Effects of Cassava-Leaf-Enhanced Carbonitriding on Case-Hardening of Barite Mining Tools
Thesis
This study presents the results of an experimental study of the effects of cassava leaves carbonitriding on the microstructure, hardness and abrasive wear behaviour of AISI 1065 and AISI 1070 steels used for barite mining operations. The pack-biocyaniding of the mining tools was achieved using processed cassava leaves powder mixed with BaCl2 as an energiser in the heat-treatment process. Heat treatment was done at different temperatures of 400°C, 450°C, 500°C and 550°C for 3 hours to allow the diffusion of nitrogen and carbon into the interstitials of the low-alloy steel samples and then cooling in air. The experimental work showed that at carbonitriding temperature of 550˚C, maximum hardness was achieved for the steel specimen of AISI 1070 and AISI 1065, from 255HV and 241HV to 327HV and 295HV respectively. A pin-on-disc wear tribometer machine was used to evaluate the wear characteristic of materials. The test results showed that at carbonitrided temperature of 550°C, the harder steel specimens gave the highest wear resistance and also the wear rate was reduced by 2.56 x 10-3mm3/m. The implication of these results revealed that the hardening of steels with locally pulverised cassava leaves increased the hardness and wear resistance of the steel specimens as a result of diffusion. Also, the use of waste cassava leaves for improving hardness of steel specimens saves on cost and is environmentally friendly compared to conventional means.