Patent ID: 6679954
Filing Date: 2004-01-20
Classification: C21D,C22C,C23C

Abstract:
A stainless steel excellent in delayed fracture resistance characterized in that the stainless steel consists essentially of, by mass %, 0.06 to 0.25%. of C, 0.05 to 1.0% of Si, 0.1 to 2.0% of Mn, 0.1 to 3.0% of Ni, 11.0 to 16.0% of Cr, 0.01 to 0.15% of N, and 0.01 to 3.0% of Mo, with the balance Fe and unavoidable impurities;said stainless steel having a surface layer consisting of a dual structure of martensite and 3 to 30% of austenite in the surface layer from an outermost surface to a depth of at least 1 &mgr;m and a center portion consisting of less than 10% of ferrite with the center portion balance consisting of a martensite phase free from austenite phase.