What is cast iron, its process, properties and applications
- 1. What is cast iron, its process, properties and applications: What is cast iron? Cast Iron is a ferrous alloy consisting of 2 to 4.5 % of Carbon, 0.5 to 3 % Silicon and small amount of Sulphur, Manganese and Phosphorous. It is generally cast as soft and strong or as hard and brittle iron. Usually made from Pig Iron, cast iron is formed by liquefying it, followed by pouring it in a mould and allowing it to cool. It has got four types- Grey Cast Iron, White Cast Iron, Malleable Cast Iron and Ductile Cast Iron. Each of these types has got unique physical and chemical properties. What is the Manufacturing Process of Cast Iron? Pig iron is re-melted along with large quantity of Scrap Steel, Scrap iron, Limestone and Coke. This mixture is infused with required amount of Carbon and Silicon. Mostly, the amount of Carbon lies between 2 to 3.5 % and the amount of Silicon lies between 1 to 3 %. This mixture is melted in an Electric Induction Furnace or an Electric Arc Furnace after which the molten metal is transferred to a holding furnace. The alloying elements that is added to cast iron determine its type. These alloyants, if not added in the right proportions can result in several casting defect such as short runs. Additives are added to prevent any such occurrences of defects. The composition of Grey Cast Iron is: Carbon (2.5 to 4 % ), Silicon (1 to 3 % ) and Iron. The composition of White Cast Iron is: Carbon ( 2 to 2.5 % ), Silicon (1 to 1.3 %) and Iron. The composition of Malleable Cast Iron is: Carbon ( 2.16 to 2.90 % ), Silicon ( 0.90 to 1.90 %) and Iron. The composition of Ductile Cast Iron is: Carbon ( 3.5 to 3.9 %) , Silicon ( 2.25 to 2.75 %) and Iron. What are the properties of Ductile Iron? It has crystalline structure, so it acts as a strong metal for compression but is brittle in tension. It can be easily moulded into intricate shapes and complex designs. Cast Iron has less tensile strength than Wrought iron and has lesser Ductility when compared to Wrought Iron as well. Its Shear Tensile strength ranges between 22 to 62.5 KPSI. Its Shear Compressive Strength between 83 to 187.5 KPSI. Few of its other mechanical parameters include Shear Modulus of Rupture, Tensile Modulus of Elasticity, Endurance Limit and Torsional Modulus of Elasticity.
- 2. What are the Applications of Cast Iron? Cast iron has a number of applications in the culinary field. It is used to make pots and pans and all sort of utensils that are used for heating purposes. This is because the cast iron surface distributes the heat from the stone evenly all over its surface. It can also be used for baking purposes. It is even used to make stoves from a single piece of mould. Besides this, cast iron is widely used in Piping applications, engines, parts of automobiles and were earlier used in building nridges. Check out Calmet, a specialized cast iron manufacturer in india that provides high standard iron castings, machines iron castings & plastic coated copper tubing. Also develops forging parts through fine blanking process.