Microstructure and Mechanical Properties of Heat-Treated 30CrMo Steels Produced by Compact Strip Production and Conventional Rolling Processes

In this paper, the microstructure and mechanical properties of heat-treated 30CrMo hot-rolled steels, manufactured by the compact strip production (CSP) process, and the traditional continuous casting and rolling (CCR) process were systematically investigated. The results show that the microstructure of hot-rolled 30CrMo steel is finer and more homogeneous when produced by the CSP process. Lath martensite and plate martensite were obtained in both of steels after oil quenching. However, the specimens produced by CSP process exhibited a finer microstructure and a higher fraction of plate martensite after quenching. After tempering, the mechanical properties of the CSP-produced specimen were better than the specimens derived from the hot-rolled steel produced by CCR process. When the specimen was tempered at 500 °C for 2 h, the optimized mechanical properties were obtained. The tensile strength, yield strength, and elongation were 1135 MPa, 1084 MPa, and 10%, respectively.