EM - Escola de Minas
URI permanente desta comunidadehttp://www.hml.repositorio.ufop.br/handle/123456789/6
Notícias
A Escola de Minas de Ouro Preto foi fundada pelo cientista Claude Henri Gorceix e inaugurada em 12 de outubro de 1876.
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Resultados da Pesquisa
Item Heat treatment effects on the hardness and wear behavior of laser-welded AISI40 martensitic steel plates.(2021) Gonçalves, Karina Aparecida Martins Barcelos; Faria, Geraldo Lúcio de; Siqueira, Rafael Humberto Mota de; Oliveira, Tarcísio Reis de; Lima, Milton Sérgio Fernandes deThe use of laser beams for joining materials has grown along with the need to weld more challenging materials such as martensitic steels. In this work, an AISI 420 martensitic steel plate was autogeneously welded using a fiber laser. The process parameters were 2000 W power and weld speed of 16 mm/s with the focus on the plate surface. Before welding, the plates were prepared in two conditions, tempered, or annealed, and tempering was performed at temperatures of 300°C, 400°C, 500°C, and 700°C after welding. The finite element analysis and dilatometric tests allowed to determine the phase transformations of this steel under development by the company Aperam. The observed microstructure varies according to the initial state of the plate and subsequent heat treatments. The hardness of the fusion and heat-affected zones varied according to the samples. The welded sample in the tempered state softened moderately due to the reheating of the laser beam. In the case of the annealed sample, the hardness of the molten zone was the highest obtained. This high hardness was reflected by a high resistance to wear by reciprocal sliding in the annealed case, compared to the other conditions. The fusion zone generally proved to be much more resistant to wear than the base material.