西部某气田井场分离器液相管线法兰腐蚀原因分析

目的 解决西部某气田井场分离器液相出口管线法兰严重腐蚀问题。方法 通过宏观形貌观察、无损检测、化学成分分析、金相组织分析、力学性能测试、腐蚀区域微观形貌观察、腐蚀产物物相分析以及腐蚀电化学实验的方法，分析该法兰发生腐蚀的原因。结果 A105制法兰与316L制密封圈存在较强的电偶腐蚀倾向。结论 电偶腐蚀是导致法兰面严重腐蚀的主要原因，另外，液相管线停用前放空不彻底，法兰底部存在积液，导致气液界面位置叠加发生水线腐蚀。根据法兰腐蚀原因提出了针对性的防腐建议。

Corrosion Causes of Liquid Phase Pipeline Flanges for Separators of a Gas Field in the West of China

The work aims to solve the severe corrosion on the liquid phase outlet pipeline flange for a separator of a gas field in the western region. An analysis was conducted to ascertain the causes of the flange corrosion. This analysis involved macroscopic morphology observation, non-destructive testing, chemical composition analysis, metallographic structure analysis, mechanical performance testing, microscopic morphology observation of the corrosion area, phase analysis of corrosion products, and corrosion electrochemical experiments. The findings suggested that the A105 flange and the 316L sealing ring materials were highly susceptible to galvanic corrosion. In conclusion, galvanic corrosion is the primary contributor to the severe corrosion observed on the flange surface. Moreover, inadequate venting of the liquid phase pipeline prior to shutdown also leads to liquid accumulation at the flange base, resulting in compounded waterline corrosion at the gas-liquid interface. Based on the identified causes of flange corrosion, specific anti-corrosion recommendations are proposed.