... to atmospheric corrosion of the base metal iron.3 hot-dip galvanizing layer formation process Hot-dip ... 40 to 60 ° C, or with HCl 20%, methenamine 3 ~ 5g / L, 20 ~ 40 °C for pickling. Adding corrosion ... the plating, plated zinc or zinc coating off. (3) dip fluxing agent Also known as solvents, can ... , as Na2Cr2O7 80 ~ 100g / L, the sulfuric 3 to 4ml / L, but this passivation solution serious impact ...