Corrosion Resistance of Steel/Zinc with Silicate Nanoparticles/Polyurethane Paint Systems in NaCl Solution

Abstract

Surface characteristics and corrosion behaviour of bare electrogalvanized steel coated with polymer/nano-silicate particles added to the electrogalvanizing bath were studied by scanning electron microscopy (SEM), energy dispersive spectrometer (EDXS) and electrochemical impedance spectroscopy (EIS). After applying a barrier polyurethane paint, the paint hardness, porosity, flexibility, colour, gloss, blistering and rusting degrees, and anticorrosive protective properties in 0.05 mol·L-1 NaCl solution were also evaluated. The results correlated well and, being demonstrative of the very slow deterioration rate of the immersed coated electrogalvanized steel, they enabled to assume that if a chemically analogous but thicker coating system was applied; it could be an acceptable alternative in real service conditions.