Corrosion of Monel-400 in Aerated Stagnant Arabian Gulf Seawater after Different Exposure Intervals

The corrosion of Monel-400 after varied exposure periods in naturally aerated Arabian Gulf seawater (AGS) has been carried out using gravimetric, cyclic potentiodynamic polarization, chronoamperometry, open-circuit potential, and impedance spectroscopy measurements along with SEM/EDX investigations. Gravimetric data within 160 days showed that the weight loss increased, while the corrosion rate decreased with time. SEM/EDX investigations after 160 days immersion indicated that dissolution of Monel takes place due to the selective dissolution of Ni. The electrochemical measurements confirmed the gravimetric data and proved that severity of uniform corrosion of Monel decreases, while pitting one increases with increasing the exposure period