Publication

Abstract : In this study, the erosion behaviour of laser clad chromium carbide-Ni rich alloy composite coatings with a wide range of carbide contents at room temperature and 600 °C were investigated. The variation in carbide content of the coatings was due to dilution from the substrate and the high cooling rate in the laser cladding process preventing re-solidification of the molten carbides. Erosion rate was observed to be a function of carbide content alone and was significantly higher at 600 °C as compared to room temperature. Erosion wear ratio (E90/E30) was also dependent on carbide content but decreased at higher temperature and higher carbide contents. A comparison of erosion behaviour with detonation and plasma sprayed counterparts showed the superior performance of laser clad coatings at 600 °C. The poor erosion performance of the detonation and plasma sprayed coatings was due to weak splat bonding. Thick oxide layer formed on the steel substrate after pre-oxidation resulted in its poor erosion performance.