Publication Type Journal Article
Title Corrosion inhibition at galvanized steel cut edges by phosphate pigments
Authors AMP Simoes J. Torres R. Picciochi JCS Fernandes
Groups
Journal ELECTROCHIMICA ACTA
Year 2009
Month June
Volume 54
Number 15
Pages 3857-3865
Abstract The corrosion mechanisms and the inhibiting effect of sodium phosphate at cut edges on galvanized steel was studied by potentiodynamic polarization, EIS and monitoring of local ionic currents made by means of the scanning vibrating electrode technique (SVET). Assessment of zinc and of iron single electrodes was also made for comparison. In the absence of phosphate, corrosion of electrogalvanized steel at the cut edge is cathodically inhibited by the precipitation of zinc corrosion products over the steel surface. Mapping of the ionic currents revealed that the cathodic area becomes laterally shifted away from the anode as zinc corrosion products precipitate along parallel lines that are dictated by the location of the maximum cathodic currents. Sodium phosphate revealed inhibiting properties on the cut edge by precipitation of zinc phosphate, in the form of gel-like zinc phosphate Clusters. Estimated inhibiting efficiencies for the cut edge were slightly above 80\%. (C) 2009 Elsevier Ltd. All rights reserved.
DOI http://dx.doi.org/10.1016/j.electacta.2009.01.065
ISBN
Publisher
Book Title
ISSN 0013-4686
EISSN
Conference Name
Bibtex ID ISI:000266197000002
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