| 摘要 |
A high-strength cold-rolled steel sheet according to the present invention: satisfies the requirement of a prescribed chemical composition; has a structure comprising a mother phase structure of ferrite and a second phase structure of retained austenite and martensite (the martensite may not be included); and satisfies the following expressions (1) and (2) when the volume fraction of the ferrite in the whole structure is represented by Vf (%), the volume fraction of the retained austenite in the whole structure is represented by Vy (%), the carbon content in the retained austenite is represented by C³ (mass %), the shortest distance between the second phase structures is represented by dis (µm), and the average grain size of the second phase structures is represented by dia (µm), Vf × V³ × C³ × dis / dia ‰¥ 300 dis ‰¥ 1.0 ¼m By such a configuration, the improvement of TS-EL balance and the reduction of a springback value are attained in a high strength region of about 550 to 900 MPa class and excellent workability and shape freezing property are obtained. |
