Galvanic Corrosion Risk Calculator

Galvanic Corrosion Risk Calculator

Mixing dissimilar metals in a wet or humid environment risks galvanic corrosion - this calculator assesses that risk from each metal's standard galvanic series potential.

Potential Difference = |Metal 1 Potential - Metal 2 Potential|

Example

Two metals with potentials of -0.66V and -0.20V (values from a standard galvanic series reference table):

Potential Difference = 0.46V → High galvanic corrosion risk

How Galvanic Corrosion Works

When two dissimilar metals are in electrical contact in the presence of an electrolyte (water, especially salt water, is a strong electrolyte), the less noble ("more active") metal on the galvanic series corrodes more aggressively, sacrificially protecting the more noble metal - the greater the potential difference between the two metals, the more aggressive this effect becomes.

Deliberate Use vs. Accidental Problem

This same principle is deliberately exploited in sacrificial anodes - like the zinc anodes commonly bolted to boat hulls and underwater structures specifically to corrode first and protect more critical metal components - but it's an unwanted problem when it occurs accidentally in fasteners, fittings, or structural connections that unintentionally mix dissimilar metals without proper isolation.