Effect of Temperature and pH on Electrochemical Corrosion of Al-Zn Sacrificial Anode in Production Water

The open circuit potential,polarization curve and cyclic voltammetric curve of Al-Zn sacrificial anode were tested in-oilfield produced water with different temperatures and pH. The sacrificial anode surface corrosion morphology was analyzed. The results showed that the open circuit potential of sacrificial anode became negative and had a strong corrosion tendency with increasing the water temperature. And the corrosion rate was controlled by the anode at the varied temperatures. The corrosion current density (Jcorr) at 48 ℃ was larger than that at room temperature. The sacrificial anode easily produced intergranular corrosion at 42 ℃ and 48 ℃. With increasing the water pH,the open circuit potential became high first,and then low. The corrosion rate was controlled by the anode first,and then by cathode or by both anode and cathode. The rate first lowered and then climbed.