Lightweight steel-aluminum structures have broad application prospects because of their lowering weight characteristics, however, the corrosion of welding-brazing joints in steel-aluminum structures is less concerned or studied. In this paper, the corrosion behavior of the laser-MIG (metal inert gas) hybrid welding-brazing joints of steel-aluminum is investigated through the tests and analysis of salt spray, immersion, and electrochemistry. The salt spray and immersion tests show that obvious galvanic corrosion occurs at the welded joints, in which the aluminum side is seriously corroded while the steel side is not corroded. The open-circuit potential (OCP) values of the aluminum alloy and the weld metal are similar (approximately −0.48 V), and the stainless steel has a higher OCP value of −0.33 V. The corrosion resistance of the weld metal is lower than aluminum- and steel-based materials. The corrosion resistance of the joints is controlled by the aluminum alloy part of the two metals based on the OCP and electrochemical impedance spectroscopy (EIS) analysis. A possible corrosion process schematic for the physical/chemical properties of a welding-brazing joint immersed in a sodium chloride solution is proposed according to EIS.

You do not currently have access to this content.