Hydrogen induced cracking of pipeline and pressure vessel steels: A review

Pipelines and pressure vessels made of carbon and low alloy steels have suffered from Hydrogen Induced Cracking (HIC) in wet hydrogen sulfide environment in the oil & gas industry. Hydrogen which is produced at cathode due to corrosion reaction, diffuses into the steel and result in cracking in wet hydrogen sulfide environment. Hydrogen assisted cracking usually manifests in carbon and low alloy steels with unique crack initiation and propagation characteristics. The origin and morphology of cracks are dependent on various factors viz., mechanical properties & composition of the material, manufacturing process including heat treatment, applicable stresses etc. Hydrogen assisted cracking is commonly classified into three categories based on initiation, morphology and stress requirement in cracking as, Hydrogen Induced Cracking (HIC), Sulfide Stress Cracking (SSC) and Stress Oriented Hydrogen Induced Cracking (SOHIC). The current paper discusses the metallurgical factors which play a major role in Hydrogen Induced Cracking of flat rolled steels commonly used in manufacturing of pipelines and pressure vessels in oil & gas industry as found in several studies.