基于电阻技术的管道内壁腐蚀实验研究

发布时间：2018-12-31 20:15

【摘要】：管道内腐蚀是引起管道失效的主要因素之一,腐蚀监测技术日益成为现代管道工业研究的热点问题。传统的管道腐蚀监测技术受限于工作环境与介质环境,电化学方法不适用于非电解质油气管道的内腐蚀监测,插入式电阻探针监测数据只是管道内的均匀腐蚀状态,对管道内壁的局部腐蚀具有很大局限性。本文针对这些问题,建立基于环形结构电阻探针的管道内壁腐蚀监测实验平台,进行长期的腐蚀监测与缓释剂对管道作用效果的实验,最后对实验结果进行了分析讨论。首先,采用电阻法结合电化学方法对同一电子试片进行腐蚀监测,研究X65管线钢在海水中的氧去极化腐蚀过程及特性。对比分析了失重法、电阻法、LPR和EIS四种监测方法的腐蚀速率,实验发现电阻法在长期腐蚀监测种具有更高的准确性,实验得到X65钢在海水环境中的腐蚀速率为分布为0.06～0.36mma之间,为实验平台的实验结果分析奠定数据基础。其次,搭建基于电阻技术的的管道内壁腐蚀监测实验平台。其核心为集成了环形探针的腐蚀监测管线,研究预先完成了环形探针的温度标定实验,得到腐蚀测量的初始参数,然后完成了管道内壁腐蚀的长期监测实验。实验结果显示,管道内壁腐蚀存在周向差异,底部沉积物等因素造成了管道周向的电位差异,形成了电偶腐蚀,底部为阳极区,腐蚀速率加剧；实验平台能实现管道周向的腐蚀监测,对管道周向局部腐蚀具有很好的敏感性；由于腐蚀产物与沉积物的作用,缓蚀剂对管道周向的作用效果存在差异。
[Abstract]:Pipeline internal corrosion is one of the main factors causing pipeline failure. Corrosion monitoring technology has become a hot issue in modern pipeline industry. The traditional pipeline corrosion monitoring technology is limited by the working environment and the medium environment. The electrochemical method is not suitable for the internal corrosion monitoring of non-electrolyte oil and gas pipelines. The plug-in resistance probe monitoring data is only the uniform corrosion state in the pipeline. It is very limited to the local corrosion of the inner wall of the pipeline. In order to solve these problems, an experimental platform of pipeline inner wall corrosion monitoring based on ring structure resistance probe is established, and the effect of corrosion monitoring and slow release agent on pipeline is tested for a long time. Finally, the experimental results are analyzed and discussed. Firstly, the corrosion process and characteristics of X65 pipeline steel under oxygen depolarization in seawater were investigated by means of resistance method and electrochemical method. The corrosion rates of weightlessness method, resistance method, LPR method and EIS method are compared and analyzed. It is found that the resistance method has higher accuracy in long-term corrosion monitoring. The results show that the corrosion rate of X65 steel in seawater environment is distributed between 0.06~0.36mma, which provides a data basis for the experimental results analysis of the experimental platform. Secondly, an experimental platform for corrosion monitoring of pipeline inner wall based on resistance technology is built. The core is the corrosion monitoring pipeline integrated with the ring probe. The temperature calibration experiment of the ring probe is completed in advance, the initial parameters of the corrosion measurement are obtained, and the long-term monitoring experiment of the corrosion of the inner wall of the pipeline is completed. The experimental results show that there are circumferential differences in the corrosion of the inner wall of the pipeline, and some factors, such as sediment at the bottom, cause the difference of the potential in the circumferential direction of the pipeline and form the galvanic corrosion, the bottom of which is the anode area, and the corrosion rate is aggravated. The experimental platform can realize pipeline circumferential corrosion monitoring and has good sensitivity to circumferential local corrosion of pipeline, and the effect of corrosion inhibitor on pipeline circumferential corrosion is different due to the effect of corrosion products and sediment.
【学位授予单位】：大连理工大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：TE988.2

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