Evaluación de microestructura en probetas Jominy con Temple a temperaturas intercríticas más revenido para acero AISI SAE 8620

Abstract

This project presents an experimental study that seeks to analyze the microstructure of AISI SAE 8620 steel in Jominy-type probes subjected to quenching at intercritical temperatures, with and without subsequent annealing. To this end, heat treatments were carried out at 800°C, 820°C, 860°C, and 900°C, followed by annealing at 150°C and 300°C, in order to evaluate the evolution of phases such as martensite, bainite, ferrite, and pearlite, and their specification with the obtained hardness profiles. The experimental analysis demonstrated that quenching temperatures directly influence the proportion and distribution of microstructural phases, especially the amount of martensite formed, which is higher in areas close to the quenched end. Furthermore, annealing showed a clear effect on the decrease in hardness, being greater at higher temperatures, which is directly related to the progressive growth of martensite. Through hardness testing and metallographic analysis, the applied treatments were correlated with structural changes in the material, validating the use of projected CCT diagrams as a complementary tool. The results provide a better understanding of the thermal behavior of AISI SAE 8620 steel and provide a useful experimental basis for designing heat treatments for industrial applications.