Protection of Substation Grounding Grid by Gadolinium Magnesium Sacrificial Anode

Abstract

Abstract Since lower galvanic efficiency and potential reversal might occur in magnesium (Mg) sacrificial anode applied in anti-corrosion project for grounding grid in substation, rare earth gadolinium (Gd) was incorporated into Mg sacrificial anode material for activating and improving the performance of the anode, and the influence of Gd concentration on properties of Mg sacrificial anode was evaluated by electrochemical method. The results revealed that the incorporation of Gd could effectively improve the electrochemical properties of magnesium sacrificial anode. The present of 0.1%(wt) Gd in the anode caused the best electrochemical properties as follows: the OCP decreased to as low as -1.78V (SEC) while the galvanic efficiency increased to as high as 62%, and the minimal anodic corrosion current, 0.0186mA, was realized, also the reverse potential and current density in DC leakage process increased from 500mV to 900mV and 1mA/dm2 to 2.27mA/dm2, respectively.