Metals and alloys can be subject to different forms of corrosion in seawater, including general wastage, impingement attack and localised corrosion such as pitting, crevice corrosion, stress corrosion cracking and intergranular attack. Cupronickel alloys however provide excellent corrosion resistance, particularly in rapid-moving seawater where they are widely used for applications such as connectors, fasteners and shafts. The corrosion resistance of such alloys increases with the increasing nickel content.
General corrosion rates for 90-10 and 70-30 cupronickel alloys in seawater are quite low, ranging between 0.025 and 0.0025 mm/yr(5). For most applications, these rates allow the alloys to last the required lifetime and there would be little probability of premature failure in service because of the corrosion mechanism.
If you would like to find out more about the corrosion resistance of cupronickels, please contact the Langley Alloys team today. We can talk you through the specifications for our complete range of cupronickels and we can also advise you on the best solution for your application.