| 摘要 |
PROBLEM TO BE SOLVED: To provide an ultra-thin steel sheet of <=0.2 mm thick, excellent in surface characteristic, hardly causing problems such as rusting, and having >=540 MPa tensile strength in a rolling direction, a plated steel sheet, and a method of their manufacture. SOLUTION: This steel sheet has a composition consisting of, by weight, 0.01-0.10% C, <=0.2% Si, 0.05-1.0% Mn, <=0.02% P, 0.015-0.10% Ti, 0.001-0.01% Al, <=0.02% N, 0.0005-0.01%, in total, of either or both of Ca and REM, further S in an amount satisfying the relation of inequality S-5×((32/40)Ca+(32/140) REM)<=0.0014% in correlation with the contents of either or both of Ca and REM, and the balance Fe with inevitable impurities. Further, in this steel sheet, oxide inclusions of 1-50μm grain size include Ti oxide and either or both of CaO and REM oxide. Such a steel sheet can be suitably used for DRD cans.
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