普光气田集输管线L360钢硫化物应力腐蚀门槛值研究

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

研究了L360MCS和L360QCS钢在普光气田集输系统中的氢渗透行为,以及不同载荷水平下L360钢的断裂临界氢浓度。结果表明,L360MCS钢中可扩散氢质量浓度低于2.67mg·kg-1时不易发生硫化物应力腐蚀开裂,高于3.86mg·kg-1为开裂危险区;L360QCS钢中的可扩散氢质量浓度低于2.93mg·kg-1时不易发生硫化物应力腐蚀开裂,高于4.41mg·kg-1时为开裂危险区。结合氢探针技术对于现场在用管道氢浓度进行了测试和比对,表明普光气田目前集输管道在正常工况下发生硫化物应力腐蚀的可能性较小。

The hydrogen permeation behavior of L360 MCS and L360 QCS 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 L360 MCS steel when diffusion hydrogen concentration was lower than 2.67mg·L^-1,above 3.86mg·L^-1 the cracking was danger.While for L360 QCS,when diffusion hydrogen concentration was lower than 2.93mg·L^-1,sulfide stress corrosion cracking was not easy to occut,higher than 4.41mg·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.