Chlorine resistance of tannic acid anticorrosive coating on galvanized steel in simulated concrete pore solution

Reinforced concrete structures are easily damaged by corrosion in a chloride environment. Although zinc coating provides a promising method for inhibiting steel corrosion, it can inevitably dissolve and fail under a chlorine-containing concrete environment. In this study, the chloride corrosion resistance of coatings prepared with different concentrations of tannic acid was studied in a simulated concrete pore solution. The surface morphology and chemical composition of the different samples were investigated. The results of the corrosion immersion and electrochemical tests showed that the prepared corrosion resistance coating effectively enhanced the chlorine corrosion resistance of steel. The 10 wt% tannic acid coating on the galvanized steel surface had good corrosion resistance. The corrosion resistance efficiency increased 77.8%. The green and environmentally friendly method is expected to provide an essential application in chloride corrosion protection of concrete structures.