Investigation of Enhancing Temper Resistance and Hot Hardness for Tool Steel

Abstract

Hot strength, temper resistance and low thermal expansion are a few amongst many desirable properties to ensure longer life for dies and punches in AISI type H tool steels, during hot forging. A compromise over hardness invariably reduces die and punch life during thermal fatigue and same applies for hardness on lower side. In this research work, optimum level of hardness and heat treatment parameters (hot strength, temper resistance, and thermal expansion for hot work die steel) is investigated by varying heat treatment variables for enhanced service life of dies and punches. Moreover, three different heat treatment techniques were adopted to attain an optimum level of microstructure and surface hardness in hot forging punches for hot-work tool steels. Considerable improvements were observed in surface micro-hardness. The choice of selected optimum parameters shows clear signs of improved service life for H13 tool steel during forging.