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Title: Modelling the localized corrosion effects experienced by electroplated zinc and zinc – 4.5 wt.% aluminium steel coatings
Author: Barnard, N. C.
Awarding Body: University of Wales Swansea
Current Institution: Swansea University
Date of Award: 2006
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Experimental work has been reported that demonstrates the effects of microstructural variations within Zn-A1 Galfan type coatings on the corrosion behaviour of cut-edge material, i.e. those cases where both the underlying steel and the organic coated Galfan layer are simultaneously exposed to a corrosive environment. An attempt to model the localized corrosion effects in electroplated zinc and hot-dip Galfan coatings has been made. The model combines both diffusive and electrochemical phenomena and describes corrosion effects on micro scale coating layers in NaC1 electrolyte. The model predicts the 3D form of electrical potential, localized current densities and concentrations and also the time-dependent degradation of the micro scale coating layer. Results of the prototype model are quantitatively compared with measured current densities obtained from Scanning Vibrating Electrode Technique (SVET) studies. Simulations have been performed to predict the microstructural influence on the corrosion of Galfan coatings cooled at different rates. The model is in good agreement with experimental findings with respect to the cut-edge behaviour of these coatings, although contradicts those SVET measurements made in respect of the surface corrosion performance.
Supervisor: Not available Sponsor: Not available
Qualification Name: Thesis (Eng.D.) Qualification Level: Doctoral
EThOS ID:  DOI: Not available