20钢和16Mn钢天然气管道失效分析  

Failure Analysis on Natural Gas Pipeline of 20 Steel and 16Mn Steel

作　　者：徐学旭 刘智勇[1] 李建宽[1] 杜翠薇[1] 黄辉[2] 何仁洋[2] XU Xuexu1, LIU Zhiyong1, LI Jiankuan, DU Cuiwei, HUANG Hui2, HE Renyang2(1 Corrosion and Protection Center, University of Science and Technology Beifing, Belting 100083, China 2 China Special Equipment Inspection and Research Institute, Beijing 100013, Chin)

机构地区：[1]北京科技大学腐蚀与防护中心,北京100083 [2]中国特种设备检测研究院,北京100013

出　　处：《腐蚀科学与防护技术》2018年第2期195-201,共7页Corrosion Science and Protection Technology

基　　金：国家自然科学基金(51471034);国家科技支撑计划(2011BAK06B01-01-02)~~

摘　　要：采用宏观形貌、金相组织、夹杂物分析以及腐蚀形貌观察和成分分析等方法,分析了某20钢和16Mn钢管道在含CO_2天然气介质中的内腐蚀失效原因。结果表明,严重的腐蚀现象主要发生在Mn含量较高的焊缝区域及直角弯头区域;管道失效的主要原因是CO_2薄液膜环境的冲刷加速腐蚀,同时加工及焊接引起的组织劣化缺陷也会加速腐蚀的进行,最终造成天然气管道的局部严重减薄。The failure analysis for a natural gas pipeline, composed of pipes of 20 steel and 16 Mn steel, was performed by means of examination of macro-morpholopy, metallograph, inclusion analysis as well as scanning electron microscope examination and chemical analysis for the relevant materials. Results showed that the areas with higher Mn-content such as the weld joint and the right-angle elbow,were serious corroded. The failure of the natural gas pipeline is mainly due to the erosion-corrosion beneath the CO2-cotaining thin electrolyte film. Machining defects and the microstructure deterioration caused by welding could also promote the corrosion process, thereby, inducing the serious wall-thinning of the pipeline.

关 键 词：20钢 16MN钢 天然气管道 薄液膜 冲刷腐蚀 

分 类 号：U177[交通运输工程]