All you need to know about Corrosion

Corrosion

Corrosion has a huge economic impact due to its immense damage to infrastructure such as highways, bridges, power lines, etc. This requires extensive repair and damage control which has immense costs to governments, industries and the general population who are affected by the damage and repair processes. The annual cost to repair damage from corrosion adds up to around $1.8 trillion worldwide. Corrosion is a naturally occurring development which can be defined as the decay and deterioration of materials, in our case – metals such as steel, copper, iron, etc.

Electrochemical Process of Corrosion

Fe → Fe²⁺ + 2e
Electrons produced by the anode react in many ways. Shown above are Ferrous Ions.

4e + O₂ + 2H₂O → 4OH
The electrons react with Oxygen and Water to produce Hydroxyl Ions

Fe²⁺ + 2OH → Fe(OH)₂
Ferrous Ions and Hydroxyl Ions react to make Ferrous Hydroxide

4Fe(OH)₂ + 2H₂O + O₂ → 2Fe₂ O₃.6H₂O
Ferrous hydroxide reacts with Oxygen and Water to give Ferric Oxide (rust)

 

One of the best ways to stop and/or delay corrosion is by using protective coating.