The electrochemical process that occurs when two metals with different electrode potentials are electrically connected and immersed in a conductive electrolyte. The metal with the more negative potential becomes the anode and corrodes, while the more noble metal acts as the cathode and is protected. This mechanism drives both galvanic corrosion and the function of sacrificial anodes in cathodic protection systems.
We have severe galvanic action happening where the carbon steel pipe ties into the stainless valve.
Do not mix it up with
- Galvanic corrosion: Galvanic action is the electrical mechanism itself, whereas galvanic corrosion is the resulting damage to the anodic metal.
Related terms
Galvanic corrosion
Accelerated corrosion of the more active metal when two dissimilar metals touch in a shared electrolyte.
Galvanic series
Ranking of real metals and alloys by their measured potential in a given electrolyte, usually seawater.
Sacrificial anode
Block of a more active metal such as magnesium, zinc or aluminum that corrodes to protect connected steel.
Electrolyte
Conductive medium such as soil, seawater or concrete pore water that carries ionic current between anode and cathode.