焊接专业英语 教学课件 ppt 作者 洪宇翔 Unit 3

1、Unit 3,Text,Shielded Metal-arc Welding 1. Help stabilize and direct the arc for effective penetration. 2. Provide a gaseous shield to prevent atmospheric contamination. 3. Control surface tension in the pool to influence the shape of the bead formed when the mental freezes. 4. Act as scavengers to reduce oxides. 5. Add alloying elements to the weld. 6. Form a slag to carry off impurities, protect the hot metal, and slow the cooling rate. 7. Electrically insulate the electrodes. 8. Minimize spatt

2、er of weld metal. 9. Form a plasma to conduct current across the arc.,New Words and Phrases,decomposition ,di:kmpzin n. 分解，腐烂 particle p:tikl n. 微粒，颗粒，极小量 (物)粒子，质点 puddle pdl n. 水坑，泥潭，洼，胶土(由粘土与水和成，不透水) vt. 使泥泞，搅浑，把捣制成胶土 horizontal ,hrizntl a. 水平的，横的，卧式的，地平线的，同一阶层的 n. 水平线，水平面，水平位置 molecular mlekjl a. 分子的，由分子组成的 instantaneously ,instnteinjsli ad. 即刻，突如其来地 stabilize steibilaiz vt. 使稳定，使稳固，平抑的价格，使稳定平衡 vi. 稳定，安定,minimize minmaiz vt. 使减到最少，使缩到最小，低估，小看，极度轻视 spatter spt vt. 溅，洒，溅污，污蔑，中伤 vi. 溅出水滴，滴下，飞溅 n

3、. 洒，飞溅，飞溅声，泼溅的污迹，少量 plasma plzm n. 血浆，乳浆，深绿玉髓，生原生质，物等离子体 rectifier rektifai n. 矫正者，矫正器，电整流器，化精馏器 polarity pulriti n. 两极，极性，磁性引力，相反，对立,Notes,1 The shielding and filler metal largely control the mechanical, chemical, metallurgical and electrical characteristics. 焊条的类型不同，药皮和填充金属的组成也各有差异，它们对控制焊缝的机械、化学、冶金和导电特性起着主要作用。 2 When powdered iron is added in relatively large amounts, weld metal deposition rate and welding speed usually increase and weld bead appearance is improved 加入较多铁粉，通常能提高焊缝金属熔敷率和焊接速度，并改善

4、焊缝外形。,3 Selection of power source should also take into consideration the type of input power available. Motor-generator and rectifier-type welding machines normally perform only on three-phase power 选择焊机还应考虑可以得到的输入电源的类型。电动机发电机组和整流器式焊机，在正常情况下只适应三相电源。,Exercises,Answer the following questions according to the text. 1. What advantages does the CO2 welding have? 2. What are the problems that must be solved with CO2 welding? 3. What functions does the Electrode have?,Translating Skills,科技英语翻译方法与技巧词性转

5、译 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。 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 characterized by its compactness and portability. 这个仪器的特点是结构紧凑，携带方便。,4）The cutting tools must be strong, tough, hard and wear resistant. 刀具必须有足够的强度、韧性、硬度、而且耐磨。 5）Dynamics is divided into statics and kinetics, th

6、e former treating of forces in equilibrium, the latter of the relation of force to motion. 力学分为静力学和动力学：前者研究平衡力，后者研究力和运动的关系。 6）The image must be dimensionally correct. 图形的尺寸必须正确。,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. 代替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 application 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。,4）In any machi

7、ne input work equals output work plus work done against friction. 任何机器的输入功，都等于输出功加上克服摩擦所做的功。 5）Open the valve to let air in . 打开阀门，让空气进入。,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 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。 4）They said that such knowledge is needed before they can develop a successf

8、ul early warning system for earthquakes. 他们说，这只是对他们要发明的一种有效的地震早期警报是必要的。,四、英语形容词、名词译成汉语副词 1）He had the honor to meat the U.S President. 他荣幸地见到了美国总统。 2）A continuous increase in the temperature of a gas confined in a container will lead to a continuous incerase 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。,Reading Material,Arc Length,New Words and Phrases,fundamental ,fndmentl a. 基础的，根本的，十分重要的，原始的，主要的 n. 基本原则(或原理)，根本法则(或规律)，纲要 exposed ikspuzd a. 暴露的，无遮蔽的，易受攻击的 combination ,kmbinein n. 结合(体)，联合(体)，(有共同目的的)团体，联盟 surrounding sraundi n. 环境，周围的事物 a. 周围的，附近的 nitrogen naitrdn n. 氮,

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