COLD DIE STEEL EXCELLENT IN CHARACTERISTIC OF SUPPRESSING DIMENSIONAL CHANGE

摘要

A cold die steel excellent in the characteristic of suppressing dimensional change, which has a chemical composition in mass %: C: 0.7% or more and less than 1.6%, Si: 0.5 to 3.0 %, Mn: 0.1 to 3.0 %, P: less than 0.05% including 0%, S: 0.01 to 0.12%, Cr: 7.0 to 13.0 %, one or two elements selected from the group consisting of Mo and W: amounts satisfying the formula (Mo + (W/2)) = 0.5 to 1.7 %, V: less than 0.7% including 0, Ni: 0.3 to 1.5 %, Cu: 0.1 to 1.0% and Al: 0.1 to 0.7 %. Preferably, the die steel satisfies the formula in mass %: Ni/Al = 1 to 3.7. It is preferred that the die steel also satisfies the following formula in mass %: (Cr - 4.2 X C) = 5 or less and (Cr - 6.3 X C) = 1.4 or more and that it contains 0.3 % or less of Nb.