Efecto de la carburización sólida y líquida en la dureza del acero AISI 1018

Abstract

The objective of the present project was to analyze the effect of solid and liquid carburization on the hardness of AISI 1018 carbon steel aiming to improve the individual properties of the steel to increase the service life and performance of the parts. The study started with the analysis of the current situation and review of technical sheets of AISI 1018 steel to know its properties and structure, followed by the study and understanding of the application of the thermochemical treatment of solid and liquid carburization through the existing scientific literature. The specimens were obtained by machining with a sufficient area to visualize their microstructure. The microstructural characterization after carburization tests were performed by instrumental analytical techniques, such as Vickers hardness (microhardness) and optical microscopy. The results obtained showed that the most effective solid carburization treatment was the one applied to specimen 18 with an average microhardness of 852.40 HV. This treatment was carried out at 1223 °K for 10.60 hours, a surface concentration of 0.60% of carbon and a carburized layer of 1.25 mm was obtained and the liquid carburization was the one corresponding to specimen 24, with an average microhardness of 778 HV and a time of 3.24 hours; specimen 22 was discarded since there was a long time in 0.64 hours and with a lower average microhardness (767 HV). It was concluded that the final carbon concentration, the carburization temperature, and the depth of the carburized layer are directly proportional to the Vickers microhardness, the latter being the most influential. It is recommended to propose an experimental design that considers the carburization method as a factor whose levels are solid and liquid.