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Abstract(s)
Estudar e conhecer a usinabilidade de um determinado material é de amplo interesse, desde os fabricantes dos metais e das ferramentas de corte aos consumidores, sejam por questões econômicas ou relacionadas à produtividade. O presente estudo será sobre a usinagem dos aços inoxidáveis, que formam um grupo de larga aplicação industrial, principalmente na indústria de petróleo e gás, devido à sua boa resistência mecânica e/ou resistência à corrosão. Além dos aços ferrítico e austenítico amplamente aplicados, tem crescido cada vez mais a demanda dos aços inoxidáveis duplex e superduplex, que possuem excelente resistência à corrosão combinados com altos valores de resistência mecânica, além de possuírem elevada tenacidade ao impacto. O planejamento experimental desenvolvido teve como objetivo principal verificar, principalmente, a variação na força de usinagem considerando os parâmetros de corte selecionados: avanço da ferramenta, profundidade de corte, velocidade de corte e raio de ponta do inserto de torneamento. Para cada um dos parâmetros, foram considerados dois níveis. Com base na análise de variância e no método Taguchi, foram identificados os fatores de maior influência em cada variável de saída. Os modelos mecanísticos propostos inicialmente para cada aço foram determinados de maneira homogênea e, posteriormente, de maneira heterogênea para o aço duplex, com base nos dados dos outros dois aços. Os coeficientes de calibração do modelo mecanístico homogêneo foram encontrados como função da profundidade de corte e do raio de ponta. De posse dos resultados encontrados, ao realizar a primeira análise das forças de corte obtidas, verifica-se que o valor da força resultante para o aço inoxidável duplex (UNS S31803) fica entre os valores da força resultante dos aços inoxidáveis austenítico (AISI 316) e ferrítico (AISI 410). Obtêm-se resultados satisfatórios em relação ao modelo proposto para o cálculo da pressão específica de corte e em relação ao coeficiente de atrito, para pequenas razões entre a profundidade de corte e o raio de ponta. Assim, com o estudo realizado e com base nos resultados obtidos, conclui-se que, quando o processo é realizado na escala convencional, a usinabilidade do aço duplex pode ser estudada a partir dos dados obtidos dos aços inoxidáveis autenítico e ferrítico. Utilizando as mesmas ferramentas de análise estatística usadas para o estudo dar força, foi possível observar que a rugosidade é influenciada pela variação do avanço da ferramenta e do seu raio de ponta.
Studying and knowing the machinability of a given material is of great interest, from the manufacturers of metals and cutting tools to consumers, whether for economic or productivity-related issues. The present study will be about the machining of stainless steels, which form a group with wide industrial application, mainly in the oil and gas industry, due to its good mechanical resistance and / or resistance to corrosion. In addition to the widely applied ferritic and austenitic steels, the demand for duplex and superduplex stainless steels, which have excellent corrosion resistance combined with high mechanical strength values, has also grown increasingly, in addition to having high impact toughness. The experimental planning developed had the main objective of verifying, mainly, the variation in the machining force considering the selected cutting parameters: feed rate, depth of cut, cutting speed and nose radius turning insert. For all parameters, two levels were considered. Based on the analysis of variance and the Taguchi method, the factors of greatest influence in each output variable were identified. The mechanistic models initially proposed for each steel were determined homogeneously and subsequently heterogeneously for duplex steel, based on data from the other two steels. The calibration coefficients of the homogeneous mechanistic model were found as a function of the depth of cut and the tool nose radius. With the results found, when performing the first analysis of the cutting forces obtained, it appears that the average value of this force for duplex stainless steel (UNS S31803) is among the average values obtained for austenitic stainless steels (AISI 316) and ferritic (AISI 410). It is also verified that satisfactory results are obtained in relation to the proposed model for the calculation of the specific cutting force and in relation to the friction coefficient, for small ratios between the depth of cut and the nose radius. Thus, with the study carried out and based on the results obtained, it is concluded that when the process is carried out on the conventional scale, the machinability of the duplex steel can be studied from the data obtained from the autenitic and ferritic stainless steels. Using the same statistical analysis tools used for the study to give strength, it was possible to observe that the roughness is influenced by the variation of the feed rate and its nose radius.
Studying and knowing the machinability of a given material is of great interest, from the manufacturers of metals and cutting tools to consumers, whether for economic or productivity-related issues. The present study will be about the machining of stainless steels, which form a group with wide industrial application, mainly in the oil and gas industry, due to its good mechanical resistance and / or resistance to corrosion. In addition to the widely applied ferritic and austenitic steels, the demand for duplex and superduplex stainless steels, which have excellent corrosion resistance combined with high mechanical strength values, has also grown increasingly, in addition to having high impact toughness. The experimental planning developed had the main objective of verifying, mainly, the variation in the machining force considering the selected cutting parameters: feed rate, depth of cut, cutting speed and nose radius turning insert. For all parameters, two levels were considered. Based on the analysis of variance and the Taguchi method, the factors of greatest influence in each output variable were identified. The mechanistic models initially proposed for each steel were determined homogeneously and subsequently heterogeneously for duplex steel, based on data from the other two steels. The calibration coefficients of the homogeneous mechanistic model were found as a function of the depth of cut and the tool nose radius. With the results found, when performing the first analysis of the cutting forces obtained, it appears that the average value of this force for duplex stainless steel (UNS S31803) is among the average values obtained for austenitic stainless steels (AISI 316) and ferritic (AISI 410). It is also verified that satisfactory results are obtained in relation to the proposed model for the calculation of the specific cutting force and in relation to the friction coefficient, for small ratios between the depth of cut and the nose radius. Thus, with the study carried out and based on the results obtained, it is concluded that when the process is carried out on the conventional scale, the machinability of the duplex steel can be studied from the data obtained from the autenitic and ferritic stainless steels. Using the same statistical analysis tools used for the study to give strength, it was possible to observe that the roughness is influenced by the variation of the feed rate and its nose radius.
Description
Mestrado de dupla diplomação com o Centro Federal de Educação Tecnológica Celso Suckow da Fonseca - CEFET/RJ
Keywords
Torneamento Usinabilidade Aços inoxidáveis Força de usinagem Pressão específica de corte Atrito Rugosidade