Investigation of the corrosion mechanism in flanged joints of car bodies
The objective of the project was the investigation of corrosion mechanisms in flanged joints of car bodies, in order to get a generalised description of the electrochemical parameters within gaps. At first, a basic catalogue of influencing parameters was generated. Testing parameters such as climatic chambers and flange geometries were defined and round robin tests (VDA 621-415) done. For evaluation of corrosion propagation, the percentage of red rust was determined visually and by optical evaluation systems. Besides the VDA 621-415 test, other known corrosion tests, such as PVW 1210 and ECC1, were validated. One aim was to evaluate the process of perforation corrosion using visual and optical evaluation methods (e.g. flange camera) and to characterise the chemical reaction of perforation corrosion. To get predictable facts and results for evaluating the percentage of red and white rust, the corrosion products were removed with special pickling solutions. Different pickling solutions were tested and the pickling effects and material loss were determined. In a new procedure, depths of perforation corrosion were determined using laser triangulation. The second main goal of the project was to characterise the chemical reaction of the perforation corrosion in the flange area using different methods of surface analysis. The mechanism was examined with in situ methods (e.g. microelectrode arrays). Corrosion products over the flange area were examined with a non-destructive Raman spectroscopy. This information was correlated with the visual evaluation. The influence of premature damage of Granocoat ZE and the local ageing process during testing were analysed by SEM after microtome cutting preparation.
Bibliographic Reference: EUR 23879 EN (2009) 125 pp., Euro: 20
Availability: http://bookshop.europa.eu/is-bin/INTERSHOP.enfinity/WFS/EU-Bookshop-Site/en_GB/-/EUR/ViewPublication-Start?PublicationKey=KINA23879 (Catalogue Number: KI-NA-23879-EN-S)
ISBN: ISBN: 978-92-79-11702-2
Record Number: 200910519 / Last updated on: 2009-12-11
Original language: en
Available languages: en