Estudo comparativo de soldagem GMAW em aços galvanizados

Abstract

This study investigates and compares the performance of solid wires with a diameter of 0.9 mm, AWS 5.18 ER70S-6 and AWS 5.18 ER70S-3, in the robotic welding of galvanized steel using the Gas Metal Arc Welding (GMAW) process in short-circuit transfer mode. A shielding gas mixture composed of 80% argon and 20% CO₂ (80/20 mixture) was employed, with all process parameters kept constant for both wire types to ensure a reliable comparison and to observe only the process behavior and the results obtained through the change of wire and their respective chemical compositions, aiming to analyze the Marangoni effect. The evaluation included visual inspections to verify the degree of degradation of the zinc layer, pore formation, and spatter levels, as well as dimensional measurements, macrographic analyses of the weld beads, and corrosion and accelerated aging tests through exposure to salt spray. The results demonstrated that the GMAW process with ER70S-3 wire showed superior performance in terms of weld bead appearance, penetration consistency, corrosion and accelerated aging test results under salt spray exposure, and lower distortion of the welded parts.