Corrosion protection performance of graphene-modified zinc-rich epoxy coatings under high-temperature and high-concentration NaCl solution.

In this study, physically exfoliated graphene was embedded in zinc-rich epoxy coatings with different zinc contents to study the corrosion protection of graphene-modified zinc-rich epoxy (GZRE) coatings to steel substrates under high-temperature and high-concentration NaCl solution. Electrochemical impedance spectroscopy and open-circuit potential were conducted to investigate the corrosion resistance of GZRE coatings with different zinc contents under intact and damaged conditions. The supporting evidence was also provided by surface morphology, cross-sectional morphology, scratch morphology, and salt spray experiment. The contact mode of zinc particles–graphene–zinc particles can be formed between graphene and zinc particles in GZRE, thus improving the electrical connection between zinc particles. The role of graphene in improving the barrier effect and cathodic protection performance of GZRE depends on the zinc content in the coating. Moreover, it was discovered that highly active zinc particles could effectively attenuate the galvanic corrosion effect between graphene and steel substrate. This research will provide promising enlightenment for the application of graphene-modified zinc-rich epoxy coatings for the corrosion protection of steel substrates under high-temperature and high-concentration NaCl solution. [ABSTRACT FROM AUTHOR]