A negative effect of the insoluble particles of dross on the quality of the galvanized coatings

In continuous galvanizing process several byproducts are formed. Amongst these byproducts insoluble particles composed by different compounds are grown. The most problematic seems to be a complex oxide of a ZnAl2−xFeyO4 stoichiometry (spinels) with variable lattice parameters, which is formed at the zinc/substrate interface. This oxide accelerates the breakdown of Fe-Al passive layer, resulting in the formation of a series of Fe-Zn intermetallic phases by an outburst growth. The samples used in this study were industrially galvanized wires and byproducts, which were studied by different methods, i.e., Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM) and X-Rays-Diffraction (XRD).