各种锻造成型设备英文解释.docx

各种锻造成型设备英文解释.docx

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各种锻造成型设备英文解释

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ProcessofForging

∙Forging

∙TypesofForging

oHammerForging（FlatDie）

oPressForging

oDieForging

∙Forgingequipment 

oSmithForgingHammer

oBoardDropHammer

oForgingPress

oMechanicalForgingPress

oHydraulicForgingPress

∙HeatTreatments 

oPreheating

oAnnealing

oNormalizing

oHardening

∙LISTSOFFORGINGMANUFACTURERS 

oForgingandFormingResources

oForgingIndustryAssociation

oForgingEquipment–JohnsonForgingEquipmentCompany

oForgingEquipment–SIFCOIndurtries,Inc.-ForgeGroup

oForgingEquipment–DeltaforgingServices,Inc

Process:

Forgingisametalformingprocessusedtoproducelargequantitiesofidenticalparts,asinthemanufactureofautomobiles,andtoimprovethemechanicalpropertiesofthemetalbeingforged,asinaerospacepartsormilitaryequipment.Thedesignofforgedpartsislimitedwhenundercutsorcoredsectionsarerequired.Allcavitiesmustbecomparativelystraightandlargestatthemouth,sothattheforgingdiemaybewithdrawn.Theproductsofforgingmaybetinyormassiveandcanbemadeofsteel（automobileaxles）,brass（watervalves）,tungsten（rocketnozzles）,aluminum（aircraftstructuralmembers）,oranyothermetal.MorethantwothirdsofforgingintheUnitedStatesisconcentratedinfourgeneralareas:

30percentintheaerospaceindustry,20percentinautomotiveandtruckmanufacture,10percentinoff-highwayvehicles,and10percentinmilitaryequipment.Thisprocessisalsousedforcoining,butwithslowcontinuouspushes.

TheforgingmetalformingprocesshasbeenpracticedsincetheBronzeAge.Hammeringmetalbyhandcanbedatedbackover4000yearsago.Thepurpose,asitstillistoday,wastochangetheshapeand/orpropertiesofmetalintousefultools.Steelwashammeredintoshapeandusedmostlyforcarpentryandfarmingtools.Anaxmadeeasyworkofcuttingdowntreesandmetalknivesweremuchmoreefficientthanstonecuttingtools.Huntersusedmetal-pointedspearsandarrowstocatchprey.Blacksmithsusedaforgeandanviltocreatemanyusefulinstrumentssuchashorseshoes,nails,wagontires,andchains.

Militariesusedforgedweaponstoequiptheirarmies,resultinginmanyterritoriesbeingwonandlostwiththeuseandstrengthoftheseweapons. Today,forgingisusedtocreatevariousandsundrythings.Theoperationrequiresnocuttingorshearing,andismerelyareshapingoperationthatdoesnotchangethevolumeofthematerial.

Forging:

Forgingchangesthesizeandshape,butnotthevolume,ofapart.Thechangeismadebyforceappliedtothematerialsothatitstretchesbeyondtheyieldpoint.Theforcemustbestrongenoughtomakethematerialdeform.Itmustnotbesostrong,however,thatitdestroysthematerial.Theyieldpointisreachedwhenthematerialwillreformintoanewshape.Thepointatwhichthematerialwouldbedestroyediscalledthefracturepoint.

Inforging,ablockofmetalisdeformedunderimpactorpressuretoformthedesiredshape.Coldforging,inwhichthemetalisnotheated,isgenerallylimitedtorelativelysoftmetals.Mostmetalsarehotforged;forexample,steelisforgedattemperaturesbetween2,100oFand2,300oF（1,150oCto1,260oC）.Thesetemperaturescausedeformation,inwhichthegrainsofthemetalelongateandassumeafibrousstructureofincreasedstrengthalongthedirectionofflow.（SeeFigure）

Figure-Flowlinesinaforgedpart

Normallythisresultsinmetallurgicalsoundnessandimprovedmechanicalproperties.Strength,toughness,andgeneraldurabilitydependuponthewaythegrainisplaced.Forgingsaresomewhatstrongerandmoreductilealongthegrainstructurethanacrossit.Thefeatureofgreatestimportanceisthatalongthegrainstructurethereisagreaterabilitytoresistshock,wear,andimpactthanacrossthegrain.Materialpropertiesalsodependontheheat-treatingprocessafterforging.Slowcoolinginairmaynormalizeworkpieces,ortheycanbequenchedinoilandthentemperedorreheatedtoachievethedesiredmechanicalpropertiesandtorelieveanyinternalstresses.Goodforgingpracticemakesitpossibletocontroltheflowpatternresultinginmaximumstrengthofthematerialandtheleastchancesoffatiguefailure.Thesecharacteristicsofforging,aswellasfewerflawsandhiddendefects,makeitmoredesirablethansomeotheroperations（i.e.casting）forproductsthatwillundergohighstresses.

Inforging,thedimensionaltolerancesthatcanbeheldvarybasedonthesizeoftheworkpiece.Theprocessiscapableofproducingshapesof0.5to>50.0cminthicknessand10to<100cmindiameter.Thetolerancesvaryfrom1/32in.forsmallpartsto¼in.forlargeforgings.Tolerancesof0.010in.havebeenheldinsomeprecisionforgings,butthecostassociatedwithsuchprecisionisonlyjustifiedinexceptionalcases,suchassomeaircraftwork. 

Typesofforging:

Forgingisdividedintothreemainmethods:

hammer,press,androlledtypes.

（1）           HammerForging（FlatDie）:

Preferredmethodforindividualforgings.Theshapingofametal,orothermaterial,byaninstantaneousapplicationofpressuretoarelativelysmallarea.Ahammerorram,deliveringintermittentblowstothesectiontobeforged,appliesthispressure.Thehammerisdroppedfromitsmaximumheight,usuallyraisedbysteamorairpressure.Hammerforgingcanproduceawidevarietyofshapesandsizesand,ifsufficientlyreduced,cancreateahighdegreeofgrainrefinementatthesametime.Thedisadvantagetothisprocessisthatfinishmachiningisoftenrequired,asclosedimensionaltolerancescannotbeobtained.

（2）           PressForging:

Thisprocessissimilartokneading,whereaslowcontinuouspressureisappliedtotheareatobeforged.Thepressurewillextenddeepintothematerialandcanbecompletedeithercoldorhot.Acoldpressforgingisusedonathin,annealedmaterial,andahotpressforgingisdoneonlargeworksuchasarmorplating,locomotivesandheavymachinery. PressForgingismoreeconomicalthanhammerforging（exceptwhendealingwithlowproductionnumbers）,andclosertolerancescanbeobtained.Agreaterproportionoftheworkdoneistransmittedtotheworkpiece,differingfromthatofthehammerforgingoperation,wheremuchoftheworkisabsorbedbythemachineandfoundation.Thismethodcanalsobeusedtoproducelargerforgings,asthereisnolimitationinthesizeofthemachine.

（3）           DieForging:

Openandcloseddieoperationscanbeusedinforging.Inopen-dieforgingthediesareeitherflatorrounded.Largeforgingscanbeformedbysuccessiveapplicationsofforceondifferentpartsofthematerial.Hydraulicpressesandforgingmachinesarebothemployedincloseddieforging.Inclosed-dieforgingthemetalistrappedinrecessedimpressions,whicharemachinedintothetopandbottomdies.Asthediespresstogether,thematerialisforcedtofilltheimpressions.Flash,orexcessmetal,issqueezedoutbetweenthedies.Closed-dieforgingcanproducepartswithmorecomplexshapesthanopen-dieforging. Dieforgingisthebestmethod,asfarastolerancesthatcanbemet,andalsoresultsinafinishedpartthatiscompletelyfilledoutandisproducedwiththeleastamountofflashing.Thefinalshapeandtheimprovementinmetallurgicalpropertiesaredependentontheskilloftheoperator.Closerdimensionaltolerancescanbeheldwithcloseddieforgingsthanwithopendieforgingsandtheoperatorrequireslessskill.

ForgingEquipment:

Thetypeofmachinerytobeuseddependsontheshape,size,material,andnumberofpiecestobemade.Forginghammersapplyforcebytheimpactofalargeram.Thismaybeadrophammer,orweightfallingundertheforceofgravity,oritmaybeapowerhammer,drivenbysteamorcompressedair.Twotypesofpowerhammersare:

thesmithforginghammerandthedrophammer.Thelargesthammerscanprovideatotalforceashighas80,000pounds.

SmithForgingHammerandBoardDropHammer

∙∙       SmithForgingHammerHeavyworkpiecescouldbeprocessedusingasmith-forginghammer,andsmallerforgingsaredieformedindrophammers. Smithforginghammersaretypicallysteamorair-operated,consistingofapoweractuatedramsupportedbyaheavycastironframe.Thefinalproductisaresultoftherambeingpoweredintothediescontainingtheworkpiece.

∙∙       BoardDropHammerAdrophammerdiffersinthattheanvilisanintegratedpartofthehammerbase.Itisnecessaryforthealignmentbetweentheforgingdieelementsused.Thismethodisadvantageousinthatthephysicalpropertiesofthemetalareimprovedbytheseveremechanicalworking,theoperationisrapid,manycomplicatedpartscanbeforgedtoshape,aminimumamountofmachiningisnecessary,andinternaldefectsareeliminated. Thedisadvantagesarethecostofmachineryanddies,whichdemandsahighquantityofpartstobemanufacturedinorderfortheprocesstobecosteffective.

∙∙       ForgingPressAforgingpressconsistsofahydraulicpress,whichexertsaforcecapableofpressingsteelorametalalloyintotheshapeoftheforgingdie.Thesemachinescanbepositionedhorizontallyorvertically.Thismethodcanbeusedtoformcarwheels,gears,bushings,andothersuchparts.

∙∙       MechanicalForgingPress Mechanicalpresseshaveamotor-drivenflywheelthatstoresenergytodrivearam--muchlighterthanahammer--throughacrankorothermechanicaldevice.Theraminapressmovesmoreslowlythanahammerandsqueezestheworkpiece.Thelargestmechanicalpresseshaveatotalforceof12,000tonsandcannotforgeaslargeorcomplicatedpartsasthelargerhammers. 

∙∙       Hydrauli