Failure analysis of a carbon steel pipeline exposed to wet hydrogen sulfide environment

Stress Corrosion Cracking (SCC) is one of the most common failure phenomena in the wet hydrogen sulfide environment. In this paper, the fracture failure of a fuel gas pipeline during operation has been analyzed. Through service environmental investigation, crack morphology detection, and stress analysis of fuel gas pipeline, the fracture has the morphology and characteristic of wet hydrogen sulfide SCC in the welding joint between pipeline and flange. The analysis shows that the abnormal martensitic microstructure in the pipeline has provided the advantage for SCC.