THE EFFECT OF GRAPHENE-EPOXY COATINGS ON ANTICORROSION PERFORMANCE FOR HEAT EXCHANGER

The present work focuses on the effect of graphene-epoxy coatings as corrosion inhibitors on the plate carbon steel substrates utilized for heat exchangers in the oil and gas industries. Graphene-epoxy composites with various graphene concentrations are coated on the substrates using bath method. The corrosion behaviours of the substrates immersed in 1 M sulphuric acid solution at room temperature were studied using potentiodynamic polarization. The results obtained reveal that graphene-epoxy coatings act effectively as a corrosion inhibitor. The corrosion potentials of the coated carbon steels shift to more positive values than that of the uncoated carbon steel. The corrosion current densities and corrosion rates are reduced by 30 to 36 times in magnitude due to the effective barrier and impermeability of graphene-epoxy coatings from ions and other species in acid solutions. These cause an increased inhibition efficiency from 96.72% to 97.23%. Scanning electron microscopy investigations suggest that graphene is dispersed homogeneously throughout the composite coatings that enhance their corrosion protection.