Patent ID: 10907235

Abstract:
A steel sheet according to an aspect of the present invention has a chemical composition within a predetermined range; in which a metallographic structure at a thickness ¼ portion includes, by unit area %, ferrite: 10% or more and less than 50%, granular bainite: 5% or more and less than 50%, and martensite: 20% or more and less than 60%; in the metallographic structure at the thickness ¼ portion, a total of upper bainite, lower bainite, residual austenite, and pearlite is 0% or more and less than 15% by unit area %; at the thickness ¼ portion, a product of an area ratio Vm of the martensite and an average hardness Hv of the martensite is 12,000 to 34,000; and a tensile strength is 980 MPa or higher.