Improvement in Service Life of Skip Car by Using Chromium Carbide Overlay Plate with Special Reference to Rourkela Steel Plant

Abstract

Wear is becoming increasingly important in industrial applications,in particular due to its environmental impact through the reduction of the service life of machinery. Extremely heavy wear takes place in construction and mining,where large amounts of rocks and soil are processed. The skip car in blast furnace of RSP is used to transfer and charge raw materials such as coke,iron ore,sinter and additives like limes stone dolomites into the furnace. This Skip Car has to withstand heavy wear caused by loading and unloading of those raw materials onto the Car body,which subjects it to impact-abrasion wear caused by impacts and scratching by the minerals.Wear-resistant steels are often used as a material for this kind of machinery since it has better durability than mild steels and thus provides longer service life.At present mild steel is used as skip car liner plates in BF stock house of RSP.Its service life is found to be around 2 months.Under such circumstances a selection of high wear resistance steel is essential for better wear resistant and higher life for the skip car. Wear-resistant steels are often used as a material for this kind of machinery since it has better durability than mild steels and thus provides longer service life.Literature reveals that there are further developments in improving the wear properties of steel by using carbide coatings on base metals.Because of its immense popularity and versatility for severe abrasion applications,carbide coated products are being used in industries.Keeping this in view,the objective of this work is to investigate the performance of chromium carbide Overlay Plate to improve the service life of skip car.Experiments have been carried out(Solid particle erosion test,three body abrasion)on the developed coatings in the laboratory conditions to assess the suitability of the material for actual operations in the steel plant.Plant trials have been carried out and the results achieved are discussed in the thesis.