Iron and Steel Yangson Choi Eunsoo An. Iron Ore Rock contains 30~70% of Fe Magnetite (Fe 3 O 4 ),...
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Transcript of Iron and Steel Yangson Choi Eunsoo An. Iron Ore Rock contains 30~70% of Fe Magnetite (Fe 3 O 4 ),...
Iron and Steel
Yangson Choi
Eunsoo An
Iron Ore
• Rock contains 30~70% of Fe
• Magnetite (Fe3O4), Hematite (Fe2O3).
• Also contains impurities C, S, P and Cu
• http://www.posco.co.kr/homepage/docs/kor/html/product/exper/s91c5000140c.html
• http://en.wikipedia.org/wiki/Iron_ore
Blast Furnace
• Iron Ore (Fe)
• Limestone (CaCO3)
• Coke (C)• Step 1 Heat Source and producing CO
– C + O2 → CO2 + 94.2kal
– C + 1/2O2 → CO + 26.5kal
– CH4 + 1/2O → CO + 2H2
– CO2 + C → 2CO
– H2O + C → H2 + CO
– http://www.posco.co.kr/homepage/docs/kor/html/product/exper/s91c5000110c.html
– IB Study Guides Chemistry, Geoffrey Neuss, Oxford pg 105.
• Step 2 Reduction of oxygen
– Fe2O3 + 3CO → 3CO2 + 2Fe Begins at 400°C
– FeO + CO → CO2 + Fe Begins at
700°C
– Fe3O4 + 4H2 → 4Fe + 4H2O
– Fe2O3 + 3C → 2Fe +3CO
– Fe becomes Pig Iron and CO2 escapes as form of Gas.
• Step 3 Limestone Flux (Reduce impurities)
– CaCO3 → CaO + CO2
– CaO + SiO2 → CaSiO3
– Also reduce Silica (SiO2), Alumina (Al2O3), Magnesia (MgO) or Calcia (CaO)
– CaSiO3 and etc forms ‘Slag’
– http://www.thepotteries.org/shelton/blast_furnace.htm
– 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
– http://www.posco.co.kr/homepage/docs/kor/html/product/exper/s91c5000110c.html
– IB Study Guides Chemistry, Geoffrey Neuss, Oxford pg 105.
• C + O2 → CO2
• P4 + 5O2 → P4O10
• Si + O2 → SiO2
• 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
– http://en.wikipedia.org/wiki/Tempering
– http://en.wikipedia.org/wiki/Annealing
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.– http://kin.naver.com/detail/detail.php?
d1id=11&dir_id=110202&docid=871431&qb=6rCV7LKg7J2YIOyiheulmA==&enc=utf8§ion=kin&rank=1&sort=0&spq=0&pid=fpfkmloi5U4ssZZB5pVsss--302530&sid=SpSbhSVtlEoAABuefC8
• Stainless steel– Stainless, High oxidation-resistance– Alloys of iron, nickel, manganese, chrome and
tungsten• Knife, tableware, watch, cutlery, key, etc
– http://en.wikipedia.org/wiki/Stainless_steel
– http://www.posco.co.kr/homepage/docs/kor/html/product/exper/s91c5000110c.html