Causes Analysis on Corrosion of Steel-reinforced Aluminum Twisted Wires Used for Electrical Cables

Serious corrosion appeared in steel-reinforced aluminum twisted wires used in one power transmission line project before setting up. Physical and chemical tests, such as macroscopic observation, chemical composition analysis, scanning electron microscope analysis, energy spectrum analysis and infrared spectral analysis, were carried out to analyze the corrosion cause and corrosion mechanism. The results show that the sulfur compounds in the air were the main source of SO2-4 in the corrosion product. Second-phase particles FeAl3 dispersed in the matrix accelerated the corrosion process of the wire. It was recommended that the content of iron element of aluminum twisted wires should be controlled to promote the corrosion resistance, and the aluminum twisted wires should be protected from the rain and wet air in the process of transportation or storage.