Corrosion characteristics of copper in magnetized sea water
(1. School of Materials Science and Engineering, Harbin Institute of Technology, Harbin 150001, China;
2. Institute of Electromagnetic and Electronic Technology, Harbin Institute of Technology, Harbin 150001, China)
2. Institute of Electromagnetic and Electronic Technology, Harbin Institute of Technology, Harbin 150001, China)
Abstract: The corrosion characteristics of copper in magnetic action system were investigated by mass loss method, electrochemical test, scanning electron microscopy (SEM) and energy analysis. It is found that the corrosion process of copper is influenced by magnetic field. The flow corrosion rate of copper decreases at the initial segment, then drives to gentle stage at the final segment. From electrochemical test, the corrosion rate of copper in the magnetized sea water is minimal compared with that in 3.5% NaCl solution and sea water. Electrochemical impedance spectroscopy (EIS) plots of copper in 3.5% NaCl, sea water and magnetized sea water are similar. However, EIS plot of copper in magnetized sea water shifts rightwards due to the effect of magnetic field on sea water. The corrosion process of copper in magnetized sea water is pitting corrosion. The surfaces of samples are finer in magnetized sea water relative to those in 3.5% NaCl solution and sea water. The corrosion products of copper include large amount of Cu element, O element and Cl element. Cu2O and CuCl2 are the primary products. This suggests that electromagnetic treatment has remarkable effect on the corrosion of copper.
Key words: copper; corrosion; magnetization; sea water