Galvanic Corrosion
Accelerated corrosion of the more reactive of two different metals in electrical contact within an electrolyte.
Unit
mm/year
In depth
The couple forms a short-circuited galvanic cell, so the more reactive metal becomes the anode and dissolves faster than it would alone, while the less reactive one is protected. The effect worsens when a small anode is paired with a large cathode.
Examples in the real world
Steel bolts corroding rapidly in an aluminium hull; copper pipework accelerating attack on galvanised fittings.