Per: Maria luiza dos santos (Universidade de Passo Fundo), pietro perussatto (Universidade de Passo Fundo), charles leonardo israel (Universidade de Passo Fundo), William Haupt (Universidade de Passo Fundo), deividi nardi (dstrac performance 4x4)
Abstract:
The present work addresses the evaluation of gears that make up electric vehicle differentials. The SAE 4320 and DIN20Mn5Cr steels were manufactured through the microfusion process, carburized and heat treated through martempering with tempering and austempering with sub-zero cooling with evaluation of the macrostructures, microstructures and microhardness profile starting from the carburized layer towards the core. During their evaluation, the pieces underwent standard metallographic preparation with different types of metallographic attack to evaluate their microstructures under an optical microscope and scanning electron microscope. A primary grain size analysis was carried out using specific metallographic etching. The macrostructure revealed cemented layers with lower thickness for group B. In the microstructural analysis, the formation of a normal microstructure of martensite and bainite was observed for groups A and B, SAE 4320 steels, whereas groups C and D, DIN20Mn5Cr steel, showed formation of martensite and bainite together with retained austenite indicating a possible weakening of the components in their subsequent application. The microhardness profiles indicated higher hardness for the materials that underwent martempering and tempering in relation to the austempered+sub-zero materials.