Utilisation of Fly Ash to Develop Hot Corrosion and Wear Resistant Coatings

摘要

It is now generally accepted practice to apply coatings to components in fossil fuel energy processes to provide thermal insulation, corrosion and wear resistance, and in chemical process plants or boilers to protect the surface of structural steels against surface degradation processes such as wear, oxidation, corrosion and erosion. Thermal spraying has emerged as an important tool of increasingly sophisticated surface engineering technology. In the present work the fly ash coating has been developed on carbon steel samples using plasma spray process. The hot corrosion behaviour of uncoated and coated steels has been evaluated in molten salt (Na_2SO_4-60%V_2O_5) environment. The rate of wear for coated and uncoated steels has also been evaluated using pin on disc sliding arrangement. The corroded products have been analysed using SEM/EDAX and EPMA techniques. The fly ash coating has been found to be effective in increasing the corrosion resistance of the given carbon steel in the above environment, where as wear resistance of carbon steel was found to decrease after fly ash coating.