The effect of ozone on wet atmospheric corrosion of aluminium of high-voltage lines

One of the factors influencing traffic safety is the uninterrupted power supply of interlocking devices. As a rule transmission of electric energy is carried out using aluminum wires. In order to assess the reliability of power lines in the work, research was carried out on the influence of ozone on corrosion of aluminum in a humid atmosphere and acidic medium. It was found that the presence of oxygen dissolved in acetic acid leads to anode currents increase, while at crossover ozone, cathode currents increase by an order of magnitude and 2-3 times the anode decreases; the corrosion potential of an Ecor shifts to the positive side at 0.15V. The decrease in the density of anode currents in the presence of ozone proceeds due to the growth of the thickness of the aluminum oxide film. According to the Auger-spectra, the film is increased by 3-4 times compared with the nonzonized medium, due to which the corrosion resistance of aluminum К m increases from 0.066 to 0.025 g/(m 2 ·h). The rate of formation of oxides depends on the concentration of oxidants in the solution, and on their oxidative activity. According to calculations of thermodynamic factors that determine the preferred route of oxidation, the probability of formation of oxides in the presence of ozone is significantly higher. Local destruction of the protective layer occurs mainly in defective places and places of local increase in pH of the electrode layer. Investigation of the cyclic polarization of a sample of aluminum, pre-cathode activated by a current of 1 mA/cm 2 density, showed the presence of hysteresis, which decreases in the next 2-3 cycles. In this case, the exterior of the aluminum shifts to (0.10 ÷ 0.15) V is more positive and the corrosion rate is reduced, which indicates the formation of an oxide film in which irreversible changes occur. The change in the inclination of the polarization curves indicates that the cathodic reaction is delayed and is associated with the change in the structure of the surface layer of the electrode and the diffusion restrictions of ozone recovery.