Thin coatings are applied as a promising surface finish to stainless steel engineering components in highly corrosive environments, where only minor deviations from the component geometry due to coating thickness can be tolerated. In particular silica-based coating systems have gained academic as well as industrial interest due to their outstanding performance in terms of mechanical and electrochemical performance. The aim of this study is to investigate the protective behavior of SiO_x coatings from hydrogen silsesquioxane, (HSiO_3/2)_n, spin-on-glass precursor on AISI 316L 2B substrates in saline environment. The precursor has been deposited on the substrate and thermally cured in oxygen deprived atmosphere at temperatures ranging from 400-800 ˚C. The results showed the formation of highly polymerized SiO_x coatings containing various amounts of residual Si-H and silanol moieties. Moreover, the degree of coating polymerization was assessed based on the amount of residual Si-H and an increase in polymerization was found with increasing curing temperature up to 800 ºC. Further, the electrochemical behavior of the coating systems was characterized by linear cyclic polarization and electrochemical impedance spectroscopy. The results showed that the coatings decreased the electrolyte-exposed substrate surface area significantly and possessed enhanced barrier properties with respect to films cured in oxidizing ambient, yielding a minimal corrosion rate in electrochemical tests. Furthermore, the excellent performance of the coating systems in short term electrochemical studies were critically evaluated in comparison to prolonged exposure in accelerated corrosion tests and substrate sensitization due to the deposition process.