Influences of Hot Rolling Conditions on the Microstructure and Mechanical Properties of Low-Alloy Steel

Abstract

The thermomechanical control processing (TMCP) was conducted through the adjustment of the rolling technological parameters to the test steel. The influence of the finishing temperature, cooling rate and alloying elements to the microstructure and mechanical properties was investigated by comprehensive utilization of grain refining strengthening and second phase strengthening.The results show that the microstructure was mainly composed of bainite, ferrite and second phase TiC; at the finishing temperature of 870°C, the yield strength was 596.7 MPa, the tensile strength reached 748.5 MPa, the elongation ratio was 20.17%; at high cooling rate of 16°C/s, the yield strength achieved 616.7 MPa, the tensile strength reached 785.5 MPa, the tensile ratio reduced for 0.78, and the elongation ratio enhanced to 20.92%. And the quantity of bainite increased with the raise of finishing temperature from 800°C to 870°C, which improved the hardness and wear resistance of the steel.