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Title: Some fundamental aspects of the electrochemical noise generated during pitting of A516-70 carbon steel

Conference ·
OSTI ID:350128
; ;  [1]
  1. Univ. of Alberta, Edmonton, Alberta (Canada). Dept. of Chemical and Materials Engineering

The potential and current noise during pitting of A516-70 carbon steel in chloride-containing solutions were monitored. Statistical analyses were performed in an attempt to achieve some fundamental understanding of the corrosion processes for this system. It was concluded that the Temkin isotherm could be used to explain the competitive adsorption of C{sup {minus}} and HCO{sub 3}{sup {minus}} on the electrode surface. The initiation of pitting was characterized by typical potential and current transients: quick drop of potential and rise of current followed by their slow recoveries. Electrode capacitance played a major role on potential fluctuations. The noise resistance analysis was capable of identifying pitting at the critical Cl{sup {minus}} concentration level, while the impedance method showed poorer sensitivity. Pitting activity in low Cl{sup {minus}} concentration solution showed an almost Poisson behavior, indicating little interaction among pitting events. Significant deviation horn Poisson behavior was observed at high Cl{sup {minus}} concentration level, indicating cooperative pitting events. The calculation of an autocorrelation function also confined these observations.

OSTI ID:
350128
Report Number(s):
CONF-980316-; TRN: IM9925%%476
Resource Relation:
Conference: Corrosion `98, San Diego, CA (United States), 22-27 Mar 1998; Other Information: PBD: 1998; Related Information: Is Part Of Corrosion `98: 53. annual conference and exposition, proceedings; PB: [6600] p.
Country of Publication:
United States
Language:
English