Steel Sheet

Abstract: Provided is a steel sheet that exhibits an excellent bendability, an excellent hardenability at short heating times, and an excellent resistance to hydrogen embrittlement when used as a mechanical component. The steel sheet according to the present disclosure comprises, in mass%, C : 0.50 to 0.90%, Si : 0.10 to 0.50%, Mn : 0.20 to 1.30%, P : not more than 0.100%, S : not more than 0.100%, Al : not more than 0.100%, Cr : 0.01 to 1.20%, N : not more than 0.0150%, and balance: Fe and impurities. The total area ratio for ferrite and cementite grains is at least 95%, the average grain size for ferrite is 20.0 µm or less, the average grain size for cementite grains is 1.50 µm or less, and the cementite spheroidization ratio is 75% to less than 85%. Letting [C]s be the C content in the surface layer of the steel sheet and [C]c be the C content at the center position in the sheet thickness direction of the steel sheet, the C concentration ratio F1 defined by formula (1) is 0.50 or less. (1): F1 = [C]s/[C]c

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