Precipitation hardening type martensitic stainless steel, steam turbine moving blade and steam turbine

摘要

PROBLEM TO BE SOLVED: To provide a precipitation hardening based martensitic stainless steel having excellent stability of a structure, mechanical property and corrosion resistance, a steam turbine rotor blade using the same and a steam turbine using the same.SOLUTION: The precipitation hardening based martensitic stainless steel contains, by mass, C:0.1% or less, Cr:11 to 13%, Ni:10.5 to 11.5%, Al:0.25% or less, Ti:0.9 to 1.5%, Mo+0.5W:0.5 to 1.5%, Si:1.0% or less, Mn:1.0% or less, Mo/W (mass% ratio) of 0.4 to 0.6 and the balance iron with inevitable impurities.