A method of producing excellent high-strength ultra-thin steel sheet for cans of the in-plane anisotropy

摘要

PURPOSE:To manufacture a high strength and extremely thin steel sheet for can having excellent plane anisotropy by hot-rolling a specific composition of steel slab of low carbon steel highly enriched with N, coiling at a low temp. and executing cold-rolling at a prescribed rolling ratio before and after the specific continuous annealing. CONSTITUTION:The hot-rolling is executed to a steel slab composed of 0.006-0.02% C, =0.06% Si, =0.6% Mn, =0.03% P, =0.03% S, =0.08% sol. Al, 0.002-0.015% N and the balance of Fe with inevitable components, and the finishment of the steel slab is performed desirably at =Ar3 point and coiled at =700 deg.C. After pickling the hot-rolled steel sheet, the primary cold-rolling is executed at a rolling ratio (R1) of 80-90%. Successively, this is continuously annealed and then, heated and soaked at the temp. range of the recrystallized temp. or more and the austenizing temp. or less. After executing recrystallize- annealing to this cold-rolled sheet, the secondary cold-rolling is executed at 20-50% rolling ratio (R2). By this method, the high strength and extremely thin steel sheet having an excellent plane anisotropy without developing numerous earnings and being suitable to deep drawing work, is obtd.