The original plate and its production manner null where for the finishing steel sheet the being superior and lug rate of occurrence are small to resistance aging

摘要

PROBLEM TO BE SOLVED: To provide an extremely thin steel sheet excellent in deep drawability and aging resistance, free from the generation of surface roughness and stretcher strains after can-making, low in the generating rate of earing after can-making and suitable as the original sheet of a surface treated steel sheet for a deep drawn can. ;SOLUTION: A steel stock contg., by weight, 0.02% C, 0.4 to 1.0% Mn, 0.01 to 0.1% Al, ≤0.0050% N and 0.0010 to 0.0050% B is subjected to hot rolling at the Ar₃ transformation point or above and is coiled at 700 to 650°C. Then, it is subjected to primary cold rolling at 80 to 88% draft, is thereafter subjected to continuous annealing of holding in a short time at the recrystallization temp. to 720°C and is subjected to secondary cold rolling at 1.0 to 8% draft to regulate the average grain size to ≤6 μm, the index of aging property, i.e., AI value to ≤40 MPa, the (r) value to 1.0, and Δr showing the face anisotropy of the (r) value to ±0.1.;COPYRIGHT: (C)1999,JPO