FERRITIC/AUSTENITIC TWO-PHASE STAINLESS-STEEL SHEET WITH EXCELLENT POLISHABILITY AND PROCESS FOR PRODUCING SAME

摘要

A ferritic/austenitic two-phase stainless-steel sheet from which mirror-finished products that are less apt to develop flaws or cracks even in long-term use and that can be reduced in weight due to enhanced strength are provided by subjecting the stainless-steel sheet to mirror polishing for accurately forming reflected images.The ferritic/austenitic two-phase stainless-steel sheet has excellent polishability, and is characterized by: having a composition which contains, in terms of mass%, up to 0.03% C, 19.0-22.0% Cr, 0.06-0.20% N, 5.0-7.5% one or more of Ni, Mn, and Cu, up to 1.0% Si and/or Al, up to 0.045% P, up to 1.0% Mo, up to 0.005% S, and up to 0.01% O, with the remainder comprising Fe and unavoidable impurities; having a dual-phase structure composed of a ferrite phase and an austenite phase; and having a grain-diameter difference between the ferrite grains and the austenite grains, ΔGs, of 15 µm or less.