Galvanic Corrosion Behavior of Al Alloy A6061/High-Tensile Strength Steel Couples Jointed By Friction Stir Lap Welding in an NaCl Solution

摘要

Recently, improvements in fuel efficiency of transportation systems have been called for, as part of measures to reduce carbon dioxide emissions. Reducing the body weight is quite effective in improving fuel efficiency. Therefore, part of heavier materials like steel is replaced by lighter materials such as aluminum alloys, carbon fiber reinforced plastics, and so on. However, when dissimilar materials are jointed, appropriate jointing methods are needed in terms of assembly, bonding performance, and costs. Friction stir welding (FSW) has attracted much attention as a promising jointing method in various engineering applications. FSW is a solid-state joining technique that has shown significant advantages over conventional fusion welding in terms of higher strength and quality of the joint produced. For this reason, FSW has attracted considerable attention for industrial applications, and further development of the technology is expected. However, during bonding of metallic materials by FSW, microstructure changes are produced that can affect their corrosion degradation. In this study, galvanic corrosion behavior of couples of A6061 and high-strength steel (SPCC) jointed by FSW in aqueous NaCl solutions is investigated.