Caracterização mecânica e microestrutural do SAE D-5506 austemperado em diferentes temperaturas de tratamento térmico

Abstract

Austempered ductile iron has been the object of study by researchers for showing comparative advantages with many competing materials, mainly with respect to its similar or superior mechanical properties, such as when compared to forged steel. The main focus of this work was determined as mechanical properties and microstructures of SAE D-5506 submitted to different Austemper cycles, and compared to Tempering subjected to the following variables. As part of the process there was the need to perform a literature review to determine the study variables, carry out the planning of the heat treatment cycles of austempering and tempering, design the mold and model for casting and machining the specimens, perform the austempering and tempering treatment cycles, characterize the specimens with respect to light microscopy, and perform the tensile and hardness tests. Results show the determination of the mechanical properties of nodular cast iron, being exposed to the heat treatment characterized by 900 ° C austenitization and four temperature variables of austemper, being 260, 300, 340 and 380 ° C, and two variables of tempering temperature, which is 260 and 380 ° C. In addition to its microstructural characterization, which shows the effects that temperature has on the material, the data show the superiority of austemper's mechanical properties over tempering and possible material classification according to ASTM A 897, which was the main one used. for conducting the research.