Fabrication and characterization of a Fe3O4/polyvinylpyrrolidone (Fe3O4/PVP) nanocomposite as a coating for carbon steel in saline media

Corrosion of carbon steel (CS) is a security and financial concern for numerous industries involving oil, petroleum, and automotive industries. The outstanding mechanical properties and comparatively low price of CS have made it one of the most commonly used materials in many industries. Nevertheless, CS is very vulnerable to corrosion through many applications and media where the iron content of the alloy suffers from oxidation in saline or acidic media. Protection of these alloys against corrosion is an essential strategy to reduce damage and costs of industrial operations. Corrosion protection by polyvinylpyrrolidone (PVP) coating composed of several magnetite (Fe3O4) nanoparticle contents was investigated in this research. Primarily, a Fe3O4/PVP nanocomposite was prepared and then it was examined by multiple characterization techniques such as FT-IR, XRD, and SEM. CS samples were coated by using the as-prepared nanocomposite through an immersion method. The coating function was evaluated by several electrochemical methods such as electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization, in NaCl 3.5% media. Electrochemical tests results showed that the nanocomposite coating decreased the corrosion current density from 10.56 mu A to less than 0.42 mu A. Electrochemical impedance spectroscopy data analysis revealed that the charge transfer resistance for the corrosion reaction was increased from 94 omega for the bare sample up to 159 omega for the coated sample. The inhibition efficiency of the Fe3O4/PVP nanocomposite was found to beca.96%. Therefore, the Fe3O4/PVP nanocomposite coating can be used as an efficient corrosion protection method for CS.