| 摘要 |
PURPOSE:To improve the adhesive strength of a coated compound film of silicate/ chromate corrosion resistance of a coated plate with said compound film by treating the surface of Zn which covers the surface of a metal with an acid solution containing >=1 metallic ion selected from Ni, Fe, Co. CONSTITUTION:The surface of a galvanized sheet is treated with an aq. acidic solution containing >=1 metallic ion selected from Ni, Fe, Co. After the completion of the treatment, it is washed with water to remove an excess treating solution from the zinc surface. Then, a treating solution consisting essentially of chromic acid, its reduced product and silicic acid is applied thereto and dried to form compound film of silicate and chromate on the zinc surface. |
