Chromate solution for hot-dip galvanized steel sheet excellent in corrosion resistance and reduction resistance

摘要

An object of the present invention is to provide a chromate treatment solution for a galvanized steel sheet which is excellent in resistance to deformation and corrosion resistance and does not deteriorate the surface appearance of the galvanized steel sheet. The present invention relates to a chromium-free chromic acid solution having a chromium concentration of 3 to 10 g / l in terms of chromium 6, and a phosphoric acid of 0.5 to 1 g / l and a molybdate of 20 to 40 g / This chromate treatment solution for a zinc-plated steel sheet is an important point.