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1、书名：模具设计与制造专业英语 第2版 ISBN： 978-7-111-08537-9作者：王晓江出版社：机械工业出版社本书配有电子课件,模具设计与制造专业英语 第2版 ppt 课件,Unit one Lesson2 Heat Treatment of Tool Steels,教学目标及要求 1.掌握课文中有关热处理方面的专业词汇和专业术语； 2.结合热处理的相关专业知识阅读课文，提高翻译能力。重点 1.有关热处理的专业词汇和专业术语； 2.翻译课文：热处理的原理; 热处理的类型; 热处理的步骤。难句分析及翻译的基础知识 Part（） 翻译的基础知识简介 二、翻译的标准,模具设计与制造专业英语
2、第2版 ppt 课件,教学思路设计 时间分配（共100min）： 1.讲解课文中的专业词汇和术语； 2.讲解课后生词、大声朗读； 3.翻译课文，注意穿插相关专业知识； 4.分析难点句型，讲解相关翻译基础知识； 5.学生答疑。,模具设计与制造专业英语 第2版 ppt 课件,Contents,Background KnowledgeNew Words and PhrasedText AnalysisQuestionsGlossary of TermsLanguage Points & Translating TechniquesReading Materials Summary Reference
3、s,模具设计与制造专业英语 第2版 ppt 课件,The Principles of Heat Treatment,Heat treatment consists of Heating-Up and Cooling-Down process. Heating up the steel will change the microstructure to Austenite. Cooling down the steel at different cooling rates will change the microstructure from Austenite to different str
4、uctures correspondingly. Change in Microstructures result in change in mechanical properties.,Background Knowledge,模具设计与制造专业英语 第2版 ppt 课件,By heat treatment, we can change the mechanical properties of moulds and machine components to our desired state. For example, to harden the mould will increase s
5、trength and wear resistance resulting in longer mould life. To anneal a hard steel bar will soften it to a state good for machining. To normalize a steel bar will toughen it to a state good for impact.,模具设计与制造专业英语 第2版 ppt 课件,New Words and Expressions,Terms： 1. Heat treating 热处理 normalize 正火 spheroid
6、iz 球化处理 anneal 退火 harden 淬火 temper 回火 case harden 表面淬火 stress relieving 应力消除热处理 carburize 渗碳 quench-hardening 淬火硬化,模具设计与制造专业英语 第2版 ppt 课件,New Words and Expressions,Terms： 2.Iron-carbon equilibrium diagram 铁碳平衡相图 ferrite 铁素体 austenite 奥氏体 pearlite 珠光体 carbide 碳化物 bainite 贝氏体 martensite 马氏体 liquid 液态
7、delta-iron -铁 alpha-iron -铁 gamma-iron -铁,模具设计与制造专业英语 第2版 ppt 课件,Iron-carbon equilibrium diagram,Time-temperature transformation (TTT) diagrams,A Continuous cooling transformation (CCT) curve compared to TTT diagram,亚微观的；普通显微镜下看不出来的,Tempering,During tempering, martensite undergoes a transformation p
8、rocess from that of carbon atoms supersaturated in iron to a structure termed tempered martensite which consists of highly dispersed submicroscopic carbide particles in a ferrite matrix. The extent of increase in ductility hence toughness and the corresponding reduction in hardness and strength is a
9、 function of tempering temperature and time.,回火；调和,Annealing,If a steel bar is cooled slowly in a furnace from a temperature above its upper critical temperature to a temperature below the lower critical temperature, the structure of the steel will become ferrite and cementite again. This steel cons
10、ists of a somewhat coarser grain structure that is low in strength, high in ductile and soft. This process of heat treatment is called Annealing.,退火，缓冷，韧化,正火,Normalizing,However, instead of cooling in furnace as described above, the steel is taken out from the furnace and cooled in still air, it is
11、termed Normalizing. A normalized steel bar possesses higher strength and toughness than its annealed counterpart.,对应物，配对物,Quench-Hardening,If a steel bar is rapidly cooled from its upper critical temperature by plunging it into a coolant such as water or oil (termed quenching), the effect is to tran
12、sform the austenite into a structure called martensite. Martensite is a very hard, but brittle constituent of steel.For steels having a carbon content less than 0.8%, a temperature at between 30 deg C to 50 deg C above the upper critical temperature (723 deg C) is used for quenching and the resultin
13、g structure comprises martensite and ferrite.,The Heat Treatment Process,Basically, Heat Treatment just consists of heating up and cooling down process. These process can be further divided into four steps.,One Step1 Construction of Time-Temperature-Transformation Diagram (TTT)and Continuous Cooling
14、 Transformations Diagram (CCT) TTT Diagrams - can be quite useful in determining the kinetics of transformation and the nature of the products. The curve shows the time required to complete the transformation at that temperature.,One Step2,CCT Diagrams - Although the TTT diagrams can provide useful
15、information about the structures obtained through non-equilibrium thermal processing, they are not rigorously applicable to engineering applications because the assumptions of instantaneous cooling from elevated temperature is far more realistic, and a diagram showing the results of continuous cooling at various rates would be far more useful.,
