Threshold of Sulfide Stress Corrosion Cracking for L360 Pipeline Steel in Gathering and Transportation System in Puguang Sour Gas Field

The hydrogen permeation behavior of L360MCS and L360QCS steels in Puguang gas field gathering and transferring system as well as the fracture critical hydrogen concentration of L360 steel under different load levels were investigated. The results showed that sulfide stress corrosion cracking seldom happened for L360MCS steel when diffusion hydrogen concentration was lower than 2.67 mg·L-1, above 3.86 mg·L-1 the cracking was danger. While for L360QCS, when diffusion hydrogen concentration was lower than 2.93 mg·L-1, sulfide stress corrosion cracking was not easy to occut, higher than 4.41 mg·L-1 the cracking was danger. Combined with hydrogen probe field tests and experiment results, it is found that under normal conditions in Puguang gas field, the sulfide stress corrosion of L360 pipeline steel is much less likely to occre.