Free Potentials for metals in seawater referenced to a zinc reference electrode
Metals at this end of the chart are 1100 mV
*corrosion resistant PLATINUM / TITANIUM 1050 mV
*the most "nobel" 1000 mV --------- ( or 1 volt )
*the least active 900 mV
LEAD / COPPER 800 mV
BRASS / BRONZE / STAINLESS 780 mV 600 500
STEELS / IORN 450 mV 400
ALUMINUM 350 mV and lower, depending on alloy 200 100
ZINC (same as reference electrode) 000 --------- ( 0 volts difference ) -100
Metals at this end of the chart
*corrodes easily MAGNESIUM -200 mV *are called least "nobel"
*are the most reactive
Note: these voltages are approximate, and are for each of these metals,
individually suspended in seawater. Combine any of these,
and a whole new number will result somewhere in between,
such as bolting a stainless steel skeg of considerable surface area to an aluminum hull.
The new hull free potential will
be between aluminum and stainless steel.