Effects of metallurgical properties and chemical compositions upon corrosion behaviour of cold rolled steels in hydrochloric acid electrolytes

This paper describes the experiments conducted to provide a measurable evidence in support of the widely accepted assumption that the pre-treatment of steel has a deciding effect upon the quality of subsequent plating, especially cyanide-free alkaline zinc plating. Special attention is given to the acid cleaning process. The effects of steel compositions and several pre-plating processes (industrial manufacture, heat-treatments) upon corrosion properties, are determined based on a statistic evaluation of a factorial test matrix termed (2¹x3²) array. Corrosion behaviour is investigated by determining the weight loss, the potential evolution and the polarization measurements in HCl (220g.l-¹). A galvanostatic method is subsequently used to evaluate the relative effectiveness of cleaning surface and the surface aptitude to be zinc plated.