Evaluation of the corrosion inhibition performance of silane coatings filled with cerium salt-activated nanoparticles on hot-dip galvanized steel substrates

摘要

The present work investigates the morphological and electrochemical behavior of hot-dip galvanized (HDG) steel substrates that were pre-treated with 3-glycidoxypropyltrimethoxysilane (GPTMS) and bisphenol A (BPA) modified with cerium ion-activated CeO2 nanoparticles. The morphology of the coatings before and after the corrosion test was examined using atomic force microscopy (AFM) and scanning electron microscopy (SEM). The results indicated the formation of a comparatively smooth, nanostructured surface, with a small heterogeneity in the coating thickness. Microscopic observations also confirmed that the integral surface morphology of the silane coating filled with activated CeO2 nanoparticles was maintained after short-term corrosion tests (144 h). The corrosion behavior of the sol–gel coatings was investigated using natural salt spray tests, electrochemical impedance spectroscopy (EIS), and potentiodynamic polarization tests. The results showed that the presence of the nanoparticles reinforced the barrier properties of the silane films, and a synergy seemed to be created between the activated nanoparticles and the cerium ions, reducing the corrosion activity.