Iron and Steel Yangson Choi Eunsoo An

Iron Ore Rock contains 30~70% of Fe Magnetite (Fe 3 O 4 ), Hematite (Fe 2 O 3 ). Also contains impurities C, S, P and Cu

Blast Furnace Iron Ore (Fe) Limestone (CaCO 3 ) Coke (C) Step 1 Heat Source and producing CO –C + O 2 → CO kal –C + 1/2O 2 → CO kal –CH4 + 1/2O → CO + 2H 2 –CO 2 + C → 2CO –H 2 O + C → H 2 + CO – –IB Study Guides Chemistry, Geoffrey Neuss, Oxford pg 105.

Step 2 Reduction of oxygen –Fe 2 O 3 + 3CO → 3CO 2 + 2Fe Begins at 400°C –FeO + CO → CO 2 + Fe Begins at 700°C –Fe 3 O 4 + 4H 2 → 4Fe + 4H 2 O –Fe 2 O 3 + 3C → 2Fe +3CO –Fe becomes Pig Iron and CO 2 escapes as form of Gas.

Step 3 Limestone Flux (Reduce impurities) –CaCO 3 → CaO + CO 2 –CaO + SiO 2 → CaSiO 3 –Also reduce Silica (SiO2), Alumina (Al2O3), Magnesia (MgO) or Calcia (CaO) –CaSiO 3 and etc forms ‘Slag’ – –IB Study Guides Chemistry, Geoffrey Neuss, Oxford pg 105

Conversion of Iron into Steel Scrap steel : Recycle, temperature control Limestone : Form Slag, reduce impurities Pig iron : Loose impurities Other elements : Make alloy – –IB Study Guides Chemistry, Geoffrey Neuss, Oxford pg 105.

C + O 2 → CO 2 P 4 + 5O 2 → P 4 O 10 Si + O 2 → SiO 2 During this process other elements, such as chromium and nickels are also added to from the precise alloy required –IB Study Guides Chemistry, Geoffrey Neuss, Oxford pg 106

Alloys Homogeneous mixture of metals, Or a mixture of metals and a non-metal. Their atoms have similar atomic radii and the crystal structure is not seriously disrupted Alter the physical properties –IB Study Guides Chemistry, Geoffrey Neuss, Oxford pg 106

Heat treatment of steel Control heating and cooling of the steel to change the nature of the crystal structure in the steel. Change mechanical properties but not shape. Quenching –Cool rapidly –Very hard, high stress, very brittle

Tempering –Heated to about 400~600°C and cool it slowly –More ductile, less stress, less brittle Annealing –Heated to about 1040°C –Most ductile, least stress, least brittle – –

Properties Pure iron (C content < 0.035%) –Good conductor, easily react Parts of electronic machine, catalyst and alloy Steal (C content < 2.0%) –Strong, not much ductile Structural steel in buildings, machine, railroad track Carbon steel ( C content 2%~6.7%) –Very strong, brittle, cheep Tools, machine parts. – 7J2YIOyiheulmA==&enc=utf8&section=kin&rank=1&sort=0&spq=0&pid=fpfkmloi5U4ssZZB5 pVsss &sid=SpSbhSVtlEoAABuefC8http://kin.naver.com/detail/detail.php?d1id=11&dir_id=110202&docid=871431&qb=6rCV7LKg 7J2YIOyiheulmA==&enc=utf8&section=kin&rank=1&sort=0&spq=0&pid=fpfkmloi5U4ssZZB5 pVsss &sid=SpSbhSVtlEoAABuefC8

Stainless steel –Stainless, High oxidation-resistance –Alloys of iron, nickel, manganese, chrome and tungsten Knife, tableware, watch, cutlery, key, etc – –