Influence of Arc Brazing Parameters on Microstructure and Joint Properties of Electro-Galvanized Steel

Arc brazing of zinc-coated steel (EG, Electro-galvanized steel) using Cu-3 wt%Si filler metal was performed. The influence of arc current and brazing speed on the bonding properties of the joint, such as bead characteristics, arc penetration, joint hardness, and tensile shear strength were evaluated. The microstructural characteristics of the joint were examined by scanning electron microscopy (SEM) and the compositional information was revealed by energy dispersive spectroscopy (EDS). The throat thickness varies inversely with the brazing speed. The EG joint shows the formation of Fe2Si phases, which result in higher microhardness than the base metal. The tensile samples were fractured in base metal, while minor bead cracks developed in the samples brazed at 80 cm/min-80 A, 60 cm/min-70 A, 70 cm/min-70 A.