Salient Differences between Iron and Steel
Iron is one of the chemical elements symbolized as Fe and having the atomic number 26. It is a metal and the largest element forming Earth’s inner and outer core. Iron is particularly common in the rocky planets due to fusion in high-mass stars. Steel is an alloy of iron and other elements including silicon, carbon, phosphorus, manganese, sulfur, and traces of nitrogen, oxygen, and aluminum. The alloying elements that adjust the features of steel include boron, titanium, manganese, nickel, niobium, chromium, vanadium, and molybdenum. When carbon is the main alloying component, its content is 0.002%-2.1% by the corresponding weight.
Many differences exist between iron and steel. Predominantly, steel is an alloy containing carbon and iron, while iron is an element. Iron is usually present in a greater quantity of the alloys. Other metals can be added to steel to produce alloys with different properties. For instance, adding chromium to produce stainless steel that is durable and does not rust easily. Steel is largely used in the construction industry, as it has better tension and compression properties than iron; in addition, it is stronger.
Another difference is in the percentage of carbon. Iron containing more than 2% of carbon is identified as pig iron, while that containing less than 2% is known as steel. Pig iron is obtained when iron ore is processed with coke in a blast heater. Further processing of pig iron reduces the carbon proportion; hence, steel is obtained. Steel can also be further processed in order to obtain other alloys.
Until 1400 AD, manufactured iron was categorized as wrought iron, which after 14th century witnessed smelting process that increased as a result of furnaces (Sparrow 39). The iron was then reduced to metallic iron and the carbon rich gases introduced for the metallic iron to absorb them. The resulting product was pig iron, which on further refining makes steel.
Forming process of steel
When iron is melted from the ore, it contains a lot of carbon. To make steel it must be reprocessed melted to reduce the carbon amounts, after which other elements can be added (Correspondence, Chicago, Bacon 23). The resulting liquid is then repeatedly cast into ingots or long slabs. About 4% of steel is produced as ingots, while 96% is continuously cast.
The ingots are heated in a soaking pit and rolled into blooms, slabs, or billets. Billets are cold or hot rolled into rods, bars, and wire; slabs into sheet plates or metal; blooms are rolled on rails and structural steel like I-beams. A modern steel mill does these processes with iron ore going in and refined steel coming out in one assembly line. Sometimes steel is heat-treated for strength after the final rolling. The additional elements contained in alloy steels give them more strength and definite properties. During the steelmaking process, the damaging elements like silicon, phosphorus, and sulphur, which make steel frail, must be detached (Gale, Vernon 23).
In the steelmaking process, the ore is fed into a converter. Oxygen and lime are introduced into the bath of hot metal. The lime produces a slag that dissolves impurities like sulphur. It does not corrode the lining of the converter. The oxygen generates heat by oxidizing carbon dissolved to form carbon monoxide. Alloying elements are added, when the carbon is reduced to the desired level, and the liquid steel is produced and tapped into a ladle. Producers of scrap-based steel use electric arc furnaces. The scrap is accused into the furnace, and three graphite electrodes run down the furnace roof. As the electrodes touch the scrap, arcs form. Intense heat-radiated and high electrical resistance melts the scrap.
How structural shapes are produced
There are two basic processes, which are used in manufacturing of structural steel. The hot-rolled shapes comprising angles, channels, and wide-flange sections are produced in the mills using the electric arc furnaces. Hollow steel sections and plate steels are made from the rolls of sheet steel originally produced in either an electric arc furnaces or a basic oxygen furnace.
In the electric arc furnaces process steel scrap from appliances, old automobiles; curbside recycling collection and industrial waste are melted in the electric furnaces. Impurities are removed, and additives are introduced to enhance the desired metallurgical balance of the steel. The liquid steel is then put in a beam blank, where it is cooled, reheated, and then passed through rollers forming the beam into its shape (Osborne 43). Thereafter, the beams are straightened, cut into given lengths, cooled, and organized for shipment.
The basic oxygen furnace process uses iron ore and coke. The ore is liquefied in a coke fired furnace then conveyed to a ladle. There it is pretreated and introduced into the basic oxygen furnace, where the mix is molten together. Oxygen is added through a water-cooled lance. The mix is then dispensed into a ladle for rolling into sheets or plates. The Hollow steel sections are produced by making rolled sheet steel of the preferred thickness into the geometric shape indicated.
How to obtain the weight of hot rolls mild steel in metric units
W = 7.85 t
W = weight of steel plate (kg/m2)
t = plate thickness (mm)
Production of iron shapes and forms
Iron is a majorly useful metal but difficult to understand in history. Iron emanates in the several forms and each form has a complication in producing. The three forms of iron include:
Pure iron, which is moderately hard. When red hot, it can easily be bent and formed into shapes like hinges, straps, or horseshoes. Cast iron, on the contrary, is massively strong. Its name came from its emergence from the smelter in liquid form and can be cast into Moulds. It is, however, brittle, and cannot be bent or shaped, once it has solidified. Hitting, when hot, will simply break it. Steel is the iron with a lesser amount of carbon. Meyer and Sydney (27), note that iron can be molded from the furnace and shaped when red hot. When sharpened it holds an edge, even with heavy use. Steel is, however, not easy to make.