The electrochemical behaviour of stainless steel AISI 304 in alkaline solutions with different pH in the presence of chlorides

► The passivation and passivation breakdown of AISI 304 in alkaline solutions with different pH was studied. ► The electrochemical behaviour and the corrosion resistance in chloride environments were evaluated using d.c. potentiodynamic polarization and electrochemical impedance spectroscopy. ► The results were modelled using a hierarchically distributed circuit and revealed a more susceptible surface at pH 9. ► The passive film characterization was carried out by SEM and EDS analysis, revealing the existence of MnS inclusions and the increase of Cr/Fe ratio in the attacked areas, preferably the vicinity of those inclusions.