Abstract
The analysis of the corrosion of copper alloys (brass [Cu65/Zn35], bronze B10 [Cu90/Sn10], and bronze B5 [Cu85/Zn5/Sn5/Pb5]) and zinc in commercial lithium bromide (LiBr) heavy brine solutions, with and without additives, was analyzed using polarization curves. Corrosion rates were determined by the Tafel slope method. The inhibitor effect was analyzed in a commercial solution. Galvanic current and mixed potentials were determined using polarization curves according to the mixed potential theory. Zinc content in alloys displaced open-circuit potentials (OCP) toward more negative values following a linear relationship. The differences in the potentials of the materials increased with zinc content in the alloy in the different LiBr solutions. Generally, the highest current corrosion was obtained in 700 g/L LiBr solution at the most negative corrosion potentials. Chromate and lithium hydroxide (LiOH) presence in commercial LiBr solution produced complete inhibition on brass but this inhibitor effect was not suitable in the particular case of bronze B5. Copper is always the cathodic metal when coupled to copper alloys, and it promotes galvanic corrosion. Corrosion acceleration was also important between B10, B5, and brass in 700 g/L, while galvanic currents diminished in commercial LiBr solution in all the pairs.
