通过抗硫化物应力腐蚀试验、慢应变速率拉伸试验、氢含量测试等方法研究条形缺陷对H2S环境下L360 管线钢环焊缝硫化物应力腐蚀开裂敏感性的影响.结果表明,环焊缝在 72%、85%和 110%SMYS(最小屈服强度)应力水平下,热影响区出现裂纹且裂纹长度随加载应力增大而增大;条形缺陷环焊缝试样在屈服点后快速发生断裂,其断裂应变(0.024)仅为非缺陷环焊缝试样的21.05%;条形缺陷存在促进氢离子在裂纹尖端聚集从而加剧发生开裂倾向,消氢处理技术可以有效降低氢含量,降低环焊缝抗硫化物应力腐蚀开裂敏感性降低.
The effect of bar defects on the stress corrosion cracking sensitivity of sulfide in L360 pipeline steel girth weld under H2S environ-ment was studied by anti-sulfide stress corrosion experiment,slow strain rate tensile experiment and hydrogen content test.The results show that cracks appear in the heat-affected zone of the girth weld at the stress levels of 72%,85%and 110%SMYS,and the crack length increases with the increase of the loading stress.The bar defected girth weld specimen breaks rapidly after the yield point,and its fracture strain(0.024)is only 21.05%of the non-defective girth weld specimen.The presence of bar defects promotes the aggregation of hydrogen ions at the crack tip,thereby aggravating the cracking tendency.The hydrogen elimination treatment can effectively reduce the hy-drogen content and reduce the sensitivity of the girth weld to sulfur stress corrosion and cracking.