A brief analysis of the similarities and differences between pig iron and wrought iron

Pig iron generally refers to an alloy of iron containing 2 to 4.3% of carbon. Also known as cast iron. In addition to carbon, pig iron also contains silicon, manganese and a small amount of sulfur, phosphorus, etc., which can be cast and not forged. According to the different forms of carbon in pig iron, it can be divided into steelmaking pig iron, foundry pig iron and ductile iron. The carbon in the steelmaking pig iron is mainly in the form of iron carbide, and its cross section is white, usually called white iron. This pig iron is hard and brittle and is generally used as a raw material for steel making. The carbon in the cast pig iron exists in the form of flake graphite, and its fracture is gray, usually called gray iron. Because the graphite is soft and has a lubricating effect, the cast pig iron has good cutting, wear resistance and casting properties. However, its resistance strength is not enough, so it can not be forged and can only be used to manufacture various castings, such as casting various machine bed bases and iron pipes. The carbon in ductile iron exists in the form of spherical graphite. Its mechanical properties are far better than that of gray iron and close to steel. It has excellent casting, cutting and wear resistance, and has certain elasticity. It is widely used in the manufacture of crankshafts. Advanced castings such as gears and pistons, as well as a variety of mechanical parts. In addition, there are pig irons containing silicon, manganese, nickel or other elements with a particularly high amount, called alloy pig iron, such as ferrosilicon, ferromanganese, etc., which are commonly used as raw materials for steel making. The addition of certain alloy pig iron during steelmaking can improve the properties of the steel.

Generally, the content of carbon containing less than 0.2% is called Wrought Iron or pure iron, the content of which is 0.2-1.7% of steel, and the content of 2% or more is called pig iron. The cooked iron is soft, plastic, easy to deform, low in strength and hardness, and not widely used; pig iron contains a lot of carbon, hard and brittle, and almost no plasticity.