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.
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