What is rust?
Rust is an iron oxide and a form of corrosion.
It is caused by a chemical reaction that affects masses of iron and steel.
Once formed, rust begins to eat away at the metal, creating a crispy, orange-red coating that weakens the iron.
It occurs when the metal reacts with oxygen and water.
What causes rusting?
Water is the leading cause of rust.
Rusting is an example of corrosion, which occurs when iron or steel reacts with oxygen and water:
iron + oxygen + water → hydrated iron(III) oxide
Hydrated iron(III) oxide is the orange-brown substance seen on the surface of rusty objects.
Due to water in the equation, rust is more likely to occur on metal that has not been treated or protected against moisture.
Salt also helps to speed up the rusting process.
Ways to prevent rusting
- Keep metal dry
- Protect metal with oil, grease, or paint
- Use galvanized metal
- Use other metal as sacrificial protection, allowing that to rust away to protect structural metal