材料成型级控制工程专业英语阅读

1、材料成型级控制工程专业英语阅读1.2.1 Plain Carbon Steel 普通碳钢Hot-rolled steel delivered （供给）by steelmaking works as rolled sections(bars, beams，sheetstubes，etc) is the most wildly used material for manufacture of various machines，machine tools, building structures，consumer goods，etcDelivered steel should have the pr

2、operties as specified by State Standards（国家标准）钢铁制造车间供给的热轧钢主要为棒材、柱材、板材、管材等，热轧钢是制造各种机械、机器工具、建筑结构和消费品中应用最广泛的材料。所供给的钢应具有国家标准规定的各种性能。 In the RSSUPlain carbon steels are classified into three groups：A, B and C，depending on their application. 在RSSU中，普通碳钢根据其用途分为A、B、C三类。A: If a steel is to be used for making

3、 products without hot working (welding, ForgingEtc.). Its structure and properties in the final product will be the same as delivered from the rolling millIn that case the user requests for a steel of warranted（保证） mechanical properties，while the chemical composition is not guaranteed（保证、担保）A:如果钢在制造

4、产品的过程中没有进行热加工（焊接、锻造等），则最终产品的组织和性能将与轧厂提供的相同。这种情况下，用户只需要求材料应有的机械性能，而不必保证其成分。B: If a steel is to be subjected to hot working(forging，stamping，etc)，its initial structure and mechanical properties will be changed.In that case the composition of the steel will be of prime importance for the user，since it

5、determines the conditions of hot working and the final mechanical properties of steel productsNow a steel of warranted composition is delivered to the user. B.如果钢要进行热加工（锻造、冲压等），则其初始组织和机械性能将会改变。此时/在这种情况下，钢的成分对用户来讲是最重要的，因为它(成分)决定了热加工的条件，钢制品的最终机械性能。因此，提供给用户的钢应保证其成分含量。C: If a steel is to be weldedthe us

6、er wants to know the composition of the steelsince it determines the properties of the metal in the zone subjected to thermal effect of weld（焊接热影响区）The user is also interested in the initial mechanical properties of the metal，since these properties will remain the same in portions not subjected to w

7、eldingIn that case the metal is delivered with warranted composition and mechanical properties.C如果钢要进行焊接，则用户需要知道钢的成分，因为成分决定钢焊接时热影响区的性能。用户也会对钢材的原始机械性能感兴趣，因为未焊接的部分的性能是原始性能。这种情况下，供给用户的钢应具有规定的成分和机械性能。General-purpose plain steels are not alloyedSome alloying elements may sometimes be present in them occa

8、sionally and their content（含量） is limited非特殊用途/一般用途的普通钢不是合金钢。一些合金元素偶尔会出现，其含量受限制。The presence of silicon and manganese may be due to the steelmaking process(the necessity of deoxidation脱氧)Surphur（硫）and phosphorus（磷） are harmful impurities（杂质） in steel and their content should be minimized as it may a

9、ffect the quality of steel 在钢冶炼过程中由于脱氧的需要，会出现硅和锰。硫、磷是钢中有害的杂质，应尽可能减少其含量，它们会影响钢的质量。The principal element whose content is responsible for the properties of steels is carbon 影响钢性能最主要的元素是碳。1.3Non-ferry AlloysAlthough ferrous alloys ale used in the majority of metallic applications in current engineering

10、 designs，nonferrous alloys play a large and indispensable role in our technology. As compared to ferrous alloys，the list of nonferrous alloys is，of course，long and complexWe shall briefly list the major families of nonferrous alloys and their key attributes尽管现代工业设计中，铁合金是主要应用的金属，但是非铁合金在当前科技中也起着很大并不可替

11、代的作用。当然，与铁合金相比，非铁合金的种类多且复杂。我们将简要介绍几种非铁合金及其主要特征。Aluminum alloys are best known for low density and corrosion resistance. Electrical conductivity，easy of fabrication，and appearance are also attractive featuresBecause of these，the world production of aluminum roughly doubled in one recent 10 year perio

12、dOre reserves for aluminum are large (representing 8of the earths crust) and aluminum can be easily recycled铝合金以其低密度和腐蚀抗力而闻名。电导率、易加工以及好的外观也是其具有吸引力的特征。基于以上特点，近10年来铝合金的产量几乎翻了一番。铝矿石的产量很大（占地壳的8），并且铝是可以回收的。Magnesium alloys have even lower density than aluminum and，as a result，appear in numerous structura

13、l applications such as aerospace designsAluminum is a fcc material and therefore has numerous (12) slip systems, leading to good ductilityBy contrastmagnesium is hcp with only three slip systems and characteristic brittleness镁合金的密度比铝合金的还低，因此，设计航空飞行器时大量的结构件用镁合金。铝合金是面心立方结构金属，因此，有12个滑移系，使其延展性好。相反，镁合金是密

14、排六方结构，仅有3个滑移系，易脆断（具有脆性）。Titanium alloys have become widely used since World WarBefore that time，a practical method of separating titanium metal from reactive oxides and nitrites was not available. Once formed, titaniums reactivity works to its advantageA thin tenacious oxide coating forms on its sur

15、face, giving excellent resistance to corrosion. This “passivation” will be discussed in detail later. Titanium alloys，like Al and Mg，are of lower density than ion. Although more dense than Al or Mg，titanium alloys have a distinct advantage of retaining strength at moderate service temperatures, lead

16、ing to numerous aerospace design applications. Titanium shares the hcp structure with magnesium leading to characteristically low ductility. However，a high temperature bcc structure can be stabilized at room temperature by certain alloy additions such as vanadium.二战以后钛合金被广泛应用，在此之前，还没有通过活性氧和硝酸盐分离钛金属的

17、工艺。一旦形成钛合金，钛的活性显现出其优点。其表面形成致密的氧化膜，使其就有优良的抗腐蚀性。“钝化性”将在后面详细讨论。与Al、Mg一样，钛合金密度比铁低。尽管密度要比Al、Mg高，钛合金的显著特点之一是在中等服役温度下能保持其强度，因此航天中应用多。与镁合金一样，钛合金也是Hcp晶格结构，延展性低。然而，通过添加钒等合金，其高温下bcc晶格结构可以在室温下保存。Copper alloys possess a number of superior properties. Their excellent electrical conductivity makes copper alloys th

18、e leading material for electrical wiring. Their excellent thermal conductivity leads to applications for radiators and heat exchangers. Superior corrosion resistance is exhibited in marine and other corrosion environments. 铜合金也拥有许多优良的性能。优良的电导率使铜合金成为电线的首选材料。优良的热导率使其应用于散热器和热交换器上。超级抗腐蚀性使其用于船舶及其它腐蚀性环境中。

19、The fcc structure contributes to their generally high ductility and formability. Their coloration is frequently used for architectural appearance. Widespread uses of copper alloy through history have led to a somewhat confusing collection of descriptive termsThe mechanical properties of these alloys

20、 rival the steels in their variability.Fcc晶格结构使其具有高延展性和成形性。其颜色经常用于建筑装饰中。铜合金的广泛应用使其描述词语选择时经常混淆。优良的机械性能使其应用上很具有竞争性。High purity copper is an exceptionally soft material. The addition of 2 wt beryllium followed by a heal treatment to produce CuBe precipitates is sufficient to push the tensile strength b

21、eyond l000 MPa纯铜非常软。热处理时添加2wt的铍元素，产生的CuBe沉淀相使其拉伸强度可超过1000MPaNickel alloys have much in common with copper alloysWe have already used the Cu-Ni system as the classic example of complete solid solubility. Monel is the name given to commercial alloys with Ni-Cu ratios of roughly 2:1 by weight. These ar

22、e good examples of solution hardening. Nickel is harder than copper, but Monel is harder than nickel. 镍合金比铜合金更普通。CuNi合金已是典型的完全固溶例子。比例接近2：1的Ni Cu商业合金称之为蒙乃尔合金。这是很好的固溶硬化的例子。Ni比铜硬，但是蒙乃尔合金比Ni硬。Nickel exhibits excellent corrosion resistance and high temperature strength. Zinc alloys are ideally suited for

23、 die castings due to their low melting point and lack of corrosion reaction with steel crucibles and dies. Automobile parts and hardware are typical structural applications. Zinc coatings on ferrous alloys are important means of corrosion protection. This method is termed as galvanization镍有优良的腐蚀性和高温

24、强度。由于熔点低不与铁质坩锅和模具材料发生腐蚀反应，锌合金是模具铸造的理想材料。其(锌合金)应用于典型的汽车结构零件及硬度高的零件。铁合金上镀锌层是重要的防腐蚀措施，该方法称之为镀锌。Lead alloys are durable and versatile materials. The lead pipes installed by the Romans at the public baths in Bath, England, nearly 2000 years ago are still in use. Leads high density and deformability combi

25、ned with a low melting point adds to its versatilityLead alloys find use in battery grids (alloyed with calcium or antimony), solders (alloyed with tin), radiation shielding，and sound control structures. The toxicity of lead restricts design applications and the handling of its alloys.铅合金是耐用的多功能材料。2

26、000年前罗马人安装在英国公共浴室的铅管至今仍然在用。铅的高密度、高成形性和低熔点使其具有多种用途。铅合金用于电池铅版(与钙、锑混合)、焊料（与锡混合）、辐射屏蔽及进行有效的组织控制。铅的毒性限制了其设计应用和合金处理。The refractory metals include molybdenum，niobium，tantalum，and tungstenThey are, even more than the superalloys, especially resistant to high temperatures. However, their general reactivity w

27、ith oxygen requires the high temperature service to be in a controlled atmosphere or with protective coatings难熔金属包括钼、铌、钽、钨，它们不仅仅是超合金，还特别耐高温。然而，它们一般与氧反应，高温服役时需控制气氛，或带有保护层。The precious metals include gold, iridium, osmium, palladium, platinum, rhodium，ruthenium，and silver. Excellent corrosion resistan

28、ce combined with various inherent properties justify the many costly applications of these metals and alloysGold circuit in the electronics industry, various dental alloys, and platinum coatings for catalytic converters are a few of the better, known examples.贵重金属包括金、铱、锇、钯、铂、铑、钌和银。优秀的防腐性能以及其他各种性能使这些

29、金属及其合金应用非常昂贵。金线用于电子工业、各种假牙合金，催化转炉中的铂金层是少数众所周知的例子。2.22.AnnealingisastructuralrecrystallizationconsistingofheatingaboveAC3andsubsequentslowcooling.WithheatingaboveAc1butbelowAc3,fullrecrystallizationwillnotoccurandtheprocedureiscalledpartialannealing.Thestateofannealedsteelisclosetothestateofstructura

30、lequilibriumanditsstructureispearlite+ferrite,pearlite,orpearlite+cementite.退火是一种结构再结晶，由加热到AC3以上并随后缓慢冷却组成。加热到Ac1以上但低于AC3,完全再结晶将不会发生并且该过程被称为局部退火,退火钢的状态接近于结构平衡状态，其结构是珠光体+铁素体,珠光体或珠光体+渗碳体。3.If a steel is heated above AC3 and then cooled in air, this will be the first step to change it to a state farther

31、 from the structural equilibrium.如果一个钢加热到AC3以上,然后在空气中冷却,这将是改变它远离结构平衡状态的第一步。This type of heat treatment is called normalizing and is an intermediate stage between the second- group procedure (annealing) and the third-group procedure (hardening).这种类型的热处理被称为正火,且为第二组之间的中间阶段过程(退火)和第三种过程(硬化)。4.Hardeningis

32、heatingabovethecriticalpoint,Ac3,followedbyquickcooling.Withslowcooling,austenitedecomposesintoferrite+cementiteatAr1.Withincreasingcoolingrate,thetransformationoccursatlowertemperatures.淬火是加热到临界点以上,Ac3,随后快速冷却。再缓慢冷却,奥氏体分解为铁素体+渗碳体在Ar1。随着冷却速率增加,转换发生在更低的温度。AstheAr1 pointislowered,theferrite-cementitemi

33、xturebecomesmoreandmorefine-disperseandhard.Ifthecoolingrateissohighandtheundercoolingsosubstantialthattheprecipitationofcementiteandferritedoesnottakeplace,therewillbenodecompositionofthesolidsolutionandaustenite(r-solidsolution)willtransformintomartensite(supersaturatedsolidsolutionofcarbonina-iro

34、n).IncompletehardeningisaheattreatmentprocedurewithheatingthemetalaboveAc1,butbelowAC3(Accm),afterwhichthesteelstructureretainshypoeutectoidferrite(hypereutectoidcementite).Ar1点降低,铁素体渗碳体的混合物变得越来越细小和坚硬。如果冷却速度很高,和过冷度大幅的提高，渗碳体和铁素体没有发生,不会有固溶体的分解并且奥氏体(r -固溶体)将转变成马氏体(a-iron碳过饱和固溶体)。不完全淬火是热处理过程加热金属到Ac1之上,但

35、低于AC3(Accm)之后,钢结构保留亚共析铁素体(过共析渗碳体)。5.Temperingisaprocedureofheatingahardenedsteelto a temperaturebelowAc1andthencoolingtoroomtemperatureatcertaincoolingrate.回火是淬火钢加热到低于Ac1相的温度，然后以一定的冷却速率冷却至室温的步骤。31As the phenomenon of superplasticity moves from the laboratory into the industrial arena, as in the case

36、 of a number of engineering metals, the need for quality and process control during superplastic forming becomes increasingly important. This calls for laboratory characterization of superplastic metals which can reflect their behavior in actual forming applications. Such requirements are not limite

37、d to determining tensile elongations under optimum superplastic conditions, but include detailed characterization of the constitutive relations for superplastic flow, since a reasonably accurate control of the pressurization cycle during forming is required. This provides a significant challenge to

38、the materials engineer because of the complexity associated with microstructural changes occurring simultaneously during forming.超塑性的现象从实验室转移到工业领域，如在许多工程金属中，这种需求在超塑性质量和过程控制成形变得越来越重要。这就要求超塑性金属的可反映其在实际应用中形成的行为的实验室鉴定。由于加压循环的成型过程中一个相当精确的控制是必需的，这样的要求并不限于确定最佳超塑性条件下的拉伸伸长率，且包括本构RELA蒸发散的超塑性流动的详细的表征。由于形成过程微观结

39、构的变化同时发生的复杂性，这给材料工程师们提出了一个严峻的挑战。 The characterization of superplastic behavior broadly includes the characterization of plastic flow, internal cavitation and fracture behaviors. The processing variables needed for an overall characterization of superplastic behavior are introduced in this section. T

40、he parameter which is commonly selected as a measure of superplastic formability is the tensile elongation at the optimum superplastic temperature and strain rate. However, since this is a highly strain-rate sensitive property, and actual parts can experience significant variations in strain rate du

41、ring forming, it is sensible to measure tensile elongation as a function of strain rate. While this is somewhat time consuming, an alternate possibility is to determine the strain-rate sensitivity of the flow stress, m(m is defined as d(lg o) /d(lg ) which has been shown to correlate well with tensi

42、le elongation for different classes of materials. Measurements of flow stress and strain-rate sensitivity of flow stress can be conducted in a single test and may be used to determine the optimum strain rate for superplastic forming(where m is a maximum). Several methods for determining m exist in t

43、he literature, some of which will be reviewed subsequently. 超塑性行为的性质大致包括塑性流动，内部空化和断裂行为的表征。需要的超塑性行为的总体特征的处理变量在本节进行了介绍。通常选择作为超塑性成形性质的度量参数是在最佳超塑性温度和应变速率时的拉伸伸长率。然而，由于这是一个高度应变敏感性，实际上工件在成型过程中遇到的应变速率有很大的差异，用应变速率的函数来测量拉伸伸长率是合理的。虽然这是有点耗时，另一种可选用的可能性是确定流变应力的应变率敏感性，m（ m定义为d（ LG O） / D（ LG ） ）对于不同类别的材料都被指出与拉伸伸长率

44、具有良好的相关性。流动应力和流动应力的应变率敏感性的测量可以在一个单一的测试进行，并可以用来确定超塑性成形的最佳应变速率（其中m是一个最大值）。在文献中存在多种方法用于确定米，其中一些将在下面评论。32While strain rate sensitivity is the dominant parameter in superplastic forming, more recent results show that significant amount of hardening can occur as a function of superplastic strain even at a

45、 constant strain rate. This kind of “strain hardening” is believed to be related primarily to grain growth occurring during superplastic forming. At the higher strain rates, strain hardening is associated with dislocation cell formation in a classical manner. For complete characterization of superpl

46、astic flow behavior, however, the characterization of strain induced hardening is necessary . This is generally accomplished by means of a constant strain rate tensile test.虽然应变率敏感性是超塑成形的主要参数，但最近的结果表明，大量硬化甚至能以恒定应变速率作为超塑应变的一个函数。在在超塑性成形中，这种“应变硬化”被认为是主要与晶粒生长发生有关。在较高的应变率，应变硬化与位错胞形成有关以一种典型的方式。对于超塑性流动特性完整

47、的特征，但是，应变诱导硬化的特性是必要的。这通常是通过一个恒定应变速率拉伸试验的手段来完成。35Forgings are commonly found in machines and conveyances at critical points of shock or stress-particularly where reliability and human safety are affected, and yet the great variety of shapes, sizes and properties available in forgings has extended the

48、 list of current applications and potential future uses far beyond this point.锻件通常是用在在机器和交通工具中发生冲击和压力尤其是在可靠性和人身安全受到影响的关键处，但在提供种类繁多的形状，尺寸和性能的锻件中，锻件的可用性已经扩展了现有的应用，并且在未来潜在的用途远远超出了现在。In earlier days forging was the process of shaping metal by heating and hammering. Today, metal is not always heated for

49、forging and the work may be performed by several types of heavy machines which apply impact or squeeze pressure with swift precision. In todays forging industry the skill and seasoned judgment of the forgeman is enhanced by the machines of modern technology to produce metal parts of unparalleled str

50、ength and utility.在早期，锻造是金属通过加热并锤打而成形的过程。今天，金属并不总是通过加热锻造，这种工作可以由多种类型的能提供压力或迅速精密挤压力的重型机械来执行。在今天的锻造行业中锻造工人的技能和经验丰富的判断通过现代工艺的机器而得到增强，生产出无与伦比的力量和实用的金属部件。Pressworking operations have increased dramatically over the last few years, but like many other manufacturing operations, the existing technology has

51、sometimes failed to keep pace with the changing applications. One area where this is especially true is die bending. 在过去的几年里压力加工行业日益昌盛，但像许多其他制造业务一样，现有的技术有时无法跟上不断变化的应用的步伐。尤其是在模具弯曲这个领域。although there is a substantial increase in the applications for bending, the two most common forms of bending-repres

52、ent technologies that are sometimes quite outdated for todays high volume production runs and precision requirements.虽然弯曲的方法在大幅增加，这两个最常见的具有代表形的弯曲工艺，对如今的大批量的生产运营和精度要求来说有时是相当过时的。1.1金属和非金属许多属性具有材料之一，其机械性能，在大多数情况下，是最重要的，因此，他们将在本书太多的考虑。所有关键部件和元件，其中一个高可靠性的要求，都是用金属制作的，而不是玻璃，塑料或石头。已升了SEC，金属的特点是金属键；在正离子占据晶格的

53、网站和周围的电子气。所有非金属离子和共价键。这些类型的债券是刚性的，是由于两个不同的电荷离子的静电引力。由于金属键，金属塑性变形能力和自我强化的塑性变形。因此，如果在一个物质或者元素的形状是这样，有应力集中的缺陷，在这些点上的应力可以达到一个巨大的价值，甚至导致开裂。但是，由于材料的塑性越高，金属在塑性变形这一点，说，在裂纹尖端，经过强化，骨折的过程中，涉及到一个逮捕。这不是在非金属发生。他们是不可能的塑性变形和自我强化；因此，裂缝将尽快在缺损的尖端的应力超过一定值时发生。这些事实说明为什么金属是可靠的结构材料和不可超越的非金属材料。 1.2铁合金以上的人类使用的金属材料，重量90%铁合金。这

54、代表了范围广泛的组织工程材料的一个巨大的家庭及相关性质。工程设计要求结构承重或电力传输大多数涉及铁合金。作为一个实际问题，这些合金分为基于碳在合金成分两大类。钢通常包含在0。05和2重量%的碳。铸铁通常含有2和4.5重量%的碳之间。在钢的范畴，我们应当区分是否显着量的合金元素碳以外的使用。的组合物的5重量%的总的非碳的加入将作为低合金高合金钢之间的边界。这些合金元素都经过精心挑选，因为他们总是带来大幅增加材料成本。只有在性能如强度高、耐蚀性能提高的改进证明他们是必不可少的。2.1.1温度和时间目的的任何热处理工艺是通过加热到指定的温度和随后的冷却产生在金属结构所需的变化。因此，在热处理的主要因素是温度和时间，所以，任何热处理过程可以在温度时间（T）坐标表示热处理条件的特点是通过以下参数：加热温度T最大，即为合金金属加热的最高温度；在加热温度H保温时间；加热速率H和冷却速率如果加热（或冷却）是在一个恒定的速率，温度时间关系会以各自的角度