2022-12-212022-12-212022-10-27MORAIS, Silmara da Conceição. Caracterização mecânica, macro e microestrutural de trilhos ferroviários do tipo TR-68 em condições de novo e usado. Orientador: Deibson Silva da Costa. 2022. 61 f. Trabalho de Curso (Bacharelado em Engenharia de Materiais) – Campus Universitário de Ananindeua, Universidade Federal do Pará, Ananindeua, 2022. Disponível em: https://bdm.ufpa.br:8443/jspui/handle/prefix/4819. Acesso em:.https://bdm.ufpa.br/handle/prefix/4819The industries that need to transport heavy loads use railroad tracks as the most suitable means of transportation for their supply and locomotion, which is widely expanded all over the world. To ensure the quality of transportation of these loads, railway maintenance is essential. When the load is exceeded, it has a negative influence, damaging the structure and affecting the service life of the material. With this, it is necessary to prevent the natural wear of the rails, maintaining the capacity of cargo flow and avoiding economic losses. At work, a comparison of the mechanical macro and microstructural characteristics of TR-68 railroad tracks was performed, with one track used and another not used. Thus, the objective of this work was to analyze the microstructure variation of the two rails, emphasizing the hardness values made on the billet surface. The rails were submitted to chemical characterization, which was performed by means of an optical emission spectrometer. In the mechanical characterization was performed the Rockwell C hardness test and in the metallographic characterizations were used stereoscope and optical microscope to analyze the macro and microstructure of the rails. The results of the chemical composition showed that both rails are hyperetetoid steels. Moreover, the alloying element contents are in agreement with the literatures. The analysis of microstructural variation in the used rail due to the successive passage of the rail wheels found deformation on the rail surface. Furthermore, the comparison of mechanical strength between new and used rail showed that there is an intense strain-hardening effect on the used rail, especially in the corner region of the gauge. In the rail used, the microstructure and hardness around the aluminothermal weld showed a reduction in hardness values in the region of the Thermally Affected Zone (ZTA) justified by the microstructure present in this region. The new rail did not present deformations in the microstructure.Acesso AbertoTrilhos ferroviáriosCaracterizaçãoTribologiaBoletoRail tracksDescriptionTribologyCNPQ::ENGENHARIAS::ENGENHARIA DE MATERIAIS E METALURGICATrabalho de Curso - Graduação - Monografia