Advantages of asymmetrical over symmetrical cells for detection of under deposit CO2 corrosion using electrochemical noise. Issue 11 (12th June 2019)

• Record Type: Journal Article
• Authors: Zeidabadinejad, Mahdieh; Shahidi‐Zandi, Mehdi; Foroughi, Mohammad Mehdi; Asadollahzadeh, Hamideh
• Is Part Of: Materials and corrosion. Volume 70:Issue 11(2019)
• Page Start: 1999
• Page End: 2008
• Publication Date: 2019-06-12
• Subjects: asymmetrical cells -- electrochemical noise -- recurrence plots -- under‐deposit corrosion (UDC) -- wavelet analysis; Materials -- Periodicals; Metals -- Periodicals; Corrosion and anti-corrosives -- Periodicals; 620.1122305
• DOI: 10.1002/maco.201910950
• Languages: English
• ISSNs: 0947-5117

Abstract

Abstract : Electrochemical noise (EN) measurements were done on symmetrical and asymmetrical cells after immersion in 3.5% NaCl solutions saturated with CO2 and containing different concentrations of sodium bicarbonate to get a better interpretation of the under‐deposit corrosion of mild steel. The symmetrical cell was constructed from two sand‐deposited electrodes and the asymmetrical cell was prepared from one sand‐deposited electrode and one bare electrode. The combination of the standard deviation of partial signal (SDPS) plots arising from wavelet analysis and recurrence plots for analyzing the EN signals obtained from symmetrical and asymmetrical cells confirmed the higher detective ability of the asymmetrical cells in comparison with the symmetrical cells for measuring the under‐deposit corrosion of mild steel. Both the SDPS and recurrence plots arising from symmetrical cells showed no significant change in the corrosion severity of the steel alloy with adding sodium bicarbonate. In contrast, the SDPS and recurrence plots of the asymmetrical cells proved that the corrosion severity decreased initially with adding the bicarbonate and thereafter remained constant with increasing the bicarbonate concentration. The optical microscopy images of the sand‐covered electrode surface confirmed the latter result. Abstract : Electrochemical noise measurements were done on symmetrical and asymmetrical cells after immersion in 3.5% NaCl solutions saturated with CO2 and containing different concentrations of sodium bicarbonate to get a better interpretation of the under‐deposit corrosion of mild steel. Both the standard deviation of partial signal and recurrence plots arising from symmetrical cells showed no significant change in the corrosion severity of steel alloy with adding sodium bicarbonate.