Cast iron is a hard product obtained by combining iron with carbon. This can be easily cast in a mould and it contains a higher proportion of carbon than steel. This percentage is usually between 2% and 4.3%.
Cast iron also contains varying amounts of silicon, manganese and some trace impurities, namely sulfur and phosphorus. Iron ore is reduced in a blast furnace to form cast iron. Liquid iron is cast, poured, and then hardened into rough ingots called pigs. These pigs are then remelted in a cupola along with scrap and other alloying elements, and then recast into molds to produce various products.
Cast iron production
Cast iron is made from pig iron, the product of melting iron ore in a blast furnace. In other aspects, cast iron can come directly from molten pig iron or through a process of remelting pig iron. This process is usually done with other large quantities of iron, steel, limestone and carbon (coke). Various steps are then taken to remove the unwanted contaminants to be contained.
Cast iron production
Contaminants such as sulphur and phosphorus can be burnt off from the molten iron, but this has a downside as it can also burn off the required carbon that must be replaced. Adjust the carbon and silicon content to the desired level according to the application of the final product. These levels may be between 2% to 3.5% and 1% to 3%, respectively. Other required elements must be added to the melt before the final product can be produced by casting.
This casting process refers to when liquid metal is delivered into a mold, usually through a crucible in most cases, which contains negative compression of the desired shape. The metal is poured into the mold through a hollow channel. The metal and mold are then cooled, and the metal parts are removed as castings.
Casting is most commonly used to create shapes that are inherently difficult to use or uneconomical to manufacture using other production methods. In this foundry business, traditional casting techniques include lost wax casting. This type can be further divided into centrifugal casting and vacuum assisted direct pouring, and also includes disc casting and sand casting.
cast iron smelting
Cast iron is sometimes melted in a special type of blast furnace, called a cupola. Cast iron is usually melted in an electric induction furnace or electric arc furnace. After the melting process is complete, the molten cast iron is poured into a holding furnace or ladle.
Mechanical properties of iron castings
Cast iron is hard, which makes the material resistant to wear and indentation. Toughness is included in iron castings because they absorb energy. Iron castings have the ability to return to their original dimensions after deformation and therefore have elasticity as their mechanical properties. In terms of elasticity, iron castings are inherently ductile because they can deform rather than break.
Ductility is reflected in characteristic properties, as this allows components to withstand compression and avoid cracking. Tensile strength and fatigue strength are some of the mechanical properties of iron castings. Tensile strength refers to the maximum longitudinal stress a material can withstand without tearing, while fatigue strength refers to the maximum stress a material (in this case, a cast iron piece can withstand a given number of cycles without breaking).
