Heat treatment and its effect on mechanical properties of grey and nodular cast irons / Nazri Said

Without doubt iron is the world's most important metal. The industrial civilisation is largely based on iron and on its alloys. Cast iron is produced by remelting pig iron and scrap in a cupola furnace, where the charge is in contact with the fuel and fluxes; or in a reverberatory furnace, a rotary furnace, or an electric furnace. The majority of commercial plain cast iron is produced by the foundary cupola method. Its low melting point, compared with steel, allows full use to be made of the economical cupola furnace, resulting in a cheaper end-product. The fluidity of molten cast iron is greater than that of molten steel, while the shrinkage in the mould is much less, permitting the production of thin-section and intricate castings. Cast iron has a high resistance to compressive forces, a moderate tensile strength and an ability to absorb and dampen vibrations. Its structure is partially self-lubricating, due to the presence of graphite, making machining relatively easy.