A study of the morphology and optical properties of electro polished steel in the presence of Vitamin-C

Abstract

The studies of steel electrochemical polishing Electropolishing (EP) in orthophoshoric acid were performed by potentiodynamic polarization. Electropolishing was conducted in solution containing Vitamin C. Addition of Vitamin C to electropolishing solution results in a lower limiting current. Vitamin C concentration influence on electropolishing process and surface texture (AFM, SEM) and UV-VIS-NIR Spectroscopy was established. The results show that by increasing Vitamin C concentration from 2 × 10-5 to 5 × 10-5 M, roughness and reflectance of steel specimens decrease/increase respectively. The opposite trend is seen when the concentration increases to 10 × 10-5 M. The roughness of steel specimen before electropolishing is 236.7 nm and it will decrease to 140 nm by electropolishing in the presence of 5 × 10-5 M Vitamin C. A similar trend is also seen in reflection. The SEM study confirms that low and moderate concentration of Vitamin C was effective to enhance levelling and brightness more than higher concentrations.   Key words: Steel, electropolishing, Vitamin C, scanning electron microscope (SEM), atomic force microscope (AFM), reflectance.