Probing the corrosion mechanism of zinc under direct current electric field

Abstract The influence mechanism of a direct current (DC) electric field on the corrosion behaviour of zinc in a simulated industrial environment was studied by using weight loss measurement, electrochemical tests, XRD and SEM/EDS techniques. The results show that the corrosion rate of zinc increased with the increase of DC electric field intensities. The main corrosion products formed on the sample in ZnSO 4 solution are Zn(OH) 2, ZnO, Zn 5 (OH) 6 (CO 3 ) 2 and Zn 4 SO 4 (OH) 6 .5H 2 O. It was found that the DC electric field enables OH − and SO 4 2− ions to migrate from the solution/electrode interface to the upper layer of the solution quickly. Thus it can change the reaction site of the formation of Zn 4 SO 4 (OH) 6 .5H 2 O and can increase the quantity of the porous hexagonal plate Zn 4 SO 4 (OH) 6 .5H 2 O. All these features can promote the corrosion rate of zinc.