Texture and corrosion resistance in hot-dip galvanized steel sheet coatings

The relationships among textures,phase distribution and corrosion resistance of hot-dip galvanized coatings were investigated with X-ray diffraction and potentiodynamic techniques.Experimental results indicate the major texture component of pure zinc phase in the galvanized coatings is 0002 basal texture.As the thickness of the galvanized coatings increases,the 0002 basal texture component as well as the free corrosion potential increases,the corrosion current density decreases,and the corrosion resistance of the galvanized coatings increase.X-ray diffraction analysis results of an electrochemical stripping Fe-Zn phase coating show that the galvanized coatings are composed of alloy phases and pure zinc phase.Electrochemical experiments indicate the corrosion resistances of alloy phases and pure zinc phase are different,the corrosion resistance of alloy phases is higher than that of pure zinc phase,and the corrosion resistance of Fe-Zn alloy phase increases with the increase of iron content.