Resistance Electrochemical Noise as a Tool for Corrosion Rate Prediction

Abstract The current and potential fluctuations (Electrochemical Noise) between two nominally identical carbon steel electrodes were recorded in a solution of Na3PO4 at different concentrations. After the passivation was reached, pitting was induced by the addition of chlorides. The data were collected with different sampling rates. The Linear Polarization Resistances (LPR) were also measured. The electrochemical signals were studied in the time and frequency domains. The statistical parameters coming from the signals in the time and in the frequency domains were compared with the corrosion rates through LPR. The resistance noise was also calculated. A good correlation between data coming from the different techniques was found. A study on how sampling rate can affect the electrochemical noise data collection is also reported.