机电专业英语第2版4Unit4HeatTreatmentandHotWorkingofMetals

HeatTreatment&HotWorkingofMetalsUnit4金属的热处理和热加工HeatTreatmentandWorkingEquipmentTestingBeforeClass：Whatthemeaningof“Shaping”?(radio)HeatTreatment&HotWorkingofMetals

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Unit4HeatTreatment&HotWorkingofMetals

Wecanalterthecharacteristicsofsteelinvariousways.Inthefirstplace,steelwhichcontainsverylittlecarbon,willbemilderthansteel,whichcontainsahigherpercentageofcarbon,uptothelimitofabout1.5％.Secondly,wecanheatthesteelaboveacertaincriticaltemperature,andthenallowittocoolatdifferentrates.Atthiscriticaltemperature,changesbegintotakeplaceinthemolecularstructureofthemeta1.Intheprocessknownasannealingweheatthesteelabovethecriticaltemperatureandpermitittocoolveryslowly.Thiscausesthemetaltobecomesofterthanbefore,andmucheasiertomachine.

Annealinghasasecondadvantage.Ithelpstorelieveanyinternalstresseswhichexistinthemetal.Thesestressesareliabletooccurthroughhammeringorworkingthemetal,orthroughrapidcooling.Metalwhichwecausetocoolrapidlycontractsmorerapidlyontheoutsidethanontheinside.Thisproducesunequalcontraction,whichmaygiverisetodistortionorcracking.Metalwhichcoolsslowlyislessliabletohavetheseinternalstressesthanmetal,whichcoolsquickly.Ontheotherhand,wecanmakesteelharderbyrapidcooling.Weheatitupbeyondthecriticaltemperature,andthenquenchitinwaterorsomeotherliquid.Therapidtemperaturedropfixesthestructuralchangeinthesteel,whichoccurredatthecriticaltemperature,andmakesitveryhard.Butabarofthishardenedsteelismoreliabletofracturethannormalsteel.Wethereforeheatitagaintoatemperaturebelowthecriticaltemperature,andcoolitslowly.Thistreatmentiscalledtempering.Ithelpstorelievetheinternalstresses,andmakesthesteellessbrittlethanbefore.ThepropertiesoftemperedsteelenableUStouseitinthemanufactureoftools,whichneedafairlyhardsteel.Highcarbonsteelisharderthantemperedsteel,butitismuchmoredifficulttowork.Theseheattreatmentstakeplaceduringthevariousshapingoperations.Wecanobtainbarsandsheetsofsteelbyrolling

themetalthroughhugerollsinarollingmill.Therollpressuresmustbemuchgreaterforcoldrollingthanforhotrolling,butcoldrollingenablestheoperatorstoproducerollsofgreataccuracyanduniformity,andwithabettersurfacefinish.Othershapingoperationsincludedrawingintowire,castinginmoulds,andforging.Themechanicalworkingofmetalistheshapingofmetalineitheracoldorahotstatebysomemechanicalmeans.Thisdoesnotincludetheshapingofmetalsbymachiningorgrinding,inwhichprocessesmetalisactuallymachinedoff,nordoesitincludethecastingofmoltenmetalintosomeformbyuseofmolds.Inmechanicalworkingprocesses,themetalisshapedbypressure---acutelyforging,bending,squeezing,drawing,orshearingittoitsfinalshape.Intheseprocessesthemetalmaybeeithercoldorhotworked.Althoughnormalroomtemperaturesareordinarilyusedforcoldworkingofsteel,temperaturesuptothere-crystallizationrangearesometimesused.Hotworkingofmetalstakesplaceabovethere-crystallizationorwork—hardeningrange.Forsteel,re-crystallizationstartsaround650to700~C,althoughmosthotworkonsteelisdoneattemperaturesconsiderablyabovethisrange.Thereisnotendencyforhardeningbymechanicalworkuntilthelowerlimitofthere-crystallinerangeisreached.Somemetals,suchasleadandtin,havealowre-crystallinerangeandcanbehotworkedatroomtemperature,butmostcommercialmetalsrequiresomeheating.Alloycompositionhasagreatinfluenceupontheproperworkingrange,theusualresultbeingtoraisethere-crystallinerangetemperature.Thisrangemayalsobeincreasedbypriorcoldworking.

molecular[mə'lekjələ]a.由分子组成的,分子的annealing[ə'ni:liŋ]n.(低温)退火，焖火，磨炼relieve[ri'li:v]v.解除，减轻，使不单调乏味liable['laiəbl]a.有责任的，有义务的，应受罚的，有…倾向的contract['kən'trækt]v.收缩，缩紧，感染，订约rise[raiz]v.上升，增强，起立，高耸shaping[ʃeipiŋ]n.成形，造型，塑造mechanical[mi'kænikəl]a.机械的，呆板的，力学的machining[mə'ʃi:niŋ]n.切肖，制造，机械加工grinding[ɡraindiŋ]n.磨肖力工machined[mə'ʃi:nd]a.机械加工的pressure['preʃə]n.压力，压强bend[bend]v.使弯曲，使屈服，使致力，使朝向bending['bendiŋ]n.弯曲(度)，扭曲(度)Newwordsandphrases

squeeze[skwi:z]v.挤(压，干)，压榨，勒索，紧握prior['praiə]a.在先的，在前的，优先的distortion[dis'tɔ:ʃən]n.变形，扭曲，曲解，失真crack[kræk]v.&n．破裂，裂纹，打开beyond[bi'jɔnd]prep.超过……的范围,超过,越过quench[kwentʃ]v.&n．熄灭，[机]淬火,解渴；fix[fiks]v.&n.安装,修理，使固定，准备tempering['tempəriŋ]v.回火rolls[rəuls]n.薄板卷，泛指钢材draw[drɔ:]v.拉,画,吸引drawing['drɔ:iŋ]n.冲压成形shear[ʃiə]v.剪断，切断，修剪，剥夺recrystallization[ri:,kristəlai'zeiʃən]n.再结晶hardening['hɑ:dəniŋ]n.硬化，淬火,锻炼crystalline['kristəlain]a.结晶的凡．结晶体influence['influəns]n.影响，作用Newwordsandphrases

mechanicalmeans机械设备(工具)beknownas…称为……work—hardeningrange淬火温度区TechnicalTerms

Thisproducesunequalcontractions，whichmaygiverisetodistortionorcracking．译文：这将引起不均匀压缩，增加其出现畸变和破裂的可能。说明：此句为非限定性定语从句。“Which”引导的从句时对“unequalcontractions”的进一步解释说明。Languagepoints2.Thisdoesnotincludetheshapingofmetalsbymachiningorgrinding，inwhichprocessesmetalisactuallymachinedoff，nordoesitincludethecastingofmoltenmetalintosomeformbyuseofmolds．译文：这既不包括金属已经过机械或磨削加工的成形，也不包括熔化的金属注入铸造模所进行的成形。说明：“inwhichprocessesmetalisactuallymachinedoff”为非限定性定语从句，对前面的主句起进一步解释说明作用。“nordoesitincludethecastingofmoltenmetalintosomeformbyuseofmolds”此句为倒装句，由于“nor”提前，整个句子发生了部分倒装。Languagepoints3.Thesestressesareliabletooccurthroughhammeringorworkingthemetal,orthroughrapidcooling.金属在锻打加工或快速冷却时外层收缩比内层收缩速度快，极易导致内应力。beliableto:易于…的；有…倾向的；应付有责任，应遵守…(1)Athirdparty,whosefaultcausesthefuelgasaccident,shallbeliabletopaydamagesaccordingtolaw.因第三人的过错造成燃气事故的，第三人应当依法承担损害赔偿责任。(2)Non-complyingtrustsarealsodeemedtobeliabletotaxationonthetrust'sworldwideincome.“非照办信托”同时也被推定为按其信托之全球收入征税。Languagepoints4.Weheatitupbeyondthecriticaltemperature,andthenquenchitinwaterorsomeotherliquid.我们将金属加热到超过极限温度，然后在水或其他液体中淬火。heatup：加热（1）Theelectronicheatercanheatupfastandsafely.Italsofunctionsasasteamer.以电热为燃料能源，既方便，而且加热速度快，有蒸气锅炉之同功效。（2）Materialspiralingintoablackholecanheatuptomillionsofdegreesandglowbrightly.捲入黑洞中的物质，将会被加热至数百万度并放出耀眼的光芒。

Languagepoints5.ThepropertiesoftemperedsteelenableUStouseitinthemanufactureoftools,whichneedafairlyhardsteel.当制造的工具需要高硬度的钢铁时，我们可以用回火钢。enable…to…:使…;使…能够;能够

(1)UsingICONcontrollingcircuit,enabletodetectthestatusofthemechanismoperation.

本机采用ICON控制回路，可侦测机械操作状况。

(2)Thespacebetweentheinnerandouterplateisfullofheatinsulationmaterialswhichenabletoprovidetheniceperformanceofheatinsulation.内外板之间形成的空间可以填充保温材料，能够提供良好的保温功能。Languagepoints6.Othershapingoperationsincludedrawingintowire,castinginmoulds,andforging.其他的塑性加工有拉丝、模铸和锻造。drawinginto:使卷入

(1)SMSDrawintegratesintothetargetapplicationandappearsasanewserviceinthetoolbar.短信抽奖集成到目标应用，似乎作为一种新的服务工具栏。(2)Nowthepatternrepeatwithmanualtwist,willitselfdrawintotheactivelevelofthePhotoshopdatafileandtheoriginalismaintainedagainonaseparatelevel.现在的模式重复与手工捻，本身将提请进入活跃水平的Photoshop的数据文件和原再次是保持在一个单独的水平。

Languagepoints7.Thereisnotendencyforhardeningbymechanicalworkuntilthelowerlimitofthere-crystallinerangeisreached.在达到最低的再结晶温度之前，机械加工的金属没有硬化的趋势。tendency['tendənsi]n.倾向，趋势；癖好(1)Sincegravityworksequallyoneverything,therewouldbeatendencytopullthoseunevenplacesdown.由于重力作用于物体上是相等的，会有倾向于将受力不相等的地方拉平。(2)Thetendencyofmodernscienceistoreduceprooftoabsurditybycontinuallyreducingabsurditytoproof.现代科学的倾向，是不断把谬论化为根据来使实证变得荒谬。

Languagepoints8.Alloycompositionhasagreatinfluenceupontheproperworkingrange,theusualresultbeingtoraisethere-crystallinerangetemperature.合金的成分对合适的加工范围有极大的影响，通常会提高再结晶的温度范围。

have/hasinfluenceupon:有影响

(1)Thelevelofweightingratehasdirectinfluenceuponthefabricproperties.增重率的高低对织物性能有直接影响。

(2)Inthelegalsystemofterminationoflaborcontract,dismissalsystemhasgreatinfluenceuponemployee.劳动法律关系解除法律制度中，解雇制度对劳动者权益的影响尤其重大。LanguagepointsI.Answerthefollowingquestions.1.Explainthewaysthatcanalterthecharacteristicsofsteel．

Inthefirstplace,steelwhichcontainsverylittlecarbon,willbemilderthansteel,whichcontainsahigherpercentageofcarbon,uptothelimitofabout1.5％.Secondly,wecanheatthesteelaboveacertaincriticaltemperature,andthenallowittocoolatdifferentrates.Ontheotherhand,wecanmakesteelharderbyrapidcooling.keyExercises

2.Whataretheadvantagesofannealing?

Intheprocessknownasannealingweheatthesteelabovethecriticaltemperatureandpermitittocoolveryslowly.Thiscausesthemetaltobecomesofterthanbefore,andmucheasiertomachine.Annealinghasasecondadvantage.Ithelpstorelieveanyinternalstresseswhichexistinthemetal.Thesestressesareliabletooccurthroughhammeringorworkingthemetal,orthroughrapidcooling.keyExercises3.Whatisthemeaningoftempering?

Weheatupthesteelbeyondthecriticaltemperature,andthenquenchitinwaterorsomeotherliquid.Therapidtemperaturedropfixesthestructuralchangeinthesteel,whichoccurredatthecriticaltemperature,andmakesitveryhard.Butabarofthishardenedsteelismoreliabletofracturethannormalsteel.Wethereforeheatitagaintoatemperaturebelowthecriticaltemperature,andcoolitslowly.Thistreatmentiscalledtempering.keyExercises4.Whatisthetemperatureatwhichsteelstartstore-crystallize?

Forsteel,re-crystallizationstartsaround650to700~C.keyExercises

金属的分子结构

2.不均匀压缩3.快速冷却4.各种塑性加工II．TranslatethefollowingintoEnglish．structureofthemeta1unequalcontractionrapidcoolingvariousshapingoperationskeykeykeykey5.金属的机械加工6.金属的冷热加工mechanicalworkingofmetalcoldorhotworkingofsteelkeykeyⅡ.PutthephrasesintoEnglish:

在翻译过程中，由于英汉两种语言的表达方式不同，不能逐词对译。原文中有些词在译文中须要转换词性，才能使译文通顺流畅。词性转译的几种情况如下：一、英语动词、形容词、副词译成汉语名词1.Telecommunicationsmeanssomuchinmodernlifethatwithoutitourmodernlifewouldbeimpossible.电信在现代生活中意义重大，没有它就不可能有我们现在的生活。

词性转译Translating2.Gasesdifferfromsolidsinthattheformerhasgreatercompressibilitythanthelatter.气体和固体的区别在于气体的可压缩性比固体大。3.Theinstrumentischaracterizedbyitscompactnessandportability.这个仪器的特点是结构紧凑，携带方便。Translating二、英语名词、介词、形容词、副词译成汉语动词1.SubstitutionofmanualfinishingisoneexampleofHSMapplication.替代手工精加工是高速加工应用的一个例子。2.Scientistsareconfidentthatallmatterisindestructible.科学家们深信一切物质是不灭的。3.Theapplicationofelectroniccomputersmakesforatremendousriseinlaborproductivity.使用电子计算机可以大大提高劳动生产率。Translating三、英语的名词、副词和动词译成汉语形容词

1.Thiswaveguidetubeischieflycharacterizedbyitssimplicityofstructure.这种波导管的主要特点是结构简单。2.Themaidenvoyageofthenewlybuiltsteamshipwasasuccess.那艘新造轮船的处女航是成功的。3.Itisafactthatnostructuralmaterialisperfectlyelastic.事实上没有一种结构材料是十全十美的弹性体。Translating四、英语形容词、名词译成汉语副词1.Quasi-starswerediscoveredin1963asaresultofanefforttoovercometheshortcomingsofradiotelescopes.类星体是1963年发现的，是人们努力克服射电望远镜的缺点所取得的一项成果。2.Acontinuousincreaseinthetemperatureofagasconfinedinacontainerwillleadtoacontinuousincreaseintheinternalpressurewithinthegas.不断提高密封容器内气体的温度，会使气体的内压力不断增大。TranslatingSolderingandWeldingThereareanumberofmethodsofjoiningmetalarticlestogether,dependingonthetypeofmetalandthestrengthofthejointthatisrequired.1.SolderingandBrazing钎焊和焊接

金属连接在一起的方法很多，选用哪种方法要取决于金属的类别和所要求的接缝强度。1.软钎焊与硬钎焊

ReadingSolderinggivesasatisfactoryjointforlightarticlesofsteel,copperorbrass,butthestrengthofsolderedjointisratherlessthanajointwhichisbrazed,rivetedorwelded.Thesemethodsofjoiningmetalarenormallyadoptedforstrongpermanentjoint.Solderingistheprocessofjoiningtwometalsbyathirdmetaltobeappliedinthemoltenstate.Solderconsistsoftinandlead,whilebismuthandcadmiumareoftenincludedtolowerthemeltingpoint.Oneofthemostimportantoperationsinsolderingisthatofcleaningsurfacestobejoined,thismaybedonebysomeacidcleaner.

软钎焊能使薄的钢件、铜件或黄铜件获得合乎要求的接缝。但软钎焊的接缝强度比硬钎焊、铆接或焊接的接缝强度低的多，硬钎焊、铆接或焊接等这些接合方法通常用于高强度的永久接合。软钎焊是靠施加熔融状态的第三中金属使两块金属连接在一起的焊接方法。焊料由锡，铅组成，而加入铋和镉是为了降低焊料的熔点。钎焊的重要工序之一是将需要焊接的接缝表面洗擦干净，这一工序可用某种酸洗液进行。

ReadingAlthoughtheoxidesareremovedbythecleaningoperation,anewoxidecoatingformsimmediatelyaftercleaning,thusispreventingthesoldertounitewiththesurfaceofthemetal.Fluxisusedtoremoveandpreventoxidationofthemetalsurfacetobesoldered,allowingthesoldertoflowfreelyandunitewiththemetal.Zinc

chlorideisthebestfluxtouseforsolderingmostferrousandnon-ferrousmetals,forsolderingaluminum

stearinacidorvase-lineistobeusedasfluxes.

虽然通过清理操作，氧化物被除去，但清洗完毕之后，会立即产生新的氧化膜，从而阻碍了焊料与金属件表面的连接。助焊剂是用来去除氧化物和防止需要焊接的金属表面的氧化，以使焊料能自由地流动并于金属件连接。在钎焊大多数黑色金属和有色金属时氯化锌是最好的助焊剂，钎焊铝时，用硬脂酸和凡士林作为助焊剂。

ReadingInsomecasesitmaybenecessarytoconnectmetalsurfacesbymeansofhardzincsolderwhichfusesathightemperature.Thiskindofsolderingiscalledbrazing.2.Welding在有些情况下，用高熔点的硬锌焊料来焊接金属是必要的，这种钎焊称之为硬钎焊。2)焊接

ReadingWeldingisthejoiningoftwometalpiecesbysofteningwithheatandthenpressing,hammering,offusingthemtogether.Manypartsofmachines,automobiles,airplanes,ships,bridges,andbuildingsarewelded.焊接是借助于热量，使金属软化后加压、锤锻或使金属熔合将两块金属连接在一起的一种工艺方法。机器、汽车、飞机、船舶、桥梁及各种建筑物的许多构件都是焊接的。ReadingOxyacetyleneweldingistheheatingoftwopiecesofmetalwithaflamethatburnsamixtureofoxygenandacetylenegas.Theoxygenandacetylenegasarekeptittwoseparatesteeltanksfromwhichtheyflowtoatorch;therethetwogasesmixandthenpassintotheflame.Itisthehottestflameknownforordinaryuse;itstemperatureisabout6,300degreesFahrenheit.Theoxyacetyleneflamemaybeusedtocutironandsteel.

氧—乙炔（气焊）用氧气和乙炔气混合物燃烧产生的火焰加热两块金属。氧气和乙炔分别贮存在两个钢制的贮气瓶内，由贮气瓶流入焊炬，这两种气体在焊炬内混合后通向火焰。就通常使用的火焰而言，氧—乙炔是最炽热的火焰，其温度约6300F（3482C），氧—乙炔火焰还可用于切割铁和钢。

ReadingElectricoftheweldingistheheatingoftwopiecesofmetaltobeweldedbyelectricity.Thisheatisthehottestthatcanbeobtainedforengineeringpurposes;itisabout7,232degreesFahrenheit.Theendsarethusmeltedtogether,makingaweldedjoint.Spotweldingisweldingtwopiecesofmetalinspotswithelectricityandisdonewithamachinecalledspotwelder.Aforgedweldismadebysofteningtheendsoftwometalpiecesinafurnaceandthenhammeringthemtogether.电焊即电弧焊，是用电能对施焊的两件金属加热。在工程方面所有获得的最高热量要算电弧热量，它约为7232F（4000C），因而焊接端被熔合成焊缝。点焊是借助电能以焊点形式将两块金属焊接在一起。人们采用称作点焊机的机器来完成这一工作。锻焊是将两块金属焊接端在炉中加热软化,然后将它们锤击在一起。Readingsolder['sɔldə]n.焊料，焊锡v.（锡）焊，焊接brass[brɑ:s]n.黄铜，黄铜制品braze[breiz]vt.用铜锌合金焊接copper['kɔpə]n.铜，铜币；铜制物a铜的rivet['rivit]n.铆钉vt.铆，铆接molten['məultən]adj.融化的，熔融的bismuth['bizməθ]n.铋cadmium['kædmiəm]n.镉acid['æsid]n.酸adj.酸的，酸味的oxide['ɔksaid]n.氧化物flux[flʌks]n.焊剂，助焊剂oxidation[,ɔksi'deiʃən]n.氧化ReadingNewwordsandphraseszinc[ziŋk]n.锌chloride['klɔ:raid]n.氯化物ferrous['ferəs]adj.含铁的，铁的aluminum[ə'lju:minəm]n.铝stearin['sti:ərin,'stiə-]n.[化]硬脂精；硬脂=stearinevaseline['væsili:n]n.[化]石油冻；矿脂；凡士林（商品名）fuse[fju:z]v.熔（化），熔合n.保险丝，熔丝soften['sɔfən,'sɔ:-]v.使软化；使柔和；变软弱oxyacetylene[,ɔksiə'setili:n,-lin]adj.[化]氧乙炔的acetylene[ə'setili:n]n.[化]乙炔tank[tæŋk]n.(盛液体盛气体的)大容器,槽,罐,坦克torch[tɔ:tʃ]n.火炬，火把；[机]气炬；吹管furnace['fə:nis]n.炉子，熔炉；[冶]鼓风炉，高炉ReadingNewwordsandphrases

twoseparatesteeltanks分别两个钢制的储气瓶solderingiron焊铁，烙铁ferrousandnon-ferrousmetals

黑色及有色金属ReadingNeww