| abstract |
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 sheetwhich is excellent in corrosion resistance and blackening resistance. |