| 摘要 |
PURPOSE:To increase the corrosion resistance of the phosphate film and the coated surface on this film, by treating the object filmed in phosphate treating solution by supplying AC or DC while contacting with zinc phosphate treating solution. CONSTITUTION:The object of treatment on which is formed a chemical conversion film of at least one kind of iron phosphate film, zinc phosphate film, calcium phosphate film and managese phosphate film by spray method, spray-dipping method, or dipping method is treated with DC or AC current for 1-60 seconds of power supply at the current density of 0.01-2A/dm<2>, while contacting with zinc phosphate treating solution of pH 2.0-4.0 at ordinary temperature to 80 deg.C. By this method, in the corrosion resistance without applying paint, the rust inhibiting power is excellent as compared with the case of the conventional chromium base treatment. And in the corrosion resistance after coating with paint such as electrodeposition paint, powder paint, water-based paint, and oil-based paint, the resistance is higher than in the Cr base after-treatment. |
