Ferritic stainless hot-rolled annealed steel sheet, its manufacturing methods and ferritic stainless cold-rolled annealed steel sheet

摘要

Provided are a cold rolled and annealed ferritic stainless steel sheet having good high-temperature fatigue resistance and good oxidation resistance and a hot rolled and annealed ferritic stainless steel sheet suitable as a material for the cold rolled and annealed steel sheet. The hot rolled and annealed ferritic stainless steel sheet has a composition containing, on a mass percent basis, 0.015% or less of C, 1.00% or less of Si, 1.00% or less of Mn, 0.040% or less of P, 0.010% or less of S, 12.0% or more and 23.0% or less of Cr, 0.20% or more and 1.00% or less of Al, 0.020% or less of N, 1.00% or more and 2.00% or less of Cu, and 0.30% or more and 0.65% or less of Nb, Si and Al being contained so as to satisfy Si ‰¥ Al, the balance being Fe and unavoidable impurities, and the hot rolled and annealed ferritic stainless steel sheet has a Vickers hardness less than 205. The cold rolled and annealed ferritic stainless steel sheet having good high-temperature fatigue resistance and good oxidation resistance is produced by subjecting the hot rolled and annealed ferritic stainless steel sheet to cold rolling and annealing treatment.