柠檬酸杆菌对X70管线钢腐蚀行为的影响  

Effect of Citrobacter on Corrosion Behavior of X70 Pipeline Steel

作　　者：张歌(译) 马璇 罗刚[2,3] 郑浩(编译) ZHANG Ge;MA Xuan;LUO Gang;ZHENG Hao(Shaanxi Institute of Electronic Industry,Xi’an 710065,China;Chinese National Engineering Research Center for Petroleum and Natural Gas Tubular Goods,Baoji 721008,Shaanxi,China;Baoji Petroleum Steel Pipe Co.,Ltd.,Baoji 721008,Shaanxi,China;Shaanxi Aerospace Times Navigation Equipment Co.,Ltd.,Baoji 721006,Shaanxi,China)

机构地区：[1]陕西电子工业研究院,西安710065 [2]国家石油天然气管材工程技术研究中心,陕西宝鸡721008 [3]宝鸡石油钢管有限责任公司,陕西宝鸡721008 [4]陕西航天时代导航设备有限公司,陕西宝鸡721006

出　　处：《焊管》2021年第11期50-57,共8页Welded Pipe and Tube

基　　金：国家重点研发计划项目“高应变海洋管线管研制”(项目编号2018YFC0310300)。

摘　　要：为了研究柠檬酸杆菌对X70管线钢的腐蚀机理,进行了X70管线钢在柠檬酸杆菌模拟土壤溶液中的腐蚀试验。采用场发射扫描电子显微镜(FESEM)和能谱仪(EDS)对不同腐蚀时间的金属表面形成的腐蚀产物和生物膜形貌进行了表征,同时采用开路电位(OCP)和电化学阻抗谱(EIS)对试验钢的电化学性能进行了测试。研究发现,在不含细菌的溶液中,底层钢表面形成了一层包括氧化铁、硫化物和碳基化合物在内的腐蚀产物保护膜,致使前21天的耐蚀性提高;在含有细菌的溶液中,电化学阻抗谱的结果表明,由于生物膜的形成,电荷转移电阻从第7天的400Ω·cm2明显减小至第21天的55Ω·cm2。分析表明,耐蚀性的降低与细菌新陈代谢产生的高浓度硫化物以及形成的相对致密的生物膜有关。此外,在含有细菌的溶液中试样具有更高的点蚀敏感性。In order to study the corrosion mechanism of X70 pipeline steel by Citrobacter,the corrosion test of X70 pipeline steel in citric acid bacteria simulated soil solution was carried out.The corrosion products and biofilm morphology formed on the metal surface at different corrosion times were characterized by field emission scanning electron microscopy(FESEM)and energy dispersive spectroscopy(EDS).At the same time,the electrochemical properties of the test steel were tested by open circuit potential(OCP)and electrochemical impedance spectroscopy(EIS).It is found that in the solution without bacteria,a protective layer of corrosion products including iron oxide,sulfide and carbon based compounds is formed on the surface of the underlying steel,which improves the corrosion resistance in the first 21 days.In the solution containing bacteria,the results of electrochemical impedance spectroscopy showed that due to the formation of biofilm,the charge transfer resistance decreased significantly from 400Ω·cm2 on the 7 th day to 55Ω·cm2 on the 21 st day.The analysis shows that the decrease of corrosion resistance is related to the high concentration of sulfide produced by bacterial metabolism and the formation of relatively dense biofilm.In addition,the sample has higher pitting sensitivity in the solution containing bacteria.

关 键 词：API X70微合金钢 微生物腐蚀 硫酸盐还原菌 生物薄膜 电化学阻抗谱 

分 类 号：TG178[金属学及工艺—金属表面处理]