The correct answer is (2) Wrought Iron.
Let's explore the characteristics of each type of iron mentioned in the options:
1. Cast Iron:
Cast iron is an alloy of iron containing a significant amount of carbon (more than 2%). It also contains small amounts of silicon, manganese, sulfur, and phosphorus.
It is brittle and cannot be easily forged or welded. It is mainly used for casting, hence the name "cast" iron.
2. Wrought Iron:
Wrought iron is a very pure form of commercial iron with a very low carbon content (less than 0.1%). It also contains small amounts of impurities like silicon, sulfur, and phosphorus.
Wrought iron is tough, malleable, and ductile. It can be easily forged, welded, and shaped. It has a fibrous structure due to the slag inclusions, giving it distinctive properties.
- This form of iron was traditionally produced by the puddling process and was widely used for making tools, implements, and decorative items.
3. Pig Iron:
Pig iron is an intermediate product in the production of iron and steel. It is produced by smelting iron ore with a high-carbon fuel and reductant in a blast furnace.
Pig iron contains a significant amount of carbon (more than 2%) and other impurities. It is not the purest form of iron and requires further processing to remove impurities to make steel.
4. Steel:
Steel is an alloy of iron and carbon, typically containing a carbon content between 0.2% and 2.1% by weight.
The carbon content in steel is higher than that in wrought iron but lower than in cast iron. The properties of steel, including hardness, strength, and ductility, can be adjusted by varying the carbon content and adding other alloying elements.
Based on the purity criterion, wrought iron is the purest form among the options provided. It has a very low carbon content and is relatively free of impurities, making it suitable for various applications where purity and malleability are important. |
