Macro-galvanic corrosion of tower grounding device consisting of graphite and Zn-coated steel in a simulated soil environment
By Liu, Ling; Li, Jingjing; Peng, Mingxiao; Li, Wenbo; Lei, Bing; Meng, Guozhe
Published in Engineering Failure Analysis
2022
Abstract
The galvanic corrosion of a tower grounding device consisting of a flexible graphite grounding electrode and Zn-coated steel grounding wire was investigated in a simulated soil environment using corrosion tests and numerical simulation. The significant potential differences between graphite and Zn-coated steel suggest that macro-galvanic corrosion could occur readily in soil, while the dissolution of Zn-coated steel parts was accelerated under the galvanic interaction. The most preferential fracture site resulted from galvanic corrosion of such grounding device was the metallic grounding wire. The conductivity of the soil environment also had a significant influence on the galvanic effect of the couple. The results suggest that the coupling structure of graphite and Zn-coated steel should be avoided in the grounding device design.