The development of high manganese steel casting using vanadium and chromium as macro alloys

M.Tech.Abstract: High manganese steel invented by Sir Robert Hadfield in 1882, has high toughness, high ductility, high strain hardening capacity and excellent wear resistance when used under gauging abrasion. The steel is mostly used in the mining industries for crushing equipment. Further development of high manganese steel casting was investigated in this study, and the emphasis was on the effect of alloying with vanadium and chromium content on the microstructure, mechanical properties and wear behaviour of high manganese steel. The results showed that alloying with vanadium and chromium to high manganese steel has a direct influence on the properties and wearing behaviour of high manganese steel. The samples alloyed with vanadium had a microstructure consisting of improved vanadium carbide on the austenitic matrix and the morphology of this carbide changed from normal austenitic structure to lumpy, lamellar and round to semi rounded as the vanadium cos. The lumpy carbides where distributed along the grain boundaries resulting in the sample having cracks propagating in different direction. For the chromium containing alloys, the microstructure had chromium carbides that ranges from lamellar like to lumpy and evenly distributed, there also exist elongated and dendritic carbides. The increase in hardness and wear rate as the vanadium and chromium content increase was explained based on the carbides that have formed on the austenitic matrix. It was also evident that as the hardness increases and the wear rate decreases, the impact energy of the samples decreases. It can be said that, the mechanical properties of high manganese steel are influenced by alloying with vanadium and chromium content