In galvanic corrosion, which factor primarily influences the rate of corrosion?

The rate of galvanic corrosion is fundamentally influenced by the difference in electrode potentials between the anode and cathode materials involved in the corrosion process. When two dissimilar metals are in contact in the presence of an electrolyte, the one with the lower electrode potential (the anode) will corrode faster than the one with the higher electrode potential (the cathode). This potential difference drives the electrochemical reactions that result in corrosion.

As such, a greater disparity in electrode potentials between the metals will lead to an increase in the galvanic current, thereby accelerating the corrosion rate of the anodic material. Hence, understanding the electrode potentials of different materials is crucial in predicting and mitigating galvanic corrosion. While factors like surface area, electrolyte temperature, and thickness can play roles in the overall corrosion process, none are as critical in establishing the intrinsic driving force for galvanic corrosion as the difference in electrode potentials.