Abstract
Magnesium (Mg) and its alloys have increased applications in industry. These applications are getting limited due to Mg corrosion, especially in chloride containing environments, because of its high negative potential. The objective of the present work thus was to report the corrosion of Mg in stagnant solutions of the naturally aerated Arabian Gulf seawater (AGS) and 3.5% NaCl. Weight-loss (WtL) after different exposure periods and scanning electron microscopy (SEM) with X-ray analyzer (EDX) investigations along with cyclic potentiodynamic polarization (CPP), potentiostatic current-time (PCT), and electrochemical impedance spectroscopy (EIS) measurements were employed to achieve this objective. WtL experiments indicated that Mg dissolves linearly and its corrosion rate decreases in AGS and NaCl solutions when its exposure time increases in the range from 120 h to 600 h. CPP, PCT, and EIS measurements confirmed the data obtained by WtL that the increase of exposure time decreases the uniform. This effect also increases the severity of Mg pitting corrosion. Results together showed clearly that AGS is more aggressive towards Mg surface than 3.5% NaCl solutions at the same condition.