Investigation on corrosion behavior of cryogenically treated friction stir welded AA5083

Abstract

The aluminum alloy 5083 is widely used as a structural material in marine applications due to very good corrosion resistance and low temperature mechanical properties. Friction stir welding, being a solid state process, offers several benefits over the traditional fusion welding processes. In this study, 10 mm thick AA5083–H321 plates were successfully friction stir welded and the welds were investigated for corrosion behavior using salt fog corrosion tests. The friction stir welds exhibited more corrosion rate compared to that of the base material. However, the corrosion rate was observed to decrease with increase in time of exposure. The cryogenic treatment was found to improve corrosion resistance of the base material and the welds. Furthermore, the corrosion rate increases with decrease in pH value of the salt solution. By and large, it is determined that the cryogenic treatment advantageously effects the corrosion behavior