应力腐蚀门槛值是评价管道抗应力腐蚀能力的重要性能参数。采用胜利油田现场使用的20g,13CrMo44,ST45.8和ST45.8-Ⅵ注汽管材，制作含有预制裂纹的恒位移双悬臂梁(DCB)试件，在硫化氢介质中进行了应力腐蚀试验，得到4种钢材的应力腐蚀门槛值KISCC和应力腐蚀裂纹扩展速率da/dt。试验结果表明，ST45-Ⅵ钢的KISCC值最大，裂纹扩展速率最小，具有较强的抗应力腐蚀开裂能力；含碳量低，减少块状铁素体，细化组织有利于提高管材抗应力腐蚀的能力。

Four kinds of DCB specimens with precrack from different injection pipelines (20g, 13CrMo44, ST45.8, ST45.8-Ⅵ) was adopted. The difference of stress corrosion was tested in solution of H2S. At the same time the stress intensity factor threshold (KISCC) and crack propagation rate da/dt was determined in stress corrosion test. The test results indicates that the value of KISCC in ST45-Ⅵ steel is the greatest one, so which has higher property of stress corrosion resistance. Based on the above study, low carbon content, reducing massive ferrite and refining structure are good for increasing the ability to resist stress corrosion cracking of pipelines.