Stray Current Corrosion of Aluminum Electrolysis System

The aluminum smelting process requires large amounts of electricity, and the leakage of current from aluminum cells is through the earth forming stray current. Stray current induce corrosion on metallic pipeline and steel in concrete, leading to severe localized attack. Stray current corrosion in the metallic pipeline is totally similar to the classic; stray current rarely can corrosive consequences on steel in concrete, because steel in alkaline and chloride-free concrete is passive, and the high electrical resistivity of concrete. If the driving voltage is increased, the steel embedded in the concrete can be induced to corrode. Stray current corrosion of steel in concrete under single load can be divided into accelerated corrosion and steady development in 2 stages. Stray current can obviously increase the transmission rate of chloride ion into concrete and reduce the time of chloride ion penetrating the concrete to the surface of the steel bar. (paper)