Zinc-plated steel sheet and manufacturing method thereof

A zinc-plated steel sheet comprising:

• a steel sheet;
• and
• a zinc-plated layer disposed on a surface of the steel sheet,
• the steel sheet has a chemical composition containing, by mass %,
• C:
• 0.150% to 0.500%,
• Si:
• 0.01% to 2.50%,
• Mn:
• 1.00% to 5.00%,
• P:
• 0.100% or less,
• S:
• 0.0100% or less,
• Al:
• 0.001% to 1.000%,
• N:
• 0.0100% or less,
• O:
• 0.0100% or less,
• Cr:
• 0% to 2.00%,
• Mo:
• 0% to 1.00%,
• B:
• 0% to 0.010%,
• Cu:
• 0% to 1.00%,
• Ni:
• 0% to 1.00%,
• Co:
• 0% to 1.00%,
• W:
• 0% to 1.00%,
• Sn:
• 0% to 1.00%,
• Sb:
• 0% to 0.50%,
• Ti:
• 0% to 0.30%,
• Nb:
• 0% to 0.30%,
• V:
• 0% to 1.00%,
• Ca:
• 0% to 0.0100%,
• Mg:
• 0% to 0.0100%,
• Ce:
• 0% to 0.0100%,
• Zr:
• 0% to 0.0100%,
• La:
• 0% to 0.0100%,
• Hf:
• 0% to 0.0100%,
• Bi:
• 0% to 0.0100%, and
• REM:
• 0% to 0.0100%
• with a remainder including Fe and an impurity,
• steel microstructures in a range of ⅛ thickness to ⅜ thickness, having a center at ¼ thickness from the surface of the steel sheet, include, by vol %,
• ferrite:
• 0% to 10%,
• bainite:
• 0% to 20%,
• tempered martensite:
• 70% or more,
• fresh martensite:
• 0% to 10%,
• retained austenite:
• 0% to 10%, and
• pearlite:
• 0% to 5%,
• an amount of hydrogen that is emitted when the steel sheet is heated up to 200° C. from a room temperature after removal of the zinc-plated layer is 0.40 ppm or less per mass of the steel sheet,
• a tensile strength is 1470 MPa or more, and
• cracking does not occur in a U-shape bending test in which a stress equivalent to 1000 MPa is applied for 24 hours.