上海理工大学金工实习答案doc.docx

上海理工大学金工实习答案doc.docx

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上海理工大学金工实习答案doc

上海理工大学金工实习答案

Chapter1heattreatment

Nontitle（Title）:

Forovereutectoidsteels,thehigherthecarboncontent,thehigherthequenchingtemperature・

Quenchingandtemperingofheattreatmentprocesscalledquenchingandtempering,Quenchedandtemperedpartscanobtainstrength,toughness,plasticityarebettercomprehensivemechanicalproperties・

Springquenchingtreatmentgenerallyusehightemperaturetempering,becausethehightemperaturetempering,thehighestelasticlimit・

Brinellhardnessissuitableformeasuringmaterialsofhighhardness,suchashardenedsteel,etc・・

Choicequestion：

Manufacturingconnectingrod,transmissionshaft

Generallyused（mediumcarbonsteel）

Theheattreatmentandquenchingandtemperingprocessis

（quenchingandtemperingathightemperature）

Springsteelpartsareusedafterquenching（mediumtemperaturetempering）

OxidationdecarburizationIlealtreatmentisselected

（controlledatmosphereheattreatmentfurnace）

InordertochangethespeedgearAlloysteelgear

（carburizing,quenching,lowtemperaturetempering）

Thesteelwithrelativelygoodmachinabilityis（highcarbonsteel）

SlendershaftWhenquenchingshouldbe（vertical

downward）

Theheatingrangeofgascarburizingis（900^930）

CarbonsteelquenchingThetissueistransformedinto

（martensite）

Rockwellhardnessof45,theexpressionforthe45HRC

Fillintheblanks:

[（annealing）furnacecooling（aircoolingnormalizing）[][]（quenching）rapidquenchcooling（quenchingtempering）[][]（heattreatment）heating,cooling[][]（general）internalorganization（metalmaterial）hardness,strength,tensilestrength,typeof][（mostcommonlyused）carburizing,nitriding,chromizing]

Thesecondchapteriscastingpracticereport

Todeterminetheproblemoferror:

Inmanualmolding,thesandispressedastightlyaspossible,andthestrengthishigh

Theimportantworkingface,stresssurfaceormainprocessingsurfaceofthecastingshallbefacingupwardswhenpouring

Choicequestion

Thefunctionofpartingsandistoanalyzethemoldingsandandthemoldingsandsmoothly

Themainreasonforcastingsandisthatthepouringtemperatureistoohighandtherefractoryofmoldingmaterialisnotobvious

Inordertoimprovethefluidityofmoltenmetal,theincreaseofpouringtemperatureshouldbeadopted

Theactionofaddingpulverizedcoaltosandistopreventstickingsandand・・・

Theimportantprocessingsurfaceofthecasting,asfaraspossibleintheshapeofthecasting（below）

Investmentcastingissuitableformanufacturing（shape,complexcasting）

Theroleoftheriser（feedingandexhaust）

Themeltingtemperatureofmoltenaluminumis（800）

BecauseofmetalTheshrinkageisabout（1.5%）

Whatissuitableforcastingis（lathetailstockandslideplatehandwheel）

Completion

[Special][（casting）（sandcomposition）ofsandandbinderandadditives（[]isthesandsandbody）goodpermeability,suitabletemperature,hightemperature,certainconcessions,sufficientdurability[]（handmolding）thewholemold,parting,dredging,floatingblock,[three]tank（threeboxstyling）two,three[]（typicalcasting）outsidethegate,gate,gatemode[][]（castironcrucible）（castings）sandblasting,watercleaning,watercleaning[]（Foundry）investmentcasting,pressurecasting,centrifugalcasting,ceramiccast[]（castingspeedpositive）]

ShortAnswerQuestions

1..Whatarethecharacteristicsoffoundryproduction?

Answer:

1.castingcanobtaincomplexshapecasting;2.castingsizeandweightcanbebigorsmall;3.,castingcostislow

2.whatisthepartingsurfaceinCastingmodeling?

Whatarethefactorsthatshouldbetakenintoconsiderationintheselectionofpartingplanes?

Answer:

partingsurfacereferstothesandinterface,generallychoosethelargestsectionofthecastingisthepartingsurface,butalsoconsiderconvenientmolding,mold・

WhyshouldIbrushthewateronthesandpatternaroundthe3.moulds?

Whatpointsshouldbenoticedinmoldlifting?

Answer:

increasethestrengthofthispartofmoldingsand,preventmouldfromdamagingsandmould・Note:

1.watershouldbeabrushandbrush;2.die,dietodieandneedlepositioncenterofgravityverticaloverlap・

4.whatarethefunctionsofthegatingsystem?

Answer:

1・，themetalliquidcanbecontinuous,smooth,uniformintothecavity,

Avoidpunchingmould,cavityandcore;2.preventslag,sandandothermagazinesintothecavity;3.adjustthesolidificationsequenceofeachpartofthecasting・

Whatistheroleofthe5.riser?

Whereisthegeneralriserlocated?

Answer:

1.exhaustcavitygas;2.toslag;3.feeding;4.observation;5.guaranteethequalityofcasting・Thepositionisusuallylocatedonthethickestwallofthecastingandatthefinalsetting.

6.whatarethecharacteristicsofmetalmouldcastinginspecialcasting?

Answer:

1.goodmechanicalperformanee,longservicelife;2.highprecision,smoothsurfaceandgoodthermalconductivityofmetaltype,coolingspeed;3.thelackofairpermeabilityanddeformability,heatresistancethansand;4.complexcastingscrack;5.isnotsuitableforhighmeltingpointmetalcasting;6.processingcomplex,highcost・

9.,pouringtemperatureistoohighortoolowwillhaveanyadverseeffects?

Answer:

toolow:

metalliquidfluidityispoor,gatesizeistoosmall,metalliquidfillingspeedistooslow,moldventilation,poorexhaust,partingsurfacerunningfire,maketheupperboxcastinginsufficient・

Excessive:

producestickysand,shrinkhole,sand,shortpouring,coldseparation,slageye・

Thethirdchapterisforging

Yesnoquestionswrong

Thecoolingmethodafterforginghaslittleeffectonthequalityoftheforgings

Thereisnoneedforanyfurtherprocessingoftheforgings

Dieforgingistoplacetheheatedmetalgermintoit

Methodo

Choicequestion

45steelstartswithforgingtemperatureandfinalforgingtemperature（1150、800）

GrainofforgingembryoThisdefectisoftenreferredto

as（overheating）

Theforgeheatingfurnace（hightemperatureboxresistancefurnace）usedinengineeringtraining

Thefollowingmetalcanbeusedforforging（45steel）

Ifyouwanttoprocess3pieces45（freeforging）

Ifyouwanttoprocess3000piecesof40rMosteel（die

forging）

Inordertoavoidupsetting（lessthan2.5）

Forexample,duringtheprocessofforgingheating,thecorrecttreatmentmethodisscrap

Completion

[（forgingmetalforging,forgingpress）[]（forging）initialforgingtemperature,forgingtemperature[]（forging）manual,machine,manualandmachine[]（forging）stretching,punching,cutting,bending[]（forgingcanbedividedintomembranes,model]）

Thefourthchapterweldingpracticereport

Yesnoquestionswrong

Inwelding,thefastertheelectrodemoves,thebetter

Argonarcweldingisdividedintotwokindsofargonarcweldingandnonmeltingargonarcwelding

Whenwelding,theweldingworkpiecethicknessonthedeformationoftheworkpiecehaslittleeffect

Choicequestion

Thediameteris3,2mm（b）

Inmanualarcwelding,thelengthofthenormalarc（equaltothediameteroftheelectrode）

Eyecannot（nighteyepainandphotophobia）

Gas,oxygenandacetylene（3500）

Useoxygen,acetylene（preheating,combustion,slag

blowing）

Thefollowing3weldingmethodsFusionwelding（argonarc

welding）

Whensoldering,theweldmentandthesolder（theweldmentdoesnotmeltandthebrazedpiecemelts）

Weldedstainlesssteel（argonarcwelding）

NationalstandardsOxygenbottle（skyblue）

NationalstandardsAcetylene（white）

Completion

[（electricwelderno-loadvoltage60^70AC,DC）40、90,[20〜30V]（electrodecoating）ore,ironalloy,chemicalcomposition,organicmatter,improvetheweldingprocessofwelding,protection,goodmetallurgicalchemistry[]（welding）welding,brazing,pressure（[]themainweldbutt,T）,fillet,lap]

[（WeldInternal）weldingcrack,weldporosity,slaginclusion,unweld[]（SMAW）percussion,friction]

ShortAnswerQuestions

10.whataretheprotectivemeasuresduringweldingoperations?

Answer:

footcover,overalls,masks,gloves,workcap

Thefifthchapteristurning

Yesnoquestionswrong

Whenthevehicleisoutsidethecircle,theutilitymodelcanalsobedrivenbyascrewrodtorealizealongitudinalautomaticcutter

Intheroughlathe,thelathetoolshouldtakethebigrakeangle

Thecaroutsidescrewtap,dieinsidethread

Choicequestion

Turningslendershaft（bulging）

Turningtoolatcrosssection（graduallydecreasing）

Transmitpowerinthewindowheadstock（frictionclutch）

Handitonalathe（aworkpiecewithahighprecisionand

asmallamountofproduction）

Alathetoolwithasmallerrakeangle（Roughcar）

Takethebackangleofthelathetool（positive）

Footmeasurementhastolerancerequirements（vernier

caliper）

FinishingtimeConsider（cuttingdepth）

SurfacefinishqualityandAfter（conditioning,heat

treatment）

RemovalofturningprocessMustuse（specialhook）

Completion[（C616）spindlebox,gearbox,tailstock,knife,feedbox,slideboard[]（generalturning）7~10,1.6〜0.8（[]lathemain）turningfacinggroovingandcutting,chamfering,carvertebrae,threading,knurling,drilling,car[]（installationsteps（[]）toolaxisinyourpractice）1980rpm,45rpm,12[]（threejawchuck）shape,irregularshape[]（bycutting）90degrees75degreesturning,turning,cuttingknife[]（usuallyturningcone）torotateasmallcarriage,offsetthetailstockprofilingmethod,[]（turningformingsurface）handscontrolmethod,formingblade][]pitch（replacement）

ShortAnswerQuestions

1.writedownthetypeoflatheyouareworkingonandexplainwhatthesymbolsrepresent

C616C-lathetype6-horizontallathegroupcode16-themaximumturningdiameterofmachinedworkpiece1