Avaliação do comportamento no torneamento do aço SAE 8640 em diferentes condições de lubri-refrigeração

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Data

2020-03-30

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Universidade Federal de Goiás

Resumo

During machining processes, methods and parameters are sought that enable low roughness values of the machined surface, due to their influence on the final quality of the part. Thus, it is necessary to associate machining parameters with the cutting tool and more suitable lubrication and cooling conditions, as they are directly or indirectly linked to the final quality of the machined surface. In this sense, this work presents a study on the solid lubricant in the SAE 8640 steel turning process. The tests were dry, with Minimum Amount of Lubrication - MQL and MQL, containing in the solution 10% by weight of solid lubricant, with cemented Carbide GR 20 (cemented Carbide with particle size of 20 μm). For the MQL system, two nebulizer nozzles were used with a pressure of 6 bar and a flow rate of 4 ml / min. Cutting speed - Vc (360 m / min, 290 m / min, 220 m / min and 150 m / min), feed - f (0.01 mm / rev and 0.06 mm / rot) and the depth of cut - constant ap (0.5 mm), for the three lubricationcooling conditions mentioned. The parameters evaluated in the tests were: finishing of the machined surface (Ra and Rt), wear of the cutting tool and chip analysis and degree of repression (Rc). The results of the tests showed that when adding graphite, the roughness decreases, considering that using the same volume of fluid, temperature was not a decisive factor in this reduction (from MQL to MQL + graphite). This is evidence that, in fact, MQL has an important action as a lubricant, so much so that the graphite showed lower values of Ra and Rt roughness - less wear of the cutting tool, as well as a reduction in the degree of repression. Thus, flank wear was prevalent in the tests for all lubrication and cooling conditions. Therefore, it is possible to conclude that the application of graphite in the turning of SAE 8640 steel can offer greater productivity in the machining process and better finishing of the workpiece.

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Palavras-chave

Mínima quantidade de lubrificação (MQL), Metal duro, Rugosidade (Ra e Rt), Grafite, Desgaste da ferramenta, Minimum amount of lubrication (MQL), Cemented carbide, Roughness (Ra e Rt), Graphite, Tool wear

Citação

LEANDRO, G. H. C. R. Avaliação do comportamento no torneamento do aço SAE 8640 em diferentes condições de lubri-refrigeração. 2020. 91 f. Dissertação (Mestrado em Engenharia de Produção) - Universidade Federal de Goiás, Catalão, 2020.