Steel sheet, member, and methods for producing the same
AssigneeJfe Steel Corporation
InventorsTakuya Hirashima, Shimpei Yoshioka, Shinjiro Kaneko, Soshi Yoshimoto, Tomohiro Hashimukai
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Abstract
The steel sheet of the present invention has a steel microstructure containing, in area fraction, martensite: from 20% to 100%, ferrite: from 0% to 80%, and another metal phase: 5% or less, and in which a ratio of a dislocation density in metal phases on a surface of the steel sheet to a dislocation density in the metal phases in a thicknesswise central portion of the steel sheet is from 30% to 80%. The maximum amount of warpage of the steel sheet when the steel sheet is sheared to a length of 1 m in a rolling direction is 15 mm or less.
Claims14
A steel sheet comprising a steel microstructure containing:
- in area fraction, martensite:
- from 20% to 100%, ferrite:
- from 0% to 80%, and another metal phase:
- 5% or less;
- and
- in which a ratio of a dislocation density in metal phases on a surface of the steel sheet to a dislocation density in the metal phases in a thicknesswise central portion of the steel sheet is from 30% to 80%,
- wherein the maximum amount of warpage of the steel sheet when the steel sheet is sheared to a length of 1 m in a rolling direction is 15 mm or less.
Dependencies are inferred from the claim text.