| 摘要 |
PURPOSE:To raise the quality of the galvanized steel plate by improving greatly the corrosion resistance and the blistering resistance by a method in which the galvanized steel plate subjected to the alloying treatment is chromate-treated by a treating liquid composed of specific components, e.g., Cr2O3, H3PO4, etc. CONSTITUTION:The galvanized steel plate subjected to the alloying treatment is chromate-treated by the treating liquid composed of 20-50g/l of CrO3, 12-30g/l of H3PO4, 0.2-5g/l of H2SO4, and 0.2-5g/l of F ion. Thus, a film which is excellent in corrosion resistance and adhesiveness to paints can be formed in a treating time of approx. 3-4 seconds, and therefore its blistering resistance is more greatly improved than the conventional methods, permitting the quality of the galvanized steel plate to be raised. |
