Question

Is rust a galvanic corrosion?

Answer 1

Corrosion is the process of solving degradation of metal by the action of gases and moisture present in the atmosphere due to the formation of chemical compounds.

Complete step-by-step answer: - Galvanic corrosion is also known as bimetallic corrosion or dissimilar corrosion. In this process, metals are placed within an electrolyte with another metal. Due to the involvement of two metals, it is called bimetallic corrosion.
- The two metals are needed to be electrochemically different from each other that is why it is denoted as dissimilar corrosion.
- Every galvanic cell functions due to potential difference. This potential difference causes the flow of electrons within the cell. On the basis of the oxidation potential of metals, an electrochemical series is arranged.
- The elements at the top of the series are more easily oxidized thus there are major chances of losing the electrons. The entire mechanism depends upon the oxidation potential of the two metals. The difference in the oxidation potential of the two metals is the driving force of galvanic corrosion.
- When the metal electrodes are placed in an electrolyte and the circuit is completed by joining the metal through a wire then this is the point where the process of corrosion takes place. The activity of the metals is based on the electrochemical series. Thus, the flow of current is from more active metal to less active metal.
- For example, the process of rusting.

Note: Corrosion usually refers to a metal degrading in the presence of oxygen and moisture whereas galvanic corrosion involves degeneration of one metal and protection of another metal placed with the precious metal.