摘要
某厂的硫磺回收装置出口酸性气管道发生了异常失效。为了找到管道失效的根本原因,对失效试样进行了材料化学成分分析、力学性能分析、腐蚀孔的宏观及微观观察、能谱分析以及金相组织分析等一系列检验与分析,并对管道内壁进行了蓝点试验。结果表明,管道的化学成分、力学性能以及金相组织均符合相关标准要求。失效管道因错边和在进行水压试验后未对管道内壁进行吹扫而导致除盐水沉积在管道底部,使得氯离子在该处浓缩聚集,加之内壁整体钝化效果不好且有较多打磨痕迹,最终引发氯离子腐蚀穿孔。氯离子腐蚀是失效的根本原因;错边导致的除盐水堆积、进行水压试验后未对内壁进行吹扫以及内壁钝化效果不好是导致氯离子浓缩富集并产生破坏的重要原因。最后提出了解决措施,对此类装置的安全运行有指导作用。
An abnormal failure occurred in the outlet sour gas pipeline of a sulfur recovery unit in a certain plant.In order to find the root cause of the failure of the pipeline,a series of inspections and analyses were carried out on the failed samples,such as material chemical composition analysis,mechanical property analysis,macro and micro observation of corrosion holes,energy spectrum analysis and metallographic structure analysis,and blue dots were performed on the inner wall of the pipeline.The results show that the chemical composition,mechanical properties and metallographic structure of the pipeline meet the requirements of relevant standards.Desalted water is deposited on the bottom of the pipeline due to wrong edges and the failure to purge the inner wall of the pipeline after the water pressure test,which makes the chloride ions concentrate and accumulate there,and the overall passivation effect of the inner wall is not good and there is more polishing traces,and eventually lead to chloride ion corrosion perforation.Chloride ion corrosion is the root cause of the failure;the accumulation of desalinated water is caused by wrong edges,the failure to purge the inner wall after the hydraulic test and the poor passivation effect of the inner wall are important reasons that lead to the concentration and enrichment of chloride ions and their destruction.At the end of the thesis,the solutions are put forward,which have a certain guiding effect on the safe operation of such devices.
作者
马小明
席泽瑞
MA Xiaoming;XI Zerui(School of Mechanical and Automotive Engineering,South China University of Technology,Guangzhou 510640,China)
出处
《热加工工艺》
北大核心
2022年第8期146-150,154,共6页
Hot Working Technology
关键词
氯离子
腐蚀穿孔
沉积
浓缩
钝化
chloride
corrosion perforation
deposition
concentrating
passivation
