Abstract

In this study, 36CrB4 boron steels were annealed at 870 °C for 2 hours and then cooled in oil. The steels cooled in oil were subjected to tempering at temperatures ranging from 480 to 520 °C for 2 hours to investigate the effects of quenching and tempering on their microstructure and mechanical properties. Tensile tests, impact tests, and Vickers microhardness tests were carried out. The results revealed that with tempering, the microstructure, which was initially martensitic after quenching, began to form bainite in addition to the tempered martensitic microstructure. It was observed that mechanical properties (except elongation) and hardness values significantly improved with quenching compared to the non-heat-treated samples but exhibited a decline with increasing tempering temperature.

Keywords:Boron steel; Quenching; Tempering; Mechanical properties; Impact energy