西南某成品油X60钢管道内壁的模拟腐蚀行为分析  

Analysis of Simulated Corrosion Behavior on the Inner Wall of Refined Oil X60 Steel Pipelines in Southwest China

作　　者：陈思雅 张晨 熊道英 王垚 CHEN Siya;ZHANG Chen;XIONG Daoying;WANG Yao(South China Branch,PipeChina Co.,Ltd.,Guangzhou 510000,China)

机构地区：[1]国家石油天然气管网集团有限公司华南分公司,广东广州510000

出　　处：《材料保护》2023年第11期181-192,共12页Materials Protection

基　　金：广东省重点领域研发计划项目“油气储运重大基础设施灾害防御关键技术及装备研发与示范”(2019B111102001)资助。

摘　　要：为了探索成品油管道内壁在汽/柴油中的腐蚀行为,将X60钢试样在模拟西南某成品油管线服役环境下浸泡7 d,采用腐蚀失重试验、扫描电镜(SEM)、3D形貌表征、应力应变分析、开路电位等方法就机械杂质、含水率、管道缺陷对X60管线钢内腐蚀行为的影响进行了实验室研究。结果表明:机械杂质沉积时管道内的腐蚀速率影响是无机械杂质沉积条件下的7倍左右,机械杂质沉积存在的环境比成品油介质对管道的腐蚀造成的危害更大;随着含水率(0~1%)的升高,腐蚀速率加快,点蚀数量增加,管道内腐蚀主要为电化学腐蚀并伴随有Cl^(-)造成的点蚀,母材在含自来水1%的汽油中最大腐蚀速率为0.047 mm/a;缺陷的存在会提高管线钢的腐蚀速率,平滑凹陷主要表现为应力腐蚀,凹陷深度为9%时,凹陷中心局部腐蚀严重,含水率1%时的腐蚀速率为0.0752 mm/a;焊接接头主要表现为电偶腐蚀,以局部腐蚀和点蚀为主,热影响区的腐蚀倾向严重,含水率1%时的腐蚀速率为0.08035 mm/a。To explore the corrosion behavior on the inner wall of refined oil pipelines in gasoline and diesel,X60 steel samples were immersed for 7 d in a simulated service environment of refined oil pipelines in Southwest China.Laboratory research was conducted on the effects of me-chanical impurities,water content and pipeline defects on the internal corrosion behavior of X60 pipeline steel using methods such as corrosion weight loss test,scanning electron microscope(SEM),3D morphology characterization,stress-strain analysis,and open circuit potential(OCP).Results showed that the internal corrosion rate of the pipeline under conditions with mechanical impurity deposition was approximately seven times higher than that in deposition-free conditions.Furthermore,environments with mechanical impurities posed greater corrosion risks on pipeline than refined oil media.As water content increased from 0 to 1%,there was a corresponding acceleration in the corrosion rate,an increase in the incidence of pitting corrosion,the internal corrosion of the pipeline was mainly electrochemical corrosion accompanied by pitting corrosion caused by Cl^(-).The maximal corrosion rate of the base material observed in gasoline containing 1%(volume fraction)tap water was 0.047 mm/a.The analysis of pipeline defects showed that the existence of defects increased the corrosion rate of pipeline steel.The smooth dent was primarily characterized by stress corrosion.When the depth of the dent reached 9%,severe localized corrosion was observed at the center of the dent.With a water content of 1%,the corrosion rate was measured to be 0.0752 mm/a.Welded joints were primarily characterized by galvanic corrosion,with localized corrosion and pitting being predominant,and the heat-affected zone(HAZ)exhibited a significant tendency for corrosion.When the water content was 1%,the corrosion rate was measured to be 0.08035 mm/a.

关 键 词：X60钢 腐蚀失重 机械杂质 含水率 平滑凹陷 焊接接头 

分 类 号：TE988[石油与天然气工程—石油机械设备]