Effect of oxygen on aluminum corrosion in pure water

When aluminum is immersed in pure water, hydrogen evolves at the cathode in pure water where there is no oxygen, although hydrogen dose not evolve in pure water with oxygen present. Based upon the fact, the effect of hydrogen evolved at the cathode on aluminum corrosion was investigated in relation to oxygen concentration in pure water in the present study. The length of incubation period, which is the time from the beginning of the corrosion test to a sharp increase in the corrosion amount, is almost constant regardless of the oxygen concentration. However, the corrosion period which begins right after the incubation period and continues until the saturation point is reached varies depending on the oxygen concentration. When the oxygen concentration is low, the amount of hydrogen at the cathode is large and small pits through the barrier layer spread rapidly over the entire surface, resulting in increase in the corrosion amount. From these results, it is thought that the hydrogen evolved by the cathode reaction greatly affects the deterioration of barrier layer and the aluminum corrosion.