Análise da variação das propriedades microestruturais de um aço SAE 1020, após tratamento de cementação em caixa

Abstract

Carburizing is one of the most used thermochemical treatments in the industry to increase the hardness and service life of mechanical components and tools. In this work, we will talk about box cementation and how this process affects the hardness and the surface microstructure of a SAE 1020 low carbon steel. The diffusion of the carbon in this process happens through the austenitization of the sample, so that austenite phase, which involves up to 1.2% C, absorbs carbon from the enviroment into the structure, through the reaction caused by a fuel mixture. The treatment was carried out at approximately 920 °C for 4 hours and followed by water cooling. Using microstructural characterization, based on optical microscopy, we try to correlate the microstructure changes of the sample with the changes in the mechanical properties analyzed, and their chemical composition, before and after the treatment. With the carburizing it was possible to increase the surface hardness in the sample, with a carbon penetration approximately 0.3 mm, it was also possible to identify alterations in the microstructures and chemical composition, as proposed by the literature.