复杂管道浓差腐蚀机制深入分析  

Further analysis of FAC mechanism of differential aeration corrosion of complex pipeline

作　　者：刘斌[1] 刘英伟[2] 王艳秋[2] LIU Bin;LIU Yingwei;WANG Yanqiu(School of Material Science and Engineering,Xinjiang University,Urumqi 830046,China;College of Materials Science and Chemical Engineering,Harbin Engineering University,Harbin 150001,China)

机构地区：[1]新疆大学材料科学与工程学院,新疆乌鲁木齐830046 [2]哈尔滨工程大学材料科学与化学工程学院,黑龙江哈尔滨150001

出　　处：《哈尔滨工程大学学报》2024年第5期1024-1032,共9页Journal of Harbin Engineering University

摘　　要：在关于管道的流动加速腐蚀研究中,浓差腐蚀这一机制一直被忽视,这是因为这种腐蚀的出现需要一定的条件,即流体中的氧的分布存在较大的差异。为了揭示这种机制的腐蚀过程,本文以复杂形状管道为例,采用数值模拟技术建立了关于浓差腐蚀的数学模型。将管道壁面附近的流体粘性底层作为研究对象,对其进行离散化处理,然后根据基尔霍夫第二定律建立了关于极化后的腐蚀电流的离散方程组,并对其进行求解,得到了浓差腐蚀条件下,离子导电层的电流分布。结果表明:浓差腐蚀会引起腐蚀电流的极大的改变,使管路各部位的腐蚀情况有所改变,如果不考虑浓差腐蚀,对管路的腐蚀情况会产生错误判断。Research on flow accelerated corrosion(FAC)of pipelines ignores the differential aeration corrosion mechanism because the occurrence of such corrosion requires certain conditions;the distribution of oxygen in the fluid is quite different.To reveal the corrosion process of this mechanism,a mathematical model of concentration difference corrosion is established using the numerical simulation technology for a complex-shaped pipe.The fluid viscous bottom layer near the pipe wall is taken as the research object and is discretized.Subsequently,according to Kirchhoff’s second law,a set of discrete equations about the corrosion current after polarization is established and resolved.Finally,the current distribution of the ionic conductive layer under the concentration corrosion condi-tion is obtained.The results show that differential aeration corrosion will cause a great change in the corrosion cur-rent,which will change the corrosion situation of various parts of the pipeline.If the concentration difference corro-sion is not considered,the corrosion situation of the pipeline will be misjudged.

关 键 词：腐蚀 浓差腐蚀 腐蚀机制 阳极极化 阴极极化 氧分布 管道流体 流动加速腐蚀 

分 类 号：TG171[金属学及工艺—金属表面处理]