Castro, Nicolau ApoenaSena, Rizelania Kelly2023-12-262023-12-262023-12-13Sena, Rizelânia Kelly. O impacto da usinagem criogênica na microestrutura de ferro fundido branco alto cromo caracterizada via EBSD. 2023. 38 f. Trabalho de Conclusão de Curso (Graduação em Engenharia Mecânica) - Centro de Tecnologia, Universidade Federal do Rio Grande do Norte, Natal, 2023.https://repositorio.ufrn.br/handle/123456789/56893High chromium white cast iron (FFBAC) is characterized as a material resistant to abrasive and corrosive wear and commonly used in the mining industry. The microstructure of the FFBAC matrix, which contains primary and secondary carbides, determines the mechanical properties of the alloy. Thus, the combination of the matrix with M7C3 type carbides gives the alloy properties such as high hardness, wear resistance and good toughness. However, it is important to note that the impact of carbides present in the microstructure of the material such as the edges of a cutting tool during the machining process can result in wear of the tool and damage to the machined surface, thus bringing FFBAC as a material of lowability. Research aimed at improving the machining of materials with low machinability, such as FFBAC, suggests that nitrogen-assisted machining can offer several benefits in its use. This mainly includes delaying tool wear, increasing machining time and promoting good surface integrity in the machined material. The purpose of this work is to carry out an evaluation of the microstructure of two machined samples, using Electron Backscattered Diffraction (EBSD) and compare the effects of different lubricants on the microstructure: emulsion and liquid nitrogen. The analysis focused on the cross section of the machined face, with the aim of identifying the main microstructural differences. Factors such as the proportion and composition of the phases present, in addition to the distribution of hardening, were examined. The comparison was made with existing results in similar research conditions, validating and contextualizing the new findings. The results demonstrated that the material recovery process after machining was limited in cryogenic machining, due to the low temperature, with evidence of a surface with higher dislocation density. On the other hand, machining with emulsion promotes a high level of recovery. In this case, a lower concentration of carbides and chromium was also observed close to the machined surface, indicating that this condition promoted a greater arrangement of carbides, compared to machining with LN2. Furthermore, the results obtained via EBSD corroborate the residual stress results, previously obtained in previous work, in which cryogenic machining promotes greater compressive residual stress on the surface of the part.usinagem criogênicaferro fundido branco alto cromoEBSDbachelorThesisCNPQ::ENGENHARIAS