Resumen

MILLANO, Valentina et al. Electrochemical behavior study of AISI 304 and 316 in carbonate or chloride contaminated concrete . Rev. Téc. Ing. Univ. Zulia [online]. 2006, vol.29, n.3, pp.291-298. ISSN 0254-0770.

In this work the behavior of steel AISI-SAE 304 and 316 were studied in reinforced concrete, using prisms exposed in environments with chlorides, with chlorides incorporated or exposed with high contents of CO₂. All of them with a a/c relation of 0.65, compressive strength of 150 Kgf/cm² and they were at environments of 30 ± 5°C and 90% HR. At the same time, several electrodes of stainless steel AISI 304 were studied immersing them in pore water solution to different times and chloride ion concentrations from 1 and 2% p/p. The techniques of measurement used were: potential, linear polarization and electrochemical impedance spectroscopy (EIS). Stainless steel 304 and 316 reported average corrosion rates below 0.02 µA/cm², for all the conditions evaluated in the reinforced concrete prism. Nevertheless, when comparing the values of corrosion rate obtained through EIS with those from linear polarization for the reinforcements that presented greater corrosion rates (³0.1 µA/cm²), these were similar when the Nyquist diagram showed capacitive oxide film. On the contrary, when the corrosion rate were very low (<0.01 µA/cm²), the mathematical adjustment found limitation for the systems with high resistance polarization. The corrosion rates reported for AISI-SAE 304 in the pore water tests were greater (0.05 and 0.12 µA/cm²/1% NaCl; 0.24 and 0.05 µA/cm²/2% NaCl), after 6 and 336 hours, respectively; which indicates that the corrosion rate is increased with time of exposure for 1% of NaCl, not thus for 2%. 

Palabras clave : AISI304; AISI316; concrete; chloride; carbonation; EIS; LPR.