OPTIMISING THE WEAR RESISTANCE OF M3C WHITE CAST IRON FOR GRINDING PLATE APPLICATION

Abstract

The hardness property, abrasion resistance property and corrosion behaviour of M3C white cast iron was investigated in this study. A control (unalloyed white cast iron) and fifteen low alloy white cast iron of varied % composition of Cr (1.5, 2.0 and 2.5) and Mo (0.1, 0.3 and 0.5) were produced using Indirect Electric Arc Furnace (IEAF). Characterization of the sixteen cast specimen was done by examining their microstructures, hardness properties, abrasion wear properties and corrosion behaviour. The result showed the direct relationship between hardness and abrasion wear resistance influenced by the addition of secondary carbide forming elements. As the % composition of the alloying element(s) is increasing, the carbidic phase increases with corresponding increase in both the hardness and abrasion resistance properties. Optimum properties of hardness and abrasion resistance were obtained for samples including M10 (0.5%Mo + 2.5%Cr), M12 (0.5%Mo + 2.0%Cr) and M16 (0.3%Mo + 2.5%Cr). Weight loss method was employed in the study of corrosion behaviour of the sixteen specimens in water at room temperature for an immersion period of eight weeks. The corrosion property was primarily influenced by chromium addition which has the ability to form protective (Cr2O3) layers on the surface of the material. The cumulative weight loss obtained showed that M10 is least susceptible to corrosion attack. Others with relatively less susceptibility to corrosion attack are: M16, M13, M7 and M12. Consequently, specimen M10 with a relatively best combination of hardness, abrasive resistance and corrosion resistance properties was recommended for the production of pepper grinding plate posing less health hazard and improved service life.