Study of the corrosion behavior of electrogalvanised steel/Cr(III) and Zr conversion layer/paint system by electrochemical and visual methods

Abstract

Finding environmentally friendly conversion layers with the same performance of those previously existing has been the great challenge for researchers of the surface treatment field. Successful examples are the Cr(III)-based pretreatments, which used to replace the Cr(VI) ones are, so far, the best alternative. In the last years, studies in nanotechnology are increasing and nanoparticulate systems based on silica, titanium and zirconium have been evaluated. In this work, the corrosion behavior of an electrogalvanised-zirconium conversion treatment-paint system was characterized by evaluating not only the open corrosion potential (OCP) and electrochemical impedance spectroscopy (EIS) evolution as a function of the exposure time but also the samples performance subjected to accelerated corrosion tests.