Patent ID: 6416648
Filing Date: 2002-07-09
Classification: C25D

Abstract:
A method of manufacturing steel sheets coated with a layer of Znâ€”Fe alloy with an excellent corrosion resistance comprising three major steps of a pre-treatment including a general rinse and an acid rinse, a main process of coating steel sheets in a cell and finally a post-treatment of washing, oiling and drying, wherein the thickness of the coated layer on produced steel sheets falls between 5-7 &mgr;m by using a coating electrolyte consisting of 23-34 wt. % of ZnSO4.7H2O, 37-48 wt % of FeSO4.7H2O, 21-32 wt. % of (NH4)2SO4 and 1-8 wt. % of KCl kept at 48-52Â° C. with a pH of 3-4 under an electric current density of 50-100 mA/cm2.