tempering temperature (100 ~650°C ) are studied by means of scanning electron microscopy (SEM) , hardness test, V-impact test, uniaxial tensile test combined with finite element modeling and simulation. The results show that, with the increase of quenching temperature, spherical caibide gradually dissolves into martensite matrix, martensite structure grows and coarsens, and residual austenite increases gradually； after quenching, the HRC hardness value is basically stable at 42 ~ 46, and the yield and tensile strength first increase and then decrease, reaching a maximum of 1380 MPa and 1485 MPa after quenching at 870 °C ,and the maximum value of impact toughness is 26 J after quenching at 850 °C. In different temperature tempering process, the content of martensite structure basically stable, with the increase o£ tempering temperature, the retained austenite gradually disappears, fine and dispersed carbides begin to precipitate at the boundary of martensite. Quenching at 870°C 4 h and tempering at 560°C 6 h can make 55NiCrMoV7 steel to have good comprehensive mechanical properties.