Galvanized steel sheet and member, and method of producing same

A galvanized steel sheet comprising a base steel sheet and a galvanized layer on a surface of the base steel sheet, wherein

• the base steel sheet comprises:
• a chemical composition containing, in mass %,
• C:
• 0.040% or more and 0.200% or less,
• Si:
• 0.20% or more and 3.00% or less,
• Mn:
• 1.00% or more and less than 3.50%,
• P:
• 0.001% or more and 0.100% or less,
• S:
• 0.0200% or less,
• Al:
• 0.005% or more and 2.000% or less,
• N:
• 0.0100% or less,
• Ti:
• 0.200% or less, including 0%,
• Nb:
• 0.200% or less, including 0%,
• V:
• 0.100% or less, including 0%,
• B:
• 0.0100% or less, including 0%,
• Cu:
• 1.000% or less, including 0%,
• Cr:
• 1.000% or less, including 0%,
• Ni:
• 1.000% or less, including 0%,
• Mo:
• 0.500% or less, including 0%,
• Sb:
• 0.200% or less, including 0%,
• Sn:
• 0.200% or less, including 0%,
• Ta:
• 0.100% or less, including 0%,
• W:
• 0.500% or less, including 0%,
• Mg:
• 0.0200% or less, including 0%,
• Zn:
• 0.0200% or less, including 0%,
• Co:
• 0.0200% or less, including 0%,
• Zr:
• 0.0200% or less, including 0%,
• Ca:
• 0.0200% or less, including 0%,
• Ce:
• 0.0200% or less, including 0%,
• Se:
• 0.0200% or less, including 0%,
• Te:
• 0.0200% or less, including 0%,
• Ge:
• 0.0200% or less, including 0%,
• As:
• 0.0200% or less, including 0%,
• Sr:
• 0.0200% or less, including 0%,
• Cs:
• 0.0200% or less, including 0%,
• Hf:
• 0.0200% or less, including 0%,
• Pb:
• 0.0200% or less, including 0%,
• Bi:
• 0.0200% or less, including 0%, and
• REM:
• 0.0200% or less, including 0%,
• with the balance being Fe and inevitable impurities,
• the steel microstructure of the base steel sheet comprises:
• area fraction of ferrite:
• 20.0% or more and 90.0% or less,
• area fraction of bainitic ferrite:
• 4.0% or more and 60.0% or less,
• area fraction of tempered martensite:
• 20.0% or less, including 0%,
• area fraction of retained austenite:
• 3.0% or more,
• area fraction of fresh martensite:
• 20.0% or less, including 0%,
• SF+SBF:
• 55.0% or more and 95.0% or less,
• SMA1:
• 4.0% or more, and
• SMA2:
• 1.5% or more, wherein
• tensile strength is 590 MPa or more,
• where
• SF is area fraction of ferrite,
• SBF is area fraction of bainitic ferrite,
• SMA1 is area fraction of the sum of island regions of hard secondary phase consisting of retained austenite and fresh martensite having a circularity of 0.40 or less, and
• SMA2 is area fraction of the sum of island regions of hard secondary phase consisting of retained austenite and fresh martensite having a circularity of 0.20 or less and an aspect ratio of 4.0 or less, and
• wherein the area fractions of ferrite, bainitic ferrite, tempered martensite, retained austenite, and fresh martensite are measured at a ¼ sheet thickness position of the base steel sheet.