Anticorrosive Enamels: Evaluation of Nanocomposite Additives on Enamel Efficiency on Cold Rolled Steel

A comparative study of different enamels and the effect of inhibitor-loaded nanocontainers on corrosion protection performance of the enamel coatings in NaCl solution are reported. The study shows that mesoporous silica nanoparticles loaded with corrosion inhibitor 8-hydroxyquinoline can be blended in commercial enamels effectively texturizing its glossy nature and reducing corrosion propagation of cold rolled steel in the absence of a standard primer in the aggressive environment. The presence of the inhibiting nanocomposite in the enamel coating effectively controlled the deleterious effect of corrosive ions reaching the substrate surface and decreased the delamination effect thereby suppressing the excessive formation of rust. ATR–FTIR was used to evaluate the enamels before and after exposure to the corrosive solution. Immersion test, electrochemical impedance spectroscopy (EIS) measurements and potentiodynamic polarization (PP) studies were performed in 3.5 wt.% NaCl. Both unscratched and scratched enamel-coated surfaces were evaluated and the results revealed that the textured enamel coatings provided enhanced corrosion protection. The most effective corrosion protection for the scribed enamel coatings was observed from E-C3. Three weeks after the immersion test were observed that underneath the textured enamel was a less corroded substrate surface, but underneath the glossy enamel was a more corroded substrate surface. The presence of the inhibitor-loaded fillers positively influenced the corrosion protection efficiency of the enamels.