Classification of Iron and Steel

Most important commercial form of iron are :

• Pig iron. It is the product of  the blast furnace and is made by the reduction of iron ore.
• Cast iron. It is an alloy of iron containing so much carbon that , as cast, it is not appreciably malleable at any temperature.
• Malleable cast iron. It is made by changing all the combined carbon in a special white cast iron to free or  temper carbon by suitable heat-treatment.
• White cast iron. It contains carbon in the combined form which makes the metal hard  and bittle, and the absence of graphite  gives the fracture  a white color.
• Grey cast iron. This one as cast, has combined  or cementitic  carbon not in a excess of a eutectoid percentage, the balance of the carbon occurring as graphite flakes.
• Ingot iron. It is an open-hearth iron very low in carbon, manganese and other impurities.
• Wrought Iron. It is ferrous material aggregated from a solidifying mass of pasty particles of highly refined metallic iron with which is incorporated, without subsequent, fusion, a minutely and uniformly distributed quantity of slag.
• Puddled iron.  It is wrought iron made by the pudding process.
• Steel. It is a malleable alloy of iron and carbon, usually containing substantial quantities of manganese.
• Carbon steel. It owes its distinctive properties chiefly to the carbon that it contains.
• Alloy steel. It owes its distinctive properties chiefly to some element or elements other than carbon, or jointly to such other elements and carbon.
• Bessemer steel. open hearth steel, cruicible steel, and electric-firnace steel. These are names given according to the process from which steel is made, irrespective of carbon content.
• Electrolytic iron. It is produced in the form of thin-wall large-diameter tubes by employing large revolving mandrels as cathodes and ferrous-chloride as electrolyte. It is extremely brittle and can therefore be readily pulverised to a fine powder.