VALCARCE Maria beatriz
Impact of Nitrites and Phosphates on the Electrical Properties of the Passive Film Formed on Steel in Concrete Pore Simulating Solutions
M.A. FRONTINI; M. VÁZQUEZ; M.B. VALCARCE
The Electochemical Society
Año: 2017 vol. 80 p. 621 - 633
The electronic properties of passive films grown at open circuitpotential for 24 h and 7 days in pore simulating solutions arecorrelated to the inhibiting effect of nitrite and phosphate ions inchloride-rich alkaline solutions. Electrochemical impedance andMott-Schottky plots were used to investigate the electronicproperties of the films grown. Changes in composition wereanalyzed by X-ray photoelectron spectroscopy.Both anions are excellent inhibitors. However, the donor density(ND) decreases when nitrites are incorporated and remains constantwhen phosphates are added. ND increases with ageing time. Thesedifferences are interpreted in terms of the composition of eachsurface layer.