| 摘要 |
PURPOSE:To obtain a stainless steel material having superior strength, workability and resistance to softening by welding, by heating a steel material having a specified composition and a martensite structure under specified conditions. CONSTITUTION:A hot rolled material, a cold rolled material or an annealed material of a steel consisting of <=0.10% C, <=4.5% Si, <=5.0% Mn, <=0.060% P, <=0.030% S, 10.0-17.0% Cr, 3.0-8.0% Ni, <=0.10% N and the balance Fe or further contg. <=4% one or more among Cu, Mo, W and Co and/or <=1% one or more among Ti, Nb, V, Zr, Al and B and having 13.0-17.5 Ni equiv. defined by the formula is heat treated at 550-675 deg.C for 1-30hr to obtain a high strength stainless steel material having superior workability, without softening by welding. The steel material has a single-phase structure of a martensite phase or a multiphase structure consisting of a martensite phase and a fine austenite phase.
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