Corrosion Behavior and Mechanism of X80 Steel for Oil and Gas Pipeline in Sulfur-Containing Medium

The corrosion test of X80 steel for oil and gas pipeline was carried out in dynamic non-sulfur-containing corrosion environment and dynamic sulfur-containing corrosion environment. The macroscopic and microscopic morphology of the corrosion products and the composition of the corrosion products were analyzed. The results show that the corrosion products of X80 steel in non-sulfur-containing environment were closely bound to the substrate, and played a certain role in protecting the substrate. However, in the sulfur-containing environment, the FeS precipitation structure formed on the surface of X80 steel was loose, which provided a fast channel for ions and accelerated the corrosion of the steel.