Enhancing corrosion resistance of additively manufactured 316L stainless steel by fabricating pillar arrays

By using the electrochemical etching technique, pillar arrays with a size of -50-200 nm are fabricated on the surface of 316L manufactured by laser powder bed fusion. The nanopillars morphology is induced by the selective anodic dissolution of dislocation cell walls that are decorated with high local concentrations of Cr/Fe/Ni solute atoms. The appearance of pillar arrays extends the passivation range and increases the pitting potential of 316L in HNO3 solution, while the corrosion current density decreases in NaNO3 solution. The enhanced corrosion resistance was attributed to the coeffect of elimination of corrosionsensitive features and hydrophobicity prompted by electrochemical etching.& COPY; 2023 The Author(s). Published by Elsevier Ltd. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).

Automated summary

Pillar arrays with sizes of -50-200 nm are created on the surface of 316L material using electrochemical etching. The appearance of nanopillars is attributed to the selective anodic dissolution of dislocation cell walls decorated with high concentrations of Cr/Fe/Ni solute atoms. The pillar arrays extend the passivation range and increase the pitting potential in an HNO3 solution, while reducing the corrosion current density in a NaNO3 solution. The enhanced corrosion resistance is a result of eliminating corrosion-sensitive features and improving hydrophobicity through electrochemical etching.