摘要
参考一维模型,以变径管道流体为研究对象,提出了一个新的二维浓差腐蚀模型,并采用数值方法对该模型进行求解.结果表明:当不考虑浓差腐蚀时,管道壁面氧浓度越大的部位,腐蚀电位和腐蚀电流均越大,而氧浓度越低的部位,腐蚀电位和腐蚀电流均较低;但当考虑浓差腐蚀时,电位将产生极化,原来腐蚀电位较高的部位将产生阳极极化,同时腐蚀速度亦有所降低;而原腐蚀电位较低的部位将产生阴极极化,同时腐蚀电流也有所增大.根据这一结果可以更准确地预测各点的腐蚀速度,并且由此初步揭示了浓差腐蚀的机制,即此机制有一种去极化的作用,在此作用下,腐蚀区域的腐蚀电位和电流都有均匀化的趋势.
A new two-dimensional differential concentration corrosion model was proposed based on one-dimensional model,considering fluid flow in a variable diameter pipeline as a study object.The model was solved by the numerial method.Results show that when the differential concentration corrosion is not taken into account,the calculated corrosion potential and the corrosion current of the parts on the pipe wall are higher and there exists a high oxygen concentration near them in the pipe,and vice versa.However,when considering the concentration corrosion in the simulation,the parts with higher corrosion potential can produce the anode polarization,causing the decrease of the corrosion rate.Similarly,the cathode polarization can occur on the parts with lower corrosion potential,increasing the corrosion rate and the current.Based on it the corrosion rate of each point can be accurately predicted and the mechanism of the concentration corrosion is preliminarily revealed,that is,the mechanism has a depolarization effect.Thus,the corrosion potential and the current in the corrosion area have a trend of homogenization.
作者
刘英伟
张洋
Liu Yingwei;Zhang Yang(College of Materials Science and Chemical Engineering, Harbin Engineering University, Harbin 150001, China)
出处
《东南大学学报（自然科学版）》
EI
CAS
CSCD
北大核心
2020年第3期507-515,共9页
Journal of Southeast University：Natural Science Edition
基金
中央高校基础科研基金资助项目(HEUCFJ171005).
关键词
腐蚀
浓差腐蚀
极化
浓差宏电池
管道流体
corrosion
differential concentration corrosion
polarization
concentration difference macrocell
pipeline fluid
