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|1. (WO2018199328) HIGH STRENGTH STEEL SHEET AND METHOD FOR MANUFACTURING SAME|
|Applicants:||NIPPON STEEL & SUMITOMO METAL CORPORATION
|Title:||HIGH STRENGTH STEEL SHEET AND METHOD FOR MANUFACTURING SAME|
Provided are: a high strength steel sheet suitable as a material for automobile parts, the high strength steel sheet containing a large amount of Mn and having bendability; and a method for manufacturing the high strength steel sheet. This high strength steel sheet having excellent bendability includes a sheet-thickness central portion, and a superficial softened portion formed on one side or both sides of the sheet-thickness central portion, and is characterized in that the average concentration of Mn in the sheet-thickness central portion is greater than 4.0 mass% and less than 10.0 mass%, the thickness of each superficial softened portion is 0.1-30% of the thickness of the sheet, the concentration of Mn in the superficial softened portion is at most 2.5 mass%, and the recrystallization rate of the superficial softened portion is at least 90%.