Which of the following are corrosion control methods?

• A. Reducing dissolved oxygen
• B. Having a neutral or slightly basic pH
• C. Using corrosion inhibitors
• D. All of the above

Answer: (D)

Corrosion control relies on lowering the driving forces of corrosion and strengthening the metal surface against attack. Reducing dissolved oxygen slows the electrochemical reactions that drive corrosion, especially for iron and steel in water, by limiting the audience of oxidizing species available to oxidize metal. Keeping the solution at a neutral or slightly basic pH reduces the aggressiveness of the environment and helps maintain protective oxide films on many metals, which diminishes dissolution and attack. Using corrosion inhibitors introduces substances that adsorb onto the metal surface or modify the solution chemistry so that the anodic or cathodic reactions are slowed, forming a protective barrier or altering reaction pathways. Taken together, these strategies are commonly applied in engineering systems to minimize corrosion, so all of these methods are indeed ways to control corrosion.