Review—Electrochemical Noise Applied in Corrosion Science: Theoretical and Mathematical Models towards Quantitative Analysis

Abstract

Electrochemical noise (EN) can be used in situ to investigate corrosion processes and to detect and monitor the corrosion of metallic materials. EN data are largely influenced by the measurement mode, the surface area of the working electrodes, the electrolyte resistance, and the symmetry of the electrode system. Herein, the advantages and limitations of electrochemical kinetics, equivalent circuit, and shot noise methods for quantifying corrosion rates with EN are discussed.

Frequency Analysis of Transients in Electrochemical Noise of Superalloys Waspaloy and Ultimet

“…Some research [25][26][27][28][29][30]36,37,[53][54][55][56][57][58] indicates that Several EN procedures correlating time-dependent fluctuation of current and potential during the corrosion process have been used to indicate the type of corrosion occurring. For instance, it is well recognized that the primary source of electrochemical noise is the passive film breakdown process and repassivation process.…”

“…Eden and various researchers [35,36,50,51] propose kurtosis and skewness to analyze corrosion systems. Xia et al [28] mentioned that kurtosis and skewness could be used to determine the shape of the distribution and transients' peaks. The skewness helps determine the phenomenon of the corrosion system.…”

“…The statistical analysis includes parameters such as noise resistance (R n ), skewness, kurtosis, localization index (LI), chaos analysis, recurrence quantification analysis, and fractal analysis. The fast Fourier transform includes power spectral density, noise impedance, etc., and the time-frequency domains methods include the analysis of Hilbert-Huang transform, discrete wavelet transform, Stockwell transform, and others [26][27][28][29][30][31][32]. LI, skewness, and kurtosis values have been reported as values related to different corrosion types and values referring to the asymmetry of EN data's distribution and shape [32][33][34][35][36][37].…”

Embedded Corrosion Sensing with ZnO-PVDF Sensor Textiles

“…None of these sensors are compatible with real-time corrosion sensing in an environment under any coating system. Electrochemical noise detection can be a solution to this, but suffers from serious limitations as interpreting the noise data quantitatively becomes very difficult at times with the existing theoretical and mathematical methods [23]. Continuous monitoring via embedded sensing is receiving much interest [24].…”

Evaluation of the localized corrosion on Mg electrode surface by electrochemical noise technique

“…[28] EN assessments are commonly performed using two working electrodes (WEs) whose connection is provided through a zero-resistance ammeter (ZRA), which monitors the coupling current of inter-WEs. [29][30][31] Although two similar WEs (equal size and type) setting a symmetrical cell are commonly used to measure the electrochemical current noise (ECN), [32] current research indicates that asymmetric cell configuration using considerably different sizes of two WEs that can be otherwise identical will be preferable in measuring ECN on Al and mild steel alloys. [29,30,33,34] The authors did not find any paper about the efficiency of asymmetrical Mg electrodes (different size, equal type) in the measurement of ECN after exact reviewing of the relevant literature in this subject.…”