A influência da nitretação nas propriedades tribológicas de rolamentos de roda automotiva

• Autor(a) principal: Silva, Jorge Gonçalves
• Data de Publicação: 2020
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: Biblioteca Digital de Teses e Dissertações do Mackenzie
• Texto Completo: https://dspace.mackenzie.br/handle/10899/28441
• topic: nitretação; mancais de rolamento; atrito; automotiva; roda; CNPQ::ENGENHARIAS

This academic study presents the influence of the thermo-chemical treatment of gaseous nitriding in rolling bearings applied to automotive wheels. Rolling bearings are machine elements used to keep different components in relative motion, therefore, they follow the laws attributed to Tribology. Its application seeks to maintain low levels of friction, vibration, noise and to guarantee the necessary rigidity for the correct functioning of the system. For automotive wheel, three concepts are commonly used, they are: first generation bearings, second generation and third generation bearings. Such nomenclature is due to the evolution of this family of bearings based on the concept of the first generation bearing, which is characterized by the presence of two rows of angular contact balls. This bearing was used as an object of study for this work, because the results obtained can be applied in other evolutions. The analyzes performed demonstrate, in a comparative way, the effects of gaseous nitriding on the object of study, in terms of dimensional variation, microstructural transformations, roughness and hardness. The results obtained demonstrate that a new hardening route can be applied to the bearing rings, if the gas nitriding process is considered. The surface hardness obtained after the nitriding of the studied bearings, reached the levels practiced by the major manufacturers of this type of product and, therefore, indicates the possibility of avoiding the quenching and tempering in the manufacturing of rolling bearings. Other benefits of nitriding are presented as useful for application in rolling bearings, these are: the residual compressive stress that induces greater resistance to fatigue and greater resistance to corrosion