Chapters 5 and 6 Ferrous and Nonferrous Metals

Chapters 5 and 6: Ferrous and Nonferrous Metals Group 5 Patrick Pace Michael Linley Bryan Estvanko Matthew Sallee

CHAPTER 5 5. 1 -5. 4 Ferrous Metals and Alloys Production - General Properties Application

Introduction n What is a ‘ferrous metal’ or ‘ferrous alloy’? It is simply a metal or alloy that contains Iron (the element ferrous) as the base (starting) metal. ß 26 th element ßIron or Ferrous 55. 85 Atomic Mass

General Categories of Ferrous Metals and Alloys n n n Carbon and alloy steels Stainless steel Tool and Die steel Cast Irons Cast Steels n **Ferrous tools first appear about 4000 to 3000 BC, made from meteoritic iron. Real ironworking started in about 1100 BC in Asia Minor, and started the Iron Age.

APPLICATION OF FERROUS (IRON) METALS / ALLOYS

5. 2 Production of Iron and Steel

Raw Materials for Production n Iron Ore n Limestone ----- n Coke

Iron Ore n n Abundant, makes up 5% of earth’s crust Is not found in ‘free state’, must be found in rocks and oxides, hence Iron ore. After mining, the ore is crushed and the iron is separated, then made into pellets, balls or briquettes using binders, such as water. The pellets are typically 65% iron, and about 1” in diameter.

Coke – (…The black, legal kind) n Coke is formed by heating coal to 2100*F (1150 C), then cooling it in quenching towers. You need more than Iron? Why coke is used… 1. Generates high heat, needed in order for chemical reactions in ironmaking to take place. 2. Produces CO (carbon monoxide) which reduces iron-oxide to Iron.

Lastly, Limestone n Limestone (calcium carbonate) is used to remove impurities. – When the metal is melted, limestone combines with impurities and floats to the top of the metal, forming slag. The slag can then be removed, purifying the iron.

Ironmaking

Raw Materials Pig Iron n The three raw materials are dumped into a blast furnace. n Hot air (2000*F) is blasted into the furnace, which helps drive the chemical reaction. The coke forms CO and the CO reduces the iron oxide to iron. n The slag floats to the top and the metal is transferred to molds and cools. IT IS NOW PIG IRON, ready for more iron work or steelmaking.

Blast Furnace Tuyeres (Same height as a 10 story building)

Steelmaking

Pig Iron Steel n To make steel you are simply removing more impurities, such as, manganese, silicon, carbon…, from the pig iron. n Impurities are removed by re-melting the metal and adding carbon, steel scrap, and more limestone. – The metal can be melted using one of three methods. – Open-Hearth furnace – Electric furnace – Basic Oxygen furnace. (BOF)

Open-Hearth Furnace Uses a fuel to generate heat, and melt the metal.

Basic-Oxygen Furnace n n n Fastest steelmaking process – can make 250 tons of steel / hour Melted pig iron and scrap are poured (charged) into a vessel. Fluxing agents are added, like limestone. The molten metal is blasted with pure oxygen. This produces iron oxide which then reacts with carbon to produce CO and CO 2. The slag floats to the top of the metal. Higher steel quality than open hearth. Used to make plate, sheet, I-beam, tubing and channel.

Electric Furnace n n n Uses electric arc from electrode to metal to heat and melt it. Can produce 60 -90 tons of steel per day. Steel is higher quality than open-hearth and BOF

Vacuum Furnace n n n Uses induction furnaces. Air is removed from the furnace, this removes the gaseous impurities from the molten metal. Produces very high-quality steel.

5. 3 Casting Ingots

Ingots n n While steel is still molten, it is poured into a mold. The mold may be a square, rectangle or round. The metal becomes an “ingot” in the mold. They can weigh 100 lbs to 40 tons. The ingot will be removed from the mold and heated uniformly to be rolled or formed into a final product. HOWEVER – While the molten metal cools, or solidifies, gasses evolve and can affect the quality of the steel. This leads to three types of steel: Killed Steel, Semi. Killed Steel, and Rimmed Steel.

Killed – Semi-Killed – Rimmed Steel n Killed Steel – This is a fully deoxidized steel, and thus, has no porosity. – This is accomplished by using elements like aluminum to de-oxidize the metal. The impurities rise and mix with the slag. – It is called killed because when the metal is poured it has no bubbles, it is quiet. – Because it is so solid, not porous, the ingot shrinks considerably when it cools, and a “pipe” or “shrinkage cavity” forms. This must be cut off and scrapped.

Killed – Semi-Killed – Rimmed Steel n Semi-Killed Steel: This is practically the same as killed steel, with some minor differences. – It is only partially de-oxidized, and therefore, is a little more porous than killed steel. – Semi-Killed does not shrink as much as it cools, so the pipe is much smaller and scrap is reduced. – It is much more economical and efficient to produce.

Killed – Semi-Killed – Rimmed Steel n Rimmed Steel: This is produced by adding elements like aluminum to the molten metal to remove unwanted gases. The gasses then form blowholes around the rim. – Results in little or no piping. – HOWEVER, impurities also tend to collect in the center of the ingot, so products or rimmed steel need to be inspected and tested. **Refining

5. 4 Continuous Casting -Molten metal skips ingot step, and goes directly the furnace to a “tundish” -Metal solidifies in the mold -The metal descends @ about 1”/sec -The solidified metal then goes through ‘pinch rollers’ that determine the final form.

Benefits of Continuous Casting n n Costs less to produce final product Metal has more uniform composition and properties than ingot processing.

Sections 5. 5 - 5. 7 • Carbon Steel and Alloying • Stainless • Tool Steels and Die Steels

Carbon and Alloying Steels Carbon and alloying steels are the most commonly used metals n The structural makeup and controlled processing of these steels make them suitable for many different functions. n Basic product shapes include plate, sheet, bar, wire, tube, castings, and forgings. n Increasing the percentages of these elements in steels, increases the n

Effects of Elements in Steels Different elements are added to steels to given the steel different properties. n The elements pass on properties such as harden- ability, strength, hardness, toughness, wear resistance, etc. n Some properties are beneficial while others are detrimental. n

Effects of Elements in Steels n n n Boron: Improves hardenability without the loss of (or even with some improvement in) machinability and formability. Calcium: Deoxidizes steels, improves toughness, and may improve formability and machinability. Carbon: improves hardenability, strength, hardness, and wear resistance; it reduces ductility, weldability, and toughness. Cerium: controls the shape of inclusions and improves toughness in high-strength low alloy steels; it deoxidizes steels. Chromium: improves toughness, hardenability, wear and corrosion resistance, and hightemperature strength; it increases the depth of the hardness penetration resulting from heat treatment

Effects of Elements in Steels n n n Copper: improves resistance to atmospheric corrosion and, to a lesser extent, increases strength with little loss in ductility; it adversely affects the hot-working characteristics and surface quality. Lead: improves machinability; it causes liquid-metal embrittlement. Magnesium: has the same effects as cerium. Manganese: improves hardenability, strength, abrasion resistance, and machinability; it deoxidizes the molten steel, reduce shot shortness, and decreases weldability. Molybdenum: improves hardenability, wear resistance, toughness, elevated-temperature strength, creep resistance, and hardness; it minimizes temper embrittlement.

Effects of Elements in Steels n n n Nickel: improves strength, toughness, and corrosion resistance; it improves hardenability. Niobium (columbium): imparts fineness of grain size and improves strength and impact toughness; it lowers transition temperature and may decrease hardenability. Phosphorus: improves strength, hardenability, corrosion resistance, and machinability; it severely reduces ductility and toughness. Selenium: improves machinability. Silicon: improves strength, hardness, corrosion resistance, and electrical conductivity; it decreases magnetic-hysteresis loss, machinability, and cold

Effects of Elements in Steels n n n Sulfur: Improves machinability when combined with manganese; it lowers impact strength and ductility and impairs surface quality and weldability. Tantalum: has effects similar to those of niobium. Tellurium: improves machinability, formability, and toughness. Titanium: improves hardenability; it deoxidizes steels. Tungsten: has the same effects as cobalt. Vanadium: improves strength, toughness, abrasion resistance, and hardness at elevated temperatures; it inhibits grain growth during heat treatment.

Residual Elements n n n Molten Steel During the processing of steels some residual elements remain in the medal. These residuals are trace elements that are unwanted due to their detrimental properties but cannot be extracted completely. Some of these residual elements include: antimony, arsenic, hydrogen, nitrogen,

Carbon Steels n n Carbon steels are group by their percentage of carbon content per weight. The higher the carbon content the greater the hardness, strength and wear resistance after heat treatment. Low-carbon steel, also called mild steels, has less than 0. 30% carbon. Used in everyday industrial High Carbon Steel Nails

Carbon Steels Medium-carbon steel has 0. 30% to 0. 60% carbon. Used for jobs requiring higher strength such as machinery, automotive equipment parts, and metalworking equipment. n High-carbon steel has more than 0. 60% carbon. Used parts that require the highest strength, hardness, and wear resistance. Once manufactured they are heat treated and tempered n

Alloy Steels n Alloy steels are steels that contain significant amounts of alloying elements. – High strength low alloy steels – Microalloyed steels – Nanoalloyed steels

Alloy Steels n High-strength, low-alloy steels (HSLA) steels were developed to improve the ratio of strength to weight. – Commonly used in automobile bodies and in the transportation industry (the reduced weight n Microalloyed steels Provide superior properties without the use of heat treating. When cooled carefully these steels develop enhanced and consistent strength.

Alloy Steels n Nanoalloyed steels have extremely small grain size (10 -100 nm). Since their synthesis is done at an atomic level their properties can be controlled specifically.

Stainless Steels n Stainless steels are primarily know for their corrosion resistance, high strength, and ductility and chromium content.

Stainless Steels n The reason for the name stainless is due to the fact that in the presence of oxygen, the steel develops a thin, hard, adherent film of chromium. – Even if the surface is scratched, the protective film is rebuilt through passivation. n For passivation to occur there needs to be a minimum chromium content of 10% to 12% by weight.

Stainless Steels n Stainless steels tend to have lower carbon content since increased carbon content lowers the corrosion resistance of stainless steels. – Since the carbon reacts with chromium it decreases the available chromium content which is needed for developing the protective film.

Stainless Steels n Using stainless steels as reinforcing bars, has become a new trend, in concrete structures such as highways buildings and bridges. – It is more beneficial than carbon steels because it is resistant to corrosion from road salts and the concrete itself. Rebar corrosion in concrete

Tool and Die Steels n Tool and die steels are alloyed steels design for high strength, impact toughness, and wear resistance at normal and elevated temperatures. – High-speed steels Maintain their hardness and strength at elevated operating temperatures. There are two basic types the M-series and T-series

Tool and Die Steels n n M-series contain 10 % molybdenum and have higher abrasion resistance than Tseries T- Series contain 12 % to 18 % tungsten. They undergo less distortion in heat treatment and are less expensive than M- series steel drill bits coated with titanium

Tool and Die Steels n Dies are tools used for drawing wire, and for blanking, bending, cutting, machine forging, and embossing. . – H-series (Hot-working steels) for use at elevated temperatures. They have high toughness and high resistance to wear and cracking. – S-series (shock resisting steels) designed for impact toughness.

Chapter 6: Nonferrous Metals and Alloys 6. 1 Introduction n 6. 2 Aluminum n 6. 3 Magnesium n 6. 4 Copper n 6. 5 Nickel n 6. 6 Superalloys n 6. 7 Titanium n 6. 8 Refractory Metals n

Introduction n Nonferrous metals and alloys – Common- aluminum, copper, and magnesium – High-strength high-temperature alloys include: tungsten, tantalum, and molybdenum. – Higher cost than ferrous metals but have good properties such as: n Corrosion resistance n High thermal and electrical conductivity

Aluminum and Aluminum Alloys Most abundant metallic element (8% crust) n High strength to weight ratio n Resistant to corrosion n High thermal and electrical conductivity n Nonmagnetic n Easy formability and machinability n

UNS n UNS-Unified Numbering System – A common system used everywhere to describe the condition of a metal or an alloy. n Generally has 4 numbers and a temper designation – Temper designation tells the condition of the material. n Example: 2024 wrought aluminum is A 92024

UNS-Wrought Aluminum Form: 1 XXX n 1 st #- major alloying element n 2 nd #- modifications of alloy n 3 rd & 4 th #- minimum amount of aluminum in the alloy n – EX: 1050 is aluminum with minimum 99. 50% Al – Ex: 1090 shows a minimum of 99. 90% Al

UNS-Cast Aluminum Form: 1 XX. X n 2 nd & 3 rd #- minimum amount of aluminum n 4 th #- Product form n

Temper Designation n n F: as fabricated (by cold or hot working or by casting) O: Annealed (from the cold worked or cast state) H: strain hardened by cold working (for wrought products only) T: heat treated W: solution treated only (unstable temper)

Magnesium and Magnesium Alloys Lightest of all metals n Not sufficiently strong in pure form but alloyed to increase strength. n Uses n – Aircraft and missile components, bikes, luggage, portable power tools… n Designations for magnesium – A. 1 or 2 prefix letters – B. 2 or 3 numbers

Copper and Copper Alloys First produced in 4000 BC n Properties: n – Best conductors of electricity and heat, good corrosion resistance, and easily processed. n Uses: – Electronics, springs, cartridges, plumbing, heat exchangers, and marine equipment. n Common alloys: – Brass, Bronze, Beryllium copper

Nickel and Nickel Alloys Major alloying element for strength, toughness, and corrosion resistance. n Offers a wide range of strength at different temperatures. n Uses: n – High temperature applications, food handling, chemical processing, coins, marine applications. n Magnetic properties-electromagnetic – Used in solenoids

Superalloys n n Used in high temperature applications and have good resistant properties to: – Mechanical and thermal fatigue, thermal shock, creep, and erosion at elevated temperatures Examples: jet engines, gas turbines, and reciprocating engines – Max temp. - 1000°C (1800°F) – Max temp. (non load)- 1200°C (2200°F) n Identified by trade names or by a special numbering system

Titanium and Titanium Alloys Has the highest strength to weight ratio n Uses: n – Jet engines, race cars, golf clubs, submarines, and armor plates. Pure state: strong and light n Alloys: improved workability, strength, hardenability n High cost due to long production process n

Refractory Metals and Alloys n n n 4 refractory metals: Molybdenum, Niobium, Tungsten, and Tantlum. Called refractory because of their high melting points. Discovered about 200 years ago. Used in steels and superalloys because they maintain their strength at high temperatures. Temperature range of 1100 to 2200° C (2000 to 4000° F).

Molybdenum (Mo) n n n A silvery-white metal. Discovered in the 18 th century. Has high melting point, high modulus of elasticity, good resistance to thermal shock, and good electrical and thermal conductivity. Needs a protective coating because of low resistance to oxidation at high temperatures. Used in solid-propellant rockets, jet engines, honeycomb structures, electronic computers, heating elements, and dies for die casting. Principle alloying element for titanium and zirconium.

Niobium (Nb) n n n First identified in 1801. Also known as Columbium. Has good ductility and formability and has greater oxidation resistance than other refractory metals. Used in rockets and missiles and in nuclear, chemical, and superconductor applications. Processed from ores by reduction and refinement and from powder by melting and shaping into ingots.

Tungsten (W) n n n n First identified in 1781. Most abundant of all refractory metals. Highest melting point of any metal at 3410° C (6170° F). High strength at high temperatures. Has high density (which makes it brittle at low temperatures). Used in hottest part of missiles and rockets, weldinging electrodes, spark-plug electrodes, and the wire filament in incadescent bulbs. Processed from ore concentrates by chemical decomposition and is then reduced.

Tantalum (Ta) n n Characterized by its high melting point (3000° C, 5425° F), high density, good ductility and resistance to corrosion. Used mainly in electrolytic capacitors and various electrical, electronic and chemical industries. Sometimes used in thermal applications such as in furnaces and acid-resistant heat exchanges. Processed from ores by reduction and refinement and from powder by melting and

Beryllium (Be) n n n Steel grey in color. High strength-to-weight ratio. Used in rocket nozzles, space and missile structures, aircraft disc brakes, and precision instruments and mirrors. Low neutron absorption. Alloy element of copper and nickel. Toxic. Its dust and fumes should not be inhaled.

Zirconium (Zr) Silvery in appearance. n Good strength and ductility at elevated temperatures. n Good corrosion resistance because of adherent oxide film. n Used in electronic components and in nuclear-power reactor applications. n Low neutron absorption. n

Low-Melting Alloys n Relatively low melting points. n Consists of lead, zinc, and tin.

Lead (Pb) n n n High density, resistance to corrosion, softness, low strength, good ductility and workability. Alloying it with antimony and tin make it usable in piping, collapsible tubing, bearing alloys, cable sheathing, roofing and lead-acid storage batteries. Also used for damping sound and vibrations, radiation shielding against x-rays, ammunition, as weights, and in the chemical industry. Poisonous; major efforst are being made to replace it with other elements. Source mineral is galena (Pb. S).

Zinc (Zn) n n n n Bluish-white in color. 4 th most utilized metal in industry. Not developed until 18 th century. Used for galvanizing iron, steel sheet, and wire and as an alloy base for casting. Alloyed with aluminum, copper, and magnesium. Zinc-based alloys are used for making fuel pumps and grills for automobiles, components for household appliances, kitchen equipment, various machinery parts and photoengraving equipment. Used in superplastic alloys. Comes from a principle source mineral called zinc sulfide.

Tin (Sn) n n n n Silvery-white, lustrous metal. Developed in the 15 th century. Used mainly as a protective coating on steel sheets called tin plating which is used to make tin cans. Low shear strength. Unalloyed tin is used as a lining material for water distillation plants and as a molten layer of metal over which plate glass is made. Tin is usually alloyed with copper, antimony, lead, titanium, and zirconium. Can be used in journal-bearing materials because of its low friction coefficient.

Precious Metals Also known as Noble Metals (Gold, Silver, and Platinum)

Gold (Au) Soft and ductile. n Has good corrosion resistance and any temperature. n Used in jewelry, coinage, reflectors, gold leaf for decorative purposes, dental work, electroplating, and electrical contacts and terminals. n

Silver (Ag) Ductile n Highest electrical and thermal conductivity of any metal. n Used as tableware, jewelry, coinage, electroplating, photographic film, electrical contacts, solders, bearing linings and food and chemical equipment. n Sterling silver is an allow of silver and 7. 5% copper. n

Platinum Soft, ductile. n Grayish-white metal. n Good corrosion resistance at any temperature. n Used as electrical contacts, for sparkplug electrodes, as catalysts for automobile pollution-control devices, in filaments, in nozzles as jewelry, and in dental work. n

Shape-Memory Alloys Can be deformed into any shape at room temperature but when heated will return to original shape. n A typical one is 55% Nickel – 45% titanium. n Used as sensors, eyeglass frames, stents, relays, pumps, switches, connectors, clamps, fasteners, and seals. n

Amorphous Alloys (Metallic Glasses) n n n No long-range crystalline structure. Have no grain boundaries and the atoms are packed randomly and tightly. First obtained in the 1960 s. Typically contain iron, nickel, and chromium, which are alloyed with carbon, phosphorus, boron, aluminum, and silicon. Have excellent corrosion resistance, good ductility, and high strength. Being developed to have twice the strength has high strength steels so they can be used in large structures.

Metal Foams Foam-like substances that metal is only 5% to 20% of its volume. n Very light weight. n Used in aerospace applications. n Also used as filters and orthopedic implants. n

Nanomaterials n n Materials with grains, fibers, films, and composites having particles that are 1 -100 nm in size. First investigated in the 1980 s. Have qualities superior to those of traditional materials such as strength, hardness, ductility, wear resistance, and corrosion resistance. Used in cutting tools, ceramics, powders for powdermetallurgy processing, next generation computer chips, flat panel displays for laptop computers and televisions, spark-plug electrodes, igniters and fuels for rockets, medical implants, high-sensitivity sensors, high power magnets and high-energy-density batteries.

References n n n n Ø Ø Textbook http: //www. airforcetechnology. com/projects/kc 767/images/767 tanker_4. jpg http: //www. alcaninbc. com/kitimat/sht-l. jpg http: //www. qualitycoach. net/data/i%5 C%5 Chs-1086 -2001. gif http: //flags. com/images/Eder. Flag%20 Catalog%20 Images/Flagpole%2 0 Cleats, %20 Halyards, %20 Snaps%20&%20 Accessories/Heavy. Duty%20 Cast%20 Aluminum%20 Cleat. JPG http: //www. cyclonecycles. co. uk/store/images/pedals_tenderizerped. jpg http: //www. schultz-antiques. com/stock_images/schultz_med/med _kettle%20 copper%202. jpg http: //www. brentkrueger. com/images/2004%20 Uncirc%20 Nickel%20 obverse-gs. jpg http: //wwwrpl. stanford. edu/images/research/microengine/cad_nozzle. jpeg

References cont. n n n n n http: //www. us. cbmm. com. br/english/sources/niobium/images/photo/ pirocl. jpg http: //www. tungstenringstore. com/images/products/246_large_imag e. jpg http: //www. b-jenterprises. com/images/bj 07. jpg http: //www. etc. org/technologicalandenvironmentalissues/chemicalso fconcern/zinc/images/molten-steel. jpg http: //www. rubberimpex. com/images/Rubber. Machinery/HBTR 01/Tyr e. Recap. Fittings. High. Carbon. Steel. Tyre. Polish. Nail. jpg http: //www. sgconsulting. co. za/Products/Batch. Mixer/Mixer 2. jpghttp: / /www. acesita. com. br/eng/imgs/inox. jpg http: //corrosion. ksc. nasa. gov/images/medium/con 1_med. jpg http: //www. jcwhitney. com/wcsstore/jcwhitney/images/imagecache/I 5430. gif The Columbia Electronic Encyclopedia, 6 th ed. Copyright © 2005, Columbia University Press

References Cont. n n n n n http: //www. vanderkrogt. net/elements/images/periodic_table. gif http: //www. mcachicago. org/search/images/large/WES 79 -1. jpg http: //www. nrhs. com/railfan/2004/bnsf-grain-train-carthage-mo. jpg http: //ftp. michaeldbaker. com/train/photos/library/4/i-beam-spacers. jpg http: //www. roadraceengineering. com/rreimages/evo 5 trans-gears. jpg http: //www. joybuy. de/databecker/images/fasteners. jpg http: //www. bildon. com/catalog/Admin/photos/large/049109101 GH-c. jpg www. nstms. com/ images/crankshaft. jpg http: //www. nicholaus. com/lex/images/Lexington 05%20 view%20 of%20 the%20 ship%20 from%20 the%20 beach. jpg http: //www. rustfreetrucks. com/bridges/ibeam 7. jpg http: //www. geo. msu. edu/geo 333/images/iron-ore-closeup. jpg http: //www. geol. sci. hiroshima-u. ac. jp/~geotect/stonemuseum/photoimage/limestone. jpg http: //www. energysolutionscenter. org/Heat. Treat/Metals. Advisor/iron_and_steel/process_ descriptions/images/ironmaking. jpgs http: //www. bartleby. com/images/A 4 blfurn. jpg http: //www. schoolscience. co. uk/content/4/chemistry/steel/images/eafurnace 2_02. gif http: //www. gltaac. org/images/Ingots. gif http: //www. imt. si/images/oddelki/kovinski-laboratorij_za_metalurske_procese 02. jpg http: //www. hfinster. de/Stahl. Art 2/images/steel-industry_C-1 -8 -01. 0001. jpg