MARTENSITE HOT WORKING TOOL STEEL DIE BLOCK BODY AND MANUFACTURE THEREOF

摘要

PURPOSE: To provide a martensitic hot working tool steel die block body having an improved combination of impact toughness, machinability and thermal fatigue resistance. CONSTITUTION: Alloy particles prealloyed by gas pulverization is perfectly densely molded to form a molding. The molding is hot-worked into a required form, annealed, hardened by heating and cooling to form the martensitic structure and tempered, through which the martensitic hot working tool steel die block body can be obtained. The material composition of the same is, in weight 0.32-0.45% carbon, 0.20-2.00% manganese, 0.05-0.30% sulfur, up to 0.03% phosphorous, 0.80-1.20% silicon, 4.75-5.70% chromium, 1.10-1.75% molybdenum, 0.80-1.20% vanadium, balance iron and incidental impurities.