Potential Distribution of Cathodic Protection using Mg as a Sacrificial Anode

Abstract

Cathodic protection in the sacrificial system is essentially a controlled electrochemical cell; corrosion on the protected structure is shifted to the anode. When the anode material is coupled to steel, they behave anodically and discharge current.In this work, magnesium used as sacrificial anode for the protection of carbon steel rod that buried in soil with resistance of 1000, 1400, 1800, and 2200Ω/cm that simulate wide range of resistance of Iraqi soil.Potential distribution in different positions between sacrificial anode and the protected structure was measuredwith respect to copper - copper sulfate electrode, showing that the conditions for the sacrificial anode for the protection of carbon steel rod and simulate with contours.The result show that the increasing of soil resistivity is reduces anode life and impairs itsperformance. In addition, the changing of sacrificial anode is important because it consumed therefore, it is important to optimize the distance of sacrificial anode from protected structure according to soil resistivity so that avoiding the polarization that causes high consumption rate of anode.