Corrosion and Protection of Earth Screen in Transformer Substation
LI Su-fang · Cailiao baohu · 2004
To study the corrosion of grounding grids in transformer substation, the constitutes, pH and moisture of soil and reducing resistance reagent in transformer substation were measured by chemical analysis, and the pitting corrosion on A3 steel grounding electrodes scraped off zinc plating in reducing resistance reagent was observed in lab. Factors effecting corrosion behavior of grounding grids were investigated. Cl~- in the reducing resistance reagent is the key for the corrosion of earth screen. The pitting corrosion potential and corrosion potential of A3 steel electrode in soil containing of 4% NaCl move positively by adding some corrosion inhibitors such as NO~-_3, CO~(2-)_3, PO~(3-)_4, SiO~(2-)_3. Adding inhibitors as PO~(3-)_4 and SiO~(2-)_3 to the reducing resistance reagent can decrease the corrosion of earth screen.