Tempering behavior and mechanical properties of tempered AISI H13 steel

Abstract

Microstructural evolutions of AISI H13 steel during tempering were quantitatively investigated by scanning electron microscopy (SEM), x-ray diffractometer (XRD), impact test machine, rockwell hardness tester, ball-on-disk tester in order to describe the main mechanism of softening. Under the condition that the tempering time is 2 h, the hardness increases slightly as the tempering temperature increases, but decreases rapidly when the tempering temperature exceeds 500 °C, while the impact energy increases in proportion to the tempering temperature. Friction tests were conducted in dry condition with a load of 30 N, and the friction coefficient and wear rate according to tempering conditions were measured to prove the correlation with hardness and microstructure. In addition, primary tempering from 300 °C to 700 °C was performed at various times to establish a kinetic model to predict hardness under specific tempering conditions.

Keywords

• hot-work steel
• tempering condition
• impact energy
• wear resistance