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.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
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