5. Cathodic Protection

5.8 Stray Currents Corrosion

This name is specifically given to corrosion caused by uncontrolled corrosion which originates from electrical railways, signalling systems, DC motors, DC welding, and general DC equipment.

Consider a DC transmit system as shown in the following figure. 

The current which leaks passes through the soils and picked up by a pipe in one area and discharges from another area which would be subjected to corrosion. The most appropriate solution in such a case would be to introduce a metallic band between the pipe and the negative terminal of the DC source.