Corrosion
Electrochemical process in which a metal reacts with the substances in the environment (ex. oxygen) returning the metal to an ore-like state
Any metal appearing below the oxygen half reaction in the redox table will:
be oxidized easily
What are the conditions required to be met to cause corrosion?
Water and oxygen
What accelerates the corrosion of metals?
acidic solutions, electrolytes, mechanical stress, contact with less reactive metals
What are the main corrosion prevention methods?
protective coatings (paint, galvanizing), cathodic protection, other methods like oil spraying
How does cathodic protection work?
Forcing the metal you want to preserve to become the cathode (ex. supplying electrons to the metal, using a metal lower on the redox table as the reducing agent)
Why does aluminum, despite being a stronger reducing agent, not cause such a problem when corroded in comparison to iron when corroded?
though aluminum indeed reacts quicker than iron, the nature of aluminum oxide (the rust) causes it to adhere to the surface of the metal rather than flake off in the way that iron oxides do. it acts as a protective coating, allowing for the surface under the rust to be safe from corrosion
