Today, tool-steel heat treatment is based on a simple premise. To obtain the optimum performance from any given grade, every step of the heat-treating process must be precisely controlled — from stress relief and preheating to austenitizing temperature and time, quenching, deep freeze and tempering. Process and/or equipment variability cannot be tolerated, which is why vacuum processing (Fig. 1) is a popular choice for tool-steel heat treatment.
The selection of any tool steel depends on a combination of factors including component design, application end-use and performance expectation. For any given application, the goal of heat treating is to develop an optimized microstructure (Fig. 2)
to help achieve the proper balance of desired properties (Table 1), namely hot (red) hardness, wear resistance, deep hardening and/or toughness.