The Significance of Correlation Dimension Obtained from Electrochemical Noise

The corrosion types of Q235 carbon steel and nuclear grade 304 stainless steel (304 NG SS) in different solutions are investigated by electrochemical noise (EN) technique. EN data are analyzed by using phase space reconstruction theory. With the obtained correlation dimension from the phase space reconstruction, the chaotic behavior of EN is quantitatively evaluated. It is concluded that local corrosion shows a higher correlation dimension while passivation shows a lower correlation dimension. We propose that the correlation dimension increases with the complexity and uncertainty of the signals from passivation to local corrosion, which is the physical meaning of correlation dimension for EN.