Potentiodynamic polarisation curves of 316L stainless steel in NaCl electrolyte

The macro-scale potentiodynamic polarisation (PP) tests were performed at varying NaCl concentrations (0.005 M, 0.01 M and 0.05 M).

Using an SP-300 (Bio-logic) potentiostat, the electrochemical cell (inside a Faraday cage) comprised the stainless steel specimen as the working electrode (WE, ~1 cm² of exposed area), an Ag/AgCl/KClsat as the reference electrode (inside a Luggin capillary) and a platinum foil as the counter electrode (CE). The polarisation tests started from – 30 mV to +900 mV (Vs OCP) after 60 min of immersion to guarantee relatively stable OCP values.

The measurements were repeated 28 times for each NaCl electrolyte concentration, generating a complete dataset of 84 polarisation curves.A scan rate of 0.5 mV/s was chosen to match our previous Macro PP study on the same 316L SS sample[1].

[1] L.B. Coelho, S. Kossman, A. Mejias, X. Noirfalise, A. Montagne, A. Van Gorp, M. Poorteman, M.G. Olivier, Mechanical and corrosion characterization of industrially treated 316L stainless steel surfaces, Surf Coat Technol 382 (2020) 125175. https://doi.org/10.1016/j.surfcoat.2019.125175.