| 摘要 |
PROBLEM TO BE SOLVED: To provide a hot-rolled steel sheet superior in formability, which has high strength and simultaneously shows superior elongation and formability for extension flange. SOLUTION: The high-strength hot-rolled steel sheet superior in formability has a composition satisfying, by mass% (hereafter the same), 0.015-0.10% C, 2% or less Si (excluding 0%), 2% or less Mn (excluding 0%) and 0.08-0.2% Ti; and has a structure of granular bainitic ferrite, which contains precipitates with a circle-equivalent diameter of less than 0.03μm, in an amount of 5×10<SP>6</SP>/mm<SP>2</SP>or more, and precipitates with a circle-equivalent diameter of 0.03μm or more in an amount of 2×10<SP>6</SP>/mm<SP>2</SP>or less. COPYRIGHT: (C)2005,JPO&NCIPI
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