Unit 2 Selection of Construction Material构件材料的选择.docVIP

Unit 2 Selection of Construction Material 构件材料的选择 一、New words and expressions 二、Translation Selection of Construction Material 构件材料的选择 1、There is not a great difference between “this” steel and “that” steel; all are very similar in mechanical properties. “这种”钢与“那种”钢之间其实没有什么很大的区别，所有钢的机械性质都很近似。mechanical 名词机械mechanical, machinery, machine, mechanism形容词刻板inflexible, stiff, mechanical, mechanic生raw, living, green, crude, uncooked, mechanical property财产 属性 特性 性能 性质 Selection must be made on factors such as hardenability, price, and availability, and not with the idea that “this” steel can do something no other can do because it contains 2 percent instead of 1 percent of a certain alloying element, or because it has a mysterious name. 选择一定是根据诸如可淬性、价格、是否易于获得等方面的指标来做出的，而不是就因为“这种”钢含有2%的某种合金元素，所以它能完成其它只含有1%的这种合金元素的钢所无法完成的某些工作，更不是因为某种钢具有一个玄妙的名字。 hardenability 可硬化性 可硬化度 可淬性 price 价格 availability 可用性 有效性 可得性 mysterious 神秘 莫名其妙 A tremendous range of properties is available in any steel after heat treatment; this is particularly true of alloy steels. 任何一种钢经过热处理都可能获得范围极其宽泛性能指标，那些合金钢就更是如此了。 tremendous 巨大 heat treatment 热处理 Considerations in fabrication 生产方面的因素 2、The properties of the final part (hardness, strength, and machinability), rather than properties required by forging, govern the selection of material. 一个零部件最终获得的性能（诸如硬度、强度、切削性能），是源自于它材料的选择，而不是在于锻造能获得那些性能。machinability 可机加工性 可切削性 forge 锻造 govern 治理 管理 The properties required for forging have very little relation to the final properties of the material; therefore, not much can be done to improve its forgeability. 锻造要求的那些性能指标与材料最终性能的影响之间的关系非常小。因此，要改进锻造效果，已经没有多少手段了。 Higher-carbon steel is difficult to forge. 高碳钢无法锻造。 Large grain size is best if subsequent heat treatment will refine the grain size. 大尺寸晶粒最易热处理，热处理可以获得理性的晶粒尺寸。 subsequent 随后 连串 Low-carbon, nickel-chromium steels are just about as plastic at high temperature under a single 520ft·lb (1 ft·lb=1.35582J) blow as plain steels of similar