| 摘要 |
PROBLEM TO BE SOLVED: To provide steel for metal molds which has excellent toughness, machinability and hardness and combines polishing finish characteristics with wear resistance. SOLUTION: The steel for metal molds is a steel having: a composition which contains, by mass, 0.10 to 0.25% C,≤1.00% Si,≤2.00% Mn, 0.60 to 1.50% Ni, >1.00 to 2.50% Cr, Mo and W, independently or in combination, in amounts within the range satisfying Mo+1/2W≤1.00%, 0.03 to 0.15% V, 0.50 to 2.00% Cu and≤0.05% S, also contains Al, N and O limited to≤0.10%,≤0.06% and≤0.005%, respectively, and has the balance Fe with inevitable impurities; a structure composed mainly of lower bainite; and a hardness of 34 to 45 HRC. It is preferable that, in the above percentages in mass, the value of Ni+1.2Cu ranges from 1.30 to 2.70 and also the value of 60C+1.5Si+Ni+6Cr+2(Mo+1/2W)+20V+0.2Cu ranges from 21.00 to 28.70. COPYRIGHT: (C)2007,JPO&INPIT
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