Effect of Tempering Temperature on the Microstructure and Mechanical Properties of 42CrMo4 Steel

Abstract

This paper investigated the effects of tempering temperature (200°C, 400°C, 600°C or 800°C) on microstructures, mechanical properties, and residual stress of 42CrMo4 steel. Microstructures were characterized by OM and SEM techniques. The results show that the change in tempering temperature leads to a change in austenite, resulting in a change in hardness and toughness. The specimen showed the best combination of mechanical properties under the heat treatment condition of a tempering temperature of 600°C. The hardness, yield strength, tensile strength, area shrinkage, and elongation reached 312.74HV, 759MPa, 898MPa, 60%, and 18%, respectively. The experimental results provide a reference for the selection of the heat treatment process of 42CrMo4 steel.