Corrosion resistance of copper–nickel alloy under fluid jet impingement

Jet impingement is used as a test technique to study flow-accelerated corrosion of Cu–Ni disk electrodes in saline water. The Reynolds numbers in the range of applied impinging velocities indicated that the flow between the solution and the electrode was turbulent in the systems investigated. The role of Ni content on the resistance of spontaneously formed barrier oxide film and Cu(II)/Ni(II)-diethyldithiocarbamate film on Cu–Ni alloys (10, 20, 30 and 40 at.% Ni) was examined and evaluated using electrochemical impedance spectroscopy in dependence of the impinging velocity and the immersion time. The results are discussed in terms of the corrosion mechanisms and their relevance to the use of Cu–Ni alloys in desalination plants and in the marine engineering field because fluid hydrodynamic conditions play an important role in Cu–Ni alloy applications. Based on the analysis presented in the paper, it is anticipated that the Cu–10Ni alloy is the best choice for application in the marine environment.

Research highlights
► Flow-accelerated corrosion of bare and protected Cu–Ni alloys in saline water.
► The role of Ni content and immersion time on the resistance of Cu–Ni alloys.
► The relevance of Cu–Ni application in desalination plants and marine engineering.
► The Cu–10Ni alloy is the best choice for application in the marine environment.
► The Et2dtc surface film protects excellently Cu–Ni alloys in marine conditions.