为了探明在国内某气田使用的20G/316L双金属复合管出现失效的原因, 通过对样品的失效形貌进行分析, 结合有限元软件对焊接过程进行模拟, 得知腐蚀严重的部位位于管道下部焊缝起弧点附近, 主要腐蚀形式为点蚀, 焊接应力对工件失效起到了促进和诱导的作用。研究表明, 20G/316L双金属复合管的失效是焊接应力、腐蚀性介质Cl-和腐蚀原电池共同作用的结果。

In order to ascertain the failure reasons for the 20G/316L bimetallic composite pipe used in a domestic gas field, the failure morphology of the samples was analyzed and the welding process was simulated with ANSYS. It was found that the lower part of the pipe near the starting point of the weld was seriously corroded, and pitting was the main corrosion form, and the welding stress played a significant role in promoting and inducing the failure. The failure reasons of 20G/316L bimetallic composite pipe were welding stress, Cl- and galvanic corrosion.