HOT WORKING TOOL STEEL WITH IMPROVED STRENGTH AND TOUGHNESS OBTAINED BY INCREASING AND OPTIMALLY HARMONIZING CONTENTS OF Cr, Mo, Mn AND Ni IN ALLOY COMPOSITION

摘要

PURPOSE: To provide a hot working tool steel with improved strength and toughness at an elevated temperature for improving life of molds for hot forging, extruding and die casting. CONSTITUTION: The hot working tool steel with improved strength and toughness at an elevated temperature has an alloy composition comprising 0.3 to 0.7 wt.% of C, 0.20 to 0.50 wt.% of Si, 0.85 to 1.10 wt.% of Mn, less than 0.01 wt.% of S, 0.90 to 2.0 wt.% of Cr, 1.95 to 2.5 wt.% of Ni, 0.35 to 0.6 wt.% of Mo, 0.01 to 2.00 wt.% of V and the balance being Fe and inevitable impurities mixed during the steelmaking process.