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