The corrosion resistance of 316L stainless steel coated with a silane hybrid nanocomposite coating

The present work aims at evaluating the corrosion resistance of 316L stainless steel pre-treated with an organic–inorganic silane hybrid coating. The latter was prepared via a sol–gel process using 3-glycidoxypropyl-trimethoxysilane as a precursor and bisphenol A as a cross-linking agent. The corrosion resistance of the pre-treated substrates was evaluated by neutral salt spray tests, linear sweep voltammetry and electrochemical impedance spectroscopy techniques during immersion in a 3.5% NaCl solution. In addition, the effect of the drying method as an effective parameter on the microscopic features of the hybrid coatings was studied using Fourier transform infrared spectroscopy and scanning electron microscopy. Results show that the silane hybrid coatings provide a good coverage and an additional corrosion protection of the 316L substrate.

► Evaluation of the corrosion resistance of 316L stainless steel with hybrid coatings based on 3-glycidoxypropyl-trimethoxysilane (GPTMS) as the precursor and bisphenol A (BPA) as the cross-linking agent.
► Study of the effect of the drying method as an effective parameter on the microscopic features of the hybrid coatings.
► Results indicate the formation of a denser siloxane network upon thermal curing.
► Electrochemical analyses as well as salt spray test highlight the good barrier properties of the deposited silane film.