材料成型级控制重点工程专业英语阅读.docx

1、材料成型级控制重点工程专业英语阅读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 （供应）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 sho

2、uld have the properties as specified by State Standards（国标）钢铁制造车间供应热轧钢重要为棒材、柱材、板材、管材等，热轧钢是制造各种机械、机器工具、建筑构造和消费品中应用最广泛材料。所供应钢应具备国标规定各种性能。 In the RSSUPlain carbon steels are classified into three groups：A，B and C，depending on their application. 在RSSU中，普通碳钢依照其用途分为A、B、C三类。A： If a steel is to be used for

3、making 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

4、果钢在制造产品过程中没有进行热加工（焊接、锻造等），则最后产品组织和性能将与轧厂提供相似。这种状况下，顾客只需规定材料应有机械性能，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变化。此时/在这种状况下，钢成分对顾客来讲是最重要，由于它(成分)决定了热加工条件，钢制品最后机械性能。因而，提供应顾客钢应保证其成分含量。C：If a steel is to be weldedthe user wan

6、ts 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 welding

7、In that case the metal is delivered with warranted composition and mechanical properties.C如果钢要进行焊接，则顾客需要懂得钢成分，由于成分决定钢焊接时热影响区性能。顾客也会对钢材原始机械性能感兴趣，由于未焊接某些性能是原始性能。这种状况下，供应顾客钢应具备规定成分和机械性能。General-purpose plain steels are not alloyedSome alloying elements may sometimes be present in them occasionally and

8、their content（含量） is limited非特殊用途/普通用途普通钢不是合金钢。某些合金元素偶尔会浮现，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 affect the qual

9、ity of steel 在钢冶炼过程中由于脱氧需要，会浮现硅和锰。硫、磷是钢中有害杂质，应尽量减少其含量，它们会影响钢质量。The principal element whose content is responsible for the properties of steels is carbon 影响钢性能最重要元素是碳。1.3Non-ferry AlloysAlthough ferrous alloys ale used in the majority of metallic applications in current engineering designs，nonferrous

10、 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尽管当代工业设计中，铁合金是重要应用金属，但是非铁合金在当前科技中也起着很大并不可代替作用。固然，与铁合金相比，非铁合金种类

11、多且复杂。咱们将简要简介几种非铁合金及其重要特性。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 periodOre reserves for alum

12、inum 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、易加工以及好外观也是其具备吸引力特性。基于以上特点，近来铝合金产量几乎翻了一番。铝矿石产量很大（占地壳8），并且铝是可以回收。Magnesium alloys have even lower density than aluminum and，as a result，appear in numerous structural applications such as aerospac

13、e 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镁合金密度比铝合金还低，因而，设计航空飞行器时大量构造件用镁合金。铝合金是面心立方构造金属，因而，有12个滑移系，使其延展性好。相反，镁合金是密排六方构造，仅有3个滑移系，易脆断（具备脆性）。Titanium al

14、loys 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 surface，giving excellent resistance to

15、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，leading to numerous aerospace design appli

16、cations. 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.二战后来钛合金被广泛应用，在此之前，还没有通过活性氧和硝酸盐分离钛金属工艺。一旦形成钛合金，钛活性显现出其长处。其表面形成致密氧化膜，使其就有优良抗腐蚀性。“钝化性”将在背面详细讨论。与Al、Mg同样，钛合金密度比铁低。尽管密度要比Al、Mg高，钛合金明显特点之一是在中档服役温度下能保持其强度，因而航天中应用多。与镁合金同样，钛合金也是Hcp晶格构造，延展性低。