Corrosion due to stray currents

Corrosion due to stray current—the metal is attacked at the point where the current leaves. Typically, this kind of damage can be observed in buried stmctures in the vicinity of cathodic protection systems or the DC stray current can stem from railway traction sources. 

Protection against corrosion due to stray currents of d. c. installation [VDE specification]) (in German)... 

A metallic structure embedded in the soil can suffer corrosion due to stray currents the humidity of the soil acts as the electrolyte. The higher the mineralisation of the humidity, the more severe the corrosion [2]. 

---