对新疆稠油热采注气管取样管道在常温下的材料性能进行了分析测试,获得了服役5 a(年)后的稠油热采管道不同部位的抗拉强度、屈服强度、伸长率、断面收缩率和硬度等力学性能;又通过显微组织观察和力学性能测试,讨论了管道组织变化和性能退化之间的关系,得到了注气管道不同管段处性能退化情况。进而分析了造成管道性能退化的影响因素，对管道性能退化造成的安全隐患提出了相应的防护措施。

The mechanical properties such as tensile strength ,yielding strength ,elongation rate,percentage reduction of area and hardness were tested under normal temperature condition for 20G steel which was commonly used in Xinjiang heavy oil field heat steam injection pipeline after running for almost five years,the mechanical properties of different part of the pipeline were gained. The relations between pipe’s microstructure change and properties degradation were discussed through metallography observation and mechanical properties experiments,and mechanical properties degradation situations of different parts of the pipeline were obtained. The influencing factors of the mechanical properties degradation were analyzed. The protective measures against potential safety problems caused by performance degradation of the pipeline were also proposed.