Surface characterisation studies of CrVI and CrIII electroplated carbon steel samples

Conventional Nickel-Chromium (VI) electroplating has played an important role for corrosion protection of carbon steel blades used in ice-skating,for many decades. However in recent years, the exposure limits fir humans to chromium (VI) compounds have been further reduced due to their toxicity and carcinogenic nature, which makes the use of hexavalent chromium electroplating less likely, in the future. It is envisaged that environmentally acceptable Nickel-Chromium (III) electroplating will be a sui. table replacement. In this study, Nickel-Chromium (VI) and Nickel-Chromium (III) electroplating have been applied to carbon steel blades. Electrochemical tests were carried out on both Cr(VI) and Cr(III) electroplated blades to evaluate their anti-corrosion performance. In addition, Atomic Force Microscopy and Scanning Electron Microscopy were used to investigate the surface characteristics of the electroplated samples before and after accelerated corrosion tests. It was found that Cr(III) deposits had the lower surface roughness but exhibited higher corrosion rates than Cr(IV). This difference was attributed to multiple pit formation and coalescence in the Cr(III) coating..