PROCESS FOR CRYOGENIC TREATMENT OF TOOL STEEL

摘要

PURPOSE: A process for cryogenic treatment of tool steel by tempering tool steel at high temperature for a short period of time after tempering at low temperature for a long period time is provided which has the advantage of extending the service life of tool steel by improvement of wear resistance of steel. CONSTITUTION: The temperature of tool steel is maintained at -196deg.C by cryogenic treatment after quenching and raised to room temperature. The tool steel is then heat-treated at 180 to 230deg.C for about 24 hr and tempered at 400 to 650deg.C for 1 to 3 hr. This process produces tool steel having excellent abrasion resistance and shockability as compared to tool steel heat-treated at high temperature for 3 to 4 hr.