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A crevice corrosion study by Electrochemical Noise Analysis
Author(s) -
Montesperelli G.,
Gusmano G.,
Marchioni F.
Publication year - 2000
Publication title -
materials and corrosion
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.487
H-Index - 55
eISSN - 1521-4176
pISSN - 0947-5117
DOI - 10.1002/1521-4176(200008)51:8<537::aid-maco537>3.0.co;2-4
Subject(s) - electrochemical noise , crevice corrosion , corrosion , dielectric spectroscopy , noise (video) , analytical chemistry (journal) , chemistry , electrochemistry , polarization (electrochemistry) , time domain , metallurgy , physics , materials science , electrode , chromatography , image (mathematics) , artificial intelligence , computer science , computer vision
The use of the Electrochemical Noise Analysis (ENA) for the evaluation of crevice corrosion is illustrated in the case of AISI 430 stainless steel in 3% sodium chloride. A crevice former was used in order to induce a crevice corrosion attack. Current and potential noise signals were simultaneously recorded allowing the determination of the noise resistance (R n ). ENA was able to detect the four stages mechanism of crevice corrosion. The comparison of R n with the Polarization Resistance (R p ) determined by Electrochemical Impedance Spectroscopy (EIS) gave good agreement in particular during the initiation and propagation of the attack. The evaluation of the noise data in the frequency domain gave interesting results in particular in the evaluation of the roll‐off slopes in the Power Spectrum Density (PSD) plot that are correlated to the corrosive status. Finally a new analysis for noise data is shown. The application of spectral ratio discriminant function to noise data in the frequency domain, permits to deduce the best sampling frequency and sampling duration for ENA acquisition, able to discriminate between two different situations.