FERROMANGANESE AND IRON POWDER BEHAVIOUR ON MICROSTRUCTURE, MECHANICAL PROPERTIES AND WEAR OF GREY CAST IRON

Abstract

In this study, double inoculation of gray cast iron was investigated, varying percentage of iron powder (0.2, 0.4,0.6, 0.8 and 1.0%) and ferromanganese (1.0, 1.4 and 1.8%) were used as inoculants, a control sample and twenty other inoculated samples of grey cast iron were produced from 2 kg Indirect Electric Arc Furnace using sand casting techniques was used, The cast specimen were machined according to the standard specifications, Characterization of the samples was done by examining the microstructure, chemical composition, mechanical properties, micro-hardness properties, ultimate tensile strength, impact strength and wear resistance test on the specimen were also assessed. Rockwell Hardness value A of these inoculated treated specimens were measured, micrographs of the emerging structures were taken and examined after the necessary micrographic preparations were carried out. Results obtained showed that a wide range of structures such as ferrite, coarse and fine pearlites and retained austenite were produced, addition of iron powder inoculant into the melt decreased wear rate by 14.78%, 10.17%, 24.03%, 26.93% and 38.72% as iron powder is increased from 0.2% to 1.0%, 1% addition of ferromanganese inoculant is added to the iron powder (0.2 to 1.0%) the wear rate decrease by 40.74%, 41.22%, 42.23%,44.41% and 44.42%. When ferromanganese is increased to 1.4% the corresponding increase in wear resistance is 46.30%, 47.77%, 50.80%, 61.05%, and 65.74% and additional increase of ferromanganese to 1.8% addition improved the wear resistance by 75.86%, 85.18%, 80.55%, 86.84% and 88.92. Hence it was possible to increase the primary austenite grain and reduce the flake size of the gray cast iron and the addition of ferromanganese lead to increase in the amount of pearlite matrix formed which increased the mechanical properties of cast iron without using alloying elements that are more expensive