Evaluation of 08CH18N10T stainless steel corrosion in subcritical water by electrochemical noise analysis

Abstract

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 8C and 8 MPa. Long-term measurements were performed in two electrolytes: (i) deionised water alkalized to pH 25 ¼ 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).

Electrochemical corrosion response of a low carbon heat treated steel in a NaCl solution

“…3) can be used to provide quantitative impedance parameters in order to complement the qualitative analysis. In the last decade, such technique and particularly the proposed equivalent circuit have been intensively utilized by a number of researchers [11,15,19,[22][23][24][25][26][27][28][29][30][31].…”

Electrochemical corrosion behaviour of a Ti‐IF steel and a SAE 1020 steel in a 0.5 M NaCl solution

“…The physical significance of the elements in the proposed equivalent circuit has been intensively reported in the literature 20–26, 30–38. In the proposed equivalent circuit, R el corresponds to the resistance of the electrolyte (0.5 M NaCl solution).…”

Corrosion Monitoring Techniques in Subcritical and Supercritical Water Environments

“…Zhou et al [121] found a linear relationship between the weight loss rate of 304SS in hightemperature water and the reciprocal of noise resistance, consistent with the research results in room-temperature systems. Macák et al studied the corrosion behavior of 304SS [122] and 08CH18N10T steel [123] in high-temperature water. They found that during the initial soaking stage, the noise resistance increased first and finally became stable.…”