INTRODUCTION TO MANUFACTURING PROCESSES
INTRODUCTION TO MANUFACTURING PROCESSES ME 4563
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This 78 page Class Notes was uploaded by Katelin Goldner on Friday October 2, 2015. The Class Notes belongs to ME 4563 at Arkansas State University taught by Shivan Haran in Fall. Since its upload, it has received 52 views. For similar materials see /class/217729/me-4563-arkansas-state-university in Mechanical Engineering at Arkansas State University.
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Date Created: 10/02/15
ME 4563 introduction to Manufacturing Processes Arkansas State WWW ME 4553 mm In Manu Lab Dr 5 Hamquot Sand Casting A Simple Example The subject of the sand casting procedure below is a split pattern which forms half a hand brake drum for a scale model steam truck ME 4553 mm In Marm Lab Dr 5 Hamn Sand Casting 1 f 1 On the left is the top cope and on the right is the bottom drag molding boxes 2 The halfpattern is placed on the base plate ready to take the sand M54563 mm a Manuf Lab 0 S Ham Sand Casting 3 The sand is tipped in the box and rammed down The ramming tool is shown in front The wedged end is used for the rst ramming and the at end is used on the second ramming 5 Once the ramming is complete and the surface is leveled the box is carefully turned over on its back The exposed surface of the pattern is clearly shown M54563 mm a Manuf Lab Dr S Halan Sand Casting 5 The surface is dusted with parting powder and the other half of the pattern is placed on the first half still embedded in the sand The top box is placed on the bottom box and skewed clockwise against the registration pegs ME 454 Intro to Mimm Lab 17 5 him Sand Casting 6 The runner right tube is pushed into the sand in the bottom box and the riser left tube is placed onto the pattern hub The tubes are held in place While the sand is shoveled in ME 4553 Intro to MiaInf lab 17 5 him Sand Casting 7 The sand is rammed down and leveled off The runner basin is cut into the top surface of the sand at this stage The boxes can now be separated very carefully M54653 Intro to Manuf Lab Dr 5 Halal Sand Casting 8 The box halves with the pattern still in place The white surface is the parting powder talc The small hole in the sand is the well left by the runner tube MEMM Intro to Manuf Lab Dr 5 Halal Sand Casting L a igt 9 The pattern is removed by lightly tapping it The runner bar with its extension and the ingate is cut into the sand surface and smoothed off At this stage the boxes are put back together M5456 Irma a Manuf Lab Dr S Halal Sand Casting 10The completed mould ready to pour in the molten cast iron The iron weights help keep the boxes together during the pouring process M54563 mm a Manuf Lab Dr S Ham Sand Casting l lThe molten cast iron being poured into the mould The slag is kept away from the pouring lip 154553 1mm Mamn Lab Dr 5 Hami Sand Casting 12 The metal has cooled Note the runner basin on the right and the riser opening to the left Mum 1mm Mamn Lab Dr 5 Hm Sand Casting 13 The casting is removed from the sand and looks like this The riser and sprue are cut off the main casting M54563 rmlyWan Lab 0 5 Haran 13 ME 4563 Intmduct m to Manufacturing Pmcesses Od ege 0 Emmy Am State WWW ME 4553 Dr 5 Hanan Bulk Deformation ME 4553 Dr 5 Hanan Deformation What is deformation processing Process to make parts without material removal Deformation occurs on parts with LD approx equal to 1 Example of products Typical product dimensions Small coins surgical wire etc Large power plant turbine shafts aircraft landing gear etc ME 4553 Dr 5 Hanan Deformation Cast Structures are converted to wrought structures through some means of deformation Normally starts with material that has been cast ingots slabs rods or pipes Several different parts may be formed The process involves heat in most cases and force to create the shape ME 4553 Dr 5 Hanan Deformation Deformation Process characteristics I Material is deformed improvement of material properties grain refinement grain orientation work hardening I Material is conserved minimal trimming and machining ME 4553 Dr 5 Haran Deformation Deformation Process characteristics Effect on grain structure Large grains are broken up Grains can be made to flow ME 4553 Dr 5 Haran Deformation Deformation process may be classi ed according to Temperature of deformation Hot working 39 Cold working Warm working Purpose of Deformation 39 Primary Processes 39 Secondary Processes ME 4553 DE 5 Haran Deformation Working temperature Coid T lt 04 Tmelting strain hardening effect no strain rate effect Hot T gt 06 Tmeltlng no strain hardening effect strain rate effect ME 4553 DE 5 Haran Deformation Strain Rate Given by the ratio of the rate at which the specimen is pulled in tension or pushed in compression v to the instantaneous deformed length l e Units 7 Low strain rates allow more time for atomic or molecular rearrangement leading to lower stresses and higher ductility Effected by Temperature M54563 Dr 5 Haran g Deformation Hot working Temperature of the work piece is high above room temperaturequot 600 1000 deg C depending upon metalalloy Advantages Flow stresses are low lower forces amp power requirements very large pieces can be worked on ductility is high hence large deformations amp complex pans pair surface nish variations in n39 h temperatures lead to wide dimensional tolerances Disadvantages Energy required to heat the piece oxidizing can im Is ing M54563 Dr 5 Haran Deformation Cold working Working at room temperature May be raised to 100 200 deg C depending upon metalalloy Advantages in absence of cooling amp oxidation better tolerances and finishes high strength process can be better controlled in terms of material properties that need to be achieved Disadvantages Flow stresses high so are tool pressures and deformation forces hence higher power requirements too Ductility of many materials limited limiting the complexity of shapes that can be achieved ME 4553 Dr 5 Hanan 1 1 Deformation Warm working Working in between temperatures of hot and cold working Normally to take advantage ofthe material s behavior at speci c temperatures Example working of steel between 650 and 700 deg C Temperatures are low enough to avoid scaling leading to good surface finish yet high enough to reduce stresses and deformation forces ME 4553 Dr 5 Hanan 12 Deformation Purpose of Deformation As a Primary Process These aim to destroy the cast structure by successive deformation steps Results in a semifabricated product that will be worked on further slabs billets plates Conducted on large scale at specially constructed plants ME 4553 Dr 5 Hanan Deformation Purpose of Deformation As a Secondary Process Take products of primary process and further transform them into a nished part bolts metal parts wires rods etc Focus of all forging as well as other deformation processes ME 4553 Dr 5 Hanan Deformation Involves a machine which causes gross or bulk deformation to provide a new shape Can only use these processes when the material has a plastic regime in its stress strain behavior Most metals Most plastics Some materials must be formed hot to obtain plastic behavior Q ME 4553 Dr 5 Hanan 15 Failure ME 4553 Dr 5 Hanan 16 Bulk Deformation Processes Resultant shape is usually furtherworked or shaped Total deformations can be very large Foil 5000 Can stock 1400 Typical sheet 400 Typical Plate 3 Extrusions 8 Deformation initial dimension nal dimension ME 4553 Dr 5 Hanan Bulk Deformation Processes for Metals Falls into the following major categories Forging discrete parts with a set ofdies 39 Rolling at shapes and uniform cross sections hot and cold 0 Extrusion long lengths of solid or hollow parts with constant cross sections hot amp cold Drawing long rods and wires Swaging radial forging of components ME 4553 Dr 5 Hanan Bulk Deformation Processes Forging starts with a sawn off section of a cast or extruded ingot and ends up with a multitude of shapes close to final form Least work required to make a useful product ME 4553 Dr 5 Hanan 19 Characteristics of Products Forging Produces discrete parts with a variety of unlimited shapes Typical properties better than extrusions Surface nish fairto good High die and equipment costs Moderate to high labor costs Moderate to high operator skill ME 4553 Dr 5 Hanan 20 Bulk Deformation Processes Rolling typically starts with a rectangular ingot andresu sinvanousshapes Plates t gt 6mm Rolls ofthin sheet t lt 6mm Rods Bars Structural shapes lBeams for eg Rails Typically material must be further shaped or formed to be useful ME 4553 Dr 5 Hanan Characteristics of Products Flat Produces coils of sheet and foil rectangular at plate Excellent properties Good surface nish High capital investment low labor costs Skilled labor required to operate mill Shape Produces shapes of diverse cross section Excellent properties along the rolling direction Good surface nish Expensive specially shaped rolls Low labor costs Relatively low labor skill required to operate mill ME 4553 Dr 5 Hanan Bulk Deformation Processes Extrusion starts with typically cylindrical cast ingots and results in a multitude of shapes usually with constant cross section close to final form Less subsequent work is required to make products useful then rolled sheet or plate ME 4553 Dr 5 Hanan Characteristics of Products Extrusion Produces long lengths of solid and hollow shapes with usually constant cross section Product may be cut to form discrete products Excellent surface nish Excellent properties Moderate to high equipment cost dies are expensive Low to moderate labor costs Low to moderate operator skill ME 4553 Dr 5 Hanan Characteristics of Products Drawing Produces long lengths of solid rod or wires of constant cross section Smaller cross sections than typical extrusion Good surface finish Low to moderate equipment and labor costs Low to moderate operator Skill Ill 455 Dr 5 laban Txpical Formed and Shaped Parts In an utomo ie Ceramic Spark Plug Forged Valves Stamped wheel covers MOlded dashboard Springs Shaped Windshield Coldrolled sheet metal MOlded tires bady Metal and plastics Blow molded plastic Stamped plates tanks for uids Drawn tube for antenna Tail light lenses Ill 455 Dr 5 laban Forging ME 4553 Dr 5 Hanan 27 Forging 39239 Forging denotes a family of processes by which plastic deformation ofthe workpiece is carried out by compressive forces at room temperature cold or at elevated temperatures hot 3919 Simple forging can be made with a heavy hammer and an anvil using techniques that have been available for centuries 39239 However usually a set ofdies and a press are required ME 4553 Dr 5 Hanan 28 Forging a a 0 7 illustration of the Blocker pinbm steps involved in forging a bevel gear 322 With a shaft 6 m Source Forging Industr Association Near nu ME 456 Dr 5 Hanan Outline of Forging and Related Operations 39IPaliing Coliung Fllilwin Hubhing thrriilg Gagging Run urging 5km luiliun Fiin iarm 5 op die impression riic Cimcd div Plecisicn o rbitni SnaguIR 1 Mad l iimnmm Presses Folglng machines Di dusign ma mnnt anuriilg i iilirimiiml ME 456 Dr 5 Hanan Forging Advantages The grain ow ie the directional pattern that metal crystals assume during plastic deformation can be aligned with the directions ofthe principal stresses that will occur when the work piece is loaded in service Higher strength ductility and impact resistance are achieved along the grain ow ofthe forged material than in the randomly oriented crystals ofthe cast metal or welded metal Structural integrity from piece to piece is better Good quality forging control makes it easier to avoid internal pockets voids inclusions laps etc mam Dr 5 laban 3 Forging A part made by three different processes showing grain ow a casting b machining c forging Source Forging Industry Association a Ill 455 Dr 5 laban 32 Forging Disadvantages The forged parts often need to be machined before use Forging tooling for complicated geometry may be expensive and require multiple passes on the same work piece ME 4553 Dr 5 Hanan 33 Materials used in Forging I Material must have a good quotforgeabilityquot I that can be shaped with low forces and without cracking is said to have a good forgeability I Forgeability competes with other properties and geometry of the workpiece such as strength corrosion resistance toughness fatigue resistance heat resistance size and section thickness I Combined effects of temperature and deformation change the properties of the material I Hence helpful to know or predict how the rnrncc will altor rho mafnrial I M54le DnsHaran 39 39 34 Materials used in Forging 39 Most commonly forged materials are steels copper forging brass naval brass bronze and copper alloys 39 As for steels their forgeability decreases as their carbon and alloy content increases ME 4553 Dr 5 Hanan 35 Classification of Metals in Decreasing Order of Forg eabl I Ity TABLE 143 Metal or alloy Approximate range of hot forging temperature C Aluminum alloys 4007550 Magnesium alloys 2507350 Copper alloys 6007900 Carbon and lowialloy steels 85071150 Martensitic stainless steels 110071250 Austenitic stainless steels 110071250 Titanium alloys 7007950 Ironbase superalloys 105071180 Cobaltbase superalloys 118071250 Tantalum alloys 105071350 Molybdenum alloys 115071350 Nickelbase superalloys 105071200 Tungsten alloys 120071300 ME 4553 Dr 5 Hanan 36 mmusms Flow smzugw on ronmm Dussmmr I Low Mnnanrr MEN Forg39ng gt y Iquot 2 39 wasnmv g E Alsaleumvy masquuow 5 s WWW 2 mmmmuw vnmswmzss g mm x Anon E usmAILcMVIELy than swims 5 W E M54563 1754212 37 Forglng Processes I Open DIe I ImpreSSIon DIe I Closed DIe I Upset Forging I Precision Forging I Swaglng I Other Variations 38 M54563 17 5 Ham Open Die Forging ME 4553 Dr 5 Hanan 39 Open Die Forging It is the simplest form of forging Involves placing a solid cylindrical work piece between two flat dies and reducing its height by compressing it The die surfaces can also be shaped therefore forming the ends of the cylindrical work piece while compressing it ME 4553 Dr 5 Hanan 40 20 Open Die Forging 1 Solid cylindrical billet deformed between two flat dies 2 Uniform deformation of the billet without friction 3 Deformation with friction Note barreling ofthe billet caused by friction forces at the billetdie interface il Friction Fortes Workpi ec e anelmg M455 0 s Halal M Open Die Forging Forging Shafts W1 12 39 E w m Starting stock held by manipulator Open die forging Progressive forging Machining to finish mm 0 s Halal 42 Open Die Forging Open Die Forging MEMM Dr 5 Halal Open Die Forging Forging Disks 1 Starting stock Preliminary upsetting Progressive upsettingforging l l to disk dimensions Piercing to finish M455 0 s Halal 44 Open Die Forging Hollow Sleeve Typequot Forging Starting stock a punched disktube on a tapered draw bar held as shown Progressive reduction to required diameter Increases overall length of sleeve ME 4553 Dr 5 Hanan 45 Open Die Forging Ring Typequot Forging Starting stock a preformed disk mounted on a mandrel Progressive reduction of wall thickness to required diameter 0 Finish to the ring dimensions ME 4553 Dr 5 Hanan 46 23 Open Die Forging Rolled Ring Forging unseen we Starting stock a preformed le ring mounted on an idler x roll Pressure applied by drive roll Progressive reduction of wall thickness to required diameter Axial rolls control the height Finish to the ring dimensions MEMM Dr 5 Halal Open Die Forging Ring Forging MEMM Dr 5 Halal Impression Die Forging Mum a 5 Hami W Impression Die Forging 39 The work piece is forced to conform to the shape of the die cavity while it is being compressed between the closing dies I Closing of the die cavities occurs at high striking forces Some 0 the material flows radially outward and forms a ash 39 Workpiece acquires the shape of the die cavities Diea lII Blank 4 g 435 we II Mum a 5 Hami Impression Forging Die External and internal draft angles l Standard terminology for various features of a typical impressionforging die Ill 455 Dr 5 laban Impression Die Forging Flash 39 Formation of flash prevents further material from flowing in the radial direction in the flash gap 39 lengthtothickness ratio being high 39 results in high frictional resistance to material flow 39 In Hot forging 39 flash cools faster than the bulk of the work piece 39 higher resistance to deformation compared to the bulk 39 plays a significant role in helping filling the die cavities Ill 455 Dr 5 laban Impression Die Forging Before After Trimming ash from a forged part Punch Note that the thin material at the center is removed by punching Stationary punch Trimming die S g i ME 4553 Dr 5 Hanan 53 Impression Die Forging a Stages in forging m 3 a connecting rod for m m m in an internal i combustion engine 7 Die Note the amount 0 ingmg WWW ash required to ensure proper lling r n Bimknlx o b Fullering and c edging operations to v distribute the a material when iilnsliing preshaping the blank rging Tilimlnnu ME 4553 Dr 5 Hanan 54 Die Inserts mm m mmk V arr7 m 5G 1mm quot llrrz Irrserl lHlZ VneriPrrA llhArll rm n W lmur l li lrlHL ie inserts used in dies for forging an automotive axle housing Source Metals Handbook Desk Edition ASM International Metals Park Ohio 1985 Used with permission M5455 Dr 5 laban Closed Die Forging ME 455 Dr 5 laban Q Closed Die Forging I In closedrdierforging no ash is formed and the Work piece is completely surrounded by the dies I Therefore proper control ofthe volume of material is essential to obtain a forging o desired dimensions I Undersized blanks in closedrdie forging prevent the complete filling of the die while oversized blanks may cause premature die failure orjamming ofthe ies Mum m 5 mquot Closed Die Forging Mum m 5 mquot Closed Die Forging Forging will Flzbliless Flash Forgin Flash plush a 5mm of stroke Ill 455 Dr 5 laban Comparison of Forging Mth and Mthout Flash Forging Comparison of closeddie forging to precision or ashless forging of a cylindtical billet 0117136 Takemasu V Vazquez B Painter an T Altan h End of snake Closed Die Forging Cold Forging Heading a common technique for making fasteners gathers steel in the head and other sections along the length of the part Ill 455 Dr 5 laban Precision Forging ME 4553 Dr 5 Hanan 51 Precision Forging When Forging Demands economical manufacture greater accuracy less postforging machining operations then Precision Forqinq is used ME 4553 Dr 5 Hanan 62 31 Precision Forging Also known as Net shape forging Close tolerance forging No draft forging Machining is minimized exposure of endgrains is less reduction in corrosion amp cracking ME 4553 Dr 5 Hanan Precision Forging Accurate billet weight is first taken minimizes ash minimizes wastage Materials suited for Precision Forging process Magnesium alloys Aluminum ME 4553 Dr 5 Hanan 32 Precision Forging I Compared to conventional forging Close tolerances Low draft Close control of the process process temp pressure during forging cycle Isothermal forging part amp die are at the same temperature Ill 455 Dr 5 laban Precision Forging Through Die D39 15 Types I J UPPER DIE 7 Through D162 1 7 Wrap Die I I RING DIE l I 71 LOWER DIE in Ill 455 Dr 5 laban Precision Forging Wrap Die UPPER DIE RING DIE WRAP DIES LOWER DIES Ill 455 Dr 5 halal Precision Forging Advantages of Using Through amp Wrap Dies Excess material is flashed vertical no external drait angle mismatch allowance Small fillets die lls owthrough defects do not occur inner walls 3 degree taper to vertical Ill 455 Dr 5 halal Precision Forging Applications Turbine Blade Bene ts better qualltv control 20reduc1lo in cosi conventional M51555 Dr 3 an 59 Precision Forging Applications Gear and Pinion Benefits reduced noise by 30 improved strength by up to 30 20 reduction in cost machiningl M51555 03 W m Precision Forging Applications Pulley Clutch Assembly Benefns better durability 20 reduction in cost conventional forging ME 45 Dr 5 Hanan 71 Precision Forging Applications Hip Joint Benefns Increased durability Reduced corrosion ME 45 Dr 5 Hanan 72 36 Upset Forging ME 4553 Dr 5 Hanan 73 Upset Forging Upset Forging a process of increasing the diameter of a material by compressing its length 0 Most Widely used of all forging processes ME 4553 Dr 5 Hanan 74 37 Upset Forging Parts can be forged both hot and cold Normal starting stock would be Some machines can forge bars up to 250mm in diameter ME 455 Dr 5 Halal 75 Upset Forging a Heading operation to form heads on fasteners such as nails and rivets b Sequence of oper ions to produce a bolt head by heading ta Kickum pm Die Blank mm m i gt im 1 32 mm diam J Head umwd E C 1quot punch Hum rm ed 1 i L P m mnw lt T M54561 Dr5b aran 7B Upset Forging Die Punch F 39 woik wiro slack in mi i l e l 3i i V iii 397 mi ME 4563 Dr 5 Haran 77 Upset Forging Design Aspects The limiting length of unsupported metal that can be upset in one blow Without buckling is 3 times the bar diameter 7 WM 0 Failure gt buckling Violation 039 Rule Applications of Rule I ME 4563 Dr 5 Haran 39 Upset Forging Design Aspects Lengths of stock greater than 3 times the diameter may be upset successfully provided that the cavity diameter is not more than 15 times the bar diameter IIJlltlvnwl 9 MLA Violation of Rule 2 s Applications of Rule 2 ME 4563 Dr S Haran Upset Forging Design Aspects In an upset requiring stock with length more than 3 times the bar diameter and when the diameter upset is 15 times the bar diameter the length of unsupported metal beyond the die face must not exceed the bar diameter f eli f ZTT39 S 7 IlIIa Violation of Rule 3 Applications of Rule3 ME 4563 Dr S Haran 40 Upset Forging ysaeooquot amp 339 393 11 go by Q Y 53939 439 9 a Ill 455 Dr 5 laban Variations in Forging ME 455 Dr 5 laban Variations in Forging The following are miscellaneous forging operations 00 Coining Minting of coins where the slug is shaped in a completely closed cavity is an example of closeddie forging To produce the fine details of a coin high pressures and sometimes several operations are needed while lubricants are not used because they can prevent reproduction of fine die surface detai s ME 456 Dr 5 H673 Variations in Forging a Schematic illustration ofthe coining process The earliest coins were made by opendie forging and lacked sharp details b An example of a coining operation to produce an impression of the letter E on a block of metal a Upper die Retaining 7 Die quot5 liultler b Die imiderg kaplece I 739 Lower E rWOIkpicce Die wim l depressions 1 la die ME 4553 Dr 5 Hami 84 Variations in Forging o v Heading Heading is an example of opendie forging t transforms a rod usually of circular cross section into a shape with a larger cross section The heads of bolts screws and nails are some examples of heading The work piece has a tendency to buckle if the lengthto diameter ration is too high M54553 DniHaran Variations in Forging o v Roll Forging A bar is passes through a pair of rolls with grooves of various shapes This process reduces the crosssectional area of the bar while changing its shape This process can be the final forming operation Examples are tapered shafts tapered leaf springs table knives and numerous tools It can also be a preliminary forming operation followed by other forging processes Examples are crankshafts and other automotive components ME 4553 Dr 5 Hanan 43 Variations in Forging Two examples of the rollforging operation also known as cross rolling Taperedleaf springs and knives can be made by this process Source a J Holub b reprinted With permission of General Motors Corpora 39on m ME 456 Dr 5 Halal Variations in Forging Blank i Die 0 Finished Ejector mm a Production of steel balls by the skewrolling process b Production of steel balls by upsetting a cylindrical blank Note the formation of ash The balls made by these processes are subsequently ground and polished for use in ball bearings b ME 456 Dr 5 Halal Variations in Forging Piercing The work piece either confined to a die cavity or unconstrained is pierced by a punch to produce a cavity or an impression The piercing force depends on three factors the cross sectional area of the punch and its tip geometry the flow stress of the material and the friction at the interface lt Hubbing It is a piercing process where the die cavity produced is used for subsequent forming operations To generate a cavity by hubbing a pressure equal to three times the ultimate tensile strength of the material of the work 39 ic nnnr lnr l M54553 unsnamn 89 Variations in Forging Cogging Also called drawing out successive steps are carried to reduce the thickness ofa bar Forces needed to reduce the thickness of a long bar are moderate if the contact area is small 39239 Fullering and Edging It is an intermediate process to distribute the material in certain regions of the work piece before it undergoes other forging processes that give it its final shape ME 4553 Dr 5 Hanan 90 Variations in Forging Swaging Swaging Also called Rotary swaging or Radial Forging Solid rod or tube is reduced in diameter by the reciprocating radial movement of two or four dies 5 is carried out at room tem perature Internal diameter and thickness can be controlled with or without mandrels External shapes can also be had on the rod or tube Size usually limited to about 50mm dia 2 in Length is limited by the length of the mandrel where required Improved mechanical properties and dimensional accuracy Ill 455 Dr 5 laban m llummm mum Variations in Forging im Rotaryswaging or Radial Forging 4m Typi cal parts made bx swag Swaging of Tubes With and Without a Mandrel o o 0 Tube t dlegap u a5 id 39 39 39 39 39 tube depends on the mandrel diameter c Examples of crosssections oftubes produced by smging on shapedmandrels Ri ing spiral grooves in smallan ls can be made by this process ME 4553 Dr 5 H673 93 Forging Machines Presses Hydraulic Mechanical Screw Hammers Gravity Drop drop forging Power Drop steam air fluid Counter blow two hammers High energy rate one blow ME 4553 Dr 5 H673 94 Speed Range of Forging Equipment TABLE 144 Eguipment ms Hydraulic press 0067030 Mechanical press 006715 Screw press 0642 Gravity drop hammer 36748 Power drop hammer 30790 Counterblow hammer 45790 Ill 455 Dr 5 rm 95 Principles of Various Forging Machines Eccentric shah a n Flywlwvl Conneding rod Frame Ram or slink Schematic illustration of the principles ofvarious forging machines a Hydraulic press b Mechanical press with an eccentric drive the eccentric sh can be rep ace by a cranksha to give the upanddown motion to the ram continue Ill 455 Dr 5 laban BB Principles of Various Forging Machines i Emmi Schematic illustration of the principles of various forging ines c Knucklejoint press d Screw press e Gravity ME 456 Dr 5 Hanan Open die forging Hydraulic Press ME 456 Dr 5 Hanan Open die forging Push down Hydraulic Press ME 4553 Dr 5 Hanan Open die forging Pull down Hydraulic Press ME 4553 Dr 5 Hanan 50 Open die forging Rotator for Forging press K42 Mm Forging Dies K42 Mm Forging Dies Die design is an integral part of the forging process Several factors to be considered Final part shape determined by die accuracy Multiple parts can be made in one die Progressive shaping can be done in one die set Need to be stronger than highest forging stress M456 Dr 3 Han 103 Forging Dies Failure of Dies generally results from one or more of the following causes 39 Improper design 39 Defective material 39 Improper heat treatment and finishing operations 39 Excessive wear 39 Overloading 39 Misuse 39 Improper handling W456 Dr 5 Hanquot 104 Forging Dies Important Parameters I Die materials I Draft angles I Flash I Parting Lines I Fillet radii ME 4553 Dr 5 Hanan Forging Dies Die Materials Operating conditions of Dies I high pressures I high temperatures I abrasion Die qualities required I good strength I toughness I thermal shock resistance I hardness ME 4553 Dr 5 Hanan 53 Forging Dies Die Materials I Forging steels I special alloy steels I nickel chromium molybdenum I Forging nonferrous metals I alloy steels I chromium molybdenum vanadium I Die steels I machined hardened and tempered ME 456 Dr 5 Halal Forging Dies Draft Angles I the taper applied to external and internal sides Ufa closed die forging I Function I Outside draft angle I 3 degrees I 7 degrees I lnside Draft angle gt I to aid in metal flow I to facilitate removal 0 part after forging Inslde o39mll mm CUISIUE mall mng In the die caVIty 7 Fillet cumm 7 Upper Jiv I Al Mg 4 mung m I steel titanium Flaw 7 me A Luwm mu P Anwv Forging Dies Flash I In closeddie forging I flash is formed between the die halves Frictional resistance in flash land I increased die cavitv pressure I Flash gutter I provides space fc excess material r Upper Die I limits pressure Metal buildup Lower Die Land Cutter ME 4563 Dr 5 Haran 109 Forging Dies Parting Lines I The surface separating the upper and lower halves I straight I horizontal I inclined in one or more planes Influences I initial cost I die wear I grain flow mechanical properties postforging machiningtrimming operations ME 4563 Dr 5 Haran 110 55 Forging Dies Parting Lines It should pass through the maximum periphery of the forging Farting line Preferred Less desirable M 4563 DLSHaIan 111 Forging Dies Parting Lines Simplify die construction reduce costs eliminate possible mismatch Plane surface formed by flat upper die farting r13 Contour of forging formed by impression in bottom die 9154563 DLSHaIan 112 56 Forging Dies Fillet Radii Practice is to Provide generous radii abrupt change in metal flow direction gt defects Die Fillets min radius 3mm too small gt stress concentrations M 4563 Dr S Haran Forging Dies Effects of Fillet Radii taming M54563 Dr S Haran 57 Defects in Forged Parts Main forging defect Surface cracks due to sticking and barreling leading to tensile forces on the surface 0 operation ME456 J Dr 5 Han 1 1 5 Defects In Forged Parts m H Rd mm 1 1 l Im Han Inan Mm mumg urn hnrklm law in lluuhrd rumquot KM mm mm 0 mm nub mm aw b01va dump in prolugm Illd my quotHungry m Examples of defecw in forged parts a Laps formed by Web buckling during forging Web thickness s ould be increased to avoid this problem b Internal defects caused by oVersized billet die cavities are ed prematurely and the materi e center ows past the lled regions as the dies close M455 DI 3 Hanquot 116 Forging Economics Factors in the cost of Forgings Tool amp Die costs moderate to high depending upon the complexity of the job Spread over number ofjobs Cost of dies relative to material cost that is to be forged high for small parts Setup and tooling costs decrease as number of jobs increase Labor costs are generally seen to be moderate Die design and die manufacturing is being done by CADCAM operations leading to more economical forgings mam 05mm W l 000 S o 5 Unit cost relative Unit Cost in Forging Typical unit cost cost per piece in forging note how the setup and the tooling costs per piece decrease as Total cost a H Material cost same die l 10 100 1000 Number of utes Ill 455 D39s7am ME Relative Unit Costs of a Small Connecting Rod Relative unit costs of a small connecting rod a w Win a w forging and casting 2 mo r J V processes L g lo l F773 m I 16 Note that for large 7 io immging quantities forging is 8 mama in more economical g g a Sand casting is the a 39 T more economical l Sand Permanen process for fewer than 01 casting mum mung about 20000 pieces ii l 10 100 Number or pleccs x in Mum 0395an MB 2 Forging vs Casting Forgings are stronger Casting cannot obtain the strengthening effects ofhot and cold working Forging surpasses casting in predictable stren properties producing superior strength that is assured part to part Forging re nes defects from cast ingots or continuous cast bar A casting has neither grain ow nor directional strength and the process cannot prevent formation of certain metallurgical defects Pre working forge stock produces a grain ow oriented in directions requiring maximum strength Ill 455 Dr 5 laban Forging vs Casting Forgings are more reliable less costly Casting defects occur in a variety of forms Because hot working refines grain pattern and imparts high strength ductility and resistance properties forged products are more reliable And they are manufactured without the added costs for tighter process controls and inspection that are required for casting ME 4553 Dr 5 Hanan 121 Forging vs Casting Forgings offer better response to heat treatment Castings require close control of melting and cooling processes because alloy segregation may occur This results in nonuniform heat treatment response that can affect straightness of finished parts Forgings respond more predictably to heat treatment and offer better dimensional stability Forgings39 flexible costeffective production adapts to demand Some castings such as special performance castings require expensive materials and process controls and longer lead times Opendie and ring rolling are examples of forging processes that adapt to various production run lengths and enable shortened lead times ME 4553 Dr 5 Hanan 122 Forging Applications AUTOM011VE amp TRUCK The characteristics of forged parts strength reliability and economy are what makes them ideal for vital automotive and truck applications Forged components are commonly found at points of shock and stress such as wheel spindles kingpins axle beams and shafts torsion bars ball studs idler arms pitman arms and steering arms AGRICULTURAL MACHINERY amp EQUIPMENT VALVES FITTINGS OIL FIELD APPLICATIONS Because of their superior mechanical properties and freedom from porosity forgings are often associated with the high pressure applications of the valve and tting industry Corrosion and heatresistant materials are used for anges valve bodies and stems ow reducers saddles and other ttings Oil eld applications include rock cutter bits drilling hardware and highpressure valves and ttings HAND TOOLS amp HARDWARE Pliers hammers sledges wrenches and garden tools as well as wirerope clips sockets hooks turnbuckles and eye bolts are common examples Surgical and dental instruments are also often forged Special hardware for electrical transmission and distribution lines such as pedestal caps suspension clamps sockets and brackets are commonly forged qth quot d re i tance to corro ion ME 4553 Dr 5 Ham 123 Forging Applications OFFHIGHWAY EQUIPMENTRAILROAD Strength toughness machinability and economy account forthe many uses of forgings in offhighway and heavy construction equipment mining equipment and material handling applications GENERAL INDUSTRIAL EQUIPMENT Forgings of great size are o en found in industrial equipment and machinery used by the steel textile paper power generation and transmission chemical and re nery industries to name just a few Typical forged con gurations include bars blanks blocks connecting rods cylinders discs elbows rings T39s sha s and sleeves ORDNANCESHIPBUILDING Forged components are found in virtually every implement of defense from ri e triggers to nuclear submarine drive sha s Heavytanks missiles armored personnel carriers shells and other heavy artillery are common defenserelated applications of forged components ME 4553 Dr 5 Hanan 124 62 Forging Applications AERosPncE High svenglhrmrv eigm 131m and smamei reiiahiinvmn stuvahiv immense Parkman22 vange and Paviaad capabiimesmaimmn Made mvemusvenaus nanrievmusand Speuai euwmeieneis mvgings are wdeiv used m mmmemiai1215 heiimmevsim anengme memes miinaw awaan and saeeeaen ame exampies mv lnere 3 Wings vevssliii vmsizE shape and pmpemes make u an ideai mmpanem inciude mimeees wng yams and sees hinges enemem ms mamas beamssh nsienemeeeeymneeysenesms v hee mkemmevs n e iscsan enesme an sinie uvhineengmeg imn base mmeirhase and cahaiibase smevaiiaysave mvged m campanems sum esmss meees buexeis mupnnes memes mes chamhevsand shans M4553 m mm 25 Forging Applications This afi dame is used m Trian IV space laurich vehicles as mxmm m Railroad engine connecting rod ME 4563 17 S Harm Forging Applications The forging process can produce a variety of automotive parts including from left connecting rods and caps transmission shift forks and ujoint steering yokes ME 4563 177 S Harm Forging M54553 DE 5 Haran 129 Forging M54553 DE 5 Haran 130 65 Aircraft landing gear MEAESJ Dr S Haran 131 50000 ton press 11154563 17 S Haran 132 66 Forging pressure sticking friction Forging pressure psi 2 Distance fmm urging edge in M 4563 Dr S Haran 133 Forging force vs stroke E a E 2 m E 9 LE 3 0 02 04 06 08 Stroke in 11154563 Dr S Haran 134 67 Effect of friction coefficient 14 Friction is very important AM54563 lhSHmwn 135 Forging force vs friction coefficient it 2 5000 2 0000 i 5000 1 0000 5000 0 Forging force lbflin d epth 0 02 04 06 Friction coefficient MEASSJ Dr S Haran 136 68 Main forging defect Surface cracks due to stickng and barreling leading to tensile forces on the surface 0 operation M54563 III 5 Hanan 137 Forging Defects m kn Nlub up 1 my mama 1mm own um mu mm prx m mm mm A Forum Mm Dre mum m leug mum M54563 III 5 Hanan 138 69 Forging Part formation by pressing between dies Dies are hard metal shapes Temperature Dies Open no lateral constraints Closed lateral constraints Hot usually Cold 39 M54563 Dr 5 Hanan Forging hammer capabilities mass at drop 5000 drop 18000 energy M54563 Dr 5 Hanan 70 Forging press parameters presses presses ME 4563 Dr S Ham 141 Hot upsetting machine parameters ME 4563 Dr S Ham 142 71
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