Influence of Annealing Treatments on Welded CuNi Sheets on the Corrosion Behaviour in Sea Water

Due to their good corrosion resistance in seawater, tubes, rods, and forgings made from copper-nickel alloys (Cu-Ni) are widely used in ship building, offshore platforms, desalination plants, and numerous other applications. Welding is a major technology for joining this material. Since the microstructures of base material, weld seam, and heat affected zone may be quite different, the consequences with respect to corrosion must be considered. In this study the influence of microstructure on corrosion behaviour was investigated using welded test coupons of CuNi10Fe1.6 Mn, as-welded and after heat-treatment, by metallographic examination and electrochemical corrosion tests in synthetic seawater.