| 摘要 |
PURPOSE:To manufacture a steel for metal mold for IC molding excellent in corrosion resistance and wear resistance, by subjecting a gas-atomized steel powder containing specific compositional amounts of C, Si, Mn, Cr, Mo, and V to hot isostatic pressing treatment under specific conditions. CONSTITUTION:A capsule is filled with the atomized steel powder containing the following chemical components: 0.90-1.50% C, 0.2-1.0% Si, 0.2-1.0% Mn, 16-22% Cr, 0.2-2.2% Mo, and 0.2-1.5% V. The above capsule is subjected to vacuum heating, to deaeration, and then to hermetically sealing. Subsequently, the above capsule is subjected to hot isostatic pressing treatment for 0.5-10hr at 1000-1200 deg.C under a pressure in the pressure range where the lower limit is regulated to a value on the line connecting the point (1,000 deg.C, 800kg/cm<2>) and the point (1,200 deg.C, 400kg/cm<2>) in the temp.-pressure relation and upper limit is also regulated to 200kg/cm<2>. In this way, a true-density steel material excellent in corrosion resistance, having >=HRC58 heat-treated hardness, and free from pinholes can be obtained.
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