Bimetallic corrosion is corrosion that occurs due the the direct or indirect contact between two metals. These metals, called coupling metals, are usually different in property and composition. This type of corrosion can be observed in a number of different environments. However, although this type of corrosion may sound detrimental (and usually is), there are instances where this naturally occurring process is encouraged and used. Here we'll take a look at bimetallic corrosion in-depth.