锻造对30CrNi2MoV钢在亚温淬火下组织与性能的影响

30CrNi2MoV steel is a medium-carbon alloy steel, which is commonly applied in the manufacture of large forgings with high strength and toughness. It is widely used in the manufacture of power and transmission components in power plant equipment and large-scale metallurgy, mining, and transportation equipment for thermal power and nuclear power plants. In order to improve the low-temperature impact toughness and room temperature strength of 30CrNi2MoV steel, effects of different forging methods on the microstructure and mechanical properties of 30CrNi2MoV steel were studied by using metallographic microscope, scanning electron microscopy, and tensile tester and hardness tester for microstructure observation, fracture morphology analysis, and mechanical properties tests, respectively. Results show that after two times pressing and one drawing + one upsetting process or two times pressing and one drawing + one upsetting + one stretching process, the 30CrNi2MoV steel can be effectively refined with uniform grain, and the equiaxiality of the grains can be improved. Compared with the 30CrNi2MoV steel with two times pressing and one drawing process, the tensile strength, elongation, and impact toughness increased from 1 043.6 MPa, 35.65%, 40.33 J to 1 161.6 MPa and 1 157.4 MPa, 37.80% and 36.13%, and 103 J and 87 J, respectively. The data indicates that the microstructure and mechanical properties of 30CrNi2MoV steel achieve the best state after the two times pressing and one drawing + one up-setting process.