Coating type chromate solution showing excellent surface appearance, corrosion resistance and paintability when applied to steel sheet and chromate film formation method using the same

摘要

The present invention relates to a coated chromate solution exhibiting excellent surface appearance, corrosion resistance and paintability when applied to a steel plate surface, and a method of applying the same to a steel plate surface. The chromate solution according to the present invention has a chromium reduction ratio of 0.3 to 0.7. chromium 10-60g / 1, phosphate (PO4 ^3-) component 5-50g / 1: fluorine (F ^-) component 1-8g / 1: zirconium component 1-5g / 1, silica 3-25g / 1, surfactant It is composed of 0.05-2% by weight and 0.05-2.5% by weight of the silane coupling agent, and after coating the chromate solution of the present invention on a galvanized steel sheet, the plate is baked at a steel plate temperature of 120-200 ° C. to provide a method of treating the surface of the steel sheet. .