off topic but interesting-- the process of bringing life back to the dead using electrical current is also called galvanizing and was the theme of the Frankenstein novel. Maybe thats what happened to Prince Harry.
Chemistry part, its the electromotive potential between elements that cause electron migration and "coating". How much depends on the formula of the steel, Fe/Cr/. On the periodic chart anything to the right of an element can give up electrons to any element to the left. If a strong oxidizing or reducing agent is also present the "flow" of electrons can be increased or decreased , O2, sulfuric acid etc.
Cadmium cadmium can also be used in place of Zn, but is special purpose. "Nickel" plated cartridge cases were really cadmium plated, until it was found out that the toxic effects were cumulative similar to mercury, lead.
