bimetallic corrosion

1. n. [Enhanced Oil Recovery]
A type of corrosion in which two different metals are placed in contact in a corrosive environment. A small electric current flows from one piece of metal to the other, accelerating the corrosion rate of the more reactive of the two metals. Bimetallic corrosion is sometimes found when new pipe is added to old pipelines. The old pipeline covered by oxide and rust is cathodic to the new pipe, thus accelerating the corrosion rate in the new pipe. Another type of bimetallic corrosion is ringworm corrosion.