ME 6222: Manufacturing Processes and Systems Prof. J.S. Colton © GIT 2009 1 Deformation Processing & Forging Introduction ver. 1ME 6222: Manufacturing Processes and Systems Prof. J.S. Colton © GIT 2009 2 Overview • Types of Deformation Processing • Forging • Wire drawing • Extrusion • RollingME 6222: Manufacturing Processes and Systems Prof. J.S. Colton © GIT 2009 3 Types of deformation processing • Forging • Wire drawing • Extrusion • RollingME 6222: Manufacturing Processes and Systems Prof. J.S. Colton © GIT 2009 4 ForgingME 6222: Manufacturing Processes and Systems Prof. J.S. Colton © GIT 2009 5 Wire drawingME 6222: Manufacturing Processes and Systems Prof. J.S. Colton © GIT 2009 6 ExtrusionME 6222: Manufacturing Processes and Systems Prof. J.S. Colton © GIT 2009 7 RollingME 6222: Manufacturing Processes and Systems Prof. J.S. Colton © GIT 2009 8 What is deformation processing? • Process to make parts without material removal • Deformation occurs on parts with L/D 1 • High volumeME 6222: Manufacturing Processes and Systems Prof. J.S. Colton © GIT 2009 9 Examples of products • Connecting rods • Wire • Bars • Window framesME 6222: Manufacturing Processes and Systems Prof. J.S. Colton © GIT 2009 10 Railroad engine connecting rodME 6222: Manufacturing Processes and Systems Prof. J.S. Colton © GIT 2009 11 Typical product dimensions • Small: – coins – surgical wire • Large: – power plant turbine shafts – aircraft landing gearME 6222: Manufacturing Processes and Systems Prof. J.S. Colton © GIT 2009 12 Aircraft landing gearME 6222: Manufacturing Processes and Systems Prof. J.S. Colton © GIT 2009 13 Process characteristics • Material is deformed – improvement of material properties • grain refinement • grain orientation • work hardening • Material is conserved – minimal trimming and machining notME 6222: Manufacturing Processes and Systems Prof. J.S. Colton © GIT 2009 14 Important parameters • Plasticity • Friction • Elasticity negligible – usually much smaller magnitude than plastic deformationME 6222: Manufacturing Processes and Systems Prof. J.S. Colton © GIT 2009 15 Plasticity analysis • Slab method – plane strain – plane stress Forging Forging force Forging force Platen PlatenME 6222: Manufacturing Processes and Systems Prof. J.S. Colton © GIT 2009 16 fracture t K 1 Y Strain hardening t = on • Tresca (maximum shear stress) yield criterion: tflow = flow / 2ME 6222: Manufacturing Processes and Systems Prof. J.S. Colton © GIT 2009 17 1100tdduflowflow 2Energy / unit volume (u) by Tresca (maximum shear stress) criterionME 6222: Manufacturing Processes and Systems Prof. J.S. Colton © GIT 2009 18 Working temperature • Cold: T < 0.4 Tmelting(K) – strain hardening effect – no strain rate effect • Hot: T > 0.6 Tmelting(K) – no strain hardening effect – strain rate effect nKmCRecrystallization temperature = 0.5 Tmelting (K)ME 6222: Manufacturing Processes and Systems Prof. J.S. Colton © GIT 2009 19 ForgingME 6222: Manufacturing Processes and Systems Prof. J.S. Colton © GIT 2009 20 ForgingME 6222: Manufacturing Processes and Systems Prof. J.S. Colton © GIT 2009 21 Old Hammer ForgeME 6222: Manufacturing Processes and Systems Prof. J.S. Colton © GIT 2009 22 Forging • Part formation by pressing between dies – Dies are hard metal shapes • Temperature – Hot (usually) – Cold • Dies – Open (no lateral constraints) – Closed (lateral constraints)ME 6222: Manufacturing Processes and Systems Prof. J.S. Colton © GIT 2009 23 Open Die ForgingME 6222: Manufacturing Processes and Systems Prof. J.S. Colton © GIT 2009 24 Ring ForgingME 6222: Manufacturing Processes and Systems Prof. J.S. Colton © GIT 2009 25 Open die forging Forging Forging force Forging force Platen PlatenME 6222: Manufacturing Processes and Systems Prof. J.S. Colton © GIT 2009 26 Closed Die ForgingME 6222: Manufacturing Processes and Systems Prof. J.S. Colton © GIT 2009 27 Closed die forging Forging Forging force Forging force FlashME 6222: Manufacturing Processes and Systems Prof. J.S. Colton © GIT 2009 28 Forgings • Coins • Landing gear • Crank shafts • Turbine shaftsME 6222: Manufacturing Processes and Systems Prof. J.S. Colton © GIT 2009 29 Forging presses • Large machines – hold dies – form partsME 6222: Manufacturing Processes and Systems Prof. J.S. Colton © GIT 2009 30 Press types • Hydraulic presses • Mechanical presses • Screw presses • Hammers – gravity drop – power drop – counter blow (two rams) – high pressure gasME 6222: Manufacturing Processes and Systems Prof. J.S. Colton © GIT 2009 31 50,000 ton pressME 6222: Manufacturing Processes and Systems Prof. J.S. Colton © GIT 2009 32 Forges Schematic illustration of the principles of various forging machines. (a) Hydraulic press. (b) Mechanical press with an eccentric drive; the eccentric shaft can be replaced by a crankshaft to give the up-and-down motion to the ram. (continued)ME 6222: Manufacturing Processes and Systems Prof. J.S. Colton © GIT 2009 33 Forges Schematic illustration of the principles of various forging machines. (c) Knuckle-joint press. (d) Screw press. (e) Gravity drop hammer.ME 6222: Manufacturing Processes and Systems Prof. J.S. Colton © GIT 2009 34 Dies • 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 stressME 6222: Manufacturing Processes and Systems Prof. J.S. Colton © GIT 2009 35 Forging hammer capabilities Moving mass(kg)Energy atstrike (J)Gravity drophammers500 - 5,000 6,000 -75,000Power drophammers500 - 18,000 18,000 -600,000High energyrate forming500,000 -5,000,000ME 6222: Manufacturing Processes and Systems Prof. J.S. Colton © GIT 2009 36 Forging press parameters LoadcapacityStrokesper minutePower(kW)Mechanical pressesOpen-back,inclinable150 - 1,250kN200 - 100 3 - 15High-speed, straightside300 - 2,000KN2000 - 200Larger straight side 1 - 6 MN 100 - 20 10 - 60Transfer presses 2 - 40 MN 50 - 10Forging presses 3 - 80 MN 100 - 30 20 -500Hydraulic pressesUniversal 4 - 25 MNForging presses2 - 500 MN150 -1000ME 6222: Manufacturing Processes and Systems Prof. J.S. Colton © GIT 2009 37 Hot upsetting machine
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