Evaluation of a fractal analysis technique for corrosion studies

Corrosion tests were performed to obtain electrochemical noise (EN) data during general and pitting corrosion in NaCl solutions for type 316 and 403 stainless steels. The data were analyzed by the Hurst parameter (HP) based on the rescaled range analysis. A correlation of the HP with the noise resistance was found in general corrosion, and the variability in published HP data is in part due to the difference in the value of noise resistance. The variability is also attributed to the difference in the amount of high frequency components in EN data. The HP is, however, a useful parameter for assessing the effectiveness of an inhibitor based on the characteristics of EN spectra, but not for identifying changes in the mode of corrosion in the case where the level of EN is low.