| 摘要 |
<p>Disclosed is a method for producing a phosphate-treated galvanized steel sheet comprising a step for forming a phosphate coating film over the surface of a plating layer of a galvanized steel sheet by using a phosphate processing liquid which contains Zn2+ and Mg2+ satisfying 2.0 < Zn2+ 5.0 g/L, 2.0 Mg2+ 5.0 g/L and 0.4 Mg2+/ Zn2+ 2.5, while satisfying 0.020 free acidity/total acidity < 0.10. A uniform phosphate coating film can be formed in a short time by this production method, and thus there can be obtained a phosphate-treated galvanized steel sheet which is excellent in corrosion resistance and blackening resistance.</p> |
