機電專業(yè)英語第2版4Unit 4Heat Treatment and Hot Working of Metals

1、 徐存善主編 徐存善主編Heat Treatment and Working Equipment 徐存善主編What the meaning of “Shaping”? (radio)“shaping”是什么意思？(單選)提交 徐存善主編 徐存善主編 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

2、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. At this critical temperature, changes begin to take place in the molecular structure o

3、f the 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. 徐存善主編 Annealing has a second advantage. It helps to relieve any internal stresses which e

4、xist 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. Met

5、al which cools slowly is less liable to have these internal stresses than metal, which cools quickly. 徐存善主編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 t

6、he 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 again to a temperature below the critical temperature, and cool it slowly. This treatment is call

7、ed tempering. 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 w

8、ork. 徐存善主編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

9、 produce rolls of great accuracy and uniformity, and with a better surface finish. Other shaping operations include drawing into wire, casting in moulds, and forging. 徐存善主編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

10、include 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

11、 shearing 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-crystall

12、ization or workhardening range. 徐存善主編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. Som

13、e metals, 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. Thi

14、s range may also be increased by prior cold working. 徐存善主編 molecular mlekjl a. 由分子組成的, 分子的annealing ni:li n.(低溫)退火，燜火，磨煉relieve rili:v v.解除，減輕，使不單調乏味liable laibl a.有責任的，有義務的，應受罰的，有傾向的contract kntrkt v. 收縮，縮緊，感染，訂約 rise raiz v. 上升，增強，起立，高聳shaping eipi n. 成形，造型，塑造mechanical miknikl a. 機械的，呆板的，力學的machi

15、ning mi:ni n. 切肖，制造，機械加工grinding raindi n. 磨肖力工machined mi:nd a. 機械加工的pressure pre n. 壓力，壓強bend bend v. 使彎曲，使屈服，使致力，使朝向bending bendi n. 彎曲 (度)，扭曲(度) 徐存善主編 squeeze skwi:z v.擠 (壓，干)，壓榨，勒索，緊握prior prai a. 在先的，在前的，優(yōu)先的distortion dist:n n. 變形，扭曲，曲解，失真crack krk v. &n破裂，裂紋，打開beyond bijnd prep.超過的范圍, 超過,

16、 越過quench kwent v. &n熄滅，機 淬火, 解渴； fix fiks v. & n. 安裝, 修理，使固定，準備 tempering tempri v. 回火 rolls ruls n. 薄板卷，泛指鋼材 draw dr: v.拉, 畫, 吸引 drawing dr:i n. 沖壓成形shear i v. 剪斷，切斷，修剪，剝奪recrystallization ri:,kristlaizein n.再結晶hardening h:dni n.硬化，淬火, 鍛煉crystalline kristlain a. 結晶的凡結晶體influence influns n.

17、 影響，作用 徐存善主編 mechanical means 機械設備(工具) be known as 稱為workhardening range淬火溫度區(qū)Technical Terms 徐存善主編 v This produces unequal contractions，which may give rise to distortion or cracking譯文：這將引起不均勻壓縮，增加其出現(xiàn)畸變和破裂的可能。說明：此句為非限定性定語從句?！癢hich”引導的從句時對“unequal contractions” 的進一步解釋說明。Language points 徐存善主編2. This do

18、es not include 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 譯文：這既不包括金屬已經(jīng)過機械或磨削加工的成形，也不包括熔化的金屬注入鑄造模所進行的成形。 說明：“in which processes metal is actually machined off”為非限定性定語從句

19、，對前面的主句起進一步解釋說明作用?！皀or does it include the casting of molten metal into some form by use of molds” 此句為倒裝句，由于“nor” 提前，整個句子發(fā)生了部分倒裝。Language points 徐存善主編 3. These stresses are liable to occur through hammering or working the metal, or through rapid cooling. 金屬在鍛打加工或快速冷卻時外層收縮比內層收縮速度快，極易導致內應力。 be liable

20、to: 易于的；有傾向的；應付有責任，應遵守 (1) A third party, whose fault causes the fuel gas accident, shall be liable to pay damages according to law.因第三人的過錯造成燃氣事故的，第三人應當依法承擔損害賠償責任。 (2) Non-complying trusts are also deemed to be liable to taxation on the trusts worldwide income. “非照辦信托”同時也被推定為按其信托之全球收入征稅。Language poi

21、nts 徐存善主編4. We heat it up beyond the critical temperature, and then quench it in water or some other liquid.我們將金屬加熱到超過極限溫度，然后在水或其他液體中淬火。heat up：加熱 （1）The electronic heater can heat up fast and safely. It also functions as a steamer.以電熱為燃料能源，既方便，而且加熱速度快，有蒸氣鍋爐之同功效。 （2）Material spiraling into a black h

22、ole can heat up to millions of degrees and glow brightly .捲入黑洞中的物質，將會被加熱至數(shù)百萬度并放出耀眼的光芒。 Language points 徐存善主編5. The properties of tempered steel enable US to use it in the manufacture of tools, which need a fairly hard steel.當制造的工具需要高硬度的鋼鐵時，我們可以用回火鋼。enable to: 使 ; 使能夠 ; 能夠 (1) Using ICON controlling

23、circuit, enable to detect the status of the mechanism operation. 本機采用ICON控制回路，可偵測機械操作狀況。 (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.內外板之間形成的空間可以填充保溫材料，能夠提供良好的保溫功能。Language points 徐存善主編6. Other s

24、haping operations include drawing into wire, casting in moulds, and forging.其他的塑性加工有拉絲、模鑄和鍛造。drawing into: 使卷入 (1) SMS Draw integrates into the target application and appears as a new service in the toolbar. 短信抽獎集成到目標應用，似乎作為一種新的服務工具欄。 (2) Now the pattern repeat with manual twist, will itself draw in

25、to the active level of the Photoshop data file and the original is maintained again on a separate level.現(xiàn)在的模式重復與手工捻，本身將提請進入活躍水平的Photoshop的數(shù)據(jù)文件和原再次是保持在一個單獨的水平。 Language points 徐存善主編7. There is no tendency for hardening by mechanical work until the lower limit of the re-crystalline range is reached.在達

26、到最低的再結晶溫度之前，機械加工的金屬沒有硬化的趨勢。tendency tendnsi n. 傾向，趨勢；癖好(1) Since gravity works equally on everything, there would be a tendency to pull those uneven places down. 由于重力作用于物體上是相等的，會有傾向于將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 p

27、roof.現(xiàn)代科學的傾向，是不斷把謬論化為根據(jù)來使實證變得荒謬。 Language points 徐存善主編8. Alloy composition has a great influence upon the proper working range, the usual result being to raise the re-crystalline range temperature.合金的成分對合適的加工范圍有極大的影響，通常會提高再結晶的溫度范圍。 have/has influence upon: 有影響 (1) The level of weighting rate has dir

28、ect influence upon the fabric properties.增重率的高低對織物性能有直接影響。 (2) In the legal system of termination of labor contract, dismissal system has great influence upon employee.勞動法律關系解除法律制度中，解雇制度對勞動者權益的影響尤其重大。Language points 徐存善主編I. Answer the following questions.1. Explain the ways that can alter the charac

29、teristics of steel 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. O

30、n the other hand, we can make steel harder by rapid cooling.Exercises 徐存善主編 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 easi

31、er to machine. 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 徐存善主編 3. What is the meaning of tempering? We heat up the steel beyond th

32、e critical temperature, 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 therefo

33、re heat it again to a temperature below the critical temperature, and cool it slowly. This treatment is called tempering.Exercises 徐存善主編 4. What is the temperature at which steel starts to re-crystallize? For steel, re-crystallization starts around 650 to 700C.Exercises 徐存善主編v 金屬的分子結構 2. 不均勻壓縮3. 快速冷

34、卻4. 各種塑性加工IITranslate the following into Englishstructure of the meta1unequal contractionrapid coolingvarious shaping operations 徐存善主編5. 金屬的機械加工6. 金屬的冷熱加工mechanical working of metalcold or hot working of steel. Put the phrases into English: 徐存善主編 在翻譯過程中，由于英漢兩種語言的表達方式不同，不能逐詞對譯。原文中有些詞在譯文中須要轉換詞性，才能使譯文通

35、順流暢。詞性轉譯的幾種情況如下： 一、英語動詞、形容詞、副詞譯成漢語名詞 1. Telecommunications means so much in modern life that without it our modern life would be impossible. 電信在現(xiàn)代生活中意義重大，沒有它就不可能有我們現(xiàn)在的生活。 徐存善主編 2. Gases differ from solids in that the former has greater compressibility than the latter. 氣體和固體的區(qū)別在于氣體的可壓縮性比固體大。 3. The i

36、nstrument is characterized by its compactness and portability. 這個儀器的特點是結構緊湊，攜帶方便。 徐存善主編二、英語名詞、介詞、形容詞、副詞譯成漢語動詞二、英語名詞、介詞、形容詞、副詞譯成漢語動詞 1. Substitution of manual finishing is one example of HSM application. 替代手工精加工是高速加工應用的一個例子。 2. Scientists are confident that all matter is indestructible. 科學家們深信一切物質是不滅

37、的。 3. The application of electronic computers makes for a tremendous rise in labor productivity. 使用電子計算機可以大大提高勞動生產(chǎn)率。 徐存善主編三、英語的名詞、副詞和動詞譯成漢語形容詞三、英語的名詞、副詞和動詞譯成漢語形容詞 1.This wave guide tube is chiefly characterized by its simplicity of structure. 這種波導管的主要特點是結構簡單。 2. The maiden voyage of the newly built

38、steamship was a success. 那艘新造輪船的處女航是成功的。 3. It is a fact that no structural material is perfectly elastic. 事實上沒有一種結構材料是十全十美的彈性體。 徐存善主編四、英語形容詞、名詞譯成漢語副詞四、英語形容詞、名詞譯成漢語副詞 1. Quasi-stars were discovered in1963 as a result of an effort to overcome the shortcomings of radio telescopes. 類星體是1963年發(fā)現(xiàn)的，是人們努力克服

39、射電望遠鏡的缺點所取得的一項成果。 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. 不斷提高密封容器內氣體的溫度，會使氣體的內壓力不斷增大。 徐存善主編There are a number of methods of joining metal articles together, depending on the type of meta

40、l and the strength of the joint that is required.1. Soldering and Brazing金屬連接在一起的方法很多，選用哪種方法要取決于金屬的類別和所要求的接縫強度。 1. 軟釬焊與硬釬焊 徐存善主編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 o

41、r welded. These 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 o

42、f the most important operations in soldering is that of cleaning surfaces to be joined, this may be done by some acid cleaner. 軟釬焊能使薄的鋼件、銅件或黃銅件獲得合乎要求的接縫。但軟釬焊的接縫強度比硬釬焊、鉚接或焊接的接縫強度低的多，硬釬焊、鉚接或焊接等這些接合方法通常用于高強度的永久接合。軟釬焊是靠施加熔融狀態(tài)的第三中金屬使兩塊金屬連接在一起的焊接方法。焊料由錫，鉛組成，而加入鉍和鎘是為了降低焊料的熔點。釬焊的重要工序之一是將需要焊接的接縫表面洗擦干凈，這一工序可用

43、某種酸洗液進行。 徐存善主編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 t

44、o flow freely 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. 雖然通過清理操作，氧化物被除去，但清洗完畢之后，會立即產(chǎn)生新的氧化膜，從而阻礙了焊料與金屬件表面的連接。助焊劑是用來去除氧化物和防止需要焊接的金屬表面的氧化，以使焊料能自由地流動并于金屬件連接。

45、在釬焊大多數(shù)黑色金屬和有色金屬時氯化鋅是最好的助焊劑，釬焊鋁時，用硬脂酸和凡士林作為助焊劑。 徐存善主編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 在有些情況下，用高熔點的硬鋅焊料來焊接金屬是必要的，這種釬焊稱之為硬釬焊。 2) 焊接 徐存善主編Welding is the joining o

46、f two metal pieces by softening with heat and then pressing, hammering, of fusing them together. Many parts of machines, automobiles, airplanes, ships, bridges, and buildings are welded.焊接是借助于熱量，使金屬軟化后加壓、錘鍛或使金屬熔合將兩塊金屬連接在一起的一種工藝方法。機器、汽車、飛機、船舶、橋梁及各種建筑物的許多構件都是焊接的。 徐存善主編Oxyacetylene welding is the heati

47、ng of two pieces 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 temper

48、ature is about 6, 300 degrees Fahrenheit. The oxyacetylene flame may be used to cut iron and steel. 氧乙炔（氣焊）用氧氣和乙炔氣混合物燃燒產(chǎn)生的火焰加熱兩塊金屬。氧氣和乙炔分別貯存在兩個鋼制的貯氣瓶內，由貯氣瓶流入焊炬，這兩種氣體在焊炬內混合后通向火焰。就通常使用的火焰而言，氧乙炔是最熾熱的火焰，其溫度約6300F（3482C），氧乙炔火焰還可用于切割鐵和鋼。 徐存善主編 Electric of the welding is the heating of two pieces of metal

49、to be welded by 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 calle

50、d spot welder. A forged weld is made by softening the ends of two metal pieces in a furnace and then hammering them together. 電焊即電弧焊，是用電能對施焊的兩件金屬加熱。在工程方面所有獲得的最高熱量要算電弧熱量，它約為7232F（4000C），因而焊接端被熔合成焊縫。點焊是借助電能以焊點形式將兩塊金屬焊接在一起。人們采用稱作點焊機的機器來完成這一工作。鍛焊是將兩塊金屬焊接端在爐中加熱軟化, 然后將它們錘擊在一起。 徐存善主編solder sld n. 焊料，焊錫 v.（

51、錫）焊，焊接brass br:s n. 黃銅，黃銅制品braze breiz vt. 用銅鋅合金焊接copper kp n. 銅，銅幣；銅制物 a 銅的rivet rivit n. 鉚釘 vt. 鉚，鉚接molten multn adj. 融化的，熔融的bismuth bizm n. 鉍cadmium kdmim n. 鎘acid sid n. 酸 adj. 酸的，酸味的oxide ksaid n. 氧化物flux flks n. 焊劑，助焊劑oxidation ,ksidein n. 氧化New words and phrases 徐存善主編zinc zik n. 鋅chloride kl:

52、raid n. 氯化物ferrous fers adj. 含鐵的，鐵的aluminum lju:minm n. 鋁stearin sti:rin, sti- n. 化 硬脂精；硬脂 = stearinevaseline vsili:n n. 化 石油凍；礦脂；凡士林（商品名）fuse fju:z v. 熔（化），熔合 n. 保險絲，熔絲soften sfn, s:- v. 使軟化；使柔和；變軟弱oxyacetylene ,ksisetili:n, -lin adj. 化 氧乙炔的acetylene setili:n n. 化 乙炔tank tk n. (盛液體盛氣體的) 大容器, 槽, 罐, 坦克torch t:t n. 火炬，火把； 機 氣炬；吹管furnace f:nis n. 爐子，熔爐； 冶 鼓風爐，高爐New words and phrases 徐存善主編 two separate