Iron is made hard primarily by the addition of carbon.
The Role of Carbon in Hardening Iron
The process of hardening iron involves introducing carbon, which transforms it into steel. The increased carbon content significantly alters the properties of the iron, making it harder and tougher. Here's a breakdown:
- Carbon Addition: As stated in the reference, "to make it hard and tough carbon is added."
- Formation of Steel: This process of adding carbon in iron creates steel.
- Hardness and Toughness: The presence of carbon within the steel structure is responsible for its hardness and toughness, making it more resistant to deformation and wear.
Why is Steel Harder than Iron?
Pure iron is relatively soft and malleable, making it easy to bend and shape. However, when carbon is introduced, it forms a compound with the iron atoms. This new arrangement creates a stronger and more rigid structure, preventing the metal from being easily molded or bent.
Properties Affected by Carbon Addition
| Property | Pure Iron | Steel (Iron with Carbon) |
|---|---|---|
| Hardness | Softer | Harder |
| Toughness | Less Tough | More Tough |
| Moldability | Easier to Mold | Difficult to Mold |
In summary, the addition of carbon to iron is the key process for making it hard. The resulting material, steel, is a crucial material in various industries due to its enhanced strength and durability.
