Artículo
Carbon steel passivity examined in alkaline solutions: the effect of chloride and nitrite ions
Fecha de publicación:
09/06/2008
Editorial:
Pergamon-Elsevier Science Ltd
Revista:
Electrochimica Acta
ISSN:
0013-4686
Idioma:
Inglés
Tipo de recurso:
Artículo publicado
Clasificación temática:
Resumen
The effect of chloride and nitrite ions on the passivity of steel in alkaline solutions was investigated. Four nitrite dosages were tested, resulting in various nitrite/chloride ratios. The behavior of steel was evaluated on electrodes aged during 1 and 90 days, measuring electrochemical parameters such as the corrosion, pitting and repassivation potentials, the corrosion current density, the weight loss and performing electrochemical impedance spectra. The presence of 0.8 mol l-1 of chloride induced pitting only under polarization and when the chloride/hydroxyl ratio was not less than one. Nitrite ions behave as effective inhibitors of pit propagation for all the concentrations tested (0.2-0.8 mol l-1). A nitrite/chloride ratio of 0.25 induces complete surface repassivation. Nevertheless, at open circuit potential, the high alkalinity guarantees passivation even in the presence of chlorides. In the event that the passive layer is damaged and pitting can be initiated, nitrite ions are effective in inhibiting pit propagation. © 2008 Elsevier Ltd. All rights reserved.
Palabras clave:
Alkaline Solution
,
Carbon Steel
,
Chloride
,
Corrosion Inhibitor
,
Nitrite
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Articulos(INTEMA)
Articulos de INST.DE INV.EN CIENCIA Y TECNOL.MATERIALES (I)
Articulos de INST.DE INV.EN CIENCIA Y TECNOL.MATERIALES (I)
Citación
Valcarce, María Beatriz; Vazquez, Marcela Vivian; Carbon steel passivity examined in alkaline solutions: the effect of chloride and nitrite ions; Pergamon-Elsevier Science Ltd; Electrochimica Acta; 53; 15; 9-6-2008; 5007-5015
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