| 摘要 |
PROBLEM TO BE SOLVED: To provide a hot molded steel sheet member excellent in extensibility and impact property and having tensile strength of 900 MPa or more, and to provide a manufacturing method therefor.SOLUTION: A hot molded steel sheet member contains, by mass%, C:0.05% to 0.40%, Si:0.5% to 3.0%, Mn:1.2% to 8.0%, P:0.05% or less, S:0.01% or less, sol.Al:0.001% to 3.0% and N:0.01% or less, and the balance Fe with inevitable impurities, and a steel structure containing, by area%, 10 to 40% of austenite and having austenite + martensite with density of 1.0/μm, and has tensile strength of 900 MPa or more. |
