Can We Enhance Passivity with a Surface Finish? Spectroscopic and Electrochemical Analysis on 316L Stainless Steel

The effects of surface finish by mechanical polishing, vibratory and high-temperature annealing were studied on 316L stainless steel combining microscopic spectroscopic analysis the morphology composition electrochemical corrosion resistance. Compared to finishing promotes passivity at active-passive transition in acid solution enhances resistance chloride-induced breakdown. Cr Mo enrichments native oxide film increase owing preferential iron etching. bilayer structure develops a thicker Cr(III) inner barrier layer an outer exchange further enriched hydroxide Mo(IV/VI) oxides. Fe-rich weak sites are reinforced. High-temperature reducing hydrogen environment enables us fully reconstruct cold-worked layers left or finishing, thus allowing expose bulk microstructure topmost surface. benefits brought lost upon initial oxide. re-formed with similar as that obtained from polishing no beneficial passivity. results provide comprehensive insight into how can be enhanced enrichment engineering.