Plated steel sheet

A plated steel sheet, comprising:

• a steel sheet;
• and
• a plating layer on the steel sheet, wherein:
• the plating layer is a hot-dip galvanizing layer or an alloyed hot-dip galvanizing layer;
• the steel sheet comprises:
• a base material;
• and
• a decarburized ferrite layer on the base material;
• the base material includes a chemical composition represented by, in mass %:
• C:
• 0.03% to 0.70%;
• Si:
• 0.25% to 3.00%;
• Mn:
• 1.0% to 5.0%;
• P:
• 0.10% or less;
• S:
• 0.0100% or less;
• sol. Al:
• 0.001% to 1.500%;
• N:
• 0.02% or less;
• Ti:
• 0.0% to 0.300%;
• Nb:
• 0.0% to 0.300%;
• V:
• 0.0% to 0.300%;
• Cr:
• 0% to 2.000%;
• Mo:
• 0% to 2.000%;
• Cu:
• 0% to 2.000%;
• Ni:
• 0% to 2.000%;
• B:
• 0% to 0.0200%;
• Ca:
• 0.00% to 0.0100%;
• REM:
• 0.0% to 0.1000%;
• and
• a balance:
• Fe and impurities;
• the base material includes a structure, at a position at which a depth from a surface of the steel sheet corresponds to ¼ of a thickness of the steel sheet, represented by, in volume fraction:
• tempered martensite:
• 3.0% or more;
• ferrite:
• 4.0% or more;
• and
• retained austenite:
• 8.3% or more;
• an average hardness of the tempered martensite in the base material is 5 GPa to 10 GPa;
• a part or all of the tempered martensite and the retained austenite in the base material form a Martensite-Austenite constituent;
• a volume fraction of ferrite in the decarburized ferrite layer is 120% or more of the volume fraction of the ferrite in the base material at the position at which the depth from the surface of the steel sheet corresponds to ¼ of the thickness of the steel sheet;
• an average grain diameter of the ferrite in the decarburized ferrite layer is 20 μm or less;
• a thickness of the decarburized ferrite layer is 5 μm to 200 μm;
• a volume fraction of tempered martensite in the decarburized ferrite layer is 1.0 volume % or more;
• a number density of the tempered martensite in the decarburized ferrite layer is 0.01/μm2 or more;
• and
• an average hardness of the tempered martensite in the decarburized ferrite layer is 8 GPa or less.