Galvanic corrosion of a copper alloy in lithium bromide heavy brine environments

Galvanic corrosion of the copper alloy 84% Cu-15% Zn-1% Ni was studied in 5 5wt% lithium bromide (LiBr) environments. The galvanic couples studied were : 84% Cu-15% Zn-1% Ni-Ti2, 84% Cu-15% Zn-1% Ni-Ti7, 84% Cu-15% Zn-1% Ni-30% Cu-70% Ni, 84% Cu-l 5% Zn-1% Ni-Pb, 84% Cu-15% Zn-1% Ni Ag, and 84% Cu-15% Zn-1% Ni-Sn. Potentiodynamic polarization measurements, open-circuit poten tial (OCP), and weight change measurements were carried out to evaluate the galvanic effect. Results indicated that Ti alloys and 30% Cu-70% Ni were t he most passive alloys tested, and they behaved as cathodes. Although galva nic corrosion was expected, a negligible effect was measured because of an effective passivation layer on the surface of Ti alloys and 30% Cu-70% Ni. Pb, Ag, and Sn showed anodic behavior as compared to 84% Cu-15% Zn-1% Ni. A s a result of the galvanic coupling, significant weight loss of these metal s was measured. Sn was the most effective anode as compared to the other te sted alloys; it acted as a sacrificial anode. Sn provided effective cathodi c protection to 84% Cu-15% Zn-1% Ni in 55wt% LiBr environments at 140 degre es C.