Ref.: MmeFsu43-006
Apresentador: Denise Diniz De Sousa
Autores (Instituição): De Sousa, D.D.(Universidade Federal do Maranhão); Miranda, N.T.(Universidade Federal do Maranhão); Cruz, G.(Universidade Federal do Maranhão); Rezende, A.B.(Universidade Federal do Maranhão);
Resumo:
Carburizing is a treatment widely used in industry due to its versatility and benefits, being characterized by the diffusion of carbon on the surface of steels with low carbon content. Charcoal is used as carburizer together with activating substances, in order to improve the properties of the material. However, due to the growing demand for sources that are less harmful to the planet for use in industry, there is the problem of using charcoal from homogeneous reforestation, which is conventionally used in the steel industry as carburizer. Therefore, it is important to study other forms of solid carburizer with the aim of reducing impacts on nature as one of the objectives. The State of Maranhão stands out as an important producer of green coconut (Cocos nucifera), where the coastal region boosts the consumption of its by-products through tourism. As a result, it is necessary to think about the correct disposal of residues from plant species and use these environmental liabilities as carbon sources in the sustainably correct cementation process. In this context, this study aims to evaluate green coconut shells as a solid carburizer for carburizing SAE 1020 steel. Initially, the vegetable shell samples were processed by drying in an oven, grinding and carbonizing in a muffle furnace to obtain charcoal. Subsequently, the charcoal samples, in the presence of an activating element, were placed in alloy steel boxes together with the test specimens and taken to the oven for soaking times of two, four and six hours at 950 °C. After hardening, the samples were subjected to metallographic analysis and microhardness tests to investigate changes in microstructure and the efficiency of the carburizer. As a result, it was noted that the longer residence time resulted in a larger cemented layer. In addition, the layer is close to that found in the literature for traditional cementing agents. In this way, green coconut shells can provide a surface area close to that obtained with industrial charcoal, making use of a more sustainable alternative for the planet.