Cathodic Protection Tester Practice Exam

In a galvanic system, should anodes be more reactive than the cathode or steel structure?

1. True

2. False

3. It depends on the environmental factors

4. Reactivity does not matter

The correct answer is: True

In a galvanic system, the principle relies on the electrochemical potential differences between the anode and cathode materials. For a galvanic anode to provide effective cathodic protection, it must indeed be more reactive than the cathode or the steel structure it is intended to protect. This greater reactivity ensures that the anode will corrode preferentially, sacrificing itself to protect the cathodic structure from corrosion. When the anode is more reactive, it establishes a galvanic couple, effectively driving electrons from the anode to the cathode. This electron flow mitigates the oxidation reactions happening at the steel structure, thereby protecting it from deteriorating due to corrosion. The more reactive nature of the anode ensures that it participates in the corrosion processes, preventing the cathode's metal from losing its integrity. Understanding this relationship is fundamental in the design and implementation of cathodic protection systems, as it guarantees that the protective measures are effective in extending the life of metal structures in various environments.