Corrosion Influence of Ground Current from HVDC Earth Electrode on Buried Metal Pipelines

According to the characteristics of ground current from high voltage direct current transmission system and different environmental conditions, corrosion experiments were carried out in different conditions of metal materials, soil pH values, soil resistivities, current-releasing densities, current duration to study the corrosion rules of buried pipelines affected by DC ground current. The results show that the mass loss of pipeline steel after corrosion was little affected by metal material, soil pH value and soil resistivity, but greatly affected by current-releasing density when other test conditions were the same. The corrosion mass loss and corrosion rate of pipeline steel increased with the increase of anodic current density, displaying linear relationship. The corrosion mass loss was proportional to the corrosion time, and the corrosion rate was independent of the corrosion time.