Study on Damage Behaviour of L360QS Pipeline Steel Girth Welds in Wet Hydrogen Sulphide

The corrosion is one of the major causes of pipeline failure incidents, and hydrogen damage is the most serious corrosion problem in pipelines. Statistics from various aspects show that oil and gas pipelines are very susceptible to hydrogen damage under the action of medium containing wet H₂S, and there are two main forms of hydrogen damage in pipelines, i.e.hydrogen-induced cracking（HIC） and stress corrosion cracking（SCC）. L360QS pipeline steel girth welds were tested for resistance to HIC and SCC. The results show that during HIC tests, after 96 h of corrosion in saturated hydrogen sulphide solution, no hydrogen cracking and blistering phenomena are observed, and the crack sensitivity rate, the crack length ratio and the crack thickness ratio are all zero. During SCC test, the samples do not crack after 720 h of corrosion in saturated hydrogen sulphide solution when the load applied to the samples is 60% of the yield strength, and the samples crack after 720 h of corrosion in saturated hydrogen sulphide solution when the load applied to the samples is 100% or more of the yield strength. The cracking location is mainly located in the heat affected zone.