Patent ID: 7101446

Claim:
An austenitic stainless steel consisting of, % by mass, C: 0.03% or less, Si: 2 to 4%, Mn: 0.1 to 2%, P: 0.03% or less, S: 0.03% or less, Ni: 9 to 15%, Cr: 15 to 20%, N: 0.02 to 0.2%, Nb: 0.03% or less, each of Mo and Cu or a total of Mo and Cu: 0.2 to 4%, and the balance Fe and impurities, and satisfying the following formulas (1) and (2); 16.9+6.9Ni+12.5Cu−1.3Cr+3.2Mn+9.3Mo−205C−38.5N−6.5Si−120Nb≧40 (1) 450−440(C+N)−12.2Si−9.5Mn−13.5Cr−20(Cu+Ni)−18.5Mo≦−90 (2) wherein each element symbol in the formulas (1) and (2) represents the content, % by mass, of each element included in the steel.