resumo
Aluminium-rich metallic coated steels were found to be especially sensitive to cut-edge corrosion in various climates for both painted and unpainted material. The aim of this work is to study the corrosion process in the cut-edge and the effect of aluminium presence in the metallic coating. In this frame, painted zinc metallic coated steel samples with different amount of AI were studied by scanning vibrating electrode technique coupled with a scanning ion-selective electrode technique (SVET/SIET). SVET and micro-potentiometric pH measurements were performed quasi simultaneously. The experiments were performed in continuous immersion in 0.05 M NaCl. As a result, differences in pH and activity for the studied systems could be linked to the presence of aluminium. Formed corrosion products were identified by Raman spectroscopy, FTIR spectroscopy, SEM-EDX and by analyzing the local pH in the area of precipitation. (C) 2011 Elsevier Ltd. All rights reserved.
palavras-chave
GALVANIZED STEEL; CARBON-STEEL; ZINC; ALLOY; SVET; PRODUCTS; CHLORIDE; PH; INHIBITION; MECHANISM
categoria
Electrochemistry
autores
Alvarez-Pampliega, A; Lamaka, SV; Taryba, MG; Madani, M; De Strycker, J; Tourwe, E; Ferreira, MGS; Terryn, H
nossos autores
Mário Guerreiro Silva Ferreira
Professor(a) Jubilado(a)Projectos
RMNE-UA-National Network of Electron Microscopy (REDE/1509/RME/2005 )
Corrosion adn corrosion protection in multi-material systems (PTDC/CTM/108446/2008)
agradecimentos
The authors acknowledge financial support from the projects REDE/1509/RME/2005, PTDC/CTM/108446/2008 and SFRH/BD/72602/2010 (FCT, Portugal), DuPont Mechelen and the Belgian Royal Institute for Cultural Heritage. We are grateful to the anonymous reviewer of the article who pointed out several interesting explanations about the imbalance of cathodic and anodic current recorded by SVET.