文献翻译材料的处理和特性Word文件下载.docx

文献翻译材料的处理和特性Word文件下载.docx

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Manyoftheprojectsorproductsmadeinthemachineshophavelittleornovalueuntiltheyareheat-treated.Thisarticleincludesonlythemostelementaryinformationabouttheheattreatmentofsteel.Heattreatmentcanalsobedoneonmanyofthenonferrousmetalssuchasaluminum,copperandbrass.Theproceduresaredifferent,however,andwillnotbeconsideredhere.

Theproceduresofheattreatmentofsteelincludehardening,tempering,annealing,andcasehardening.

Hardening

Hardeningisaprocessofheatingandcoolingsteeltoincreaseitshardnessandtensilestrength,toreduceitsductility,andtoobtainafinegrainstructure.Theprocedureincludesheatingthemetalaboveitscriticalpointortemperature,followedbyrapidcooling.Assteelisheated,aphysicalandchemicalchangetakesplacebetweentheironandcarbon.Thecriticalpoint,orcriticaltemperature,isthepointatwhichthesteelhasthemostdesirablecharacteristics.Whensteelreachesthistemperature—somewherebetween1,400andl600°

F—thechangeisidealtomakeforahard,strongmaterialifftiscooledquickly.Ifthemetalcoolsslowly,itchangesbacktoitsoriginalstate.Byplungingthehotmetalintowater,oil,orbrine（quenching）,thedesirablecharacteristicsareretained.Themetalisveryhardandstrongandlessductilethanbefore.

Heatingisdoneinafurnacefiredbygas,oil,orelectricity.Adevicecalledapyrometerisattachedtothefurnace.Thisaccuratelyregisterstheexacttemperatureinthefurnace.Thetemperatureofthemetalcanalsobedeterminedbyobservingitscolour.Youcanmakeuseofthecolourswhenheat-treatingsimplemetalpartsandtools.Coloursarenotveryaccurate,however.Eventheexpertheat-treaterwillbeoffasmuchas20°

Ffromthetruetemperature.

Thehardeningprocedureis:

1.Pointofstovestoreachtheappropriatetemperature

2.Themetalintostoves,heatingittothecriticaltemperatureforcarbontoolsteel,inordertoachievethistemperature,eachone-inchthickabout20-30minutes.Inordertoquenchtemperaturesreachedarehot,eachone-inchthickaboutfoodwarming10-15minutes.

3.Choosetheappropriatecoolant.Certainsteelsinthewatercooling,whileotherssteelsinoilorwatertocool.Water-carbonsteelhardeningisthemostwidelyusedcoolant.Becausewaterpricescheapeffect.Salinewaterisusuallyaddedtothe9%intheordinarysaltproduced.Salinehelptoachieveamoreuniformhardnessforthewholepartsfastercooling.Someoilwillquenchslowerpace.Mostquenchoilismineraloil

4.Removewithtongsheatedmetaltovotepeoplecoolant.Thickmetalcoolanttoenablerapidanduniformlycool.Ifthisisthefinalpieceofthin（likeknivesorleaves）,toquenchherwhilecoolanttobeQiaoqu.Ifsidecoolingfasterthantheotherside,itwillproduceacertainQiaoqu.

5.ThenormalhardeningtoolsteelwillstiffenBiancuiandhavehightensilestrength.Itwillalsohavetostress.Ifleftinthisstate,whichwouldmakethemetaloccurredwithinstresscracks.

Flashbackarrestorsalowerhardnessandintensityandenhanceresilienceapproach.Itcaneliminatethebrittlenessquenchher.Crowdedinthehardeningofthemetaltostiffenafterachangeinpersonalways.Flashbackistore-heatingthemetaltoalowormoderatetemperature,andthenJilengorintheaircooling.Whenmetalcrowdedheating,butalsochangesintheircolour.Thesecolourscalledtemperingcolor.Thesecanbeobservedfromtimetoknowwhatcolourtothetemperature.Ofcourse,amoreprecisemethodisobservationofhigh-temperature.Manypartsandproductsaretotheoverallbackfire.Othersarepartoftheflashback,andtheremainderarestillinthehardeningstate.

Temperingmethodisasfollows:

1.Theflashbacktotheoverall,theentireworkingtoputstovesLane.Furtherheatingtotheappropriatetemperaturetoachievetherequiredstrengthandresilience.Removethemetalandrapidcooling.

2.Smallcuttingtoolsfortheflashback:

A.Theentiremachinetoolhardening,usingemeryclothtoremoveoxideskin

B.OfapieceofscrapmetaltoChekthermalheatingdegree.

C.Onthemetalcuttingtools,theedgeofbladeDepartmentplacedoutsidethisChekhotmetal

D.Observercrowdedcolor,whenappropriatetooledgeofbladecolorstotheDepartment,itJileng.

Annealannealistosoftenthesteeltoeliminateinternalstressapproach.Thiswillenablethesteeleasierprocessing.Steelheatedtoatemperatureabovethethresholdandthenslowlycooling.Themostcommonlyusedmethodistoheatthesteeltostoveshaveitrevealed.Thenturnthestovesformetalslowlycooling.Anothermethodistousemetalclaypacksupandheatingittothecriticaltemperature,thenremovefromstove,letitcoolslowly.

Caseishardertoquantifyblackmetalcase,thesurfaceortheinteriorfloors.Throughcarbonaddedtoalow-carbonsteelsurface,aheattreatmenttothesurfaceitcanstiffen,andthecenter,thatis,coreandtheDepartmentremainssoftresilience.

Therearemanywaystomeasurethesurface.Inindustry,theuseofmeltingofcyanide（whichcalledcyanidation）.Anothermethodiscarburizationindustriallaw.Thisisaoneofthewaystousecarbonfromthe。

Dead,pistonsalesandothermustwithstandvibrationandwearalotofpartsoftheActcanbeusedforprocessing.However,thelawmustnotbeusedforanybenefittohimselfthefinal.

Mechanicalpropertiesofmetal

Mechanicalperformanceismaterialplusloadsroleintheemergingidentityofthemeasure.Inotherwords,themechanicalpropertiesofmetalsisinaroleofpowerormorepower,withtheintensity.Theyknowtheintensityofmetalperformancecanbuildasolidsecuritystructure,theintensityiscarryingapayloadofmetal（externalforces）withoutfracturecapacity.

Intensitycharacteristicsusuallyrefertothetensilestrength,Kangwanintensity,andcompressivestrength,Kangniuintensity,andbeamintensity,fatiguestrengthandimpactstrength.

1.Stressisamaterialinternalresistancedeformationcapacitythroughadditionalloadtomeasurestress

2.Responsebythestressarisingfromthedeformation.Responsetothesizeofeachcmdeformationtoexpress

3.Metalfractureordeformationinaflexible,externalforcesbacktotheiroriginalshapewhenremoved.Rubber-bandiswhatisthebestexampleofflexibility.Rubberarm,ifknobloosened,itwouldreverttotheoriginalshape.However,ifmorethanarubberarmwas,itwouldbreak.Flexiblemetalalsohavethesamecharacter.

4.Limitisflexiblematerialinstretch,addedstressisnotremovedaftertheyreturntotheformerstateofdeformationofthegreateststress.

.Flexiblemoduleswithinthelimitsofflexibilityinthevolumestressandpullover.Muststressroleinthedeformationofmaterialssmaller,highervolumeflexiblemodules.Throughmoreflexiblemodulesofthesize,wecaneasilyidentifytherelativesupplyofdifferentmaterials.Formanymachinesandstructures,chemicalorcutisveryimportant.

6.Tensilestrengthistheresistanceofthemetaltopullitofftheoutside.Itismoreimportanttoidentifythetargetmetalone.

7.Compressivestrengthistheresistanceofmetalcrushingcapacity.Ontheroleofloaddirection,andstretchcompressionpreciselytheopposite.Mostmetalshaveahightensilestrengthandcompressivestrength.However,thebrittlenessmaterialssuchascastironhighcompressivestrength,butonlyamediumtensilestrength

8.Kangwanintensityresistanceistheroleofexternalforcescausecomponentsalongtheloadingdirectionbendingorcurvingnature.Indeed,thebendingstressisacombinationofpullingstressandpressurestress

9.Kangniuintensityiscausedbythemetalcomponentstoreversethecapacitytoresistexternalforces

10.Shearedintensityreferstothesizeofthetwocomponentsintheoppositedirectionofequalrole,howstrongitscapabilitytoresist

11.Fatiguestrengthistheresistanceofvariousmaterialstotherapidlychangingnatureofthestress.Forexamplepistonrodoraxlewithstandthepressureforchangeiswideningstress.Bothsidesofthewindingupoftinselfatiguefractureisanotherexample.

12.Intensityoftheimpactresistanceofmetalsisoftenrapidandsuddenincreaseinloadpayloadcapacity.Theimpactofhighermetalintensity,theenergyneededtobreakonolder.Weldingwillseriouslyaffecttheimpactintensity,becausetheimpactofstructuralstrengthisasensitivenature.

13.Resilienceismetalfracture,bendingorreversewithoutbreaksordamage.Resiliencehighmetals,suchascopperorwroughtiron,withtheloadincreaseisthegradualdamageorfracture.Resilienceandlowmetalssuchascastiron,whencarryingheavy,willsuddenlyruptureanddamage.

14.HardnessissteelorpenetrationresistanceYahennature.HardnessisusuallyusedinthestandardpayloadGangqiuroleofthedesignertoexpressYahenarea,orusedinaparticularloadroleoftheindenterspecializedformedtoexpressthedepth.

15.Cryogenicnatureexpressedinverylowtemperatureenvironmentintheroleofmetalstressperformancechanges.Inadditiontothecrystalstructureandprocessingconditionsareve