输油站场工艺管道腐蚀失效行为分析研究

Corrosion Failure Behavior Analysis and Research of Process Pipeline in Oil Transporta ⁃tion Station

为了分析某输油站场管道静置段腐蚀穿孔原因,明确腐蚀类型及腐蚀机理,采用理化检验和电化学分析等手段对失效管段进行研究。结果表明:管材本身的各项指标满足规范要求,失效主要原因是静置段出现了油水分层现象,水中含有大量的腐蚀性介质,导致管道4点至8点钟方向形成电化学腐蚀,腐蚀类型以CO2和H2S共存环境下的酸性腐蚀为主,腐蚀机理为水解催化作用和氧浓差腐蚀原电池;此外,腐蚀产物膜在一定程度上对腐蚀过程起到自加速的作用。该研究结果可为今后的管道防腐和延长管道使用寿命提供理论依据。

In order to analyze the causes of corrosion and perforation in a pipeline standing section of an oil transportation station and clarify the corrosion type and corrosion mechanism,physical and chemical examination and electrochemical analysis are used to study the failed pipeline section.The results show that indexes of the pipe itself meet the requirements of the specification.The main reason for the failure is that the oil and water are stratified in the standing section,and the water contains a large amount of corrosive medium,resulting in the electrochemical corrosion of the pipeline from 4 to 8 o'clock.The corrosion type is mainly acid corrosion under the coexistence of CO2 and H2S,and the corrosion mechanism is hydrolysis catalysis and oxygen concentration difference corrosion cell.In addition,the corrosion product film can accelerate the corrosion process to a certain extent.The research results can provide a theoretical basis for future pipeline corrosion protection and prolonging service life.