Impedance and hydrogen evolution studies on magnesium alloy in oxalic acid solution containing different anions

The corrosion behavior of AZ31E alloy was investigated in oxalic acid solution using different electrochemical techniques. The effect of concentration was studied, where the corrosion rate was found to increase with increasing oxalic acid concentration and hydrogen evolution. The effect of adding Cl−, F− or PO43− ions on the electrochemical behavior of AZ31E electrode was studied in 0.01 M oxalic acid solution at 298 K. It was found that the corrosion rate increases with increasing Cl− or F− ion concentration, however, it decreases with increasing PO43− ion concentration. Good agreement was observed between the results obtained from electrochemical techniques and confirmed by Scanning electron micrographs.