According to cathodic protection principles, what factor increases the rate of corrosion?

The rate of corrosion can be influenced significantly by the amount of current supplied in a cathodic protection system. When a sufficient amount of current flows to the surface of a metal structure that is susceptible to corrosion, it can enhance the electrochemical reactions that contribute to the corrosion process. Specifically, a higher current can lead to an increased rate of electrolysis, which may accelerate the dissolution of metal oxides and promote the corrosion of the base metal.

Additionally, current is a key factor in cathodic protection systems as it not only combats corrosion but can also, if excessive, create conditions that could lead to localized corrosion, such as hydrogen embrittlement at high current densities. Therefore, understanding the balance and control of current is crucial in managing corrosion rates effectively within protected systems.

While the other factors—voltage, resistance, and humidity—can also impact corrosion processes, they do so in different contexts or indirect ways. For example, voltage can influence the current, as ohm’s law relates the two, but it does not directly increase the corrosion rate like current can. Resistance plays a role in controlling the efficiency of current flow, but again, it does not inherently increase corrosion rates. Humidity can create an environment that supports corrosion but