4. There are four types of iron ore :  Hematite is reddish color and contains 70% iron  Limonite is brownish color and contains 55% iron  Magnetite is grayish color and contains 40% iron  Taconite is hard rock and contains 33% iron

5.  The second raw material used by the steel industry is bituminous or soft coal. Most coal is mined deep in the ground.  Coal as it comes from the earth cannot be used in the iron-making furnace.  It must first be changed into coke.

7.  is the third raw material needed in making iron and steel. It is obtained from quarries.  Limestone acts as a kind of chemical sponge in the blast furnace and steel- making furnaces.  It takes up impurities liberated during the furnace operations to form a scum called slag

9.  Molten iron as it comes from the blast furnace has some impurities.  To change the iron into steel, the impurities must be turned out.  It is done in three different kinds of furnaces Steel manufacturing process are:  1. Bessemer converter  2. Open hearth furnace  3. Electric furnace Steel classification

13.  A. Primary industry: an industry involved in the initial processing of raw materials into standard stock  B. Primary material : a material in the form of standard stock which is utilized in secondary processing  C. Processing of material  1. Extraction: open pit mining operations for most metals ( magnesium is converted from sea ) water 

14.  2. Refining: ore is a compound of metal and oxygen or sulfur ore is refined to remove unwanted minerals  3. Converting: Metal oxides are reduced to pure metals via blast furnace or electrolysis Pure metals are in the form of pigs (iron) and are processed to make steel ingots  4. Steel ingots and nonferrous ingots undergo various deformation processes to produce standard stock forms.

21.  A. Tensile strength :Ability of metal to resist being pulled apart  B. Ductility: Ability of a metal to be changed in shape without breaking  C. Toughness :The property that enables a metal to withstand heavy impact forces of sudden shock without fracture  D. Hardness : Property of metal to resist indentation, penetration or scratching  E. Malleability : The ability of a metal to be permanently deformed by rolling, pressing or hammering  F. Machine-ability :The ease or difficulty of cutting metal with a cutting tool.

22.  A. Cast Iron  B. Carbon Steels  C. Alloy Steel  D. Metal Numbering System

23. A. Cast Iron  1. Gray cast iron 1.7% to 4.5% carbon, 1% to 3% silicon Heat resistance, wear resistance, Corrosion resistance  2. White cast iron Low ductility, compressive strength is high (200,000 PSI) Low resistance to impact load Maximum wear resistance  3. Chilled cast iron Gray iron castings with edges of white cast iron Rapid cooling results in the formation of cementite and white cast iron along the edge.

24.  4. Alloy cast iron Gray or white casting with alloying elements Increase in properties such as: strength, wear, corrosion, heat resistance Tensile strength is above 70,000 PSI  5. Malleable cast iron Produced by annealing of white iron castings  6. Nodular cast iron ( Ductile iron ) (Also known as spheraidal graphite iron) Alloyed with magnesium or cerium. Tensile strength is 60,000 to 80,000 PSI

25.  1. General Characteristics Iron with carbon content of 0.05 % to 1.5%; as carbon content increases, hardness and tensile strength increases and ductility and weld ability decrease.  2. Classification of Carbon Steel  low-carbon steel (mild steel) carbon content 0.05% to 0.30%; tensile strength 51,000 - 70,000 PSI  Medium-carbon steel carbon-content 0.30% to 0.6%; tensile strength 70,000 to 98,000 PSI  High-carbon steel (tool steels) carbon content 0.60% to 1.5%; tensile strength 98,000 to 142,000 PSI

26.  1. Over 25 common alloying elements exist  2. Alloying effects of manganese Increases from 0.30% to 1.5%; so does hardenability, strength, toughness, shock resistance.  3. Alloying effects of nickel Increases from 3% to 3.7%; so does wear, corrosion resistance, toughness, and strength.  4. Alloying effects of chromium Increases from 0.3% to 1.6%; chromium steels require additional hardening.

27.  5. Alloying effects of molybdenum Increases up to 9%; so does toughness and shock resistance; in addition, heat treatment and hardenability would be improved.  6. Alloying effects of vanadium Increases from 0.03% to 0.20%; so does tensile strength, yield strength, wear resistance, and impact toughness.  7. Alloying effects of cobalt Increases from 5% to 12%; so does hardness and wear resistance.  8. Alloying effects of tungsten Improves heat treatment quality and wear resistance.

28.  Classification System B: Bessemer Steel C: Open-Hearth Steel D: Electric Furnace Steel  Steel Numbering System Four digit number First number indicates alloy group Second number indicates impurity limits Last digits indicates specific alloy or purity

29.  Steel Numbering System 10XX plain carbon steel 11XX sulfurized free cutting carbon steel 13XX manganese steels 20XX nickel steel 31XX nickel-chromium steels 41XX molybdenum steels 50XX chromium steel  Explanation: Example C1020 20/100 x 1% carbon =.2 x 1% =.2 x.01 =.002 =.02 %

30.  A. Copper-base alloys  B. Nickel-Base Alloys (Incanel metal)  C. Aluminum-Base Alloys  D. Zinc

31.  A. Copper-base alloys  1. Brass Red brass (cartridge brass) (5 - 20% zinc) Yellow brass (20-36% zinc) Architectural brass (40% zinc) Naval brass (39% zinc and 1% tin) Manganese brass (39% zinc plus iron) has high strength and excellent wear Lead brass - increase in machinability

32.  2. Bronze (Copper and Tin) aluminum bronze - strength range 80,000 – 100,000 PSI silicon bronze - high strength, corrosion resistance beryilium bronze - tensile strength 200,000 PSI

33.  B. Nickel-Base Alloys (Incanel metal) 1. Nickel has good oxidation and corrosion resistance and also resistance at high temperatures. 2. Nickel Silver alloy of copper, nickel and zinc 60-99% nickel  C. Aluminum-Base Alloys 1. Alloying elements are copper, manganese, chromium, iron, nickel, zinc, titanium

34. Excellent machine-ability; Low weight; Heat treatable; Suitable for hot and cold forming processes. D. Zinc Low melting point of (750-800 °F) Excellent for die casting Moderate strength and toughness Inexpensive

35.  1)Thermosetting  2)Thermoplastics  3) Elastomer

36. A. MAJOR CLASSIFICATIONS  1)Thermosetting  a) Formed to shape with heat and sometimes pressure.  b) When set, the product is permanently hard.  c) Heat causes chemical action (polymerization), which causes plastic to become irreversibly hard.

37.  2)Thermoplastics  a) Will consistently remain soft at elevated temperatures and harden when cooled.  b) Exhibits no chemical change in molding cycle.  c) Will not harden with pressure and heat, but may be recycled

38.  The term elastomer is often used interchangeably with the term rubber.rubber  Elastomer comes from two terms, elastic (describing the ability of a material to return to its original shape when a load is removed) and mer (from polymer, in which poly means many and mer means parts).polymer

39.  RAW MATERIALS a) Agricultural products b) Minerals such as limestone, silica (a form of silicon) and sulfur. c) Organics such as coal, gas, petroleum d) Color pigments - provide desired color e) Solvents - soften and improve flow-ability in mold. f) Lubricants - improve molding characteristics g) Fillers - minimize shrinkage, improve heat resistance and impact strength, reduce manufacturing costs  Examples: wood powder, flour, cotton, rag fibers, asbestos, powder metals, graphite, glass, clays

40.  1. Phenolics hard, high strength, durable; derived through reaction of phenol with formaldehyde. (Particle board, Laminated parts, Electrical parts,Household)  2. Amino resins – principally ureaformaldehyde and melamine- formaldehyde Widely used as adhesives for laminating wood and paper. (circuit breakers, Table wear, Ignition parts)

41.  3. Furane Derived through processing of corn cobs, rice hulls, and cotton seeds with acids. Resins are water resistant, have good electrical properties. ( Binding agents for floor, Hardening agents for plaster and graphite)  4. Epoxides Principal characteristics include: low shrinkage, good chemical resistance, excellent electrical characteristics, high strength, excellent adhesive properties, high wear and impact resistance. ( Casting, Laminating, Paint ingredient Printed circuit boards)

42.  5. silicones principal characteristics include: high temperature resistance, low temperature performance, high electrical characteristics, high water resistance, low coefficient of friction, high shock resistance, high cost

43.  1. cellulosics –  derived through treatment of cotton and wood fibers. low density compounds, highly resistant to alkalies  2.polystyrene Formulated for injection molding and extrusion low gravity, resistant to water and chemicals, high insulation ability excellent rubber substitute for electrical insulation

44.  3. polyethylene Flexible at room and low temperatures, high water and chemical resistance suitable for injection molding, blow molding and extrusion into sheets, films,  4. polypropylene (PP) excellent electrical properties, high impact and tensile strengths, high resistance to heat, high resistance to chemicals

45.  5. ABS plastics Chemical compound of acrylonitrile, butadiene, and styrene may be compounded to have a very high degree of hardness or high flexibility and toughness, high flexibility and toughness good moisture resistance  6. polyamide available in solid, film, or solution form,extremely high heat resistance (750  F or 400  C) low coefficient of friction, high radiation resistance. good electrical properties

46.  7. Nylon (polyamides) good tensile and impact strengths, good heat resistance, good moisture resistancegood electrical properties.  8. Acrylic resin (methyl methacrylate), Lucite (DuPont) excellent light transmission qualities, high resistance to moisture,easily fabricated

47. Have a good day