| 摘要 |
PROBLEM TO BE SOLVED: To provide a high-strength steel sheet having excellent rigidity in which tensile strength is≥590 MPa, a Young's modulus in the 90°direction to the rolling direction is≥230 GPa, and the average Young's modulus in the 0°, 45°and 90°directions to the rolling direction is≥215 GPa, and to provide its production method. SOLUTION: The high-strength steel sheet having excellent rigidity has a composition comprising, by mass, 0.02 to 0.15% C,≤0.3% Si, 1.0 to 3.5% Mn,≤0.05% P,≤0.01% S,≤1.0% Al,≤0.01% N and 0.1 to 1.0% Ti, and in which the contents of C, N, S and Ti satisfy equation (1), and the balance Fe with inevitable impurities, and has the microstructure of a ferrite single phase, and, in which the average ODF (Orientation Distribution Function) analysis strength in the (111)[1-10] to (111)[-1-12] orientation of the sheet face in the 1/4 sheet thickness is≥5, and the average ODF analysis strength in the (113)[1-10] to (223)[1-10] orientation is≥3. The equation (1) is: C-(12/47.9)×Ti<SB>-1</SB>≤0 ... (1), wherein, Ti<SB>-1</SB>=Ti-(47.9/14)×N-(47.9/32.1)×S, and each atomic symbol in the equation denotes the content of each element. COPYRIGHT: (C)2007,JPO&INPIT
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