模具专业英语2.ppt

Unit one Lesson2 Heat Treatment of Tool Steelsw教学目标及要求教学目标及要求 1.1.掌握课文中有关掌握课文中有关热处理方面热处理方面的专业词汇和专业术语；的专业词汇和专业术语；2.2.结合热处理的相关专业知识阅读课文，提高翻译能力。结合热处理的相关专业知识阅读课文，提高翻译能力。w重点重点 1.1.有关有关热处理的热处理的专业词汇和专业术语；专业词汇和专业术语；2.2.翻译课文：热处理的原理翻译课文：热处理的原理;热处理的类型热处理的类型;热处理的步骤。热处理的步骤。u难句分析及翻译的基础知识难句分析及翻译的基础知识 PartPart（）翻译的基础知识简介翻译的基础知识简介 二、翻译的标准二、翻译的标准w教学思路设计教学思路设计 时间分配（共时间分配（共100min100min）：）：1.1.讲解课文中的专业词汇和术语；讲解课文中的专业词汇和术语；2.2.讲解课后生词、大声朗读；讲解课后生词、大声朗读；3.3.翻译课文，注意穿插相关专业知识；翻译课文，注意穿插相关专业知识；4.4.分析难点句型，讲解相关翻译基础知识；分析难点句型，讲解相关翻译基础知识；5.5.学生答疑。学生答疑。ContentswBackground KnowledgewNew Words and PhrasedwText AnalysiswQuestionswGlossary of TermswLanguage Points&Translating TechniqueswReading Materials wSummary wReferencesThe Principles of Heat TreatmentwHeat Heat treatment treatment consists consists of of Heating-Up Heating-Up and and Cooling-Cooling-Down process.Down process.wHeating Heating up up the the steel steel will will change change the the microstructure microstructure to Austenite.to Austenite.wCooling Cooling down down the the steel steel at at different different cooling cooling rates rates will will change change the the microstructure microstructure from from Austenite Austenite to to different structures correspondingly.different structures correspondingly.wChange Change in in Microstructures Microstructures result result in in change change in in mechanical properties.mechanical properties.Background KnowledgewBy By heat heat treatment,treatment,we we can can change change the the mechanical mechanical properties properties of of moulds moulds and and machine machine components components to to our our desired state.desired state.wFor For example,example,to to harden harden the the mould mould will will increase increase strength strength and and wear wear resistance resistance resulting resulting in in longer longer mould life.mould life.wTo To anneal anneal a a hard hard steel steel bar bar will will soften soften it it to to a a state good for machining.state good for machining.wTo To normalize normalize a a steel steel bar bar will will toughen toughen it it to to a a state state good for impact.good for impact.New Words and ExpressionsuTerms：1.1.HeatHeat treating treating 热处理热处理 normalizenormalize 正火正火 spheroidizspheroidiz 球化处理球化处理 annealanneal 退火退火 hardenharden 淬火淬火 tempertemper 回火回火 casecase harden harden 表面淬火表面淬火 stressstress relieving relieving 应力消除热处理应力消除热处理 carburizecarburize 渗碳渗碳 quench-hardeningquench-hardening 淬火硬化淬火硬化New Words and ExpressionsuTerms：2.2.Iron-carbonIron-carbon equilibrium diagram equilibrium diagram 铁碳平衡相图铁碳平衡相图 ferriteferrite 铁素体铁素体 austeniteaustenite 奥氏体奥氏体 pearlitepearlite 珠光体珠光体 carbide carbide 碳化物碳化物 bainitebainite 贝氏体贝氏体 martensitemartensite 马氏体马氏体 liquidliquid 液态液态 delta-irondelta-iron -铁铁 alpha-ironalpha-iron -铁铁 gamma-irongamma-iron -铁铁Iron-carbon equilibrium diagram Time-temperature transformation(TTT)diagrams A Continuous cooling transformation(CCT)curve compared to TTT diagram亚微观的；普通显微镜亚微观的；普通显微镜下看不出来的下看不出来的TemperingwDuring During temperingtempering,martensitemartensite undergoes undergoes a a transformation transformation process process from from that that of of carbon carbon atoms atoms supersaturated supersaturated in in iron iron to to a a structure structure termed termed tempered tempered martensitemartensite which which consists consists of of highly highly dispersed dispersed submicroscopicsubmicroscopic carbide carbide particles particles in in a a ferrite ferrite matrix.matrix.The The extent extent of of increase increase in in ductility ductility hence hence toughness toughness and and the the corresponding corresponding reduction reduction in in hardness hardness and and strength strength is is a a function function of of tempering tempering temperature and timetemperature and time.回火；调和回火；调和AnnealingwIf If a a steel steel bar bar is is cooled cooled slowly slowly in in a a furnace furnace from from a a temperature temperature above above its its upper upper critical critical temperature temperature to to a a temperature temperature below below the the lower lower critical critical temperature,temperature,the the structure structure of of the the steel steel will will become become ferrite ferrite and and cementitecementite again.again.This This steel steel consists consists of of a a somewhat somewhat coarser coarser grain grain structure structure that that is is low low in in strength,strength,high high in in ductile ductile and and soft.soft.This This process process of of heat heat treatment is called treatment is called AnnealingAnnealing.退火，缓冷，韧化退火，缓冷，韧化正火正火NormalizingwHowever,However,instead instead of of cooling cooling in in furnace furnace as as described described above,above,the the steel steel is is taken taken out out from from the the furnace furnace and and cooled cooled in in still still air,air,it it is is termed termed NormalizingNormalizing.A A normalized normalized steel steel bar bar possesses possesses higher higher strength strength and and toughness than its annealed toughness than its annealed counterpartcounterpart.对应物，配对物对应物，配对物Quench-HardeningwIf If a a steel steel bar bar is is rapidly rapidly cooled cooled from from its its upper upper critical critical temperature temperature by by plunging plunging it it into into a a coolant coolant such such as as water water or or oil oil(termed(termed quenching),quenching),the the effect effect is is to to transform transform the the austenite austenite into into a a structure structure called called martensitemartensite.MartensiteMartensite is is a a very very hard,hard,but but brittle constituent of steel.brittle constituent of steel.wFor For steels steels having having a a carbon carbon content content less less than than 0.8%,0.8%,a a temperature temperature at at between between 30 30 deg deg C C to to 50 50 deg deg C C above above the the upper upper critical critical temperature temperature(723(723 deg deg C)C)is is used used for for quenching quenching and and the the resulting resulting structure structure comprises comprises martensitemartensite and ferrite.and ferrite.The Heat Treatment ProcesswBasically,Basically,Heat Heat Treatment Treatment just just consists consists of of heating heating up up and and cooling cooling down down process.process.These These process process can can be be further divided into four steps.further divided into four steps.One Step1 Construction Construction of of Time-Temperature-Transformation Time-Temperature-Transformation Diagram Diagram(TTT)and(TTT)and Continuous Continuous Cooling Cooling Transformations Transformations Diagram(CCT)Diagram(CCT)TTT TTT Diagrams Diagrams-can can be be quite quite useful useful in in determining determining the the kinetics kinetics of of transformation transformation and and the the nature nature of of the the products.products.The The curve curve shows shows the the time time required required to to complete the transformation at that plete the transformation at that temperature.One Step2wCCT CCT Diagrams Diagrams-Although Although the the TTT TTT diagrams diagrams can can provide provide useful useful information information about about the the structures structures obtained obtained through through non-equilibrium non-equilibrium thermal thermal processing,processing,they they are are not not rigorously rigorously applicable applicable to to engineering engineering applications applications because because the the assumptions assumptions of of instantaneous instantaneous cooling cooling from from elevated elevated temperature temperature is is far far more more realistic,realistic,and and a a diagram diagram showing showing the the results results of of continuous continuous cooling cooling at at various various rates rates would would be far more useful.be far more useful.Two StepswThe The second second step step is is a a heating heating operation operation designed designed to to produce produce an an elevated elevated temperature temperature homogeneous homogeneous single-single-phase phase solid solid solution.solution.The The heating heating should should not not exceed exceed the the eutectic eutectic temperature temperature or or there there might might be be melting melting if a cored structure were present.if a cored structure were present.Three And Four StepswAfter After soaking soaking to to assure assure a a uniform uniform chemistry chemistry single single phase,phase,the the alloy alloy is is cooled.cooled.The The cooling cooling rate rate of of the the alloy depends on the property of metal required.alloy depends on the property of metal required.wThe The heat heat treated treated material material is is then then left left for for diffusion.diffusion.Diffusion Diffusion is is necessary necessary to to convert convert the the unstable unstable supersaturatedsupersaturated solution solution into into the the stable stable structure.structure.Surface HardeningwFor For many many engineering engineering purposes purposes it it is is desirable desirable for for parts parts to to have have a a hard hard surface surface to to resist resist wear wear and and abrasion abrasion and and the the inner inner portion portion remains remains soft soft and and tough to sustain impact loading.tough to sustain impact loading.wThis This depth depth of of the the hardened hardened surface surface is is normally normally from from 0.0001 0.0001 mm mm to to a a few few mm mm depending depending on on applications.applications.These These properties properties can can be be obtained obtained by by surface surface hardening hardening which which is is generally generally divided divided into into the the following three types:following three types:Gas carburizing wNitriding Method Principle of Induction Hardening QuestionswWhat process is used to remove the internal What process is used to remove the internal stresses created during a hardening operation?stresses created during a hardening operation?wWhat heat treating process makes the metallic What heat treating process makes the metallic carbides in a metal form into small rounded carbides in a metal form into small rounded globules?globules?wWhat are the main purposes of heat treating?What are the main purposes of heat treating?wHow many heat treating processes are involved How many heat treating processes are involved in ferrous materials?in ferrous materials?Glossary of Terms1 1Hardenability Hardenability 淬透性淬透性2 2hardenability curve hardenability curve 淬透性曲线淬透性曲线3 3hardening capacity hardening capacity 淬硬性（硬化能力）淬硬性（硬化能力）4 4hardness profile hardness profile 硬度分布（硬度梯度）硬度分布（硬度梯度）5 5heat treatment procedure heat treatment procedure 热处理规范热处理规范6 6heat treatment installation heat treatment installation 热处理设备热处理设备7 7heat treatment furnace heat treatment furnace 热处理炉热处理炉8 8heat treatment cycle heat treatment cycle 热处理工艺周期热处理工艺周期9 9heat time heat time 加热时间加热时间1010 heat system heat system 加热系统加热系统1111 heating up time heating up time 升温时间升温时间1212 heating curve heating curve 加热曲线加热曲线 1313high temperature carburizing high temperature carburizing 高温渗碳高温渗碳1414high temperature tempering high temperature tempering 高温回火高温回火1515isothermal transformation isothermal transformation 等温转变等温转变1616isothermal annealing isothermal annealing 等温退火等温退火1717interrupted ageing treatment interrupted ageing treatment 分级时效处理分级时效处理1818local heat treatment local heat treatment 局部热处理局部热处理1919overheated structure overheated structure 过热组织过热组织2020pack carburizing pack carburizing 固体渗碳固体渗碳2121oxynitrocarburizing oxynitrocarburizing 氧氮碳共渗氧氮碳共渗2222partial annealing partial annealing 不完全退火不完全退火2323spheroidized structure spheroidized structure 球化组织球化组织2424recrystallization temperature recrystallization temperature 再结晶温度再结晶温度uExample 1:This combination of heating and controlled cooling This combination of heating and controlled cooling determines not only the nature and distribution of determines not only the nature and distribution of the microconstituents,which in turn determine the the microconstituents,which in turn determine the properties,but also the grain size.properties,but also the grain size.（在热处理过程中），加热与冷却控制相结合的方法不仅（在热处理过程中），加热与冷却控制相结合的方法不仅决定着材料中微观组织的分布和性质（进而决定了该材料决定着材料中微观组织的分布和性质（进而决定了该材料的性能），而且也决定了材料内部晶粒的大小。的性能），而且也决定了材料内部晶粒的大小。句中第一个句中第一个andand连接的是连接的是heatingheating和和controlled coolingcontrolled cooling，第二个，第二个andand连接的是连接的是naturenature和和distributiondistribution，而，而which in which in turn determine the propertiesturn determine the properties为非限定性定语从句为非限定性定语从句,修修饰饰the nature and distributionthe nature and distribution。Language Points&Translating TechniqueswExample 2:With most of the mediumWith most of the mediumcarbon forging steels,carbon forging steels,alloyed and unalloyed,normalizing is highly alloyed and unalloyed,normalizing is highly recommended after forging and before machining to recommended after forging and before machining to produce more homogeneous structures,and in most produce more homogeneous structures,and in most cases,improved machinability.cases,improved machinability.对于大多数中碳锻钢来说，不管它是否合金化，在锻对于大多数中碳锻钢来说，不管它是否合金化，在锻造后或加工前通常推荐采用正火处理工艺，这样有利于形造后或加工前通常推荐采用正火处理工艺，这样有利于形成更均匀的组织，并且在大多数情况下可改善材料的切削成更均匀的组织，并且在大多数情况下可改善材料的切削加工性能。加工性能。句首的介词句首的介词withwith短语意为短语意为“对对来说来说”；in most in most casescases可译为可译为“在大多数情况下在大多数情况下”。二、翻译的标准二、翻译的标准w翻译的任务在于准确而完整地介绍原文的思想内容，使读者翻译的任务在于准确而完整地介绍原文的思想内容，使读者对原文的思想内容有正确的理解。然而，怎样才算是准确、对原文的思想内容有正确的理解。然而，怎样才算是准确、完整的翻译呢？要解决这个问题，就需要有一个共同的翻译完整的翻译呢？要解决这个问题，就需要有一个共同的翻译标准。标准。w谈到翻译标准，不免要提到严复的谈到翻译标准，不免要提到严复的“信、达、雅信、达、雅”。严复在。严复在他的一部译著的前言中提出了他的一部译著的前言中提出了“信、达、雅信、达、雅”。“信信”就是就是忠实原文，忠实原文，“达达”就是表达清楚，就是表达清楚，“雅雅”即是文字文雅。后即是文字文雅。后来，鲁迅先生在此基础上又提出了来，鲁迅先生在此基础上又提出了“信信”和和“顺顺”这两条标这两条标准。准。“信信”和和“顺顺”，即，即“忠实忠实”、“通顺通顺”，今天已成为，今天已成为公认的两条标准了。公认的两条标准了。Example 3:w“忠实忠实”是指译文的思想内容必须忠实于原文，这一标准对是指译文的思想内容必须忠实于原文，这一标准对科技英语尤为重要，因为科技作品的任务在于准确而系统地科技英语尤为重要，因为科技作品的任务在于准确而系统地论述科学技术问题，它要求高度的准确性，特别是对术语、论述科学技术问题，它要求高度的准确性，特别是对术语、定义、定理和结论的翻译更应重视。定义、定理和结论的翻译更应重视。w然而，忠实原文并不是形式上保持原文，而是内容上保持原然而，忠实原文并不是形式上保持原文，而是内容上保持原文。翻译时切忌逐字死译，这样会有损原意。请看例句：文。翻译时切忌逐字死译，这样会有损原意。请看例句：wA roughing cut is usually to be followed by a A roughing cut is usually to be followed by a fishing cut.fishing cut.w粗切削通常要被精切削跟随。粗切削通常要被精切削跟随。w译文的毛病在于虽然词类或句子成分都与原文一致，保持了译文的毛病在于虽然词类或句子成分都与原文一致，保持了原文的形式，但却失去了原文的精神。若译成原文的形式，但却失去了原文的精神。若译成“粗切之后，粗切之后，通常还要精切通常还要精切”才算忠实原文。才算忠实原文。w翻译的第二条标准是翻译的第二条标准是“通顺通顺”。“通顺通顺”是指译文的语言形是指译文的语言形式必须符合汉语规范，翻译时要按照汉语的语法规律和习惯式必须符合汉语规范，翻译时要按照汉语的语法规律和习惯来遣词造句，做到通顺易懂。但要指出，来遣词造句，做到通顺易懂。但要指出，“通顺通顺”是在是在“忠忠实实”的前提下，任何的前提下，任何“顺而不信顺而不信”都是不行的，属于乱译。都是不行的，属于乱译。w看下面一个例子：看下面一个例子：wThe The foundation foundation of of the the machine machine should should not not be be constructed constructed at at a a place place of of conspicuous conspicuous temperature temperature change,change,due due to to direct direct sunshine,sunshine,excessive excessive heat heat or or vibration,vibration,or or at at a a place place contaminated contaminated with with soil soil or or dust particles.dust particles.w机机床床的的地地基基不不应应建建在在由由于于日日晒晒、过过热热或或受受震震动动而而引引起起的的温温度度明显变化的地方，明显变化的地方，或受尘土污染的地方。或受尘土污染的