| 摘要 |
PURPOSE: To provide a method that increases yield strength of the steel sheet and improves formability of the steel sheet during press forming of the steel sheet at the same time, thereby improves dent-resistance of outer panels for car body by imparting a certain reduction ratio to the steel sheet during skin pass rolling, thereby giving pre-strain to the steel sheet. CONSTITUTION: The method for improving dent-resistance of steel sheet is characterized in that yield strength of the steel sheet is increased according to increase of an amount of work-hardening by imparting pre-strain to the steel sheet in the state that the steel sheet is under uniaxial tension before press forming the steel sheet, wherein the pre-strain is imparted to the steel sheet by skin pass rolling the steel sheet in a reduction ratio of 1.8 to 2.0% when manufacturing a cold rolled steel sheet.
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