Cast iron and pig iron are both materials that are derived from the smelting of iron ore, but they have different properties and applications.
Pig iron is the product obtained directly from the blast furnace, containing around 92% iron, 3-5% carbon, and other impurities such as manganese, sulfur, and phosphorus. It is a brittle material with a high carbon content and is typically not used in its pure form for any practical applications. Instead, pig iron is often refined to produce cast iron or steel.
Cast iron is a material produced by melting pig iron along with scrap iron and limestone in a furnace or cupola. The resulting molten iron is then poured into molds to create castings of various shapes and sizes. Cast iron typically contains between 2-4% carbon, which gives it a higher melting point than pig iron, making it more suitable for casting applications. Cast iron also contains silicon, which makes it more fluid when melted and easier to pour into molds. Cast iron has a coarse-grained structure and is brittle, but it is also strong and wear-resistant, making it suitable for a wide range of applications such as pipes, engine blocks, and cookware.
In summary, the key difference between cast iron and pig iron is that pig iron is a basic material that is used to make cast iron, while cast iron is a finished product that is produced by melting and refining pig iron. Cast iron is also different from pig iron in terms of its carbon content, melting point, and properties.
