机电专业英语第2版4Unit 4Heat Treatment and Hot Working of Metals

1、 徐存善主编 徐存善主编Heat Treatment and Working Equipment 徐存善主编What the meaning of “Shaping”? (radio)“shaping”是什么意思？(单选)提交 徐存善主编 徐存善主编 Unit 4 Heat Treatment& Hot Working of Metals We can alter the characteristics of steel in various ways. In the first place, steel which contains very little carbon, will be m

2、ilder than steel, which contains a higher percentage of carbon, up to the limit of about 1.5. Secondly, we can heat the steel above a certain critical temperature, and then allow it to cool at different rates. At this critical temperature, changes begin to take place in the molecular structure of th

3、e meta1. In the process known as annealing we heat the steel above the critical temperature and permit it to cool very slowly. This causes the metal to become softer than before, and much easier to machine. 徐存善主编 Annealing has a second advantage. It helps to relieve any internal stresses which exist

4、 in the metal. These stresses are liable to occur through hammering or working the metal, or through rapid cooling. Metal which we cause to cool rapidly contracts more rapidly on the outside than on the inside. This produces unequal contraction, which may give rise to distortion or cracking. Metal w

5、hich cools slowly is less liable to have these internal stresses than metal, which cools quickly. 徐存善主编On the other hand, we can make steel harder by rapid cooling. We heat it up beyond the critical temperature, and then quench it in water or some other liquid. The rapid temperature drop fixes the s

6、tructural change in the steel, which occurred at the critical temperature, and makes it very hard. But a bar of this hardened steel is more liable to fracture than normal steel. We therefore heat it again to a temperature below the critical temperature, and cool it slowly. This treatment is called t

7、empering. It helps to relieve the internal stresses, and makes the steel less brittle than before. The properties of tempered steel enable US to use it in the manufacture of tools, which need a fairly hard steel. High carbon steel is harder than tempered steel, but it is much more difficult to work.

8、 徐存善主编These heat treatments take place during the various shaping operations. We can obtain bars and sheets of steel by rolling the metal through huge rolls in a rolling mill. The roll pressures must be much greater for cold rolling than for hot rolling, but cold rolling enables the operators to pro

9、duce rolls of great accuracy and uniformity, and with a better surface finish. Other shaping operations include drawing into wire, casting in moulds, and forging. 徐存善主编The mechanical working of metal is the shaping of metal in either a cold or a hot state by some mechanical means. This does not incl

10、ude the shaping of metals by machining or grinding, in which processes metal is actually machined off, nor does it include the casting of molten metal into some form by use of molds. In mechanical working processes, the metal is shaped by pressure-acutely forging, bending, squeezing, drawing, or she

11、aring it to its final shape. In these processes the metal may be either cold or hot worked. Although normal room temperatures are ordinarily used for cold working of steel, temperatures up to the re-crystallization range are sometimes used. Hot working of metals takes place above the re-crystallizat

12、ion or workhardening range. 徐存善主编For steel, re-crystallization starts around 650 to 700C, although most hot work on steel is done at temperatures considerably above this range. There is no tendency for hardening by mechanical work until the lower limit of the re-crystalline range is reached. Some me

13、tals, such as lead and tin, have a low re-crystalline range and can be hot worked at room temperature, but most commercial metals require some heating. Alloy composition has a great influence upon the proper working range, the usual result being to raise the re-crystalline range temperature. This ra

14、nge may also be increased by prior cold working. 徐存善主编 molecular mlekjl a. 由分子组成的, 分子的annealing ni:li n.(低温)退火，焖火，磨炼relieve rili:v v.解除，减轻，使不单调乏味liable laibl a.有责任的，有义务的，应受罚的，有倾向的contract kntrkt v. 收缩，缩紧，感染，订约 rise raiz v. 上升，增强，起立，高耸shaping eipi n. 成形，造型，塑造mechanical miknikl a. 机械的，呆板的，力学的machining

15、 mi:ni n. 切肖，制造，机械加工grinding raindi n. 磨肖力工machined mi:nd a. 机械加工的pressure pre n. 压力，压强bend bend v. 使弯曲，使屈服，使致力，使朝向bending bendi n. 弯曲 (度)，扭曲(度) 徐存善主编 squeeze skwi:z v.挤 (压，干)，压榨，勒索，紧握prior prai a. 在先的，在前的，优先的distortion dist:n n. 变形，扭曲，曲解，失真crack krk v. &n破裂，裂纹，打开beyond bijnd prep.超过的范围, 超过, 越过quenc

16、h kwent v. &n熄灭，机 淬火, 解渴； fix fiks v. & n. 安装, 修理，使固定，准备 tempering tempri v. 回火 rolls ruls n. 薄板卷，泛指钢材 draw dr: v.拉, 画, 吸引 drawing dr:i n. 冲压成形shear i v. 剪断，切断，修剪，剥夺recrystallization ri:,kristlaizein n.再结晶hardening h:dni n.硬化，淬火, 锻炼crystalline kristlain a. 结晶的凡结晶体influence influns n. 影响，作用 徐存善主编 mec

17、hanical means 机械设备(工具) be known as 称为workhardening range淬火温度区Technical Terms 徐存善主编 1. This produces unequal contractions，which may give rise to distortion or cracking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“unequal contractions” 的进一步解释说明。Language points 徐存善主编2. This does not include

18、the shaping of metals by machining or grinding，in which processes metal is actually machined off，nor does it include the casting of molten metal into some form by use of molds 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：“in which processes metal is actually machined off”为非限定性定语从句，对前面的主句起进一步解释说明

19、作用。“nor does it include the casting of molten metal into some form by use of molds” 此句为倒装句，由于“nor” 提前，整个句子发生了部分倒装。Language points 徐存善主编 3. These stresses are liable to occur through hammering or working the metal, or through rapid cooling. 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。 be liable to: 易于的；有倾向的；应付

20、有责任，应遵守 (1) A third party, whose fault causes the fuel gas accident, shall be liable to pay damages according to law.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-complying trusts are also deemed to be liable to taxation on the trusts worldwide income. “非照办信托”同时也被推定为按其信托之全球收入征税。Language points 徐存善主编4. We

21、heat it up beyond the critical temperature, and then quench it in water or some other liquid.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。heat up：加热 （1）The electronic heater can heat up fast and safely. It also functions as a steamer.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）Material spiraling into a black hole can heat up

22、 to millions of degrees and glow brightly .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。 Language points 徐存善主编5. The properties of tempered steel enable US to use it in the manufacture of tools, which need a fairly hard steel.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) Using ICON controlling circuit, enable

23、 to detect the status of the mechanism operation. 本机采用ICON控制回路，可侦测机械操作状况。 (2) The space between the inner and outer plate is full of heat insulation materials which enable to provide the nice performance of heat insulation.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。Language points 徐存善主编6. Other shaping operatio

24、ns include drawing into wire, casting in moulds, and forging.其他的塑性加工有拉丝、模铸和锻造。drawing into: 使卷入 (1) SMS Draw integrates into the target application and appears as a new service in the toolbar. 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) Now the pattern repeat with manual twist, will itself draw into the active l

25、evel of the Photoshop data file and the original is maintained again on a separate level.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。 Language points 徐存善主编7. There is no tendency for hardening by mechanical work until the lower limit of the re-crystalline range is reached.在达到最低的再结晶温度之前，机械加

26、工的金属没有硬化的趋势。tendency tendnsi n. 倾向，趋势；癖好(1) Since gravity works equally on everything, there would be a tendency to pull those uneven places down. 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) The tendency of modern science is to reduce proof to absurdity by continually reducing absurdity to proof.现代科学的倾向，是不

27、断把谬论化为根据来使实证变得荒谬。 Language points 徐存善主编8. Alloy composition has a great influence upon the proper working range, the usual result being to raise the re-crystalline range temperature.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/has influence upon: 有影响 (1) The level of weighting rate has direct influence u

28、pon the fabric properties.增重率的高低对织物性能有直接影响。 (2) In the legal system of termination of labor contract, dismissal system has great influence upon employee.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。Language points 徐存善主编I. Answer the following questions.1. Explain the ways that can alter the characteristics of st

29、eel In the first place, steel which contains very little carbon, will be milder than steel, which contains a higher percentage of carbon, up to the limit of about 1.5. Secondly, we can heat the steel above a certain critical temperature, and then allow it to cool at different rates. On the other han

30、d, we can make steel harder by rapid cooling.Exercises 徐存善主编 2. What are the advantages of annealing? In the process known as annealing we heat the steel above the critical temperature and permit it to cool very slowly. This causes the metal to become softer than before, and much easier to machine.

31、Annealing has a second advantage. It helps to relieve any internal stresses which exist in the metal. These stresses are liable to occur through hammering or working the metal, or through rapid cooling.Exercises 徐存善主编 3. What is the meaning of tempering? We heat up the steel beyond the critical temp

32、erature, and then quench it in water or some other liquid. The rapid temperature drop fixes the structural change in the steel, which occurred at the critical temperature, and makes it very hard. But a bar of this hardened steel is more liable to fracture than normal steel. We therefore heat it agai

33、n to a temperature below the critical temperature, and cool it slowly. This treatment is called tempering.Exercises 徐存善主编 4. What is the temperature at which steel starts to re-crystallize? For steel, re-crystallization starts around 650 to 700C.Exercises 徐存善主编1. 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IITr

34、anslate the following into Englishstructure of the meta1unequal contractionrapid coolingvarious shaping operations 徐存善主编5. 金属的机械加工6. 金属的冷热加工mechanical working of metalcold or hot working of steel. Put the phrases into English: 徐存善主编 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

35、下： 一、英语动词、形容词、副词译成汉语名词 1. Telecommunications means so much in modern life that without it our modern life would be impossible. 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。 徐存善主编 2. Gases differ from solids in that the former has greater compressibility than the latter. 气体和固体的区别在于气体的可压缩性比固体大。 3. The instrument is c

36、haracterized by its compactness and portability. 这个仪器的特点是结构紧凑，携带方便。 徐存善主编二、英语名词、介词、形容词、副词译成汉语动词二、英语名词、介词、形容词、副词译成汉语动词 1. Substitution of manual finishing is one example of HSM application. 替代手工精加工是高速加工应用的一个例子。 2. Scientists are confident that all matter is indestructible. 科学家们深信一切物质是不灭的。 3. The appl

37、ication of electronic computers makes for a tremendous rise in labor productivity. 使用电子计算机可以大大提高劳动生产率。 徐存善主编三、英语的名词、副词和动词译成汉语形容词三、英语的名词、副词和动词译成汉语形容词 1.This wave guide tube is chiefly characterized by its simplicity of structure. 这种波导管的主要特点是结构简单。 2. The maiden voyage of the newly built steamship was

38、a success. 那艘新造轮船的处女航是成功的。 3. It is a fact that no structural material is perfectly elastic. 事实上没有一种结构材料是十全十美的弹性体。 徐存善主编四、英语形容词、名词译成汉语副词四、英语形容词、名词译成汉语副词 1. Quasi-stars were discovered in1963 as a result of an effort to overcome the shortcomings of radio telescopes. 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

39、成果。 2. A continuous increase in the temperature of a gas confined in a container will lead to a continuous increase in the internal pressure within the gas. 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。 徐存善主编There are a number of methods of joining metal articles together, depending on the type of metal and the stre

40、ngth of the joint that is required.1. Soldering and Brazing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 徐存善主编Soldering gives a satisfactory joint for light articles of steel, copper or brass, but the strength of soldered joint is rather less than a joint which is brazed, riveted or welded. Thes

41、e methods of joining metal are normally adopted for strong permanent joint. Soldering is the process of joining two metals by a third metal to be applied in the molten state. Solder consists of tin and lead, while bismuth and cadmium are often included to lower the melting point. One of the most imp

42、ortant operations in soldering is that of cleaning surfaces to be joined, this may be done by some acid cleaner. 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。 徐存善主编

43、Although the oxides are removed by the cleaning operation, a new oxide coating forms immediately after cleaning, thus is preventing the solder to unite with the surface of the metal. Flux is used to remove and prevent oxidation of the metal surface to be soldered, allowing the solder to flow freely

44、and unite with the metal. Zinc chloride is the best flux to use for soldering most ferrous and non-ferrous metals, for soldering aluminum stearin acid or vase-line is to be used as fluxes. 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

45、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。 徐存善主编In some cases it may be necessary to connect metal surfaces by means of hard zinc solder which fuses at high temperature. This kind of soldering is called brazing. 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 徐存善主编Welding is the joining of two metal pi

46、eces by softening with heat and then pressing, hammering, of fusing them together. Many parts of machines, automobiles, airplanes, ships, bridges, and buildings are welded.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。 徐存善主编Oxyacetylene welding is the heating of two piec

47、es of metal with a flame that burns a mixture of oxygen and acetylene gas. The oxygen and acetylene gas are kept it two separate steel tanks from which they flow to a torch; there the two gases mix and then pass into the flame. It is the hottest flame known for ordinary use; its temperature is about

48、 6, 300 degrees Fahrenheit. The oxyacetylene flame may be used to cut iron and steel. 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。 徐存善主编 Electric of the welding is the heating of two pieces of metal to be welded b

49、y electricity. This heat is the hottest that can be obtained for engineering purposes; it is about 7, 232 degrees Fahrenheit. The ends are thus melted together, making a welded joint. Spot welding is welding two pieces of metal in spots with electricity and is done with a machine called spot welder.

50、 A forged weld is made by softening the ends of two metal pieces in a furnace and then hammering them together. 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。 徐存善主编solder sld n. 焊料，焊锡 v.（锡）焊，焊接brass br

51、:s n. 黄铜，黄铜制品braze breiz vt. 用铜锌合金焊接copper kp n. 铜，铜币；铜制物 a 铜的rivet rivit n. 铆钉 vt. 铆，铆接molten multn adj. 融化的，熔融的bismuth bizm n. 铋cadmium kdmim n. 镉acid sid n. 酸 adj. 酸的，酸味的oxide ksaid n. 氧化物flux flks n. 焊剂，助焊剂oxidation ,ksidein n. 氧化New words and phrases 徐存善主编zinc zik n. 锌chloride kl:raid n. 氯化物fer

52、rous fers adj. 含铁的，铁的aluminum lju:minm n. 铝stearin sti:rin, sti- n. 化 硬脂精；硬脂 = stearinevaseline vsili: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 sfn, s:- v. 使软化；使柔和；变软弱oxyacetylene ,ksisetili:n, -lin adj. 化 氧乙炔的acetylene setili:n n. 化 乙炔tank tk n. (盛液体盛气体的) 大容器, 槽, 罐, 坦克torch t:t n. 火炬，火把； 机 气炬；吹管furnace f:nis n. 炉子，熔炉； 冶 鼓风炉，高炉New words and phrases 徐存善主编 two separate s