Made available in DSpace on 2014-12-17T14:06:51Z (GMT). No. of bitstreams: 1 EtevaldoMV.pdf: 1261364 bytes, checksum: f1890a7da662c7e4523bd11ec6a3278a (MD5) Previous issue date: 2008-08-23 / In the research, steel samples tool AISI D2, treated thermally, in the conditions: relief of tension, when maximum, seasoned and seasoned was treated thermally in the temperature of revenimento and revenida had been nitrited in plasma with cathodic cage, in atmosphere of 80%N2:20%H2. One used pressure of 2,5 mbar, 400 and 480?C temperatures with treatment time of 3 and 4 hours, with the objective to evaluate its performance in pipes cut tool. It was compared that the performance of the same steel when only thermally treated, both with tension relief. It was evaluated its hardness. Microstructural aspects (the layer thickness, interface, graisn size, etc) and crystalline phases on the surface. Besides, it was verified accomplishment possibility of nitriding simultaneous to annealing treatment. The tempering samples had presented hardness levels of 600 HV, while in nitrited samples these values had been 1100 HV / Neste trabalho, amostras de a?o ferramenta AISI D2, tratadas termicamente, nas condi??es de recozida, de revenimento m?ximo e na condi??o de temperada e revenida foram nitretadas em plasma com gaiola cat?dica, em atmosfera de 80%N2:20%H2. Utilizou-se press?o de 2,5mbar, temperaturas de 400 e 480?C com tempo de tratamento de 3 e 4 horas, com o objetivo de avaliar o seu desempenho em ferramenta de corte. Comparou-se com o desempenho do mesmo a?o quando apenas tratado termicamente, ambos com al?vio de tens?o. Avaliou-se a dureza, aspectos microestruturais (espessura da camada, interface, etc) e fases cristalinas presentes na superf?cie. Al?m disso, verificou-se a possibilidade de realiza??o da nitreta??o simult?nea ao tratamento de revenido. As amostras temperadas e revenidas apresentaram n?veis de dureza de aproximadamente 600HV. Quando nitretadas a uma temperatura de 480?C durante 3h, que foram as melhores condi??es de tratamento, essas amostras apresentaram dureza superficial de 1100HV