What material would have the potential for the most galvanic corrosion if it was in contact with copper?

Galvanized steel is coated with a layer of zinc to prevent corrosion. When galvanized steel comes into contact with copper in a moist environment, a significant potential for galvanic corrosion arises. This happens because copper is more noble in the galvanic series, meaning it can readily accept electrons from the more electrochemically active zinc layer. As copper attracts electrons from the zinc, the zinc begins to corrode at an accelerated rate.

The likelihood of galvanic corrosion is influenced by the differences in the electrochemical potential of the metals involved. Since galvanized steel can lead to rapid depletion of zinc when paired with copper, it exhibits a high risk of galvanic corrosion. This is particularly concerning in applications where moisture is present, creating an electrolyte that facilitates the corrosion process.

Other materials, such as mild steel, stainless steel, and nickel, do not exhibit the same level of corrosion risk when in contact with copper. Mild steel may corrode, but it does not have the same galvanic reaction potential as galvanized steel due to the absence of a protective zinc layer. Stainless steel, while more noble than galvanized steel and mild steel, generally provides more resistance to corrosion overall. Nickel, being similarly noble to copper, does not create a strong galvanic couple with copper