Microstructure and corrosion resistance of Al5083 alloy hybrid plasma-MIG welds

Al5083 alloy was welded by plasma-MIG hybrid welding with optimized parameters of 58A MIG current and 130 A plasma current with speed of 4.75 mm/s. Good appearance with defect-free of the joint was got. Microstructures and corrosion resistance of electrochemical impedance spectroscopy and potentiodynamic polarization of the welds and base metal in a 0.5 M NaCl solution at room temperature were investigated. Combined with simulated equivalent circuit by program, the relationship between microstructures and corrosion resistance was obtained. Plasma-MIG hybrid welded metal with as-cast structure presents a better corrosion resistance than the base metal with rolling structure. Unlike other welding method, the plasma-MIG welding method is helpful for improving the corrosion resistance of Al5083 welding joints.