INTEMA   05428
INSTITUTO DE INVESTIGACIONES EN CIENCIA Y TECNOLOGIA DE MATERIALES
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
Electronic properties of surface films on constructional steel in carbonated chloride-rich media containing nitrite ions
Autor/es:
M. VAZQUEZ; M. B. VALCARCE; FRONTINI, M.A.
Reunión:
Congreso; 2018 Latincorr; 2018
Resumen:
Corrosion of constructional steel is one of the main pathologies affecting life extension in reinforced concrete. To mitigate the effect of aggressive environments, sodium nitrite (NaNO2) can be used as corrosion inhibitor, favoring the formation of a compact and adherent layer composed by iron oxides. The effect of nitrite ions on the electronic properties of passive films formed in an alkaline electrolyte simulating a good-quality concrete pore solution (APS, pH = 13) is evaluated. Anodic polarization curves, electrochemical impedance spectroscopy (EIS) and Mott-Schottky plots were analyzed. The results are compared to those in chloride?contaminated solutions simulating carbonated concrete (CPS, pH = 9). The inhibitor/chloride is 1. The results indicate that steel is passive in APS and active in CPS. However, passivity is achieved in CPS when nitrite ions are incorporated. Mott-Schottky plots indicate that the passivating film behaves as an n-type semiconductor. Donor density values are similar in APS and CPS containing nitrite ions. Pitting is inhibited in both solutions, although the Epit-Ecorr difference is 2.7 times higher in APS