The influence of surface treatment on filiform corrosion resistance of painted aluminium alloy sheet
Filiform corrosion of AA 5005 H14 aluminium alloy sheet has been investigated. Painted and scribed panels, with different surface treatments, were inoculated in HCl and exposed in a constant humidity cabinet maintained at 40 °C and 75–85% RH for 1000 h. After exposure, the panels were examined by op...
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Published in | Corrosion science Vol. 45; no. 8; pp. 1767 - 1777 |
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Main Authors | , , |
Format | Journal Article |
Language | English |
Published |
Oxford
Elsevier Ltd
01.08.2003
Elsevier Science |
Subjects | |
Online Access | Get full text |
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Summary: | Filiform corrosion of AA 5005 H14 aluminium alloy sheet has been investigated. Painted and scribed panels, with different surface treatments, were inoculated in HCl and exposed in a constant humidity cabinet maintained at 40 °C and 75–85% RH for 1000 h. After exposure, the panels were examined by optical and electron microscopy. It is evident that filiform corrosion susceptibility is determined largely by the near-surface microstructure. Heavily deformed layers, comprising oxide-decorated fine grains and dispersoids on as-rolled and mechanically ground alloy surfaces, are readily susceptible to filiform corrosion. Removal of these deformed layers, by caustic etching and acid cleaning, results in a high filiform corrosion resistance. On such surfaces, underfilm corrosion progresses by localized corrosion of the substrate; with comparatively slowly growing filaments propagating by repeated blistering of the overlying lacquer. |
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Bibliography: | ObjectType-Article-2 SourceType-Scholarly Journals-1 ObjectType-Feature-1 content type line 23 |
ISSN: | 0010-938X 1879-0496 |
DOI: | 10.1016/S0010-938X(03)00003-9 |