VALCARCE Maria beatriz
Unexpected effect of citrate ions on the corrosion process of carbon steel in alkaline solutions
S. TOUJAS; M. VÁZQUEZ; M. B. VALCARCE
PERGAMON-ELSEVIER SCIENCE LTD
Lugar: Amsterdam; Año: 2017 vol. 128 p. 94 - 99
The effect of citrate ions on the passive film stability on carbon steel, at pH 13, wasevaluated. The study involved cyclic voltammograms, potentiodynamic polarizationcurves, micro-Raman spectroscopy and weight-loss tests. No beneficial effects ondelaying or inhibiting pitting were observed in the presence of citrate ions. Organiccompounds with carboxylate groups are promising corrosion inhibitors. However, theincorporation of citrate ions is clearly harmful to carbon steel in alkaline solutions andaccelerates the corrosion process. Citrate ions adsorption is not observed on passivesteel. Instead, citrate ions can unexpectedly dissolve the passive layer facilitating thecorrosion process.