Research into the corrosion behaviour of CuNi10Fe alloys in seawater

Abstract

Report concerning the corrosion behaviour of CuNi10Fe in seawater, based on investigations carried out at Royal Naval College of the Royal Netherlands Navy. The testing program included exposition to flowing seawater, tests aimed at determining the erosion behaviour, electrochemical measurement of polarization behaviour, corrosion potential and polarization resistance, and electron microscopic investigations into the structure and composition of protective layers. The tests were carried out with natural and synthetic seawater in the laboratory and under conditions encountered on ships. Studies made with the electron microprobe reveal that the protective layers are of a very complex structure and that the formation of a really protecting layer requires two weeks' time. The protective action is due to concentration polarization because of the reduction of oxygen and oxidation of copper (due to concentration phenomena in pores) and to a reduction of the active surface.

Corrosivity Evaluation of Copper-Nickel Alloy (90/10) in Pumps Used in Offshore Platforms for Seawater Pumping

“…According to [7], for copper in pure water during the primary corrosion reaction, a cuprous oxide film (Cu 2 O) is produced that is predominately responsible for corrosion protection. Authors in [8,9] report that in salt solutions, with oxygenation and the addition of oxidizing substances, cuprous oxide can initially react to form multilayer structures, for example, basic copper chloride to CuCl 2 , Cu(OH) 2 or Cu 2 (OH) 3 Cl. These products do not adhere well to the surface and can be easily removed.…”

Improved pitting corrosion behaviour of electrodeposited nanocrystalline Ni–Cu alloys in 3.0wt.% NaCl solution

“…In the literature, enough data is available on the corrosion behaviour of copper-based Cu-Ni and Cu-Ni-Fe alloys [2][3][4][5][6][7] with the studies emphasising on the nature of passive film and its mechanism of protection against aggressive environment. However, most of the reported literature refers to corrosion behaviour of conventional polycrystalline copper-based alloys.…”