Question

Of the following, when and/or where is galvanic corrosion most likely to occur?

1) When two dissimilar metals are in contact with each other in the presence of an electrolyte
2) When two similar metals are in contact with each other in the presence of an electrolyte
3) When a metal is in contact with a non-metal in the presence of an electrolyte
4) When a metal is exposed to air and moisture

Answer 1

Galvanic corrosion occurs most likely when two dissimilar metals are in contact in the presence of an electrolyte. It is an electrochemical process that can be prevented using cathodic protection or protective coatings.

Step-by-step explanation:

Galvanic corrosion is most likely to occur when two dissimilar metals are in contact with each other in the presence of an electrolyte, as described in scenario 1.

This form of electrochemical corrosion takes place because the different metals have different electrode potentials, resulting in one metal (the anode) corroding faster than it would alone, while the other (the cathode) remains protected.

In a classic example, if iron is in contact with a more corrosion-resistant metal like copper, the copper acts as a cathode and accelerates the corrosion of iron at the anode. Corrosion prevention methods include cathodic protection, using protective coatings, and the application of more easily oxidized metals as sacrificial anodes to protect the main metal.