Synergistic impact of the functionalized graphene oxide (fGO) nano-sheets and Mn2+-doped zinc phosphate conversion film on the polyester coating corrosion protection properties

Abstract

Corrosion protection is crucial for steel, and one effective method is applying organic coatings as a barrier between the steel and corrosive surroundings. However, defects and poor adhesion can compromise their effectiveness. Phosphating-based treatment is a widely used method to enhance corrosion resistance, but traditional processes are time-consuming. Recent advancements include low-temperature phosphating and nanoparticle-based accelerators. Graphene oxide (GO) nanoparticles have gained attention for improving corrosion resistance. The purpose of this study is to investigate the corrosion resistance of zinc phosphate conversion coatings on steel with functionalized graphene oxide (fGO) and Mn²⁺ cations, as well as polyester coatings. FT-IR, Raman, XRD, XPS, and FE-SEM analyses were conducted for thin film characterization. Furthermore, results show improved corrosion resistance for coated samples, especially with fGO and Mn²⁺. EIS, polarization tests, and salt spray tests confirm the enhanced protection. Evaluation of the intact and scratched coatings further demonstrates the barrier properties and self-healing ability. Overall, the study highlights the potential of incorporating nanomaterials and phosphating treatments to enhance the corrosion resistance of steel.