Microscopic study on the corrosion of underground pipeline

Corrosion on the water pipelines can potentially cause substantial human and economic
losses. This paper concentrates on corrosion observation on the underground pipeline material as a
part of our continuous study regarding this work. The samples which is mild steel taken from
actually used pipeline at the site. Mild steels have been investigated intensively as a promising pipe
material for underground pipeline due to their advantages such as high availability, low cost,
environmental friendliness and high resistance to corrosion. However, their practical application
exposes them to the attack of corrosion related to the soil condition. In this study, microscopic
observations were performed on the surface of pipeline material using scanning electron microscope
(SEM) and energy-dispersive x-ray (EDX) technique in order to study the morphology and basic
composition of the corrosion, respectively. Based on the observation and visual analyses, it was
determined that the surface of the mild steel was affected by continuous exposure to moist soil,
which leads to pitting type of corrosion.