Análise comparativa da junta soldada do aço SAE 4130 pelos processos GMAW e GTAW aplicados a fabricação do chassi de veículo off-road BAJA SAE

Abstract

The present job aimed the analysis of mechanical and metallurgical characteristics from welded joints, used to splice SAE 4130 ultra-high strength low thickness steel tubes by GMAW and GTAW welding processes. This review compared which of the two processes has the most appropriate metallurgical characteristics and properties for the BAJA SAE project. In this job, SAE 4130 steel pipes have a 31,75mm external diameter and a 28,55mm internal diameter, with a 1.60mm wall. The tubes were welded in pairs, resulting in a 90 degree welded joint, such that on GMAW process the welding was done using wired electrodes, while on GTAW process with addition material electrodes. The welded joints were submited to tensile, fatigue, metallography and microhardness tests. The outcoming performed tests showed that, in this case, the GMAW welding process was better than the GTAW process. The conclusion is that, in all GMAW process welded joints, the broke up zone was in the basis metal, while on GTAW process, the breaking occurred exactly at the weld bead (sic).