英语翻译Properties of metalsMetals have properties that distingu

英语翻译
Properties of metals
Metals have properties that distinguish them from other materials.The most important of these properties is strength,or the ability to support weigh without bending or breaking.This property combined with toughness,or the ability to bend without breaking,is important.Metals also have advantages regarding resistance to corrosion.They are responsive to heat treatment.
Metal can be cast into many shapes and sizes.They can be welded,hardened,and softened.Metals also possess another important property-recycling and reuse.When a particular product is discarded,it can be cut into convenient sections.These sections can be put into a furnace,remelted,and used in another product.
The properties of metals may be classified in three categories:chemical properties,mechanical properties,and physical properties.Here we will emphasize the primary mechanical properties of metals.In understanding the related areas of metalworking and methods used today,the mechanical properties of metals are of the utmost importance.
The hardness of metals varies greatly.Some,like lead,can be indented easily.Others like tungsten carbide,approach diamond hardness.They are of great value as dies for cutting tools of various types.Heat treatment causes change in the hardness.Annealed tool steel can readily be machined.Often,this is difficult after it has been hardness and tempered.Annealed brass is comparatively soft.When cold-worked the hardness is greatly increased.
A tough metal possesses very high strength.It also has the capability to avoid deforming permanently and resist rupture.Toughness enables the metal to survive shock or impact without fracture.
The strength of a metal is its ability to resist deformation or rupture.In certain items,a combination of strength and plasticity is desirable.Machine tools are an example.

金属的性能
金属有许多特殊的性能,这种价值使他们与其他材料区别开来.其中最主要的性能就是强度,以及在不被弯曲和折断的情况下,乘载重量的能力.这种能够牢固的连接,并且能够弯曲部折断的能力是非常重要的.金属同样具有抗腐蚀的能力.他们会对加热产生反应,从而能被做成不同的形状和尺寸.他们能被熔接、凝固和软化.另外一个重要好处就是能被回收再利用.当一件金属制品被丢弃时,他能被切成便于携带的小部分,而这些小部分能被放入熔铁炉熔化,在用于其他产品的制造.
金属的功能可以被分成三个方面：化学性能,机械性能和物理性能.在此我们把重点放在金属的机械性能上.在理解相关领域的金属作业和方法的今天,了解金属机械性能是至关重要的.
不同金属的硬度差别很大.一些像铅这样的金属很容易切割.有些像碳化钨这样的金属的硬度能和钻石的硬度媲美,他们的巨大价值就是能被做成许多不同的切割工具.加热会导致硬度的变化.加热退火工艺炼钢能通过机械简单完成.通常来说,金属凝固或改变温度之后就很难加工了.加热退火的容器相对来说比较软.当被冷却之后,金属的硬度会大大提高.
坚硬的金属拥有很高的强度,同样具有防止永久变形和断裂的能力.硬度使金属不容易受震荡或折断.
金属的强度在于它承受变形和短些的能力.在某些产品上,拥有强度和韧性的材料是理想的材料.机床就是个例子.