STEEL FOR DIE-CASTING MOLD

PROBLEM TO BE SOLVED: To provide steel for die-casting mold by which a high-quality casting excellent in dimensional precision and cast surface are manufactured in large quantities at high cycle. SOLUTION: The steel for die casting mold is obtained by adding to steel containing, by mass%, 0.32-0.42% C, indispensable additional elements of Cr, Si, Mn and V, semi-indispensable additional elements of at least either of Mo and W, and optional additional elements optionally containable. As the optional additional elements, the steel optionally contains, by mass%, ≤1.0% Cu, ≤0.5% Ni, ≤1.0% Co, ≤0.01% B, ≤0.05% Se, Te, Pb, Bi, Ca and ≤0.1% Nb, Ta, Ti, Zr, REM, Mg. As the indispensable additional elements, 4.0-6.0% Cr, 0.05-0.2% Si, 0.3-1.5% Mn and 0.2-0.7% V are added, and as the semi-indispensable additional elements, Mo and/or W are added so as to satisfy 0.8≤Mo+1/2W≤2.0. COPYRIGHT: (C)2010,JPO&INPIT