Effect of Carburization Time and Temperature on Hardness Properties of Mild Steel

Abstract

The service conditions of automobile steel components such as crankshaft, gears and cams to mention but a few require high hardness to enable them satisfy their design requirements when in operation. In this study, hardness properties of carburized mild steel rods were investigated to determine the impact of carburization parameters on the steel. Mild steel rods were carburized using coconut charcoal powder and periwinkle shell powder. The samples were carburized at temperatures of 850°C, 900°C and 950°C respectively; and were soaked for 1 hour, followed by water quenching. Leeb hardness tester was used to determine the hardness values of the carburized mild steel rods. The highest hardness value of 774 HL was obtained with carburization parameters of 436.80g of coconut shell charcoal, 150.23g of periwinkle shell powder, carburization temperature of 9000C and at a soaking time of 109 minutes. It was established that locally sourced materials (Carburized coconut shell and periwinkle shell) could serve as effective carburization ingredients for mild steel due to the improvement in hardness of the mild steel.