An Investigation of Electrochemical Noise Analytical Methods in the Study of Carbon Steel Corrosion Behavior in Diethanolamine

Electrochemical noise measurement is considered by many researchers as one of the most well-known methods for studying corrosion mechanism due to its broad capabilities. Various analytical methods have been applied to use this technique, while in some cases; some discrepancies have been being detected in their obtained results. To further investigate these differences, various techniques consisting of localized index, wavelet transform and the slope of PSD were utilized to study corrosion behavior of carbon steel in diethanolamine aqueous solution containing different concentrations of absorbed H2S and CO2 gases. It was found that the localized index and wavelet analytical techniques were in a good agreement, while the slope of PSD changes did not indicate a logical trend. By making a comparison between the polarization test results and the noise resistance results, it could be deduced that although the trend of noise and polarization changes were quite similar, but the absolute values of corrosion rates were not equal.