专业英语翻译

1thefundamentalconcepts基本概念crosssection横截面theinternalstressesproducedinthebar杆内应力continuousdistributionofhydrostaticpressure流体静压力thetensileload拉伸载荷auniformdistributionoverthecrosssection在横截面均匀分布arbitrarycross-sectionalshape任意截面形状tensilestresses拉应力compressivestresses压应力anormalstress正应力throughthecentroidofthecrosssectionalarea经过横截面形心theuniformstresscondition压力均匀分布thestressdistributionattheendsofthebar杆末端应力分布highlocalizedstresses高度应力集中anaxiallyloadedbar轴向载荷杆件atensilestrain拉应变anelongationorstretchingofthematerial材料拉伸acompressivestrain压应变theratiooftwolengths两个长度比值purelystaticalandgeometricalconsiderations从纯静态以及几何角度考虑1.Thatbranchofscientificanalysiswhichmotions,timesandforcesiscalledmechanicsandismadeupoftwoparts,staticsanddynamics.研究位移、时间和力运动乘力是科学分析法一个分支，被称作力学，力学由两大部分组成，静力学和动力学。2.Forexample,iftheforceoperatingonasleevebearingbecomestoohigh,itwillsqueezeouttheoilfilmandcausemetal-to-metalcontact,overheatingandrapidfailureofthebearing.比如：假如止推轴承上作用力过大话，会挤出油膜，引发金属和金属之间相互接触，轴承将过热而快速失效。3.Ourintuitiveconceptofforceincludessuchideasasplaceofapplication,direction,andmagnitude,andthesearecalledthecharacteristicsofaforce.力直观概念包含力作用点、大小、方向，这些被称为力三要素。4.Allbodiesareeitherelasticorplasticandwillbedeformedifacteduponbyforces.Whenthedeformationofsuchbodiesissmall,theyarefrequentlyassumedtoberigid,i.e.,incapableofdeformation,inordertosimplifytheanalysis.全部物体既能够是弹性也能够是塑性，假如受到力作用就产生变形。当变形很小时候它们被假设成刚体，也就是不产生变形。5.Therigid-bodyassumptioncannotbeusedininternalstressesandstrainsduetotheappliedforcestobeanalyzed.Thusweconsiderthebodytobecapableofdeforming.刚体假设不能应用于内应力和内应变分析，所以在实际力分析时，要考虑物体形变。6.Ifalltheforcesactingonaparticlearebalanced,theparticlewilleitherremainatrestorwillcontinuetomoveinastraightlineatauniformvelocity.假如作用在质点上全部力是平衡，质点将会保持静止或做做匀速直线运动。21)themainmanifestationsofcapacity主要表现能力2)themaximumunitload（stress）最大单位载荷（应力）3）stress-straindiagram应力—应变图4）thesimpletensiletest简单拉伸试验5）thepercentageelongationatrupture断裂伸长率6）theendsoftensilespecimens拉伸试样两端7）permanentdeformation永久变形8）theresultingload-displacementcurve由此产生载荷位移曲线9）asubstantialyieldingofthematerial大量产生物质10）yieldpoint屈服点11)thetransitionfromelastictoplasticbehavior从弹性到塑性过分12）materialpropertytable材料属性表13）plasticdeformation塑性变形14）aspecifiedstandardlengthofthespecimen指定标准式样长度15）atthemomentofrupture此刻破裂16）shortcylindricalspecimens短圆柱标本17）ductilematerials韧性材料18）highstressconcentration高应力集中19）ultimatetensilestrength极限抗拉强度20）strainhardeningzone应变硬化区A

tensile

test

consists

of

slowly

pulling

a

sample

of

material

with

a

tensile

load

until

it

breaks.

The

ends

of

tensile

specimens

are

usually

enlarged

to

provide

extra

area

for

gripping

and

to

avoid

having

the

sample

break

where

it

is

being

gripped.拉伸试验包含慢慢加载拉伸载荷直到断裂，拉伸试件两端加粗为了提供装夹区域和防止试件断裂。Theusualmannerofconductingthe

test

is

todeformthespecimenataconstantspeed.Forexample,intheUniversaltestingmachines,the

motionbetweenthefixedandmovingcrossheadscan

becontrolledataconstantspeed.

通常进行试验方法就是使试件以恒定速度发生变形。比如，在万能拉伸试验机上，固定端和移动十字滑块之间变形是以恒定速度进行。Theloadthatmustbeappliedtoenforcethisdisplacementratevariesasthetestproceeds.ThisloadFmaybedividedbythecross-sectionalareaAtoobtainthestressinthespecimenatanytimeduringthetest.伴随试验进行，用来产生位移载荷是随位移改变而变化。在试验中，载荷F除以横截面积A能够得到任意时刻点应力。4）HoweveractualmeasurementofΔLis

preferable

where

Thisisfeasible.Stressandstrainbasedon

theinitial

(undeformed)dimensions,AiandLi,arecalledengineeringStressandstrain.然而，在可行位置ΔL实际测量是更可取，基于原始尺寸Ai和Li应力和应变称为工程应力和工程应变。5)Ductileandbrittlematerialsbehavedifferentlyincompressiontestaswell.ThecompressiontestisconductedonshortCylindricalspecimensplacedbetweenparallelplates.塑性和脆性材料在压缩试验中表现特征是不相同。压缩试验是把短圆柱形试件放在两平行平板之间进行Thecompressiontestdiagramfor

these

materialsretains.Thequalitativefeaturesofthetensiontestdiagram.Theultimatecompressivestrengthofabrittleofabrittlematerialisdeterminedinthesameway

as

in

tension.材料压缩试验图保持了拉伸试验图性能上特征。脆性材料最大压缩强度与最大拉伸强度得到方法相同。41)herringbonegears人字形齿轮2）spiralgears螺旋齿轮3）wormgears蜗轮4)bevelgears（圆）锥齿轮，伞齿轮5）hypoidgears准双曲面齿轮6）sizesofspur-gearteeth轮齿尺寸7)theautomotiverearaxledrives汽车后桥驱动8)rack-and-piniondrives齿条和小齿轮驱动9)diametralpitch径节10)pitchcircle节圆11)thetangencypoint切点12)pressureangles压力角13)aninvolutecurve渐开线曲线14)theradialdistant径向距离15)atrightangles成直角16)theaveragenumberofteethincontact平均啮合齿数17)thereciprocalofthediametralpitch径节导数18)tochangeinchestomillimeters将英寸改为毫米19)alineperpendiculartothecenterlines垂直于中心线线20)centerdistancebetweentwomeshedgears两个相互啮合齿轮中心距离1)Pressureanglesforspurgearsareusually14.5or20degress,althoughothervaluescanbeused.Meshinggearsmusthavethesamepressureangles.译文：即使直齿圆柱齿轮压力角能够取很多其余值，但通常大多是在14.5至20度之间。相互啮合齿轮压力角必须相同。2)Theshapeofthespacebetweengearteethiscomplexandvarieswiththenumberofteethonthegearaswellastoothmodule,somostgearmanufacturingmethodsgeneratethetoothflankinsteadofforming.译文：因为齿轮齿数以及齿形不一样，齿轮齿侧间隙形状也是复杂多样，所以大多数齿轮制造方法是范成发而不是成型法。3)Wormgearsareusedwherehighratiosaredesiredandwheretheshaftsarenointersectingandatrightangles.译文：蜗轮蜗杆惯用于那些要求高传动比同时两根轴不交叉但成直角场所。4)Ithasthegreatadvantagethatthecuttingtoolisasimplerackwith(nearly)straightsidedteethwhichcaneasilybegroundaccurately.译文：一个很大优势在于刀具是在一个简单齿条几乎能够直接准确地支起被磨损轮齿。5)Modernshaperscuttingcargearscanrunatcuttingperminute.Theshapeofthecutterisroughlythesameasaninvolutegearbutthetipsoftheteetharerounded.译文：当代牛头刨床削减汽车齿轮能够运行在每分钟。刀具形状大致与渐开线齿轮圆形轮齿相同。6)Bevelgearsareoftenusedwhentwoshaftsareatrightanglestoeachotherandtheircentenlineextensionsintersect;however,somebevelgearsareatanglesotherthan90degrees.译文：锥齿轮惯用于两轴相互垂直且它们中心线延长线相交场所下。可是，有些锥齿轮轴线并非相互垂直。51.platecams盘形凸轮2.cylindricalcams圆柱凸轮3.thecamassembliesinautomaticrecordplayers录音机上凸轮组件4.camprofiles凸轮轮廓5.makeafull-scaletemplate制造一个实尺样板6.inthecourseofseveralrevolutionsofthecam在凸轮转几转过程中7.atangentialplatetemplate切向盘形凸轮8.atranslationcam移动凸轮9.thegrooveintheperipheryofthecam凸轮表面上槽10.aguidedverticalreciprocatedfollower纵向做往复运动从动件11.aconstant-diametercam等径凸轮12.automaticwashingmachines自动洗衣机13.afacecam面凸轮14.theedgeofapivotedfollower摆动从动件边缘15.areciprocatingknife-edgedfollower一个做往复运动刃口式从动件16.miniaturesnap-actionelectricalswitches微型速动电开关17.apivotedflat-facedfollower一个转动平面从动件18.airpilotvalues空气试点值19.theabruptchangeincamprofile凸轮轮廓突变20.aScotchyokemechanism苏格兰约克机构1.Thepurposeofanycamistoproduceadisplacementofitsfollowerisofenusedtoproduceadditionaldisplacementinanotherlocation.使用凸轮目标是使其从动件产生位移，次级从动件惯用来在另一位置产生附加位移2.TherelativeverticalpositionofpointAwithrespecttoBneedstoberaisedifthereactionvalueatBisexcessive.假如B点值超量，点A相对于B垂直位置就要升高3.Ingeneral,thefollowerisconsideredtobethepartthatcomesincontactwiththecamprofile.However,whenasecondaryfollowerisused,themotionofthesecondaryfollowerisdicatatedbythatoftheprimaryfollower.总来说，从动件是与凸轮轮廓相接触零件。然而，当用次级从动件时，次级从动件运动就需要经过主要从动件来实现4.Thesimplesttypeoffolloweristhereciprocatingtypethatmerelymovesupanddown(orinandout)withtherotationofthecam;thecenterlinecanbeeithercollinearwiththecamcenterlineoroffsetfromit.最简单从动件是伴随凸轮转动而仅作上下（或进出）往复运动从动件，其中心线可与凸轮中心线共线，也可与之偏离。5.Fastenersaredeviceswhichpermitoneparttobejoinedtoasecondpartand,hence,theyareinvolvedinalmostalldesigns.紧固件是一个能够连接两个零件部件，所以他们几乎在全部设计中都被包括到。2.Springsaremechanicalmemberswhicharedesignedtogivearelativelylargeamountofelasticdeflectionundertheactionofanexternallyappliedload.弹簧是一个被设计为在外部负载作用下能发生相对大量弹性变形机械部件。61)adevelopinganddemandingindustry产业发展与要求2)propellershaft螺旋轴3)suspensioncomponents悬挂部件4)aslidingsplinedtypeofjoint滑动式花键5)towrearaxleshafts双转向轴轴6)tomeshwithalargerbevelgear与较大锥齿轮啮合7)theuniversaljoints万向节8)asteeringwheel转向盘9)unevennessofroadsurface路面不平整度10)thetransverselineofthetheaxleshafts该轴横向线11)tocauseexcessivetyrewear使轮胎磨损过分12)theexactlysimilardiameter完全相同直径13)quarter-ellipticleafsprings四分之一椭圆钢板弹簧片14)thetransmissionofshock震动传输15)roadsurfacevariation路面改变16)thefinal-drivegears最终传动齿轮17)theprecisealignmentofshaft轴精准定位18)arotatingdrum一个旋转筒鼓19)ahandlever手柄20)belockedintheoneposition被锁定在一个位置1)Thelubricationsystemprovidesaconstantflowoffilteredoiltoallmovingpartsoftheengine.Thesystemconsistsofanoilpantostoretheoil,apumptocirculateit,afiltertoremovesolidabrasiveparticles,andanoilgaugeorlightinthedriver’scompartmentforcheckingpurposes.译:润滑系统提供了源源不停过滤油给发动机各个运动部件，该系统由一个油箱来储存油，一个泵来输送油，一个过滤装置除去固体磨料颗粒，而且在驾驶室里有个油压表或者指示灯来方便驾驶员检验油量是否充分。2)Thedrivelineconsistsofmechanismsandunitswhichtransmittorquefromtheenginetothedrivewheelsandchangetorqueandrpminmagnitudeanddirection.译:传动系包含机制和单位，它将扭矩传送到驱动轮并改变转矩和转速大小和方向。3)Ithasbeenseenthatiftheconditionsarenotveryabnormal,sufficientamountoftyresliptakingplaceunderrunningconditionswouldreleasethesestressescompletely.译:能够看到，假如运行情况不是很正常，轮胎在行驶情况下发生足够滑移，这些压力就会被完全释放出来。4)Mucheffortisrequiredtocranktheengineduringstarting,sinceitisnecessarytoovercomefrictioninthemovingenginecomponentsandtheresistanceofferedbythechargebeingcompressed.译:发动机开始运行需要经过许多努力，比如必须要克服发动机运动部件之间阻力和内部装置间压力。5)Theclutchisafrictiondeviceusedtoconnectanddisconnectadrivingforcefromadrivenmember.Itisusedinconjunctionwithanengineflywheeltoprovidesmo0thengagementanddisengagementoftheengineandmanualtransmission.译:离合器是一个将驱动力从驱动机构连接或者断开摩擦装置，它由人力操控连接发动机飞轮来提供平滑连接与分离。6)Thedifferentialisagearsystemthattransferspowerfromthedriveshafttothedrivingaxles.Italsopermitsonedrivingwheeltoturnfasterthantheothertopreventskiddingandscuffingoftiresonturns.译:差速器是一个将动力从主动轴传送到驱动轴齿轮装置，它存在能够允许一个驱动轮速度比另一个更加快从而防止轮胎在转动时发生打滑和擦伤。71.Greensand型砂2.Pourmoltenmetalintoapreparedcavity将熔融金属倒入型腔中3.Morestableandrefractorysands耐熔砂4.Beusedtoproduceintricatemolds用来制作复杂铸型5.Bothferrousandnonferrousmaterials黑色及有色金属6.Partingpowder分形砂7.Berammed扎实8.Patterndraft拔模斜度9.Sprues,runnersandgates直浇道，横浇道和内浇口10.Apouringbasin外浇口11.Tomakeupforshrinkagelosses用于填补收缩损失12.Thecopeandthedrag上沙箱和下沙箱13.Someorganicbondingmaterials一些有机黏合材料14.Grossshrinkage缩孔15.Abottom-pouringladle底部浇注铁水包16.Therateofsolidification凝固速率17.Toaffectthedegreeofliquidcontraction影响液体收缩程度18.Columnargrowthpresentatthemoldwall铸型中针状物成长19.Thefeedingcharacteristicsoftheriseringsystem冒口补缩特征20.Unwantedmetalprotrusions多出金属突起1.Thefirststageintheproductionofsandcastingmustbethedesignandmanufactureofasuitablepattern.Castingpatternhastobemadelargerthanthefinishedcastingsizetoallowfortheshrinkagethattakesplaceduringsolidificationandcooling.在型砂铸造生产中，第一阶段是必须设计和制造适宜模型，考虑到铸件在凝固和冷却期间产生收缩，铸件模型尺寸要比铸件尺寸大。2.Ifahollowcastingistobemadethepatternwillincludeextensionpiecessothatspacestoacceptthesandcorearemoldedintothesand,Theseadditionalspacesinthemoldaretermedcoreprints.假如铸造空心铸件时，模型上包含伸长杆便于在砂中放置砂芯空间称为型芯座3.Sandmoldsfortheproductionofsmallandmedium-sizedcastingsaremadeinamoldingbox.Themoldismadeintwoormorepartsinorderthatthepatternmayberemoved.中小型尺寸铸件砂型是在一个砂箱中制造，砂型由两部分或更多部分组成，以利于模型顺利取出。4.Thisprocessoffillingandrammingmaybedonebyhandbutmoldproductionisautomatedinalargefoundrywiththemoldboxesmovingalongaconveyor,firstlytobefilledwithsandfromhoppersandthentopassundermechanicalhammersforramming.填充和扎实过程能够手工完成，但在大型铸造中砂型制造是自动完成，砂箱伴随传送带移动，首先被料斗中砂子填满，然后经过机械锤被打实。5.Therisersshouldcoincidewiththehighestpointsofthemoldcavitysothatthedisplacedaircanreadilyescapefromthemold.Thesizesofrisersshouldbesuchthatthemetalinthemdoesnotfreezetoorapidly.冒口应该与型腔最高点相连接，使得进入空气能够轻易从模型中溢出，冒口尺寸应该足够大使模型中金属不会太快凝固。6.Whenthemetalthathasbeenpouredintoasandmoldhasfullysolidified,themoldisbrokenandthecastingisremoved.Thecastingstillhastherunnerandrisersattachedtoitandtherewillbesandadheringtoportionsofthesurface.当熔融金属被倾倒到砂型内并充分凝固以后，砂型将被打破取出铸件，铸件上依然带有横浇口和冒口而且依然有砂子粘在表面。81).bulkdeformationdfmetals金属体积成形2).forging,rolling,orextruding铸造、轧制、挤压3).plasticdeformation塑性变形4).impactblows影响冲击5).therecrystallizationpointofthemetal金属再结晶点6).hotworkingandcoldworking热加工和冷加工7).bettersurfacefinish愈加好表面光洁度8).hammerforging锤铸造9).strikingthehotmetal热金属10).aslowsqueezingacting迟缓挤压作用11).opendiesangcloseddies开模和封闭模具12).bevelgearswithstraightorhelicalteeth圆锥齿轮跟直齿轮或者螺旋齿轮齿13).impressiondies型腔模具14).eachofdiecavities每个模腔15).massproduction大规模生产16).ahomogeneouscircumferentialgrainflow均匀圆周颗粒流17).thethree-dimensionaldescription三维描述18).computersimulation计算机模拟19).hydraulicpresses液压机20).berough-andfinished-machined是粗糙而且经过机加工完成1.Forgingmeanstheshapingofmetalbyaseriesofhammerblows,orbyslowapplicationofpressure.Thesimplestexampleisablacksmith'sforgingofahotpieceofmetalbyhammeringthework-pieceonananvil.铸造是指经过一系列捶打或迟缓挤压使金属成形过程。最简单例子就是铁匠经过在铁砧上捶打一块热金属来制造工件。2.Heavysmith'sforgingisfundamentallysimilar,differingonlyinthescaleoftheoperation,Thework-piecemaybeaningotof100tonsandthedeformingforceprovidedbyamassiveforginghammer,butthewholeprocessiscontrolledbythemastersmith,whodecideseachtimewhere,andwithwhatforce,theblowshouldtakeplace.铁匠们沉重铸造工作基本上是相同,不一样地方只是在于铸造规模,工件可能是一个100吨金属锭，而且金属锭变形所需要力是经过一把大规模铸造锤提供,不过整个过程都是由主铁匠控制,决定每一次捶打在什么地方，用什么力量以及是否需要冷却。3.Forgingoperationsmaybecarriedoutusingeitherforginghammersorforgingpresses.Withapress,asopposedtoahammer,pressureisslowlyappliedandplasticdeformationtendstooccurfairlyuniformlythroughoutthemeterial.铸造时能够用铸造锤，也能够用铸造压力机。与铸造锤不一样,经过铸造压力机铸造时，压力被迟缓施加，塑性变形往往会相当均匀地贯通整个材料。4.Forginghammersareoftwobasictypeswiththelargehammereitherdroppingontothework-pieceacceleratedbygravityaloneor,asinthesteamhammer,acceleratedbybothgravityandsteampressure.大型铸造锤有两种基本类型，一个捶打工件仅仅靠重力使大锤加速,另一个靠重力和蒸汽加速使大锤加速，如蒸汽锤。5.Smith'soropen-dieforgingisusedformakingverylargeforgingsorwhenthenumberofforgingsofaparticulardesignissmall.Open-dieforgingisalsousedtopreformmetalpriortofinalshapingbymeansofclosed-dieforging.锤锻或开模锻适适用于制造非常大锻件，或少许特殊设计锻件。开模锻还能够用于金属闭模锻之前粗加工。6.Closed-dieforginginvolvestheuseofaccuratelymachineddieblocks.Thecapitalcostofapairofdieblocksishigh,butthisisallowablewhenitisrequiredtomakeforgingstoclosedimensionaltolerancesandinlargequantity,aswouldbethecasefor,say,connectingrodsfirtheengineofapopularcar.闭模锻包括到精准加工模块使用。一对模具块成本很高,但当锻件尺寸公差要求很高，数量很大情况下，闭模锻是适用91)carryinghigh-amperagecurrent带有高电流2)theelectrodeandthework-piece电极和工件3)theweldpool熔池4)acolumnofionizedgascalledplasma等离子区柱状电离气体5)theoxidesandnitrides氮氧化物6）thepositiveions正离子7)deleterioussubstances有害物质8）thenewlysolidifiedmetal新凝固金属9)inoverheadwelding仰焊10）currentdensity电流密度11）depositionrate沉积速率12）anunbalancedmagneticfield不平衡磁场13）arcblow电弧偏吹14）theelectrodecoating焊条涂层15）inoverheadposition仰焊场所16）thecoolingrateofthedepositedmetal焊缝金属冷却速率17）amorehomogeneousmicrostructure更均匀显微（结构）18）asoomthflowofmoltenmetal熔融金属平稳流动19）cellulosic-coatedelectrodes纤维涂层焊条20）perpendiculartothecurrentpath垂直于电流通道1）Arcweldinginoneformoranotheristhemostwidelyusedformofwelding.Theelectricalsupplyislowvoltagebuthighamperageandmaybeeitheralternatingordirect.电弧焊在一个或另一个形式是应用最广泛焊接形式。电源供给低电压，不过大电流,能够是交流或直流。2)Theearliestformsofarcweldingusedcarbonelectrodes.Butnowadaysthearcisstruckbetweenametalelectrodeandthework-piece.Theelectrodemayeitherbeoftungstenorbeaconsumablemetalelectrodethatmelts,actingasasourceoffillermetal.最早形式电弧焊用碳电极。但如今弧金属电极和工件之间。电极能够是钨或可熔化,作为填充金属供源消耗性金属电极。3)Analternating-currentarcisbrokenandre-establishedateachhalfcycleandthisleadstoarcinstabilityalthoughtheuseofarc-establishingagentsinthefluxcoatingofelectrodewirescanovercomethisproblem.交流电弧被打破,重新建立在每个半周期和这造成电弧不稳定即使在电极布线焊剂涂层使用电弧建立剂能够克服这个问题。4)Uncoatedweldingrodscanbeusedforarcwilding,butitismoreusualtouseflux-coatedelectrodes.Whensteelsareweldedusinguncoatedelectrodes,oxidesandnitridescanformandremainintheweldwithaconsequentlossoftoughness.裸焊接棒可用于电弧野生植物,但更通常使用焊剂涂层电极。钢焊接使用裸电极时,氧化物和氮化物能够形成并保持在焊缝韧性。5)Flux-coatedelectrodesarewidelyused.Thecompositionofthecoatingiscomplexandavarietyofdifferentcoatingsareusedtocaterfordifferenttypesofweldingapplication.焊剂涂层电极被广泛使用。涂料组成很复杂,各种不一样涂料用于满足不一样类型焊接应用。6)Inthiscasetheelectronflowisfromelectrodetowork-piece.Aconcentratedarcissuesfromtheelectrodetipandheatingofthework-pieceislargelyconfinedtotheverysmallareabeneaththeelectrode.在这种情况下,电子流动从电极到工件。集中弧电极头和工件加热问题主要局限在极小区域下电极。101)plaincarbonsteel普通碳素钢2)carboncontent含碳量3)lowcarbonsteel低碳钢4)mediumcarbonsteel中碳钢5)highcarbonsteel高碳钢6)becoldworked冷加工7)beheattreated热处理8)contain20pointofcarbon碳含量0.2%9)inthehot-rolledcondition热轧状态10)heat-treat-hardenedplaincarbonsteel热处理淬硬普通碳素钢11)free-machiningsteels易切削钢12)hotshort热脆13)coldshortness冷脆性、低温脆性14)theisothermaltransformationcurves等温转变曲线15)grainrefinement晶粒细化16)stainlesssteel不锈钢17)AISIsteelsAISI钢18)iron-carbonequilibriumdiagram铁碳合金平衡相图19)toolanddiesteels工具钢和模具钢20)highcorrosionandchemicalresistance耐高腐蚀能力和抗化学作用1)Insimpleterms,aplaincarbonsteelmaybesaidtobeanalloyofironandcarboncontaininglessthan1.7%carbon.Inpractice,however,thesesteelsrarelycontainmorethan1.4%carbonandotherelementsarealsopresent,eitherasdeliberateadditions(e.g.manganese)orasimpurities(e.g.sulphurandphosphorus).简单来说，普通碳素钢被认为是一个含碳量少于1.7%铁碳合金。然而，实际上，这些钢含碳量极少超出1.4%，同时还含有一些其余元素，比如一些额外添加物（如锰）或杂质（如硫和磷）2)Inthemanufactureofmaterial,completedeoxiadationisnotcarriedoutanditismadeasrimmingsteel.Itisproducedashotandcoldworkedsheet,strip,rod,wire,andtube,andisavailableinthehot-workedorprocessannealedcondition.在材料加工过程中，不完全脱氧还原被加工成沸腾钢。它经过热加工或冷加工被制成板材、带材、棒材、线材和管材，这些也可在热加工和退火条件下取得。3)Thestrengthandhardnessofthesesteelislow,butahardsurfacecanbeobtainedbycarburizinginordertocombineawear-resistantsurfacewithtoughcoreproperties.这类钢强度和硬度很低，但能经过渗碳作用表面硬化，他兼顾了表面耐磨和内部韧性很好特点。4)Asthecarboncontentisraisedabove0.2%,thestrengthincreasesintotherangerequiredforconstructionalpurpose,buttheductilitydecreases.Thefabricationqualities(workingandweldingcharacteristics)ofthismaterialareverygood.当含碳量上升超出0.2%时，需求范围内结构用途强度增加，不过延展性会下降。材料制造质量（承载性和焊接特征）会非常好。5)Mediumcarbonsteelsareoftenquenched-hardenedandfullytemperedtogivegoodstrengthwithmaximumtoughness,whicharethepropertiesrequiredofcomponentssuchasshafts,gearsandconnectingrods.中碳钢常被淬火和完全回火处理以赋予高强度同时拥有最大韧性，这些特征都是像轴、齿轮和连杆这一类零件所需要。6)Highcarbonsteelsarequenchhardenedandlightlytemperedtogivehighhardnesswithonlylimitedtoughness.Materialinthisclassificationismainlyusedformakingfairlysmall,reactivelyinexpensivecuttingtoolssothatthegroupasawholeisknownascarbontoolsteel.高碳钢经过淬火和低温回火来给予高硬度同时兼有一定韧性。这类材料主要被用于加工相当小而可靠，而且廉价切削工具，所以通常被称为碳素工具钢。111.allotoropicmaterials同素异晶体2.plainlowcarbonsteels普通低碳钢3.hypoeutectoidsteel亚共析钢4.normalizedsteel正火钢5.hypereutectoidsteel过共析钢6.eutectoidcomposition共析成份7.grainboundaries晶界8.ferritematrix铁素体基体9.about60℃abovetheAc1temperatureAc1温度以上大约60℃10.thenoseoftheI-Tcurve等温曲线鼻部11.coolingrate冷却温度12.quenchingmedia淬火介质13.thermalstress热应力14.thermalshock热冲击15.atemperedsteel回火钢16.temperbrittlement回火脆性17.inthetemperingordrawingprocedure回火时18.hardenedsteel淬硬钢19.fullannealing完全退火20.todissolveallthecementite溶解全部渗碳体1.Theprincipalkindsofheat-treatmentusedinpractice,whichdifferentlyaffectthestructureandproperities,andwhichareassignedtomeettherequirementsmadetothesemifabricatedmaterials(casting,forging,rolledstock,etc.）andfinishedarticles,are:(1)annealing;(2)normalizing;(3)hardeningand(4)tempering.在实践中用到能对结构和性质有不一样影响，并被分配满足半成品材料（铸造，铸造，轧制成品等）要求热处理基本类型是：（1）退火；（2）正火；（3）硬化和（4）退火。2.Normalizingraisesthestrengthandhardnessofmedium-andhigh-carbonsteelsby10to15percentascomparedtoannealedsteel.与退火相比，正火提升了中碳钢和高碳钢10%—15%强度和硬度。3.Martensiteisveryhardandbrittle,havingamuchhighertensilestrengththanthesteelwithapearlitemicrostruture.马氏体非常硬和脆，具备比珠光体组织钢更高抗拉强度。4.Tempering,ordrawing,isaprocessofreheatingasteelpartthathasbeenpreviouslyhardenedtotransformhardmartensiteintosofterstructure.Thehigherthetemperingtemperatureused,thesofterandtoughthepiecebecomes.回火，是一个加热钢部分已被改造成软硬质马氏体结构以前硬化过程。回火温度越高，钢就会越柔软和坚韧5.Forlowcarbonsteels,normalizingenablesabettersurfacefinishtobeobtainedinmachinhingandraisestheproductioncapacity.对于低碳钢而言，正火在机械加工中能够取得愈加好表面光洁度和提升生产能力。6.Incommercialtemperingthetemperaturerangeof250-425℃isusuallyavoidedbecauseofanunexplaindembrittlement,orlossofductility,thatoftenoccurswithsteelstemperedinthisrange.在工业上，通常要防止在250℃到425℃范围内回火，因为这个范围内回火钢经常会产生无法解释脆性或塑性丧失现象。121.thenominalsizeornominaldimension公称尺寸或公称通径2.actualsizeandlimitsofsize实际尺寸和极限尺寸3.upperdeviationandlowerdeviation上偏差和下偏差4.clearancefitandinterferencefit间隙配合和过盈配合5.theactualdimensionsofthefinishedproducts成品实际尺寸6thematingparts配合零件7.thehole-basissystem基孔制8.generalinterchangeability通常交换性9.thepositionofthezoneoftolerance公差带基本尺寸10.representthevalueofthiszoneoftolerance代表公差带值11.thenominalsizeornominaldimension公称尺寸或公称通径12.actualsizeandlimitsofsize实际尺寸和极限尺寸13.upperdeviationandlowerdeviation上偏差和下偏差14.clearancefitandinterferencefit间隙配合和过盈配合15.theactualdimensionsofthefinishedproducts成品实际尺寸16.thematingparts配合零件17.thehole-basissystem基孔制18.generalinterchangeability通常交换性19.thepositionofthezoneoftolerance公差带基本尺寸20.representthevalueofthiszoneoftolerance代表公差带值1.Sinceitisimpossibletomachineaparttoanexactsize,adesignermustspecifyanacceptablerangeofsizesthatwillpermittheparttofitandfunctionasintended.因为它不是机械零件一部分确实切尺寸，设计者必须指定尺寸可接收范围，将允许部分误差以实现配合和功效与预期相同2.Themaximumandminimumsizesinpartdimensionsthatareacceptablearelimitsbetweenwhichtheactualpartdimensionmustfall.实际尺寸必须落在可接收最大和最小尺寸程度之间3.Toleranceondrawingisoftenindicatedbyspecifyingalimit,orbyplusandminusnotations.Withplusandminustolerancing,whenthetoleranceisbothaboveandbelowthenominal(truetheoretical)size,itissaidtobebilateral(twosides).绘图上公差是经常经过被指定一个限制,正或者是和负符号。伴随正负公差值,公差值处于公称尺寸之上和之下时,被称为双边4.Althoughamachinistisnotusuallyconcernedwithestablishingtoleranceandlimitspecifications,youcaneasilyseehowfitproblemscanbecreatedbyoverlappingtolerancesdiscussedinthisexample.尽管工程师通常不关注公差建立和规格限制，但你能很轻易从这个示例中看出,怎样配合问题能够经过重合讨论公差创建.5.Manytimesamachinistisconcernedwithpressorinterferencefits.Inthiscasetwopartsareforcedtogetherusuallybymechanicalorhydraulicpressing.很多时候，机械加工包括压力或过盈配合.在这种情况下，两部分通常是经过机械或液压压制在一起。6.Althoughstandardizedmeasurementisessentialtomodernindustry,perhapsevenmoreimportantarethedesignspecificationsthatindicatethedimensionofapart.即使标准化测量是当代工业关键,可能更为主要是表明部分尺寸设计规格。LESSON131.hydraulicpowertransmissionsystem液压动力传动系统2.Theamountoffluid-flowtotheactuators抵达执行部件液体流量3.Fromhydraulicpowertomechanicalpower将液压能转换为机械能4.Fluidstorageandconditioningequipment油液贮存和调整装置5.Thetechnologyofhydraulics液压技术6.Thegeometryofthemachine机构几何学7.Pneumaticsystems气压系统8.Oilunderpressure压力油9.Directionalcontrolvalve方向控制阀10.Constantforceortorque恒定力或力矩11.Safety,compactnessandreliability安全性，紧凑性和