石油化工设备技术 ›› 2023, Vol. 44 ›› Issue (2): 56-60,6.doi: 10.3969/j.issn.1006-8805.2023.02.012

• 腐蚀与防护 • 上一篇    下一篇

某天然气长输工程外腐蚀失效分析

严俊伟1,2,夏 立1,2,汪江伟1,陈 伟1,2,金 硕1,陈 长1,2   

  1. 1. 浙江省特种设备科学研究院,浙江 杭州 310020
    2. 浙江省特种设备安全检测技术研究重点实验室,浙江 杭州 310020
  • 收稿日期:2023-01-04 接受日期:2023-02-28 出版日期:2023-03-17 发布日期:2023-03-17
  • 作者简介:严俊伟,男,2014年业于中国石油大学(北京)油气储运工程专业,硕士,主要从事埋地管道检验检测工作,高级工程师。
  • 基金资助:
    浙江省市场监督管理局科研计划项目“长输管道安全运行风险识别及剩余寿命评估数字化管理技术研究”(ZC2021A018)。

Analysis on External Corrosion Failure of Natural Gas Long-distance Pipeline

Yan Junwei1,2, Xia Li1,2, Wang Jiangwei1, Chen Wei1,2, Jin Shuo1, Chen Zhang1,2   

  1. 1. Zhejiang Academy of Special Equipment Science, Hangzhou, Zhejiang, 310020;
    2. Key Laboratory of Special Equipment Safety Testing Technology of Zhejiang Province, Hangzhou, Zhejiang, 310020
  • Received:2023-01-04 Accepted:2023-02-28 Online:2023-03-17 Published:2023-03-17

摘要: 文章针对油气长输管道易发生腐蚀失效的问题,对某天然气长输工程中管道腐蚀失效区域进行宏观和扫描电镜观察以及腐蚀产物能谱分析;对管子进行金相和化学成分分析、力学性能检测;并对管道周围敷设土壤进行分析。分析结果表明,管子外部机械损伤首先导致管壁产生极大的损伤缺陷和壁厚减薄,同时造成管道外防腐层的破损;其二,该损伤点直接暴露在土壤电解质环境中,进一步发生化学或电化学腐蚀,直至发生局部壁厚减薄失效。上述分析揭示了管道安装过程中的机械损伤和运行期间的腐蚀作用共同诱发管道失效的一般现象。文章针对失效原因,提出了在采购、施工安装、运行维护阶段的相关建议措施,对相似问题的处理具有一定的参考价值。

关键词: L360, 长输工程, 外腐蚀, 失效分析, 机械损伤, 化学腐蚀, 电化学腐蚀

Abstract: Aiming at the problem of oil and gas long-distance pipeline being prone to corrosion failure, this paper conducted macroscopic and corrosion product analysis, metallographic analysis, chemical analysis, mechanical property testing, hardness determination, scanning electron microscopy and energy spectrum testing of the failure area and surrounding soil analysis of the natural gas longdistance pipeline. The results show that external mechanical damage first led to great damage defects and thickness thinning of the pipe wall, and also caused breakage of the external anti-corrosion coating of the pipe. Then the damage site was directly exposed to the electrolyte environment of the soil, and chemical or electrochemical corrosion occurred in the damaged site until the occurrence of the pipeline failure due to local wall thickness reduction. The above analysis demonstrates the general phenomenon of pipeline failure induced by mechanical damage during installation and subsequent corrosion during operation. According to the failure causes, this paper puts forward relevant recommendations and measures for the procurement, construction and installation, and operation and maintenance stages, which are of certain reference value for the handling of similar problems.

Key words: L360, long-distance pipeline, external corrosion, failure analysis, mechanical damage, chemical corrosion, electrochemical corrosion