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Galvanic action between different metals

Galvanic Series of Metals in Seawater ex Professional Boatbuilder Number 100 April / May 2006

Each metal has a unique voltage potential - Half-cell reference electrode, silver / silver chloride listed below: The voltage difference between any two represents the potential for corrosion.

 

grade   Metals and Alloys

Corrosion Potential

Range in Volts

A L N Magnesium and Magnesium Alloys -1.60 to -1.65
N e o Zinc -0.98 to -1.03
O a b Galvanised Steel or Galvanised Wrought Iron NA to NA
D s l Aluminium Alloys -0.76 to -1.00
I t e Cadmium -0.70 to -0.73
C Mild Steel -0.60 to -0.71
Wrought Iron -0.60 to -0.71
Cast Iron -0.60 to -0.71
13% Chromuim Stainless Steel, Type 410 [Active in still water] -0.46 to -0.58
18 / 8 Stainless Steel, Type 304 [Active in still water] -0.46 to -0.58
Ni-Resist -0.46 to -0.58
18.8, 3% Mo Stainless Steel, Type 316 [Active in still water] -0.43 to -0.54
Inconel (78% Ni, 14.5 %Cr, 6%Fe [Active in still water]) -0.35 to -0.46
Aluminium Bronze (92% Cu, 8% Al) -0.31 to -0.42
Naval Brass (60% Cu, 39% Zn) -0.30 to -0.40
Yellow Brass (65% Cu, 15% Zn) -0.30 to -0.40
Red Brass (85% Cu, 15% Zn) -0.30 to -0.40
Muntz Metal (60% Cu, 40% Zn) -0.30 to -0.40
Tin -0.31 to -0.33
Copper -0.30 to -0.57
50-50 Lead - Tin Solder -0.28 to -0.37
Admiralty Brass (71% Cu, 28% Zn, 1% Sn) -0.28 to -0.36
Aluminium Brass (76% Cu, 22% Zn, 2% Al) -0.28 to -0.36
Manganese Bronze (58.5% Cu, 39% ZN, 1% Sn, 1% Fe, 0.3% Mn) -0.27 to -0.34
Silicon Bronze (96% Cu max, 0.8% Fe, 1.5% Zn, 0.2% Sn, 0.75% Mn, 1.6% Sn)
-0.26 to -0.29
Bronze, Composition G (88% Cu, 2% Zn, 10% Sn) -0.24 to -0.31
Bronze, Composition M (88% Cu, 3% Zn, 6.5% Sn, 1.5% Pb) -0.24 to -0.31
13% Chromium Stainless Steel, Type 401 Passive -0.26 to -0.35
90% Cu - 10% Ni -0.21 to -0.28
75% Cu - 20% Ni - 5% Zn -0.19 to -0.25
Lead -0.19 to -0.25
70% Cu - 30% Ni -0.18 to -0.23
Inconel (78% Ni, 13.5% Cr, 56% Fe) Passive -0.14 to -0.17
C Nickel 200 -0.10 to -0.20
A 18/8 Stainless Steel, Type 304, Passive -0.05 to -0.10
T 70% Ni - 30% Cu Monel 400, K-500 -0.04 to -0.14
H M N 18.8  - 3% Mo Stainless Steel, Type 316, Passive 0.00 to -0.10
O o o Titanium -0.05 to +0.06
D s b Hasteloy C -0.03 to +.08
I t l Platinum +0.19 to +0.25
C e Graphite +0.20 to +0.30