The Effect of temperature and current density on the structure and properties of hard and decorative chromium platings

The Effects of Temperature and Current Density on the Structure and Properties of Hard and Decorative Chromium Platings In this study, the effects of bath temperature and current density on structure and properties of hard and decorative chromium plating made on TS Fe37 steel parts were studied. The corrosion behaviour of the electroplated and unplated samples were compared. It was found that the rate of deposition in both hard and decorative chromium platings decreased with increasing bath temperature, but increased with increasing current density. In general, fine grain structure was obtained by hard chromium plating and the grain size of the platings was found to be almost independent of bath temperature and current density. It was observed that the grain size of the decorative chromium plating was not effected by temperature, but it decreased with increasing current density. It was also found that the hardness of both hard and decorative platings decreased with increasing bath temperature, but increased with increasing current density. The chromium plated samples were found to be more corrosion resistant than the unplated samples in %1 HC1 aqueous solution. However, the corrosion resistance of the decorative chromium platings was found to be much superiour to that of hard chromium platings and unplated samples. Key Words : Hard and Decorative Chromium Plating, Rate of Chromium Plating, Properties of Chromium Platings. VI SBSnMWMJW