The plastic formation gold model steel null mass which is superior in mirror surface Characteristic

摘要

PROBLEM TO BE SOLVED: To obtain steel for a mold for molding plastics combining excellent mirror surface finishing properties with machinability.;SOLUTION: The steel has a composition which consists of 0.01 to 0.15% C, 0.5 to 2.0% Si, 0.3 to 2.0% Mn, 2.0 to 6.0% Cr, 2.0 to 5.0% Ni, 0.5 to 2.0% Cu, 0.5 to 2.0% Al, ≤0.01% B and the balance Fe with inevitable impurities and contains, if necessary, either or both of ≤1.0% Mo and ≤1.0% W and in which, among the inevitable impurities, the contents of S, O and N are regulated to ≤0.002%, ≤0.0015% and ≤0.01%, respectively. By this method, a metal mold for molding plastics combining excellent machinability and mirror surface finishing properties and having high hardness and excellent corrosion resistance can be obtained.;COPYRIGHT: (C)2004,JPO