The Corrosion Behavior of Galvanized Steel in Alkaline Soil

The grounding grid of some substation shows severely corrosion, which affects the safe running of power grid. Galvanized steel is widely used in grounding grid. However, the galvanized steel is easy to corrosion in alkaline soil. In this paper, the corrosion behavior of galvanized steel was studied through accelerated corrosion test of burying specimens in laboratory soils and the corrosion rate was measured by electrochemical test. The corrosion products and corrosion appearance were analyzed by means of SEM, and XRD. The results show that pitting corrosion and localized corrosion were observed on the surface of the galvanized steel, the corrosion products were rough and loose, indicating no protection, the corrosion products of galvanized steel were ZnO,FeO(OH),FeCl3,Zn3O(SO4)2,and ZnSO3·2.50H2O. Electrochemical test show that the corrosion rate of galvanized steel in the later corrosion stage is higher than in the initial corrosion stage.