Metals in Seawater - Galvanic Series

Galvanic series of metals in seawater at 25°C (77°F). The list is ordered from most noble (top) to most active (bottom), helping predict galvanic corrosion behavior when different metals are in contact in seawater.

Galvanic Series in Seawater at 25°C (77°F)

The galvanic series ranks metals and alloys based on their electrode potential in seawater. Metals higher in the series (more noble) will be protected, while metals lower in the series (more active) will be sacrificed in galvanic corrosion.

Key Principles:

  • Metals closer together in the series have less galvanic potential difference
  • Larger separation in the series indicates greater galvanic corrosion risk
  • The position of metals can change based on whether they are in passive or active state
RankMetal/AlloyStatus
1PlatinumMost Noble
2Gold
3Graphite
4Titanium
5Silver
6Chlorimet 3 (62 Ni + 18 Cr + 18 Mo)
7HASTELLOY® alloy C (62Ni + 17 Cr + 15 Mo)
8INCONEL® alloy 625
9INCONEL® alloy 825
10Stainless steel, type 316Passive
11Stainless steel, type 304Passive
12Stainless steel, type 410Passive
13Monel alloy 400
14INCONEL® alloy 600Passive
15Nickel 200Passive
16Copper alloy C71500 (Cu 30% Ni)
17Copper alloy C23000 (red brass 85% Cu)
18Copper alloy C27000 (yellow brass 65% Cu)
19HASTELLOY® alloy B
20INCONEL® alloy 600Active
21Nickel 200Active
22Copper alloy C46400
23Copper alloy C46500
24Copper alloy C46600
25Copper alloy C46700 (naval brass)
26Tin
27Lead
28Lead-Tin solders
29Hastelloy A
30Stainless steel, type 316Active
31Stainless steel, type 304Active
3250-50 lead tin solder
33Stainless steel, type 410Active
34Cast iron
35Wrought iron
36Low carbon steel
37Aluminum alloy 2117
38Aluminum alloy 2017
39Aluminum alloy 2024
40Cadmium
41Aluminum alloy 5052
42Aluminum alloy 3004
43Aluminum alloy 3003
44Aluminum alloy 1100
45Aluminum alloy 6053
46Galvanized steel
47Zinc
48Magnesium alloys
49MagnesiumMost Active

Galvanic Corrosion Prevention Tips

  1. Avoid dissimilar metals: Use metals close together in the galvanic series
  2. Isolate metals: Use non-conductive materials between different metals
  3. Use cathodic protection: For important structures, use sacrificial anodes or impressed current systems
  4. Apply coatings: Paint or other protective coatings can reduce galvanic effects
  5. Control electrolyte: Reduce salinity and increase pH when possible
  6. Consider surface area: Minimize the cathode/anode area ratio to reduce current flow
Metals in Seawater - Galvanic Series | MEPKit Engineering Tools | MEPKit