Reasons Analysis on Corrosion Perforation of Gas Steel Pipelines

Corrosion perforation failure happened for many times to 20 steel gas pipelines in less than a year after being buried, and the corrosion reasons were systematically analyzed by macroscopic examination, chemical compositions analysis, metallographic examination and scanning electron microscopy analysis. The results show that the corrosion holes of the gas steel pipelines extended from outer wall to inner wall and had characteristics of stray current corrosion. Meanwhile, the inner wall of the gas steel pipeline appeared plenty of corrosion pits because there were a large number of inclusions, which caused the pitting corrosion. The corrosion perforation of the gas steel pipelines was mainly due to the stray current in the soil.