MetalsMajor TopicsMajor Topics con’tHistory of MetalClassification of MetalsAlloysIronMaterials Used to Make IronTypes of IronSteelMill OutputStandard Mill ProductsDesignations of Rolled Steel ShapesExample of DesignationSamples of Steel ShapesSteel WireClassification of SteelStainless SteelStructural SteelSteel ConstructionSteel FastenersWeldingSteel Floor and Roof FramingOpen Web Steel JoistsAluminumLeadZincCopperBronzeBrassNickel, Chromium, and MonelClad MetalsGalvanic Action1MetalsMajor TopicsHistoryClassification of MetalsIronSteelSteel pipe, Tubing, and WireSteel FastenersRivetsStructural BoltsWeldingSteel Floor & Roof FramingMajor Topics con’tAluminumLeadZincCopper and AlloysNickel, Chromium, Cadmium & TitaniumClad MetalsHistory of MetalUsed as early as 8000 B.C.Early civilizations mainly used metal for weapons, tools, and body armor Metal has been used for construction material ranging from simple fasteners to main structural membersClassification of Metals2 main classificationsFerrous- metals containing a large percentage of iron (Fe)Cast ironWrought ironSteelNon-Ferrous- metals which do NOT contain ironAluminumLeadCopperBrassBronzeAlloysAlloy – a substance composed of two or more metalsBlanking- in sheet metalwork, the cutting out of a piece of metal (using a press)Braking- a mechanical bending operation usually performed on sheets and platesCasting- an article formed by solidification of molten metal in a moldCold drawing- drawing metal through a die without the application of heatCold-rolled- metal rolled at room temperature, below the softening point, usually harder, smoother, and more accurately dimensioned that hot-rolled material.Drawing- forcing metal to flow into a desired shape without melting by pulling it through diesEmbossing- creating a raised surface (design) on metal by die pressure or by stamping or hammering on the reverse surfaceExtrusion – forcing a molten metal through a die by pressureForging- heating and hammering or pressing metal into a desired shapeIronOne of the most abundant metals on earthCommercial iron is composed of carbon, manganese, silicon, phosphorus, and sulfurMaterials Used to Make IronIron oreCoke- fuel used to melt iron; derived from coalLimestone- used as a fluxFlux – a material added to react chemically with impurities and remove them from molten metalPig Iron- initial molded product from a blast-furnace; weak & brittle, but very hardTypes of IronCast iron (and gray cast iron)- brittle metals with high compressive strength and capacity to absorb vibration. Lack ductility and therefore should not be hammered or beaten. Relatively corrosion resistant. Contains 2-4 % carbonUsed for gratings, stair components, manhole covers, some pipingWrought iron- soft, corrosion and fatigue resistant, and easily machined. Contains < 1 % carbonUsed for railings, grilles, fences, screens, and various ornamental workSteelA malleable alloy of iron and carbon with substantial quantities of manganese3 main methods for making steelOpen-hearth processOxygen processElectric furnace processMill OutputIngot- molded square or rectangular blocks of cast metalIngots are further squeezed between rollers to produce:Bloom- a rectangular solid of steel formed from an ingot as an intermediate step in creating rolled steel structural shapes (over 36” square)Billet- a large cylinder or rectangular solid of metal (smaller then 36” square)Slab – if the width is 2x the thickness or moreStandard Mill ProductsAngle- a section of metal rolled, drawn, or extruded through L- Shaped rolls or diesBar- round, square, rectangular, hexagonal, or solid stock of drawn, rolled, or extruded metal. A rod.Channel – a rolled, drawn, or extruded metal section having a U shape.Flat- a rectangular bar whose width is greater than its thicknessPipe, round- a hollow, round section of metal, the size of which is determined by the nominal inside diameter in inchesPipe, square- a hollow, square section of metal, the size is determined by the nominal outside diameter in inchesPlate- a flat piece of metal; various metals are defined as plate by the following thickness criteria: Aluminum==1/4” or more; Copper==.188” or more; Steel (including stainless)== 3/16” or moreDesignations of Rolled Steel ShapesW – wide flange S -- beamsC –channelsL – angles (may be equal or unequal legs)WT or MT – structural teesExample of DesignationW 36 x 300W === a wide flange beam36 === indicates a beam 36” deep300 === weight in lbs/ linear feetSamples of Steel ShapesChannelSquare & Rectangular TubingAngleTeeS-BeamWide FlangeSteel Wire6 million tons of wire produced in the U.S. annuallyShapes are not only round, but may also include: square, rectangular, and polygonalWire is used as the starting material to form nails, bolts, screws, rivets, and welding electrodesTemper- wires hardness, stiffness, and strength is affected by the amount of carbon and alloying agents, number of passes through dies, and the final heat treatmentWire may be produced with different finishes and coated, painted, or plated depending on its intended useClassification of SteelFour main specificationsMethod of manufactureHeat treatmentChemical compositionReference to a recognized standardStainless SteelTo be considered stainless a steel must contain 11.5 % chromiumThere are basic series of stainless steel: 200, 300, 400, & 500 seriesAvailable in many finishes ranging from matte to highly reflective (mirror)Structural SteelConsists of hot-rolled steel section, shapes, and plates not less than 1/8” thickThe most commonly used strength grade is 36,000 psi yield strength (ASTM 36)For heavily loaded members such as columns, girders, or trusses, a high strength, low alloy steel with a yield strength of 50,000 psiSteel Construction3 basic types:Wall bearingSkeleton framingLong-spanLarge industrial buildings, auditoriums, sports arenasOften use steel trusses, steel arches, or rigid bents in this type of construction (see figures 5-17, 5-18, and 5-19 on page 127)Steel Fasteners3 main types of fasteners:RivetsBoltsUnfinished (common, machine)High-strength structural bolts- resist vibration (ASTM 325 or A490 are