Patent ID: 8025746

Claim:
A casing formed from an alloy containing, by mass, 0.08-0.20% C, 0.05-0.45% Si, 0.10-0.30% Mn, 0.80-1.40% Ni, 1.00-1.40% Cr, 1.20-1.60% Mo, 0.10-0.30% V, 0.06-0.10% Ti, 0.0005-0.0010% B, not more than 0.01% P, not more than 0.01% S, and 0.003-0.005% Al, the balance being Fe and unavoidable impurity elements; and wherein the content ratio of Mn/Ni is in the range of 0.07-0.32; and wherein the casing is used for a turbine.