| 摘要 |
Provided is a high strength steel sheet having a high Young's modulus which has a tensile strength TS of 780 MPa or more, a Young's modulus of 205 GPa or more in the rolling direction and in a direction at an angle of 45° to the rolling direction, a Young's modulus of 220 GPa or more in a direction at a right angle to the rolling direction, an average r value of 1.05 or more, and a limiting drawing ratio (LDR) of 2.03 or more. A high strength steel sheet having a high Young's modulus, the steel sheet having a chemical composition containing, by mass%, C: 0.060% or more and 0.150% or less, Si: 0.50% or more and 2.20% or less, Mn: 1.00% or more and 3.00% or less, Nb: 0.001% or more and 0.200% or less, and V: 0.001% or more and 0.200% or less, in which the amount of a solid solute C (C*) calculated by a certain equation on the basis of the contents of C, Nb, and V satisfies relational expression (1) below, and a microstructure including ferrite in an amount of 20% or more in terms of area ratio and martensite in an amount of 5% or more in terms of area ratio, in which the average grain size of the ferrite is 20.0 µm or less, and in which the inverse intensity ratio of ³-fiber for ±-fiber is 1.00 or more in each of the ferrite and the martensite: 500 ‰¤ C * ‰¤ 1300 where C* is represented in units of mass ppm. |
