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Identification of steel corrosion in alkaline sulfate solution by electrochemical noise
Author(s) -
Permeh Samanbar,
Lau Kingsley,
Duncan Matthew,
Simmons Ron
Publication year - 2021
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.202112347
Subject(s) - electrochemical noise , corrosion , sulfate , pitting corrosion , materials science , electrochemistry , metallurgy , sodium sulfate , ion , chemistry , electrode , sodium , organic chemistry
Research on the effects of sulfate ions on steel corrosion has been conducted in response to the observations of premature localized corrosion of steel strands in cementitious grouts in posttensioned bridge construction. Electrochemical noise (EN) was shown to be an effective technique to assess the development of localized corrosion of steel in the alkaline sulfate solution. General statistics of the EN potential and current time signatures revealed the negative effect of elevated sulfate concentrations and the development of pitting events. Spectral analysis indicated an increase in the characteristic charge and decrease in characteristic frequency with sulfate ion concentration, whereas an increase in the overall corrosion rate was observed, indicating the development of pitting corrosion. Pitting events could be sustained in solutions above 10 g Na 2 SO 4 /L H 2 O and more extensive localized corrosion developed above 20 g Na 2 SO 4 /L H 2 O.