Effect of High Voltage Direct Current Electric Field on Corrosion Behavior of 5052 Aluminum Alloy Under Simulated Seawater Cyclic Wet-Dry Condition

The corrosion behavior of 5052 aluminum alloy under simulated seawater (3.5wt% NaCl solution) cyclic wet-dry condition at direct current electric field intensity of 0-400 kV·m^-1 was studied. The results show that with the increase of electric field intensity, the mass loss per unit area and corrosion rate of aluminum alloy increased. With the increase of corrosion time, the mass loss per unit area increased, but the corrosion rate decreased. In the early corrosion (0-7 d), the pitting occurred on the surface of aluminum alloy; with the increase of electric field intensity, the pitting was intensified. In the middle stage of corrosion (7-15 d), the exfoliation corrosion occurred; the larger the electric field intensity, the more serious the peeling. In the late stage of corrosion (15-30 d), the passivation, passive film cracking, micro-couple corrosion, exfoliation corrosion alternately occurred.