A new potentiostatic electrochemical noise (P-ECN) technique has been developed for enhanced, real time corrosion monitoring for both general and localized corrosion. Two different systems, C1018/NaC1 in CO2 and SS304/FEC13 in air, were evaluated with P-ECN for its monitoring capabilities for general and localized corrosion, respectively. Quantitative analysis of the data was carried out using standard deviation and moving average (SDMA) calculation method for corrosion rate determination. The data revealed significant differences between general corrosion and localized (pitting and crevice) corrosion noise signatures. These results were compared with linear polarization and weight loss measurements.
A new potentiostatic electrochemical noise (P-ECN) technique was recently introduced and its performance demonstrated in the lab 1'2. The technique is based on the current and potential noise measurements on one-working electrode rather than two working electrodes used by the conventional noise technique (ECN) 3-5 at/near open circuit potential. The main advantages of the P-ECN over ECN are improved correlation between current and potential noise of the working electrode, reduced polarization of the working electrode and preservation of the DC current/potential components. result, discrimination between general and various types of localized corrosion becomes possible.
Significant progress has been also made towards quantitative analysis of the noise data, including noise signal calibration and "pattern" recognition. The trend removal and moving average analysis 6'7 were performed with respect to low-frequency components of current/potential transients. A new calibration procedure was introduced to aid in noise signal analysis and quantitation of localized corrosion.
