| 摘要 |
A zinc or zinc alloy coated steel sheet has a surface-treatment film formed thereon in a coating weight per one surface of 100 to 600 mg/m2. The surface-treatment film is obtained by applying, onto a surface of the zinc or zinc alloy coated steel sheet, the surface-treatment solution prepared by mixing the following components at specific ratios, the surface-treatment solution having pH of 8 to 10: a silane compound (A) having a hydrolyzable group, obtained from a silane coupling agent (a1) having a glycidyl group, a tetraalkoxysilane (a2), and a chelating agent (a3); a zirconium carbonate compound (B); a vanadate compound (C); a nitric compound (D); and water, and by subsequently heating and drying the surface-treatment solution thus applied. |
