Steel Sheet

Abstract: A steel sheet according to one aspect of the present invention comprises specified chemical components, in which a metal structure in a part corresponding to a depth of 1/4 of the thickness of the steel sheet comprises, in percentage by volume, ferrite in an amount of 10% or more and less than 50%, granular bainite in an amount of 5% or more and less than 40%, martensite in an amount of 30% to 55% inclusive, upper bainite and lower bainite in a total amount of less than 30%, pearlite in an amount of less than 10%, and retained austenite in an amount of less than 5%, the ratio of the number of the martensite parts adjacent to the ferrite to the number of the metal structure parts adjacent to the ferrite is 30% or less in a part corresponding to a depth of 1/4 of the thickness of the steel sheet, and the difference between a maximum value and a minimum value of Vickers hardness at a load of 50 gf is 60 HV or less when the Vickers hardness is determined at 30-µm intervals from a origin position corresponding to a depth of 100 µm from the surface of the steel sheet as observed in the thickness direction to a thickness center position.

Patent Information

Applicants

Inventors

Specification

Documents

Application Documents