About Galvanic Corrosion

Galvanic corrosion occurs when dissimilar metals are in electrical contact in water especially salt water. As a small electrical current flows from one metal to the other, one metal will begin corroding faster than normal (the anode) and the other will corrode more slowly than normal (the cathode). The result is that the anode material will be eaten away much more quickly than the cathode material.

Through sound design and material choice galvanic corrosion can be reduced. This involves avoiding dissimilar material combinations. In addition, a dissimilar metal may be purposely used as a ‘sacrificial anode’. This is done by purposely creating a corrosive situation where the metal being corroded faster is simply a meaningless block of metal (often zinc) thus resulting in the important materials corroding more slowly.

For more detailed information on galvanic and other forms of corrosion we recommend visiting www.corrosion-doctors.org.