Electrochemical corrosion behavior of aluminum conductor under current-carrying condition in a simulated atmospheric environment

Purpose The purpose of this paper is to study the corrosion behavior of aluminum under the current-carrying condition. It aims to investigate the corrosion electrochemical characteristics of aluminum under the influence of the applied electric current and the self-generated magnetic field. Design/methodology/approach To study the influence of the current-carrying condition, a home-made electrochemical device was used to analyze the kinetic characteristics of the atmospheric corrosion of aluminum by means of potentiodynamic polarization, electrochemical impedance spectroscopy and chronoamperometry. Scanning electron microscopy and X-ray diffraction were used to investigate the morphological characteristics and main phase compositions of corrosion products. Moreover, the atmospheric corrosion mechanism of aluminum under current-carrying condition was analyzed. Findings The passage of a direct current (DC) through a metal conductor generates a self-generated magnetic field. The presence of this magnetic field accelerates the diffusion of oxygen, thereby accelerating the electrochemical cathodic reaction. The corrosion products film, under the influence of the electric current, exhibit a loose and layered structure, which facilitates the intrusion of Cl− and accelerates the corrosion of aluminum. Research limitations/implications The research on the atmospheric corrosion of aluminum in the power grid may not fully cover the complex and variable environmental factors. For example, in the actual atmospheric environment, there are comprehensive influences such as the temperature fluctuations between day and night. Practical implications This study provides theoretical guidance for predicting the service life of metal components in the power transmission grid under working conditions. Originality/value In the investigation of aluminum’s atmospheric corrosion, the influences of the applied DC current and the self-generated magnetic field were introduced for the first time.