Passive film evolution over 2.5 years of lean-duplex stainless steel reinforcements embedded in mortar containing chlorides

The corrosion behavior, semiconducting properties and chemical composition of the passive film formed on lean-duplex stainless steel LDSS 2001, LDSS 2304 and AISI 304 reinforcements embedded in OPC mortar containing chloride, 0, 0.4, 2 and 4 wt.% Cl^‒; after 2.5 years were studied. The C_eff,film of LDSS 2001 remained constant at 3×10^‒5 F/cm² for all Cl^‒ concentrations. Flat-band potential, E_FB,A, of LDSS 2001 increased with the Cl⁻ concentration, suggesting a Cr₂O₃ film more prone to accept electrons, reducing the vacancy density. The enrichment in chromium in the passive film of LDSS 2001 after 2.5 years increases from 44% to 61%.