Cathodic Kinetics on High Resistance and Low Alloy Steels with Corrosion Inhibitors

Abstract

This paper presents a study of the cathodic kinetics of high resistance and low carbon steel by the potentiodynamic cathodic polarization curves. In this study, the steel was immersed in a NACE brine with 50 ppm of corrosion inhibitor dissolved under turbulent flow conditions, room temperature and atmospheric pressure of the Veracruz Port. In order to simulate the hydrodynamic conditions, a Rotating Cylinder Electrode (RCE) with different rotation speeds was used. Electroactive species to be reduced were determined using the Eisenberg equation, as well as an analysis with dimensionless numbers was made in order to complement this study. The analysis of cathodic kinetics shown that the system under turbulent flow conditions is dominated by a mass transfer process, this is due to the diffusion of the oxygen from the bulk of the solution toward to metallic surface. According to the comparison of the experimental and the theoretical , attained by the Eisenberg equation, it can be established that the cathodic kinetics of the process is dominated by an oxygen reduction reaction.