Inhibition of Lanthanum Salts-containing Inhibitors for Copper-zinc-nickel Alloy in 3.5% NaCl Solution

The lanthanum chloride-containing corrosion inhibitors for copper-zinc-nickel alloy were investigated by using corrosion resistance rapid test, weight loss experiment, potentiodynamic polarization measurement, and electrochemical impedance spectroscopy(EIS) study. The results indicate that the synergistic inhibitors of BTA+TTA or BTA+LaCl3 provide very good protective efficiencies for the copper alloy in 3.5% NaCl solution. The mixture of BTA, TTA and lanthanum chloride (BTA:3 g·L-1, TTA:14 g·L-1, and LaCl3:7 g·L-1) provided the highest protective efficiency. The corrosion rate of the Cu-Zn-Ni alloy with the BTA+TTA+LaCl3 inhibitor treatment in 3.5% NaCl solution at room temperature was evaluated to be 2 μm/year.