Iron & steel


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Iron & steel

  1. 1. Report on Iron And Steel 1
  2. 2. Iron  Introduction: Iron is a chemical element with the symbol Fe (from Latin: ferrum) and atomic number 26. It is a metal in the first transition series.  Oxidation state: Like other group 8 elements, iron exists in a wide range of oxidation states, −2 to +6, although +2 and +3 are the most common. 2
  3. 3. Continued…  Pure iron is soft (softer than aluminum), but is unobtainable by smelting. The material is significantly hardened and strengthened by impurities, such as carbon, from the smelting process.  History: Iron metal has been used since ancient times, though copper alloys, which have lower melting temperatures, were used first in history. It is Discovered since 5000BC. 3
  4. 4. Continued…  Carbon Contents In Iron: . A certain proportion of carbon (between 0.002% and 2.1%) produces steel, which may be up to 1000 times harder than pure iron.  Crude iron metal is produced in blast furnaces, where ore is reduced by coke to pig iron, which has high carbon content.  Iron chemical compounds, which include ferrous and ferric compounds, have many uses. Iron oxide mixed with aluminum powder can be ignited to create a termite reaction, used in welding and purifying ores. It forms binary compounds with the halogens and the chalcogens. Among its organ metallic compounds is ferrocene, the first sandwich compound discovered 4
  5. 5. Characteristics  Mechanical Properties: Mechanical properties can be determined the variety of test, 1. Brinell test, 2. Rockwell test and 3. The Vickers hardness test  The mechanical properties of iron are significantly affected by the sample's purity, 5
  6. 6. Name, symbol, Atomic Number Element category Group, period, block Standard atomic weight iron, Fe, 26 transition metal 8, 4, d 55.845(2) [Ar] 3d6 4s2 Electron configuration Phase 2, 8, 14, 2 solid Density (near r.t.) 7.874 g·cm−3 Liquid density at m.p. 6.98 g·cm−3 Melting point 1811 K2800 °F 1538 °C, , Boiling point 5182 °F 2862 °C, 3134 K, Heat of fusion 13.81 kJ·mol−1 Heat of vaporization 340 kJ·mol−1 Molar heat capacity 25-10·mol−1·K−1 6
  7. 7. Characteristics  Phase diagram and allotropes: Iron represents an example of allotropy in a metal. There are at least four allotropic forms of iron, known as α, γ, δ, and ε.  As molten iron cools it crystallizes at 1538 C into its δ allotrope, which has a body-centered cubic (bcc) crystal structure. As it cools further to 1394 C, it changes to its γ-iron allotrope, a face-centered cubic (fcc) crystal structure. 7
  8. 8. Continued…  At 912 C and below, the crystal structure again becomes the bcc α-iron allotrope, or ferrite. Finally, at 770 C (the Curie point, Tc) iron becomes magnetic. 8
  9. 9. Characteristics  Isotopes: Naturally occurring iron consists of four stable isotopes: 5.845% of 54Fe, 91.754% of 56Fe, 2.119% of 57Fe, 0.282% of 58Fe. Of these stable isotopes, only 57Fe has a nuclear spin (−1/2). The nuclide 54Fe is predicted to undergo double beta decay. 9
  10. 10. Iso 54Fe NA 5.8% half-life >3.1×1022 DM DE (MeV) DP (β+β+) 0.6800 54Cr Ε 0.231 55Mn y 55Fe Syn 56Fe 91.72% 56Fe is stable with 30 neutrons 57Fe 2.2% 57Fe is stable with 31 neutrons 58Fe 0.28% 58Fe is stable with 32 neutrons 59Fe Syn 44.503 d β− 1.565 59Co 60Fe syn 2.6×106 y β− 3.978 60Co 2.73 y 10
  11. 11. Characteristics  Nucleosynthesis: According to big bang theory, Iron is created by extremely large, extremely hot (over 2.5 billion Kelvin) stars through the silicon burning process. It is the heaviest stable element to be produced in this manner. Supernova: Supernovas also create additional forms of stable iron via the r-process. 11
  12. 12. Characteristics  Occurrence: Iron is the sixth most abundant element in the Universe, and the most common refractory element. It is formed as the final exothermic stage of stellar nucleosynthesis, by silicon fusion in massive stars.  It makes up about 5% of the Earth's crust, both the Earth's inner and outer core are believed to consist largely of an iron-nickel alloy constituting 35% of the mass of the Earth as a whole. 12
  13. 13. Chemistry and Compounds Iron forms compounds mainly in the +2 and +3 oxidation states. Traditionally, iron(II) compounds are called ferrous, and iron(III) compounds ferric.  Binary compounds: The most common are iron (II, III) oxide (Fe3O4), and iron(III) oxide (Fe2O3). Fe + 2 HX → FeX2 + H2  Fool’s Gold: . The best known sulfide is iron pyrite (FeS2), also known as fool's gold owing to its golden luster. 13
  14. 14. 14
  15. 15. Continued…  Coordination and Organometallic compounds: Several cyanide complexes are known. The most famous example is Prussian blue, (Fe4(Fe[CN]6)3). Potassium ferricyanide and potassium ferrocyanide are also known; the formation of Prussian blue upon reaction with iron (II) and iron (III) respectively forms the basis of a "wet" chemical test. Ferrocene is an extremely stable complex. The first sandwich compound, it contains an iron(II) center with two cyclopentadienyl ligands bonded through all ten carbon atoms. 15
  16. 16. History of Iron  Wrought Iron: Iron objects of great age are much rarer than objects made of gold or silver due to the ease of corrosion of iron. Beads made from meteoric iron in 3500 BC Wrought iron is an iron alloy with a very low carbon (0.1 to 0.25) content in contrast to cast iron, and has fibrous inclusions, known as slag up to 2% by weight.  Cast iron: Cast iron was first produced in China during 5th century BC, but was hardly in Europe until the medieval period. 16
  17. 17. Continued… Cast iron was used in ancient China for warfare, agriculture, and architecture. During the medieval period, means were found in Europe of producing wrought iron from cast iron (in this context known as pig iron) using finery forges.  Steel: Steel was first produced in antiquity by using a bloomer. Blacksmiths in Luristan in western Iran were making good steel by 1000 BC. Wootz steel by India and Damascus steel by China were developed around 300 BC and 500 AD. 17
  18. 18. Industrial Production  The production of iron or steel is a process containing two main stages. The first stage is to produce pig iron in a blast furnace. The second is to make wrought iron or steel from pig iron by a further process.  Blast Furnace: 90 % of all mining of metallic ores is for the extraction of iron. iron ores hematite (nominally Fe2O3) magnetite (Fe3O4). 2 C + O2 → 2 CO Fe2O3 + 3 CO → 2 Fe + 3 CO2 2 Fe2O3 + 3 C → 4 Fe + 3 CO2 18
  19. 19. Continued…  Isolation: Small amounts of pure iron can be made through the purification of crude iron with carbon monoxide. The intermediate in this process is iron pentacarbonyl, Fe(CO)5. The carbonyl decomposes on heating to about 250 C to form pure iron powder. Fe + CO → Fe(CO)5 (250 C) → Fe + 5CO 2Fe2O3 + 3C → 4Fe + 3CO2 19
  20. 20. Continued…  Direct Iron Reduction: "Direct iron reduction" reduces iron ore to a powder called "sponge" iron or "direct" iron that is suitable for steelmaking. 2 CH4 + O2 → 2 CO + 4 H2 Fe2O3 + CO + 2 H2 → 2 Fe + CO2 + 2 H2O 20
  21. 21. Application  Metallurgy: Iron is the most widely used of all the metals, accounting for 95% of worldwide metal production. Its low cost and high strength make it indispensable in engineering applications such as the construction of machinery and machine tools, automobiles etc .  Pure iron is quite soft, it is most commonly combined with alloying elements to make steel.  Pig iron is not a saleable product but it can be converted into steel and wrought iron. 21
  22. 22. Continued…  Iron Compounds: Iron compounds are pervasive in industry as well being used in many niche uses. Iron catalysts are traditionally used in the Haber - Bosch process for the production of ammonia and the Fischer-Tropsch process for conversion of carbon monoxide to hydrocarbons for fuels and lubricants.  Powdered iron in an acidic solvent was used in the Bechamp reduction the reduction of nitrobenzene to aniline.  There are many compounds of Iron that are used in daily life. 22
  23. 23. Continued…  Biological Role: Iron is abundant in biology. Iron-proteins are found in all living organisms, ranging from the evolutionarily primitive Achaea to humans.  The color of blood is due to the hemoglobin, an ironcontaining protein. As illustrated by hemoglobin, iron is often bound to cofactors, e.g. in hems.  Iron is a necessary trace element found in nearly all living organisms. Iron-containing enzymes and proteins. 23
  24. 24. Continued…  Bioinorganic compounds: The most commonly known and studied "bioinorganic" compounds of iron (i.e., iron compounds used in biology) are the heme proteins: examples are hemoglobin, myoglobin, and cytochrome P450.  Health and diet: Iron is pervasive, but particularly rich sources of dietary iron include red meat, lentils, beans, poultry, fish, leaf vegetables, watercress, tofu, chickpeas, black-eyed peas, blackstrap molasses, fortified bread, and fortified breakfast cereals. 24
  25. 25. Continued…  Toxicity: It is occurs when there is free radical of ferrous iron atom. It is very toxic and could damage DNA, proteins, lipids, and other cellular components. Thus, iron toxicity occurs when there is free iron in the cell, which generally occurs when iron levels exceed the capacity of transferring to bind the iron. 25
  26. 26. Steel  Introduction: Steel is an alloy of iron and a small amount of carbon. Carbon is the primary alloying element, and its content in the steel is between 0.002% and 2.1% by weight. Additional elements may be present in steel: manganese, phosphorus, sulfur, silicon, and traces of oxygen, nitrogen and aluminium. 26
  27. 27. Material properties  Iron is found on Earth in the form of Magnetite and Hematite and then we pure by removing the Oxygen from them.  Small quantities of iron were smelted in ancient times, in the solid state, by heating the ore buried in a charcoal fire and welding the metal together with a hammer, squeezing out the impurities.  Smelting results in an alloy (pig iron) that contains too much carbon to be called steel.  To inhibit corrosion, at least 11% chromium is added to steel so that a hard oxide forms on the metal surface 27
  28. 28. Continued…  Sulfur, nitrogen, and phosphorus make steel more brittle.  The density of steel varies based on the alloying constituents but usually ranges between 7,750 and 8,050 kg/m3 7.75 and 8.05 g/cm3  At room temperature, the most stable form of iron is the body-centered cubic (BCC) structure called ferrite or α-iron. 28
  29. 29. Heat Treatment:  The most common are annealing and quenching and tempering.  Types of Steel Steel is basically an alloy of iron and carbon with a small percentage of other metals such as nickel, chromium, aluminum, cobalt, molybdenum, tungsten etc.  Carbon Steels: Steel is considered to be carbon steel when no minimum content is specified or required for chromium, cobalt, columbium [niobium], molybdenum, nickel, titanium, tungsten, vanadium or zirconium. 29
  30. 30. Continued…  Low-carbon : Steels contain up to 0.30% C.  Medium-carbon : Steels are similar to low-carbon steels except that the carbon ranges from 0.30 to 0.60% and the manganese from 0.60 to 1.65%.  Ultrahigh-carbon : Steels are experimental alloys containing 1.25 to 2.0% C  High-Strength Low-Alloy Steels: The HSLA steels have low carbon contents (0.05-0.25% C) in order to produce adequate formability and weld ability, and they have manganese contents up to 2.0%. 30
  31. 31. Low-alloy Steels  Low-alloy steels constitute a category of ferrous materials that exhibit mechanical properties superior to plain carbon steels as the result of additions of alloying elements such as nickel, chromium, and molybdenum. Total alloy content can range from 2.07% up to levels just below that of stainless steels, which contain a minimum of 10% Cr.  As with steels in general, low-alloy steels can be classified according to:  Chemical composition, such as nickel steels, nickel-chromium steels, molybdenum steels, chromium-molybdenum steels  Heat treatment, such as quenched and tempered, normalized and tempered, annealed. 31
  32. 32. Continued…  Low-carbon quenched and tempered steels: Combine high yield strength (from 350 to 1035 MPa) and high tensile strength with good notch toughness, ductility, corrosion resistance, or weld ability.  Medium-carbon ultrahigh-strength steels: They are structural steels with yield strengths that can exceed 1380 MPa.  Bearing steels: It used for ball and roller bearing applications are comprised of low carbon (0.10 to 0.20% C) case-hardened steels and high carbon (-1.0% C) through-hardened steels. 32
  33. 33. Continued…  Chromium-molybdenum heat-resistant steels: It contain 0.5 to 9% Cr and 0.5 to 1.0% Mo. The carbon content is usually below 0.2%.  History Of Steel Making  Ancient steel: Steel was known in antiquity, and may have been produced by managing bloomeries, or iron-smelting facilities, in which the bloom contained carbon.  Steel was produced in large quantities in Sparta around 650BC.  Wootz steel and Damascus steel: Wootz steel was produced in India by about 300 BC However; the steel was an old technology in India when King Porus presented a Steel sword to the Emperor Alexander in 326 BC 33
  34. 34. Modern Steel Making  Originally using charcoal, modern methods use coke, which has proven more economical.  Processes Starts from Bar Iron: In these processes pig iron was "fined" in a finery forge to produce bar iron (wrought iron), which was then used in steelmaking. The production of steel by the cementation process was described in a treatise published in Prague in 1574 and was in use in Nuremberg from 1601.  Process Starts from Pig Iron: The modern era in steelmaking began with the introduction of Henry Bessemer's Bessemer process in 1855, the raw material for which was pig iron. 34
  35. 35. Steel Industry:  The steel industry is often considered an indicator of economic      progress. In 1980, there were more than 500,000 U.S. steelworkers. By 2000, the number of steelworkers fell to 224,000. Between 2000 and 2005, world steel demand increased by 6%. Shanghai Baosteel Group Corporation and Shagang Group. ArcelorMittal is however the world's largest steel producer. 2008, the steel industry faced a sharp downturn that led to many cut-backs. ThyssenKrupp offered the plants for sale at under $4 billion. 35
  36. 36. Contemporary Steel:  High strength low alloy steel has small additions (usually < 2% by weight) of other elements, typically 1.5% manganese, to provide additional strength for a modest price increase.  Low alloy steel is alloyed with other elements, usually molybdenum, manganese, chromium, or nickel, in amounts of up to 10% by weight to improve the harden ability of thick sections.  Stainless steels contain a minimum of 11% chromium, often combined with nickel, to resist corrosion. 36
  37. 37. Uses:  Iron and steel are used widely in the construction of roads, railways, other infrastructure, appliances, and buildings.  Most Large Structure buildings contain the skeleton of steel, such as stadiums and skyscrapers, bridges, and airports, are supported by a steel skeleton  Other common applications include shipbuilding, pipelines, mining, offshore construction, aerospace, white goods (e.g. washing machines), heavy equipment such as bulldozers, office furniture, steel wool, tools, and armour in the form of personal vests or vehicle armour (better known as rolled homogeneous armour in this role).  So Iron and Steel have many application 37