| 摘要 |
A cold-work tool steel comprising, in mass%: 0.6 - 1.2% of C; 0.7 - 2.5% of Si; 0.3 - 2.0% of Mn; 0.02 - 0.1% of S; 3.0 - less than 5.0% of Cr; 0.5 - 2.0% of Mo and W independently or as a complex (Mo+1/2W); 0.04 - less than 0.3% of Al; and Fe and unavoidable impurities as the remainder. The relational expression of the amount of S, Cr, and Al is: 21.9 × S + 124.2 × (Al/Cr) - 2.1. The cold-work tool steel has a machinability index (MP) value greater than 0. The hardness after tempering is preferably at least 60 HRC. The cold-work tool steel may further contain 1.0% or less of Ni, and 1.0% or less of Cu. Furthermore, the cold-work tool steel may contain 1.0% or less of V, and 0.5% or less of Nb. |
