| 摘要 |
PROBLEM TO BE SOLVED: To provide a hot-rolled steel sheet having excellent workability and excellent aging resistance, which is used for automobiles, household appliances, building materials or the like. SOLUTION: A steel strip having the composition consisting of, by mass, 0.04-0.25% C, 0.001-0.5% Si, 0.05-1.5% Mn,≤0.09% P,≤0.015%S, 0.01-0.08% Al, 0.0005-0.015% N, and the balance Fe with inevitable impurities is subjected to the hot rolling. Thereafter, the steel strip is cooled to the temperature below 400°C at the average cooling rate of≥60°C/s, wound and cooled, and further subjected to the cold rolling of the elongation of 0.1-1.0% by using a roll having the diameter to satisfy inequality (1), t/R≥0.0055, where t denotes the plate thickness and R denotes the diameter of the roll. Thus, the hot-rolled steel plate having the excellent aging resistance can be obtained. COPYRIGHT: (C)2008,JPO&INPIT
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