Impact of tempering conditions on mechanical properties and wear behaviour of AISI H13 steel

This study investigates the effects of tempering temperature and time on the mechanical properties and wear resistance of AISI H13 steel, a tool steel widely used in industrial die applications. The steel is austenitized at temperatures of 1000°C, 1020°C, 1040°C, and 1060°C, followed by tempering at three different temperatures (540°C, 560°C, and 580°C) for varying durations (1 h, 2 h, and 3 h). The primary objective of this study is to explore the tempering conditions that optimize the mechanical properties of tensile strength, hardness, and toughness as well as the wear resistance of H13 steel. Experiments include uniaxial tensile tests, indentation hardness tests, and sliding wear tests using a pin-on-disc tribometer, with D2 steel as the counter material. Microstructural analysis reveals the formation of tempered martensite and secondary carbides, and the wear resistance is found to improve slightly around the 560°C tempering temperature due to secondary hardening. Key findings indicate that increased tempering temperature and time generally reduce wear resistance, though an optimal tempering condition exists at 560°C, where secondary hardening enhances the steel's performance. This study contributes valuable insights into the tempering behaviour of AISI H13 steel and its impact on its mechanical properties and wear performance, providing guidance for optimizing the steel for industrial die applications.