Corrosion Resistance of Inorganic Zinc - Rich Coating Containing Calcium Carbonate and Graphene Applied on the Surface of Q235 Steel

Abstract

Q235 steel is widely used in the infrastructure industry due to its high performance and low price, but it is prone to corrode in both terrestrial atmospheric environment and high salt fog environment at the seaside. In the marine field, inorganic zinc - rich coatings are the most commonly used anticorrosive conductive coatings, and the modification research on such coatings is promising. In this paper, the coatings were added with 2% graphene + 2% calcium carbonate for the purpose of improving corrosion resistance. Subsequently, the corrosion behaviors of the as - prepared coatings were investigated through simulated seawater immersion experiments and simulated sea salt aerosol experiments with the help of electrochemical impedance (EIS), scanning electron microscopy (SEM) and X - ray diffraction (XRD) analysis. Results showed that in the comparison of the original formula coating, the coating added with 2% graphene and 2% calcium carbonate possessed higher impedance value and lower corrosion current density. In addition, the generated corrosion products prevented the intrusion of corrosive medium and slowed down the corrosion. In general, the inorganic zinc - rich coating added with 2% graphene + 2% calcium carbonate had better corrosion resistance compared with the original formula coating.

Keywords

• simulated seawater|electrochemical test|q235 steel|inorganic zinc - rich coating|calcium carbonate|graphene|corrosion resistance