| 摘要 |
The purpose of the present invention is to provide a hot-dip galvanized steel sheet and a galvannealed steel sheet having a high Si content steel sheet as base material, having a beautiful appearance with no surface defects and excellent plating adhesiveness, and a manufacturing method therefor. A hot-dip galvanized steel sheet of excellent appearance and plating adhesiveness, the steel sheet being characterized in: having a component composition comprising, in mass%, 0.08% to less than 0.20% of C, 0.1-3.0% of Si, 0.5-3.0% of Mn, 0.001%-0.10% of P, 0.01%-3.00% of Al, and not more than 0.200% of S with the remainder being obtained from Fe and unavoidable impurities; having an internal oxidation layer with a thickness of not more than 5 μm on the ferrite side from the interface between the ferrite and the zinc-plating layer and a decarbonization layer with a thickness of not more than 20 μm on the ferrite side from the interface between the ferrite and the zinc-plating layer; and the internal oxidation layer comprising, in area ratio, at least 50% of a Fe- and/or Mn-containing Si oxide, which is represented by Fe2XMn2-2XSiOY, wherein X = 0 to 1, Y = 3 or 4. |
