Per: lucas menezes de souza (UENF), Elaine Cristina Pereira (UENF), Camila Vasconcellos Fernandez (UENF), Sthefanie de Carvalho Mendes Lopes (UENF)
Abstract:
In this work, the influence of voltage variation in the resistance spot welding process and tempering heat treatment on the microstructure and mechanical properties of AISI1065 carbon steel was evaluated. Welding was carried out on three groups of samples with voltage variations between tips of 2.0 V, 2.5 V and 3.0 V for each group. After the welding process, half of the samples in each group received tempering heat treatment. The microstructure of the steel was analyzed before and after the heat treatment process. To analyze the mechanical properties, tensile, hardness and microhardness tests were carried out. In the metallographic characterization, the presence of elongated grains of ferrite and pearlite in the microstructure of the base metal was verified. The transformation of the martensite matrix located in the molten zone and the heat-affected zone into tempered martensite after the tempered heat treatment occurred. An increase in the tensile strength limit, ductility and toughness was observed in the steel after tempering compared to steel only welded. However, at a voltage between tips of 2.0 V, it showed better mechanical behavior after heat treatment.