Torneamento com ferramenta de CBN do aço ABNT 4340 endurecido

• Autor(a) principal: Salussolia, Giovanni Faus [UNESP]
• Data de Publicação: 2017
• Tipo de documento: Trabalho de conclusão de curso
• Idioma: por
• Título da fonte: Repositório Institucional da UNESP
• Texto Completo: http://hdl.handle.net/11449/156794; http://www.athena.biblioteca.unesp.br/exlibris/bd/capelo/2018-08-16/000902306.pdf
• topic: Usinagem; Aço - Análise; Nitreto de boro; Ferramentas de corte; Machining

This work aims to study the behavior of the turning of ABNT 4340 steel in its hardened state, using cubic boron nitride (CBN) tools. In this way, it is sought to verify the viability of the process and to find the best conditions for such a process to be used by the industry. It is also sought to obtain high surface quality, in a way that is possible to eliminate the grinding process that normally proceeds the turning. Among the machining processes, turning is one of the most used and has been gaining more and more space in the market with the development of new tools for machining new materials with more interesting properties. One of these materials is ABNT 4340 steel, which has excellent properties to withstand high mechanical stresses, however it presents difficulties in machining processes. As a solution for turning hardened steels, the tool made of CBN is widely used because of its properties as high chemical stability, toughness and hardness when compared to other materials used for cutting tools. To verify the behavior of the machining during the tests, were verified the acoustic emission, vibration and cutting power signals. In addition, analyzes of roughness parameters (Ra and Rt), tool wear and study of the chips were also performed. A complete factorial study was developed, varying the process parameters, such as cutting speed, feed rate and depth of cut, and then was performed the statistical analysis of the variables through analysis of variance. It was possible to verify that the process was feasible, besides finding the cutting conditions that best satisfy the parameters of roughness, acoustic emission and cutting power, and the CBN tool presented an excellent performance. The tool wear observed was negligible, and there were no tool failure that affected the final result of the process. The analysis of the chips concluded that it's formation occurred by shear processes... (Complete abstract click electronic access below)