Plastic molding die for pre-hardened steel

摘要

PROBLEM TO BE SOLVED: To provide a prehardened steel for a plastic molding die, which does not easily cause variation in hardness of a die after aging treatment while keeping specularity, corrosion resistance, thermal conductivity and impact resistance.;SOLUTION: The prehardened steel includes, by mass, 0.09-0.13% C, 0.20-0.40% Si, 0.40-0.60% Mn, 0.100% or less P, 2.00-3.00% Cr, 0.60-0.90% Cu, 2.00-2.45% Ni, 0.20-0.40% Mo, Mo/Ni being ≥0.09, 0.60-0.90% Al, 0.0100% or less O, 0.0100% or less N, and the balance being Fe and inevitable impurities.;COPYRIGHT: (C)2013,JPO&INPIT