Ferritic stainless steel sheet having good workability

Abstract

The newly proposed ferritic stainless steel sheet consists of C up to 0.03 mass %, N up to 0.03 mass %, Si up to 2.0 mass %, Mn up to 2.0 mass %, Ni up to 0.6 mass %, 9-35 mass % Cr, 0.15-0.80 mass % Nb, optionally one or more of Ti up to 0.5 mass %, Mo up to 3.0 mass %, Cu up to 2.0 mass % and Al up to 6.0 mass %, and the balance being Fe except inevitable impurities, comprises metallurgical structure involving precipitates of 2 μm or less in particle size at a ratio not more than 0.5 mass % and has crystalline orientation on a rolled surface at ¼ depth of thickness with Integrated Density defined by the formula (a) not less than 1.2. The ferritic stainless steel sheet is manufactured by 25 hours or shorter precipitation-treatment at 700-850° C. in prior to 1 minute or shorter finish-annealing at 900-1100° C. Integrated Intensity is made greater than 2.0 by controlling particle size of precipitates not more than 0.5 μm, so as to realize good workability with less in-plane anisotropy. Wherein, Integrated Intensity=[I(222)/I0(222)]/[I(200)/I0(200)]  (a) wherein, I(222) and I(200) represents diffraction intensities on (222) and (200) planes of a sample of said steel measured by XRD, while I0(222) and I0(200) represents diffraction intensities on (222) and (200) planes of a non-directional sample.

Dependencies are inferred from the claim text.