论文部分内容阅读
黄河下游冲击平原建设使用的某X60管线已发生多起由土壤外腐蚀造成的穿孔漏油事故,现场检测发现多处管道阴极保护不到位、防腐涂层完全破损,给管道安全运行带来巨大威胁。本文采用光学相机、3D成像金相显微镜、扫描电镜等方法系统分析观察了X60管线钢在黄河下游平原高盐碱性土壤中腐蚀的宏观、三维立体与微观形貌,结果表明X60管线钢在黄河下游平原高盐碱性土壤中发生了严重的腐蚀,腐蚀主要为全面的不均匀腐蚀,并伴有严重的局部坑蚀;无阴极保护的裸露管道蚀坑深度发展速率达0.7167 mm/a,结合管道腐蚀余量计算得裸露管线钢的腐蚀寿命仅为8.4年。
Several X60 pipelines used in the impact plains of the lower reaches of the Yellow River have experienced many perforation and oil leakage accidents caused by soil erosion. Field inspection found that cathodic protection was not in place in many pipelines and the anti-corrosion coating was completely damaged, posing a huge threat to the safe operation of the pipeline . In this paper, the macro, three-dimensional and micro-morphology of X60 pipeline steel in the high saline alkaline soil in the lower Yellow River were systematically analyzed by using optical camera, 3D imaging microscope and scanning electron microscope. The results show that the X60 pipeline steel has good corrosion resistance in the Yellow River Severe corrosion occurred in the high salinity and alkaline soil in the lower reaches of the plains. The corrosion mainly consisted of non-uniform corrosion with severe local pitting corrosion. The development speed of the corrosion depth of bare pits with no cathodic protection reached 0.7167 mm / a, The corrosion allowance of pipeline is calculated to be barely 8.4 years.