Martensitic stainless steel of subzero treatment hardening type

摘要

This invention provides subzero treatment hardening type martensitic stainless steels which comprise not more than 0.4 % by weight of C, not more than 0.4 % by weight of Mn, not more than 3.0 % by weight of Ni, 10 to 23 % by weight of Cr, not more than 3.0 % by weight of Mo, not more than 2.0 % by weight of Cu, not more than 2.0 % by weight of Si and the remaining portion consists of inevitable impurities and Fe, and satisfy the following formulae (1), (2) and (4), ÄCr %Ü + 1.5 ÄSi %Ü + ÄMo %Ü - ÄMn %Ü - 1.3 ÄNi %Ü - ÄCu %Ü - 19 ÄC %Ü - 19 ÄN %Ü </= 12.0 27.5 </= ÄCr %Ü + 1.3 ÄSi %Ü + 1.3 ÄMn %Ü + 1.5 ÄNi %Ü + ÄCu %Ü + ÄMo %Ü + 15 ÄC %Ü + 20 ÄN %Ü </= 32.0 1.3 ÄNi %Ü + ÄMn %Ü + ÄCu %Ü </= 4.0