| 摘要 |
PROBLEM TO BE SOLVED: To provide a phosphate solution for treating a galvanized steel sheet capable of forming a film having good post-coating corrosion resistance and whiteness and a phosphate treated steel sheet of whiteness (L value) of >=70 using the treating liquid. SOLUTION: This phosphate solution for treating the galvanized steel sheet contains 4 to 10 g/L NO3 , 0.01 to 0.14 g/L Ni<2+> , 4 to 7 g/L Zn<2+> and 0.1 to 10 g/L at least >=1 kind among malic acid, citric acid, gluconic acid and their slat or phosphate per 1 L soln. in the phosphate solution in the method for subjecting the galvanized steel sheet to the phosphate treatment. The whiteness (L value) of the appearance of the galvanized steel sheet after the phosphate treatment is >=70. The phosphate treated galvanized steel sheet is formed by using the phosphate solution described above. Its Zn coating weight is 0.1 to 200 g/m<2> , its phosphate coating weight thereof is 0.1 to 5 g/m<2> , the whiteness (L value) of its plating appearance is >=70 and the grain size of the phosphate crystal is <=40μm.
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