Corrosion reaction is a consequence of metal’s reaction with the environment. Reactions like this are causing huge construction maintenance costs. The most common type of corrosion is electrochemical corrosion, which includes stray current corrosion – it is electrochemical corrosion that occurs mostly on railway structures in urban areas. DC (direct current) transit system operators are using rails as current returning path from the vehicle to the substation. When proper drainage of the track isn’t assured, surrounding media in which rails are embedded becomes an electrolyte which leads to stray current leakage and development of corrosion. At the part where stray current is entering to the rail, rail in under cathodic protection. This is cathodic zone of rail. Corrosion occurs on parts where current is leaking from the rail, in anodic zone where deterioration of material under stray current corrosion effect can be notice.
Different type of measures for reducing stray current leakage at the source are used among operators. At that way anodic reaction of metal (rails) with the electrolyte (media in which rails are embedded) can be stopped.

electrochemical corrosion, stray current, anodic and cathodic zone, tram track