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Evaluation of 08CH18N10T stainless steel corrosion in subcritical water by electrochemical noise analysis
Author(s) -
Kučera P.,
Macák J.,
Sajdl P.,
Novotný R.
Publication year - 2008
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/maco.200804154
Subject(s) - electrochemical noise , corrosion , dielectric spectroscopy , materials science , polarization (electrochemistry) , electrolyte , noise (video) , fast fourier transform , electrical impedance , electrochemistry , analytical chemistry (journal) , metallurgy , electrode , chemistry , mathematics , electrical engineering , chromatography , engineering , computer science , image (mathematics) , algorithm , artificial intelligence
The corrosion behaviour of pressurized water reactor (PWR) steam generator tube material (08CH18N10T steel) was studied by electrochemical noise (EN) measurements and electrochemical impedance spectroscopy in high‐temperature water at 280 °C and 8 MPa. Long‐term measurements were performed in two electrolytes: (i) deionised water alkalized to pH 25 = 9.5 by KOH; (ii) the same electrolyte with 200 ppm of chlorides added (as KCl). The noise data were processed by two filtering methods and the noise resistance and spectral noise resistance values were calculated. Different contributions to the total impedance were identified and the polarization resistance values were calculated from EIS data. Noise and polarization resistances were compared and the influence of filtering methods was discussed. Instantaneous corrosion data were transformed to integral ones and comparison with mean corrosion current estimated from the oxide thickness was made. It was confirmed that the crucial point of EN analysis is selection of proper cut‐off frequency in high‐pass fast Fourier transform (HP‐FFT).