Alloy tool steels having excellent wear resistance in cold-working

摘要

Provided is alloy tool steel having an excellent wear resistance for cold working, comprising: 0.8-1.0 wt% of C; 0.15-0.25 wt% of Si; 0.15-0.25 wt% of Al; 0-0.5 wt% of Mn; 4.5-5.5 wt% of Cr; 2.45-2.65 wt% of Mo; 0.15-0.25 wt% of W; 0-0.4 wt% of V; 0.5-1.50 wt% of Nb; 0-0.3 wt% of Ni; 0.02-1.3 wt% of Cu; and remaining Fe and unavoidable impurities. The matrix structure comprises insoluble carbide whose diameter exceeds 0.1m, and which comprises MC insoluble carbide whose major substance is Nb and in which the atom percent of Nb defined by Formula 1 is 35% or greater and the atom percent of V defined by Formula 2 is less than 30% of metallic atoms that compose the carbide. In addition, the number fraction of the MC insoluble carbide defined by Formula 3 in the total insoluble carbide is 5% or greater.