Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2017-11-01T21:51:38Z No. of bitstreams: 1 ViniciusCarvalhoPinto_DISSERT.pdf: 67587704 bytes, checksum: 70af561eb15e9394f7bf6fe0b0a16461 (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2017-11-08T22:02:39Z (GMT) No. of bitstreams: 1 ViniciusCarvalhoPinto_DISSERT.pdf: 67587704 bytes, checksum: 70af561eb15e9394f7bf6fe0b0a16461 (MD5) / Made available in DSpace on 2017-11-08T22:02:39Z (GMT). No. of bitstreams: 1 ViniciusCarvalhoPinto_DISSERT.pdf: 67587704 bytes, checksum: 70af561eb15e9394f7bf6fe0b0a16461 (MD5) Previous issue date: 2017-07-17 / A integridade superficial de pe?a usinadas tem sido uma constante preocupa??o na ind?stria metal-mec?nica, impulsionada pelo fato de que grande parte de produtos acabados cont?m pe?as usinadas, o que torna o processo um dos mais usados na cadeia produtiva. Com o objetivo de estudar e entender o comportamento do material, este trabalho verificou os efeitos dos par?metros de corte na integridade estrutural de a?o SAE 1045 usinado com ferramentas de carboneto de tungst?nio (metal duro) com revestimento e morfologia de ponta romboidal de 80?. Foram desenvolvidos procedimentos para ensaio do material sob condi??es variadas dos par?metros de corte, onde a velocidade de corte, o avan?o e a profundidade de corte. Para cada um dos par?metros, foram ensaiadas 4 condi??es distintas, para possibilitar medi??es e compara??es de microdureza Vickers, tens?o residual e rugosidade. Antes de serem utilizadas nos ensaios, os corpos de prova foram tratados termicamente atrav?s do processo de normaliza??o, de forma a obter um tamanho de gr?o regular em toda pe?a e redu??o das tens?es residuais presentes no tarugo, proveniente do processo de fabrica??o do mesmo. O m?todo Sen2 atrav?s da t?cnica de difratometria de Raios X foi utilizado para quantificar as tens?es residuais. Os corpos de prova foram divididos em 4 regi?es para as avalia??es da integridade superficial. Medidas de rugosidade, microdureza Vickers e tens?o residual foram eficazes para apresentar as varia??es ocorridas na integridade superficial das pe?as ensaiadas. A an?lise da tens?o residual apresenta maior varia??o para a profundidade de corte e o avan?o. Com o incremento da profundidade de corte, a tens?o residual trativa reduz, apresentado valores compressivos na dire??o axial. J? com o incremento do avan?o, h? incremento da tens?o residual de tra??o. A rugosidade apresenta maior varia??o com o incremento do avan?o por?m, tamb?m ? sens?vel para an?lise da ondula??o na varia??o da velocidade de corte. Uma correla??o indireta entre o avan?o e a microdureza Vickers foi observada. / The surface integrity of machined parts has been a constant concern in the metal-mechanical industry, driven by the fact that most finished products contain machined parts, which makes the process one of the most used in the production chain. With the objective of studying and understanding the behavior of the material, this study verified the effects of cutting parameters on the structural integrity of SAE 1045 steel machined with tungsten carbide tools with 80?rhomboid tip morphology and coating. Procedures were developed to test the material under varying conditions of the cutting parameters, where the cutting speed, feed rate and depth of cut were determined. For each of the parameters, 4 different conditions were tested to allow measurements and comparisons of Vickers microhardness, residual stress and roughness. Before being used in the tests, the samples were thermally treated through the normalization process, in order to obtain a regular grain size in each sample and reduction of the residual stresses present in the billet from the manufacturing process. The Sen2 method through the X-ray diffraction technique was used to quantify the residual stresses. The samples were divided into 4 regions for the evaluation of the surface integrity, where the analisis were performed in the longitudinal direction. Roughness measurements, Vickers microhardness and residual stress were effective to show variations in the surface integrity of the tested specimens.The analysis of the residual stress presents greater variation for the depth of cut and feed rate. With the increase of the depth of cut, the tensile residual stresses reduces, presenting compressive values in the axial direction. With the increase of the feed rate, there is increment of the tensile residual stress. The roughness presents greater variation with the increment of the feed rate, but it is also sensitive for the analysis of the ripple in the variation of the cutting speed. An indirect correlation between the feed rate and the Vickers microhardness was observed.