| 摘要 |
An object of the present invention is to provide a high strength galvanized steel sheet excellent in terms of formability, coating adhesiveness in a portion subjected to bending forming, corrosion resistance in a portion subjected to stretch flange forming and surface appearance. The steel sheet has a chemical composition comprising, C: 0.02% or more and 0.30% or less, Si: 0.01% or more and 2.5% or less, Mn: 0.1% or more and 3.0% or less, P: 0.003% or more and 0.08% or less, S: 0.01% or less, Al: 0.001% or more and 0.20% or less, Ti: 0.03% or more and 0.40% or less and the balance being Fe and inevitable impurities, and a zinc-coated layer on both surfaces of the base steel sheet having a coating weight per surface of 20 g/m 2 or more and 120 g/m 2 or less. The concentration ratio of C to Ti (C/Ti) in a portion within 10 µm from the surface of the base steel sheet immediately under the zinc-coated layer is, in terms of atomic ratio, 0.8 or more and 1.5 or less, and the total amount of oxides of one or more selected from Fe, Si, Mn, P, Al and Ti formed in a surface portion within 100 µm from the surface of the base steel sheet immediately under the zinc-coated layer is, in terms of oxygen amount, 0.05 g/m 2 or less per surface. |
