Estudo do efeito da nitretação a plasma do desempenho tribológico de rolamentos de aerogeradores

Abstract

In Brazil, the wind industry set the first record for instantaneous wind generation in 2022, producing 14,167 Megawatts (MW) of energy, which is enough to supply the entire Northeast region for one minute and still have a surplus of more than 23.3% of the total energy produced, according to the National System Operator (ONS). Therefore, this generation ends up being profitable for investors, as it is a more viable source of green and sustainable energy, which means there is a tendency to generate an expansion of these wind farms in the coming years in the country. A major concern in this sector is damage to mechanical components and energy losses caused by repeated friction and wear, which lead to reduced efficiency and useful life of these components, as well as increased maintenance costs. The use of thermochemical surface treatment by Plasma Nitriding promises to enable these components to achieve anti-wear properties and a friction reduction capacity greater than those already presented by the material, which can make it of utmost importance, ensuring an improvement in the useful life as well as the improvement of the efficiency of these mechanical devices. In view of this, two types of plasma nitriding treatment were performed on SAE 52100 steel bearing balls, with different gas proportion conditions (20% Ar + 80% N2 and 20% H2 and 80% N2), in order to evaluate the behavior of these created surface layers, in relation to the objective of improving their mechanical characteristics. With the thermochemically treated balls, they were placed to perform a wear test, using a pin tribometer on the disc, and for this, the tribological pair chosen to perform these tests were polished discs of SAE 1045 steel, which is a medium carbon steel with properties that required satisfactory work for the balls. These wear tests were carried out under two different conditions, with and without the presence of a lubricant as an intermediary agent, and to verify the behavior of the layers, with the aid of equipment capable of scanning the surface, analyses were carried out of the tracks formed by the wear caused to the discs, as well as the hardness of the treated spheres using a microhardness tester.