Comparative Effect of Some Carbon Rich Materials on the Hardness Property of Carburized Low Alloy Carbon Steel

Abstract

Abstract This work focuses on the effects of carburization process, on the hardness property of carburized low alloy carbon steel, at temperature of 890°C with varied soaking time of 1 hour, 2 hours and 3 hours, after which the samples were later quenched in air. The carbon rich materials used in this work include: coal dust, snail shell particulate, palm kernel shell and cow bone while 20% limestone was used as the energizer. Thirteen specimens were machined to specifications from 10mm diameter mild steel and each set of the specimens were randomly assigned to hardness test. Twelve pack boxes measuring 150mm x 75mm x 75mm was fabricated from gauge 18 mild steel. Carbon rich materials and specimens were carefully placed into the pack boxes, a specimen each was packed into the four boxes meant for coal dust, snail shell, carbonized palm kernel shell and cow bone respectively. Each box was labeled accordingly, and were loaded into heat treatment furnace and carburized at a soaking temperature of 890°C. At appropriate times, each sets of boxes were removed, open and air cool. Hardness testing of the various specimen were conducted using Vickers hardness test machine. Both coal dust, snail shell, palm kernel shell and cow bone were observed to have increase the hardness of the samples when compared with the as-received sample. As holding time of specimen increase in each carbonaceous materials, carbon diffusion and penetration increases which resulted to increase hardness values recorded in samples with 3 hours holding time.