Corrosion Failure Reason of the Overhead Lightning Rod in a Transformer Substation

In order to solve the corrosion failure problem of lightning rod in a transformer substation, scanning electron microscopy, ion chromatography, X-ray diffraction and electrochemical tests were used to observe the corrosion morphology of the lightning rod and to analyze the rust components and their electrochemical properties. The results showed that the outer wall of the lightning rod was slightly corroded, but the inner wall of the hollow lightning rod was seriously corroded, and the corrosion damage developed from the inside to the outside. Rainwater infiltrated into welding defects and could not be easily discharged, resulting in the inner wall of the lightning rod being in a damp environment for a long time, which was the main cause of the high-speed corrosion of the inner wall substrate. Fe₃O₄ rust layer had a large cathodic effect and could promote corrosion of the matrix, further accelerating the inner wall failure rate. Corrosion failure of lightning rod was focused on the inner wall with strong concealment, where enough attention should be paid.