| 摘要 |
<p>There is provided a high strength steel sheet having good formability and a tensile strength of 980 MPa or higher. The high strength steel sheet having a tensile strength of 980 MPa or higher includes a composition including, on a mass% basis, C: 0.1% or more and 0.3% or less, Si: 2.0% or less, Mn: 0.5% or more and 3.0% or less, P: 0.1% or less, S: 0.07% or less, Al: 1.0% or less, and N: 0.008% or less, with the balance being Fe and incidental impurities, wherein a steel microstructure includes, on an area ratio basis, martensite: 50% or more, ferrite: 50% or less (including 0%), bainite: 10% or less (including 0%), and retained austenite: 10% or less (including 0%); and the full-width at half maximum in a frequency distribution of nano-hardness, which is obtained by measuring a hardness distribution of the martensite, is 2.0 GPa or more.</p> |
