金属不锈钢毕业论文外文文献翻译及原文

毕业设计（论文）
外文文献翻译
文献、资料中文题目：金属、不锈钢
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翻译日期：2017.02.14
Unit 1 Metals
The use of metals has always bee n a key factor in the developme nt of the social systems of man. Of the roughly 100 basic eleme nts of which all matter is composed, about half are classified as metals. The dist in ctio n betwee n a metal and a nonm etal is n ot always clear-cut. The most basic definition centers around the type of bonding existing between the atoms of the element, and around the characteristics of certa in of the electro ns associated with these atoms. In a more practical way, however, a metal can be defi ned as an eleme nt which has a particular package of properties.
Metals are crystalline when in the solid state and, with few exceptions (e.g. mercury), are solid at ambie nt temperatures. They are good con ductors of heat and electricity and are opaque to light. They usually have a comparatively high den sity. Many metals are ductile-that is, their shape can be cha nged perma nen tly by the applicati on of a force without break ing. The forces required to cause this deformation and those required to break or fracture a metal are comparatively high, although, the fracture forces is not n early as high as would be expected from simple con siderati on of the forces required to tear apart the atoms of the metal.
One of the more significant of these characteristics from our point of view is that of crystallinity.
A crystalline solid is one in which the constituent atoms are located in a regular three-dime nsional array as if they were located at the corners of the squares of a three-dime nsional chessboard. The spaci ng of the atoms in the array is of the same order as the size of the atoms, the actual spaci ng being a characteristic of the particular metal. The direct ions of the axes of the array defi ne the orie ntati on of the crystal in space. The metals commo nly used in engin eeri ng practice are composed of a large number of such crystals, called grains. In the most general case, the crystals of the various grains are randomly oriented in space. The grains are everywhere in in timate con tact with one ano ther and joined together on an atomic scale. The regi on at which they join is known as a grain boun dary.
An absolutely pure metal (i.e. one composed of only one type of atom) has never been produced. Engineers would not be particularly interested in such a metal even if it were to be produced, because it would be soft and weak. The metals used commercially in evitably contain small amounts of one or more foreign elements, either metallic or nonmetallic. These foreign eleme nts may be detrime ntal, they may be ben eficial, or they may have no in flue nee at all on a particular property. If disadvantageous, the foreign elements tend to be known as impurities. If advantageous, they tend to be known as alloying elements. Alloying elements are commonly added deliberately in substantial amounts in engineering materials. The result is known as an alloy.
The distinction between the descriptors metaland alloy ” is not clear-cut. The term metal" may be used to encompass both a commercially pure metal and its alloys. Perhaps it can be said that the more deliberately an alloyi ng additi on has bee n made and the larger the amount of the additi on, the more likely it is that the product will specifically be called an alloy .In any event, the chemical compositi on of a metal or an alloy must be known and con trolled with in certa in limits if con siste nt performa nee is to be achieved in service. Thus chemical compositi on has to be take n in to acco unt whe n develop ing an un dersta nding of the factors which determ ine the properties of metals and their alloys.
Of the 50 or so metallic eleme nts, only a few are produced and used in large qua ntities in engin eeri ng practice. The most importa nt by far is iron, on which are based the ubiquitous steels and cast irons (basically alloys of iron and carb on). They acco unt for about 98% by weight of all metals produced. Next in importa nee for structural uses (that is, for structures that are expected to
carry loads) are alu minum, copper, ni ckel, and tita nium. Alu minum acco unts for about 0.8% by weight of all metals produced, and copper about 0.7%, leav ing only 0.5% for all other metals. As might be expected, the rema in ders are all used in rather special applicati ons. For example, ni ckel alloys are used principally in corrosion-and heat-resistant applications, while titanium is used exte nsively in the aerospace in dustry because its alloys have good comb in ati ons of high stre ngth and low density. Both nickel and titanium are used in high-cost, high-quality applications, and, in deed, it is their high cost that tends to restrict their applicati on.
We cannot discuss these more esoteric properties here. Suffice it to say that a whole complex of properties in additi on to structural stre ngth is required of an alloy before it will be accepted in to, and survive in, engineering practice. It may, for example, have to be strong and yet have reas on able corrosi on resista nee; it may have to be able to be fabricated by a particular process such as deep draw ing, mach ining, or weldi ng; it may have to be readily recyclable; and its cost and availability may be of critical importa nee.
翻译如下：
第一单元金属
在人类社会的发展中，金属的应用起着关键性的作用。

构成物质的大约100种基本元
素中，大约有一半为金属。

金属和非金属之间的区别不是特别明显。

最基本的定义集中在元
素原子间存在的连接形式和与这些原子相关联的电子的某些特性。

然而，在实际应用中，可
以将具有某些特性集合金属定义为某种元素。

除了少数例外金属在常温下是固态的。

它们是热和电的良导体，不透光。

它们往往具有
较高的密度。

许多金属具有延展性，也就是说，在不被破坏的情况下它们的形状在外力的作
用下可以发生变化。

引起永久变形所需的力和最终使金属断裂所需的力相当大，尽管发生断
裂所需的力远没有像所预期的撕开金属原子所需的力那么大。

从我们的观点来看，在所有的特性中结晶性是最重要的。

结晶体是这样一种结构，组成它的
原子定位在规则的三维排列中，仿佛位于三维棋盘的方格的角上。

原子间距随着原子大小呈
规律性变化，原子间距是金属的一种特性。

三维排列的轴线决定了晶体在空间中的方向。

在工程实践中应用的金属由大量的晶体组成，这些晶体称之为晶粒。

在大多数情况下，晶粒在
空间中是自由排列的。

在原子范围内，晶粒之间相互接触紧密结合。

晶粒之间连接区域被称
为晶界。

绝对纯净的金属从来也没有被生产出来过。

即使绝对纯净的金属可以生产出来，工程师
们对它们也并不会特别感兴趣，因为它们很柔软、脆弱。

实际应用中的金属往往都包含着一
定数量的一种或多种外来金属或非金属元素，这些外来元素可能是有害的也可能是有益的或
者它们对某种特定的属性没有影响。

如果是有害的，这些外来元素被认为是杂质。

如果是有
益的，它们被认为是合金元素。

在工程材料中往往被特意地加入一定数量的合金元素。

得到
的物质被叫做合金。

金属和合金区别不大。

金属这个词可以包括工业用纯金属和它的合金。

也许可以这样说，
合金元素越故意的被添加，被添加的合金元素的量越大，那么生产出来的产品越倾向于被称之为合金。

不管怎样，如果想使一种金属或合金在使用中表现出稳定一致的特性，在其中添
加何种化学成分，它的量多大都应该在控制范围之内。

因此，当想了解决定金属和合金性质
的因素时，应充分考虑它们的化学组成。

在50种左右的金属元素里，工程实践中只有少数金属被大量生产和使用。

到目前为止最重要的是铁，以它为基础构成了处处可见的钢和铸铁。

(主要由铁和碳构成的合金)它们
的重量占所有生产出来的金属重量的98%。

在结构应用(也就是说，可以承受载荷的结构)
中居于其次位置的是铝、铜、镍和钛。

在所有的金属产量中，铝占0.8%，铜占0.7%，剩下
的占0.5%。

剩下的金属用于相对特殊的用途。

例如，镍合金主要用于抗磨损和耐高温的用途，由于钛合金具有高强度和低密度的综合特性，钛被广泛应用于航空工业中。

镍合钛有高
成本和高质量的使用特性，事实上，它们高的成本限制了它们的应用。

我们不能在这里讨论这些深奥的特性。

在合金材料被采用和应用于工程实际之前，掌握
其结构强度和它的综合性质就够了。

举例来说，它可以强度很高，并且有好的耐磨性；它可
以被例如拉伸加工，机械加工，或焊接等特殊工艺来加工出来；它可以被循环利用；它的成
本和实用性是首要的。

Reading Material 1
Stai nless Steel
Stainl ess steels do not rust in the atmosphere as most other steels do. The
term "sta ini ess" implies a resista nee to sta ining, rusti ng, and pitt ing in the
air, moist and polluted as it is, and gen erally defi nes a chromium content in excess of 11 % but less than 30%. And the fact that the stuff is "steel" mea ns that the base is iron.
Stainl ess steels have room-temperature yield stre ngths that range from 205 MPa (30 ksi) to more than 1725 MPa (250 ksi). Operati ng temperatures around 750 C (1400 F) are reached. At the other extreme of temperature some sta ini ess steels maintain their tough ness dow n to temperatures approachi ng absolute zero.
With specific restrict ions in certa in types, the sta ini ess steels can be shaped and fabricated in conven ti onal ways. They can be produced and used in the as-cast con diti on; shapes can be produced by powder-metallurgy tech niq ues; cast in gots can be rolled or forged (and this acco unts for the greatest tonn age by far). The rolled product can be drawn, bent, extruded, or spun. Stainless steel can be further shaped by machi ning, and it can be joined by solderi ng, braz ing, and weldi ng. It can be used as an in tegral claddi ng on plain carb on or low-alloy steels.
The gen eric term "sta ini ess steel" covers scores of sta ndard compositi ons as
well as variations bearing company trade names and special alloys madefor particular applications.
Stainless steels vary in their composition from a fairly simple alloy
of, essentially, iron with 11%chromium, to complex alloys that include 30%chromium, substa ntial qua ntities of ni ckel, and half a doze n other effective eleme nts. At the high-chromium, high-ni ckel end of the range they merge into other groups of heat-resisti ng alloys, and one has to be arbitrary about a cutoff poin t. If the alloy content is so high that the iron conten t is about half, however, the alloy falls outside the sta in less family. Even with these imposed restrictio ns on composition, the range is great, and naturally, the properties that affect
fabricati on and use vary eno rmously. It is obviously not eno ugh to specify simply a "sta ini ess steel. ”
Classificati on the various specify ing bodies categorize sta ini ess steels accord ing to chemical compositi on and other properties. However, all the sta ini ess
steels, whatever specificati ons they conform to, can be convenien tly classified into six major classes that represe nt three disti net types of alloy con stituti on, or structure. These classes are ferritic,
marten sitic, auste nitic,
mangan ese-substituted auste nitic, duplex auste nitic ferritic, and precipitati on-harde ning. Each class is briefly described below.
Ferrous sta ini ess steels: This class is so n amed because the crystal structure
of the steel is the same as that of iron at room temperature. The alloys in the class are magn etic at room temperature and up to their Curie temperature (about 750 C; 1400 F). Com mon alloys in the ferrous class con tain between 11% and 29% chromium, no ni ckel, and very little carb on in the wrought con diti on.
Marten sitic sta ini ess steels: Stainl ess steels of this class, which n ecessarily contain more tha n 11 % chromium, have such a great harde nability that substa ntial thickness will harden during air cooling, and nothing more drastic than oil quenching is ever required. The hard ness of the as-que nched marten sitic sta ini ess steel depe nds on its carb on content. However, the developme nt of mecha ni cal properties through que nching and temperi ng is in evitably associated with in creased
susceptibility to corrosi on.
Auste nitic sta ini ess steels: The traditi onal and familiar auste nitic sta ini ess steels have a compositi on that contains sufficie nt chromium to offer corrosi on resista nee, together with n ickel to en sure auste nite at room temperature and below. The basic auste nitic compositi on is the familiar l8% chromium, 8% n ickel alloy.
Both chromium and ni ckel contents can be in creased to improve corrosi on resista nee,
and additional elements (most commonly molybdenum) can be added to further enhance corrosi on resista nee.
Mangan ese-substituted auste nitic sta ini ess steels: The auste nitic structure can be encouraged by elements other than nickel, and the substitution of manganese
and n itroge n produces a c1ass that we believe is sufficie ntly differe nt in its properties to be separated from the chromium-nickel austenitic class just described.
The most importa nt differe nee lies in the higher stre ngth of the mangan ese-substituted alloys.
Duplex auste nitic-ferrous sta ini ess steels: The structure of these steels is a hybrid of the structures of ferrite and austenite; and the mechanical properties
likewise combine qualities of each component steel type. The duplex steels combine
desirable corrosion and mechanical properties, and their use is as a result in creas ing in both wrought and cast form.
Precipitati on-harde ning sta ini ess steels: Stainl ess steels can be desig ned so that their compositi on is ame nable to precipitati on harde ning. This class cuts across two of the other
c1asses, to give us marten sitic and auste nitic precipitati on-harde ning sta ini ess steels. In this class we find sta ini ess steels with the greatest useful strength as well as the highest useful o perating temperature.
Properties In select ion of sta ini ess steels, three kinds of properties have to
be con sidered: (1) Physical properties: den sity, thermal con ductivity, electrical resistivity, and so on; (2) Mecha ni cal properties: stre ngth, ductility, hard ness, creep resista nee, fatigue, and so on; and (3) corrosi on-resista nt properties. Note
that properties of sta ini ess steels are substa ntially in flue need by chemical composition and microstructure. Hence specifications include chemical composition,
or, more correctly, an analysis of the most important elements (traces of unreported elements also may be present) as well as a heat treatment that provides the optimum structure.
Applicati ons Since sta ini ess steels were first used in cutlery in dustry, the nu mber of applicati ons has in creased dramatically. The relative importa nee of the major fields of applicati on for flat and
long sta ini ess steel products is show n in Table 1. Chemical and power engin eeri ng is the largest market for both long and flat products. It began in about 1920 with the nitric acid industry. Today, it includes an extremely diversified range of service conditions, including nuelear reactor vessels, heat exchangers, oil industry tubular, components for the chemical processing and pulp and paper industries, furnace parts, and boilers used in fossil fuel electric power pla nts.
翻译如下
阅读材料1
不锈钢
不锈钢就像其他大多数的钢在空气中不会生锈，“不锈的”这个术语暗示了在空气中抵
抗污点，生锈和腐蚀，还具有抵抗潮湿和腐蚀。

通常含铬量大于11%且小于30%.实际上叫钢
的材料就是铁。

不锈钢在室温下的屈服强度的变化范围是从205MPa( 30ksi)到1725MPa(250ksi).工作温度可达到750 ° C (1400F)，—些不锈钢能维持其韧性当温度达到绝对零度。

由于特定的类型有特殊的限制，不锈钢可以通过常规方法成型和制造。

它们可以在铸造
状态下制造和运用。

其成型可以通过粉冶金技术，铸造锭可以轧或者锻造(这是至今为止最
大的吨位)。

轧制产品可以取出，弯曲，挤压或旋转。

不锈钢可以被进一步用机械加工塑造成型，它可以加入锡焊，铜焊和焊接。

还可以用于普通钢和低合金钢的整体电镀。

一般术语上说的“不锈钢”包括数十种标准组成部分，还包括变更轴承公司交易名称和特殊合金的独特应用。

不锈钢的合成成分各不相同，本质上，从单一的合金，如含11%各的铁到含30%各和大量镍的与五六种其他有效成分的复杂合金。

高含量的铬和镍最后组成其他
好的热稳定性的合金，并且分界点必定的任意的。

然而，如果合金含量太高，铁的含量达到
一半左右，该合金就不再是不锈家族了。

即使这加强成分的限制，但是范围很大，很自然，其性能将很大影响制造和应用。

显然，不能单纯地指定某一“不锈钢”。

划分多种指定机体种类的不锈钢要根据它们的化学成分和其他性质。

但是，全部的不锈钢，不论它们属于哪种规格，都可以被分为六大类，代表着三种不同的合金宪法或结构。

这类别是铁素体，马氏体，奥氏体，锰代铬奥氏体，奥氏体-铁素体双相和沉淀硬化型，每种类别简述如下：铁素体不锈钢：这种类被这样命名是因为钢的晶体结构在室温下和铁的相同。

该类里的合金在室温到居里温度(about750 C; 1400 F)间具有磁性。

普通的合金在铁素体类别里含有11%到29%勺铬元素，没有镍，在锻造条件中含有极少的碳。