工程训练知识点英文.docx

工程训练知识点英文.docx

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工程训练知识点英文

KnowledgePoint1:

EngineeringMaterialsandHeatTreatment

Amaterial

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Material:

metalmaterials,non-metallicmaterials;

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Metallicmaterials:

ferrousmetals,non-ferrousmetals;

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Materialproperties:

performance（mechanicalproperties,physicalpropertiesandchemicalproperties,etc.）andprocessperformance（castingproperties,weldability,

Pressureprocessingperformance,cuttingandheattreatmentperformance）;

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Masteredcommoncarbonsteel（carbonsteelQ235,45high-qualitycarbonstructuralsteel,carbontoolsteelT8,T12）,alloysteel（in

Onthebasisofcarbonsteelalloyingelementsadded,makingtheperformanceofthematerialincreaseorhavespecialproperties）andcastiron（HT200,KTH330-08）of

Classification,grade,performance,applications.

Second,theheattreatmentofsteel

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Heattreatmentconcept

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Heattreatmentofsteelarethebasicprocess:

annealing,normalizing,quenchingandtempering.

1,theannealing-heatedtoacertaintemperature,thefurnacewascooledaftertheincubation.

2,thenormalizing-heatedtoacertaintemperature,thecoolingaftertheheatintheair.

3,thequenching-isheatedtoatemperatureabovethecriticaltemperature,therapidcoolingaftertheheat（i.e.,greaterthanthecriticalcoolingrate）.

4andtempering-afterquenchingtheworkpiecereheatedtoatemperaturebelowthecriticalpoint,slowcoolingafterprolongedincubation.Canbedividedinto:

①tempering（150~250℃）Thepurposeistoeliminateandreducestressandbrittlenessofhardenedsteeltoimprovethetoughness,theparthavingahigher

Hardness（58~64HRC）.Mainlyusedforavarietyofworkers,theamountofmoldsandrollingbearings,etc.,aswithT12steelsawblade,file,etc.,generally

Areusedafterquenchingandtempering.

②tempering（350~500℃）decreasedthehardnessoftheworkpieceaftertempering,butsteelcanobtainahigherelasticlimitandstrength

（35~45HRC）.Mainlyusedforheattreatmentofvarioussprings.

③tempering（500~650℃）usuallysteelafterquenchingandtempering,calledquenching.Afterquenchingparts,both

Hasacertainstrength,hardness,butalsohasacertainplasticityandtoughness,thatbettermechanicalproperties（25~35HRC）.Mainlyusedforshafts,gear

Wheel,connectingrodandotherimportantstructuralcomponents.Suchasvarioustypesofshafts,gears,connectingrodssuchastheuseofcarbonsteel,afterquenchingandtemperingcanbeachievedusing

Performancerequirements.

Generalwiththetemperingtemperature,strengthandhardnessofsteeldecreased,whiletheplastictoughnessrise.

KnowledgePoint2:

Casting

Castingismetalsmelting,manufacturingandmoltenmetalispouredintothemoldandpartsadaptedtotheshapeofthemold,afterthesolidificationgeta

Castingmoldingmethodandtheperformanceofagivenshape.Castingsaregenerallynothighdimensionalaccuracy,surfaceroughnessoftheroughmustbeapprovedcutting

Afterprocessinginordertobecomeparts.Ifyoudonotaskforthepartsurface,canalsobeuseddirectly.

First,thecharacteristicsandapplicationsofcasting

1,features

1）andtheshapeofthecavitymaybemadeofcastingverycomplexcastings,inparticularablankhavingalumen,suchasvarioushousings,gas

Cylinderblock,cylinderhead,etc.

2）castingadaptableandcanbeusedavarietyofmaterials,suchasnon-ferrousmetals,ferrousmetals,ironandsteel,etc.,butinblack

Colormetal-based;producedifferentsizeandqualityofthecastings,suchasthewallthicknesscanbelessthan1mm,thequalityofcastingscanlight

Toafewgrams,weighinghundredsoftonsofcastings.

Low3）castingproductioncosts,lessinvestmentinequipment,lowrawmaterialprices,andwidesources.

Socastingiswidelyusedinmachinerymanufacturing,butthecastingisdifficulttopreciselycontroltheproductionprocess;castingof

Chemicalcompositionandorganizationisnotveryuniform,coarsegrains,loosetissue,oftenpores,slag,sandholesandotherdefects,making

Highmechanicalperformancethanforgingshortcomings.Butwithnewtechnology,continuousdevelopmentofnewmaterials,thequalityofthecastingisalsorising.

2,theapplication

Mainlyusedinthelowspeedgearboxandthevariousnon-loadbearingorthelike.Suchasthemachinebed,gearbox,gearbox,handwheels,

Internalcombustionenginecylinderblock,cylinderhead,thetrainwheels,pulleys,viseclampholderandsoon.

Manycastingproductionmethodscanbedividedintotwocategories:

①sandcasting;②specialcasting.

Second,thetype（core）sand-sandcoreperformancerequirementsthanordinarysandhigheroverallperformance.

Third,thecastingprocess

1,castingthemainprocessparameterstodetermine

Shrinkingmargin①②③thedraftangleoftheallowanceoftheheightofthesizeofthedraftangleofthewall,moldingmethod,themold

Samplematerialsandsurfaceroughnessandsoon.④castholes,slotsandcorecastroundedhead⑤

2,themoldingprocess

Theprocessmusttakeintoaccountthemainproblemisthesub-surfaceandpouringsystemmodeling,theydirectlyaffectthequalityandrawcastings

Yieldrate.

1）todeterminethesub-surfaceisthesub-surfaceoftheupperandlowercontactsurfaceofthesand.

Partingsurfacetodetermineprinciples:

①partingsurfaceshouldbeselectedattheappearanceofthelargestcross-section;

②shouldmakeimportantface-downonthecastingprocessorinaverticalposition;

③shouldmakeallormostofthesandcastinginthesamebox,inordertoreducethewrongboxandimprovecastingaccuracy.

2）todeterminethegatingsystem

Pouringliquidmetalintothesystemreferstothemoldchannel,andcanbesmoothlyintroducedintotheliquidmetalmold,shouldbeconducivetoretaining

Residueandexhaust,andtocontroltheorderofsolidificationofthecasting.Suchasgatingsystemopenedwell,easytoproducecastingspouredinsufficient,shrinkage,

Coldshuts,cracksandinclusionsandotherdefects.

Typicalgatingsystemgenerallyincludes:

①puddle-pouringoftheliquidmetalbuffertheimpactforce-fittingandseparationoftheslag.

②sprue-connectingtheverticalchanneloftheoutergateandrunner,usingitsheightsothatthemoltenmetaltoproduceacertainstaticpressure

Andquicklyfilledcavity.

③runner-connectingsprueandrunner,islocatedabovetherunner,steadyflowofliquidmetal,themetalfluidlevel

Steadyinflowtothecavitythroughthesprueandrunnerassignedtoeachliquidmetalandslagfromtherole.

Within④runner-channeldirectlyconnectedtothecavity,thecavitycanbecontrolledliquidmetalflowsintotheposition,speedanddirection.

Riser:

mainlyfromfeedingeffect.Butalsobothexhaust,scumandobservetheflowofliquidmetalandsoon.GeneralSecurity

Ontopofthewallthickness.

Fourth,smeltingequipment

Cast-cupola;steel-EAF;non-ferrousmetals-cruciblefurnace.

V.SpecialCasting

1,metalcasting2,investmentcasting3,pressurecasting

4,centrifugalcastingcentrifugalcastingisundertheeffectofcentrifugalforce,sodense,noshrinkage,porosity,slageyes,etc.

Defects,andthereforebettermechanicalproperties.Foundrycastinghollowrotatingbodydoesnotneedcoresandgatingsystem,castingdoesnotneedtofillriser

Shrink,laborandmaterial,highproductivity,goodqualityandlowcost.

Sixmodelingtechnique

Seven,modelingmethods

Modelingmethodsarehandmoldingandmachinemodeling.

Manualmodelingmethods:

entiremoldtwoboxmodeling,partingtwoboxmodeling,stylingandfalseWashaboxmodeling,liveablockshape,scraper

Modeling,threeboxshape.

Eight,makingthecore

Themainroleofthelumenformingthecoreofthecasting.

Nine,pouringtemperature

Pouringtemperatureislow,theliquidmetalpoormobility,easypourenoughcoldshuts,porosityandotherdefects;pouringtemperatureistoohigh,

Castingshrinklarge,easytoproduceshrinkage,cracks,coarsegrainsandstickysandandotherdefects.Suitablepouringtemperatureshouldbebasedcastingalloys

Type,sizeandshapeofthecastingisdetermined.

KnowledgePoint3:

PressureProcessing

First,thepressureprocessingcharacteristicsandapplication

Forgingpressworkingpartofmetal,whichisanexternalforceappliedtotheblank,toproduceplastic,changingtheshapeandsizeandimprovingtheperformance,

Informingmethodformanufacturingmechanicalparts,theworkpieceorblank.Itistheforgingandstampingingeneral.

1,features

Afterforgingmetalmaterials,itsorganizationandperformancehavebeenimproved,especiallycaststructure.Afterforging,orbypressworking,theinternal

Defectssuchasmicrocracks,porosity,shrinkagedefectsgetpressedtogether,sothatthestructureofdense,finegrain,greatlyimprovingthemechanicalproperties.Andcastings,

Comparedweldment,forgingprocessgenerallyonlygetroughshapesimplerparts.

2,theapplication

Thosewhobeartheheavyloadofmachineparts,suchasspindles,crankshafts,gearsandsoon.

Themainmethodofmetalpressureprocessingarerolling,drawing,extruding,forgingfreedom,forgingandsheetmetalstamping.

Forgingequipmentisunderpressureandworking（mold）withtheroleofpartoralloftheblanktoproducetheplasticdeformation,toachievecertaingeometricfoot

Size,shapeandqualityofforgingprocessingmethods.Byformingmethods,freeforgingandforgingmodelcanbedividedintotwocategoriesforging.

Second,themetalisheated

Generalmalleablemetallicmaterialscommonlyusedtomeasureplasticityanddeformationresist