Corrosion control — galvanic series

Galvanic series in seawater · vs SCE

The classical ladder every corrosion engineer pins on a wall. Pick an anode + cathode pair to see the EMF gap and galvanic-couple risk class. The bigger the EMF separation, the worse the bimetallic corrosion of the anode.

Couple analyser

Anode (anticipated)
Cathode (anticipated)
Result
EMF gap+0 mV vs SCE
Risk levelNEGLIGIBLE
Anode (active)Mild / carbon steel
Cathode (noble)
Risk classes (after Roberge / NACE):
< 50 mV
negligible
50-150 mV
low
150-300 mV
moderate
300-600 mV
high
> 600 mV
severe
For the full quantitative model — area-ratio acceleration, electrolyte resistivity, Tafel mixed potential — use/console/galvanic.

Series ladder · seawater · 25 °C · vs SCE

-1500-1000-5000+500↑ Active (anode)↓ Noble (cathode)E (mV vs SCE) — seawater 25 °CMagnesium pureMagnesium alloys (AZ31)Zinc (pure)Zinc galvanizing coatingZinc alloy anodes (Z2)Beryllium (Be)Aluminum 1100 (pure)Aluminum 5xxx (Mg)Aluminum 6xxx (MgSi)Aluminum 7xxx (Zn)Aluminum 2xxx (Cu)Aluminum sacrificial anode (Al-Zn-In)Cadmium (Cd) platingWrought ironMild / carbon steelanode →Cast iron (gray)Cast iron (ductile)Cr-Mo low-alloy (P11/P22)Lead (Pb) and Pb-Sn soldersTin (Sn)Tin-bronze13 Cr / 410 stainless (active)17-4 PH stainless (active)Yellow brass (C26000)Aluminum brass (C68700)Admiralty brass (C44300)70/30 Cu-Ni (C71500)90/10 Cu-Ni (C70600)Aluminum bronze (C95400)Manganese bronzeCopper (Cu)Lead-tin solder410 / 416 stainless (passive)Stainless 316 (active)Nickel + Monel 400Silver brazing alloysInconel 600Stainless 304 / 304L (passive)Stainless 316 / 316L (passive)Stainless 317L (passive)904L super-austenitic254 SMO super-austenitic2205 duplex2507 super-duplexInconel 625 / 825Inconel 718 (aged)Inconel 690Hastelloy B-2 / B-3Hastelloy C-276 / C-22 / C-2000Alloy 59 / 686Silver (Ag)Titanium CP Gr 2Titanium-Pd Gr 7Ti-6Al-4V Gr 5Graphite (carbon)Carbon-fiber compositeStellite 6 (Co-Cr-W)Mercury (liquid)Platinum (Pt)Palladium (Pd)Gold (Au)
Sources: ASM Vol 13 Corrosion · Roberge "Handbook of Corrosion Engineering" Ch. 6 · NACE Pub 7L107 · ranges reflect heat-to-heat scatter in flowing seawater. For galvanic-acceleration computation (area ratio, IR drop, Tafel mixed-potential) see the galvanic factor tool.