Processing of vegetable shells for solid carburizers production to achieve case hardening of a low carbon steel

Biomass waste that is abundant in Africa and especially in Cameroon can be a significant source of renewable energy. In this purpose, there has been an increasing focus on biomass by-products such as Canarium shells to valorise their carbon potential within the framework of sustainable development and environmental remediation.
In this study, the recovered shells of Canarium Schweinfurthii fruits were crushed, washed, dried, crushed and then sieved to a defined granulometry. The selected Canarium shells are considered as raw materials, which is submitted to a thermochemical route leading to a solid bio-carburizer in the form of a powder that exhibits a defined granulometry with an improved specific area. The selected aggregates were subjected to thermal decomposition at different durations, to yield a solid bio-carburizer that was used to case-hardening a carbon steel substrate.
In this work, a route for case-hardening (quenching) and post-heat treatment (tempering) is established. Microstructure characterization is carried out while focusing on the micro-hardness profile that set the case-hardening depth. The influence of the preparation of the initial bio-carburizers on carburizing efficiency in relation to the hardness profile, is also discussed.