Graphene-based spray deposition of protective coatings on 316L stainless steel for enhanced anti-corrosion and tribological performance

The present study explores the fabrication and performance of graphene-based protective coatings on 316L stainless steel using a scalable spray deposition technique. Microstructural characterization confirmed the formation of uniform, adherent carbon-rich layers with thicknesses ranging from 10 to 25 µm. Raman spectroscopy and XRD analysis revealed characteristic graphitic features with moderate disorder, while SEM–EDS elemental mapping verified homogeneous carbon distribution across the coated surface. Tribological testing demonstrated significant improvements in wear performance. The graphene-coated samples exhibited a stable coefficient of friction of ~0.28 compared to ~0.65 for bare 316L, and wear rates were reduced by nearly 70% across applied loads. These results highlight the lubricating role of graphene’s layered structure, which minimizes adhesive interactions and facilitates shear. Electrochemical evaluations in 3.5 wt.% NaCl further confirmed the protective effect: the coated samples displayed a ~70% reduction in corrosion current density (I_corr) and a fourfold increase in charge-transfer resistance (R_ct) relative to the uncoated substrate. The integration of tribological and electrochemical findings underscores the dual functionality of spray-deposited graphene coatings, which act simultaneously as solid lubricants and electrochemical barriers. The simplicity and scalability of spray deposition, combined with the demonstrated improvements in wear and corrosion resistance, make this approach a promising candidate for industrial applications in marine, biomedical, aerospace, and energy sectors where durability and reliability are critical.