| 摘要 |
A hot-rolled steel sheet having a tensile strength of 900 MPa or more, the hot-rolled steel sheet consisting of, in mass%, C: greater than 0.050% and less than or equal to 0.10%, Si: greater than or equal to 0.1% and less than or equal to 2.0%, Mn: greater than or equal to 1.0% and less than or equal to 3.0%, P: less than or equal to 0.1%, S: less than or equal to 0.01%, Al: greater than or equal to 0.005% and less than or equal to 0.05%, N: less than or equal to 0.01%,Ti: greater than or equal to 0.10% and less than or equal to 0.20%, Nb: greater than or equal to 0% and less than or equal to 0.06%, B: greater than or equal to 0% and less than or equal to 0.03%, Ca: greater than or equal to 0% and less than or equal to 0.005%, and the balance: Fe and impurities. An average crystal grain size is less than or equal to 7.0 µm, and an X-ray random intensity ratio in {211} <011> orientation that is parallel to a rolled surface and a rolling direction is less than or equal to 2.5. |
