Etude in-situ de la dégradation des tôles peintes à l’aide d’un capteur électrochimique

Electrochemical impedance measurements

¹ IRSID, Saint Germain en Laye
² Adresse permanente : Institut Suédois de la Corrosion Roslagsvagen, Stockholm, Suède

Abstract

Many investigators have studied the atmospheric corrosion of polymer-coated metal by electrochemical impedance spectroscopy using an extraneous electrolyte. It is now possible to eliminate this electrolyte and to obtain impedance spectra in situ using a monitor. This monitor is made by depositing a gold layer which cover 10% of the surface of the painted metal. In this study, the monitor was used to follow the degradation of painted steel during an indoor accelerated test (Renault 3C) and during a cyclic laboratory test. Impedance spectra obtained using this sensor provided an insight into the processes occuring at the coating-substrate interface. The monitor is an efficient tool to study the atmospheric corrosion of polymer-coated metals.