Galvanic Series (Sea Water Environment)
Metals higher in the galvanic series (Anodic) are generally more reactive and more susceptible to corrosion.
In general, the closer metals are in the galvanic series, the less the galvanic effects will be. The farther apart metals are in the galvanic series, the greater the galvanic effects will be (more susceptible to corrosion).
For design purposes, when metals are to be joined, the selection should use metals with compatible galvanic potential (closer together on the galvanic series).
This method of selection will generally reduce the susceptibility to galvanic corrosion.
When joining dissimilar metals, (metals separated a greater distance on the galvanic series), an electrically insulating barrier should be provided.
Metals lower in the galvanic series (Cathodic) are generally less reactive and more resistant to corrosion.
The following galvanic series listing is quoted from MIL-STD-889B, N1.