Corrosion of Mg alloys EV31A, WE43B, and ZE41A in chloride- and sulfate-containing solutions saturated with magnesium hydroxide

This study studied corrosion in 0.1 M Na2SO4, 0.1 M NaCl, and 0.6 M NaCl, all saturated with Mg(OH)(2), using weight loss, hydrogen evolution, and electrochemical measurements. Corrosion was similar in all cases. Nevertheless, the corrosion rates were alloy-dependent, were somewhat lower in 0.1 M Na2SO4 than in 0.1 M NaCl, and increased with NaCl concentration. The corrosion damage morphology was similar for all solutions; the extent correlated with the corrosion rate. The corrosion rates evaluated by the electrochemical methods were lower than those evaluated from hydrogen evolution, consistent with the Mg corrosion mechanism involving the unipositive Mg+ ion.