钢铁热处理中英文对照外文翻译文献

钢铁热处理中英文对照外文翻译文献
钢铁热处理中英文对照外文翻译文献

中英文对照外文翻译

(文档含英文原文和中文翻译)

原文:

Heat Treatment of Steel

Types of Heat Treating Operations Five Operations are detailed in this lesson as the basis of heat treatment. Explanations of these operations follow.

Full annealing Full annealing is the process of softening steel by a heating and cooling cycle, so that it may be bent or cut easily. In annealing, steel is heated above a transformation temperature and cooled very slowly after it has reached a suitable temperature. The distinguishing characteristics of full annealing are: (a) temperature above

the critical temperature and (b) very slow cooling, usually in the furnace.

Normalizing Normalizing is identical with annealing, except that the steel is air cooled; this is much faster than cooling in a furnace. Steel is normalized to refine grain size, make its structure more uniform, or to improve machinability.

Hardening Hardening is carried out y quenching a steel, that is, cooling it rapidly from a temperature above the transformation temperature. Steel is quenched in water or brine for the most rapid cooling, in oil for some alloy steels, and in air for certain higher alloy steels. After steel is quenched, it is usually very hard and brittle; it may even crack if dropped. To make the steel more ductile, it must be tempered.

Tempering Tempering consistes of reheating a quenched steel to a suitable temperature below the transformation temperature for an appropriate time and cooling back to room temperature. How this process makes steel tough will be discussed later.

Stress relieving Stress relieving is the heating of steel to a temperature below the transformation temperature, as in tempering, but is done primarily to relieve internal stress and thus prevent distortion or cracking during machining.

This is sometimes called process annealing.

Reasons for Heat Treating Heat treatment of steel is usually intended to accomplish any one of the following objectives:

●Remove stresses induced by cold working or to

remove stresses set up by nonuniform cooling of hot metal

objects;

●Refine the grain structure of hot worked steels

which may have developed coarse grain size;

●Secure the proper grain structure;

●Decrease the hardness and increase the ductility;

●Increase the hardness so as to increase resistance

to wear or to enable the steel to withstand more service

conditions;

●Increase the toughness; that is, to produce a steel

having both a high tensile strength and good ductility,

enabling it to withstand high impact;

●Improve the machinability;

●Improve the electrical properties;

●Change or modify the magnetic properties of steel.

Heat Treatment The hardest condition for any givens steel is obtained by quenching to a fully martensitic structure.

Since hardness is directly related to strength, a steel composed of 100% martensite is at its strongest possible condition. However, strength is not the only property that must be considered in the application of steel parts. Ductility may be equally important.

Tempering Ductility is the ability of a metal to change shape before it breaks. Fleshly quenched martensite is hard but not ductile; in fact, it is very brittle. Tempering is needed to impart ductility to the martensite, usually at a smell sacrifice in strength. In addition, tempering greatly increases the resistance of martensite to shock loading.

The effect of tempering may be illustrated as follows. If the head of a hammer were quenched to a fully martensitic structure, it probably would crack after the first few blows. Tempering during manufacture of the hammer imparts shock resistance with only a slight decrease in hardness. Tempering is accomplished by heating a quenched pert to some point below the transformation temperature, and holding it at this temperature for an hour or more, depending on its size. Most steels are tempered between 205 and 5,950C. As higher temperatures are employed, toughness or shock resistance of the steel is increased, but the hardness and strength decrease.

Annealing the two-stage heat treating process of quenching and tempering is designed to produce high strength steel capable of resisting shock and deformation without breaking. On the other hand, the annealing process is intend to make steel easier to deform of machine. In manufacturing steel products, machining and severe bending operations are often employed. Even tempered steel may not cut or bend very easily and annealing is often necessary.

Process annealing Process annealing consists of heating steel to a temperature just below the lowest transformation temperature for a short time. This makes the steel easier to form. This heat treatment is commonly applied in the sheet and wire industries, and the temperatures generally used are from 550 to 650o C.

Full annealing Process annealing, where steel is heated 50 to 100 o C above the third transformation temperature for hypoeutectoid steels, and above the lowest transformation temperature for hypereutectoid steels, and slow cooled, makes the steel much easier to cut, as well as bend. In full annealing, cooling must take place very slowly so that a coarse pearlite is formed. Show cooling is not essential for process annealing, since any cooling rate from temperatures below the lowest

transformation temperature will result in the same microstructure and hardness.

During cold deformation, steel has a tendency to harden in deformed areas, making it more difficult to bend and liable to breakage. Alternate deforming and annealing operations are performed on most manufactured steel products.

Normalizing The process of normalizing consists of heating to a temperature above the third transformation temperature and allowing the pert to cool in still air. The actual temperature required for this depends on the composition of the steel, but is usually around 870o C. Actually, the term normalize does not describe the purpose. The process might be more accurately described as a homogenizing or grain-refining treatment. Within any piece of steel, the composition is usually not uniform throughout. That is, one area may have more carbon than the area adjacent to it. These compositional differences affect the way in which the steel will respond t heat treatment. If it is heated to a high temperature, the carbon can readily diffuse throughout, and the result is a reasonably uniform composition from one area to next. The steel is then more homogeneous and will respond to the heat treatment in a more uniform way.

Because of characteristics inherent in cast steel, the normalizing treatment is more frequently applied to ingots prior to working, and to steel castings and forgings prior to hardening.

Stress Relieving When a metal is heated, expansion occurs which is more or less proportional to the temperature rise. Upon cooling metal, the reverse reaction takes place. That is, a contraction is observed. When a steel bar or plate is heated at one point more than at another, as in welding or during forging, internal stress are set up. During heating, expansion of the heated area cannot take place unhindered, and it tends to deform. On cooling, contraction is prevented from taking place by the unyielding cold metal surrounding the heated area. The forces attempting to contract the metal are not relieved, and when the metal is cold again, the forces remain as internal stresses. Stresses also result from volume changes, which accompany metal transformations and precipitation. Internal or residual stresses are bad because they may cause warping of steel parts when they are machined. To relieve these stresses, steel is heated to around 595o C, assuming that the entire pert is heated uniformly, then cooled slowly back to room temperature. This procedure is called

stress relief annealing, or merely stress relieving.

译文:

钢的热处理

各种类型的热处理本单元详细介绍了五种热处理的基本方法。这些方法如下。

完全退火完全退火是利用冷热循环使钢铁硬度下降的过程,之后它就容易被切割和弯曲。在退火时,钢被加热到相变温度上并且达到一个合适温度后就缓慢冷却。完全退火的区别其他退火的特点是:(a)温度高于临界温度(b)缓慢冷却,通常是炉冷。

正火正火与退火相同,除了钢铁的正火是空冷,这样将比在炉中冷却的快。金属进行正火是为了细化精粒,使它的组织更加规律,或提高它的机械加工性能。

淬火淬火就是钢淬火,它是将钢从临界温度以上迅速冷却。钢一般是在水中或者卤水中进行淬火,这是为了快速冷却,而另外一些合金钢用油冷,以及某些高等合金钢要用空冷。钢催后之后,一般会很硬很脆,有可能在落地后碎裂。为了是钢有更高的韧性它,必须还要经过回火

回火回火是将淬火过的钢再次加热到转变温度以下一定时间后再冷却到室温的热处理工艺。这个过程是如何使钢有高硬度之后将会讨论。

去应力去应力是加热钢到转变温度一下,如同回火一样,但

这样做主要是为了消除内应力和防止在机械加工的过程中的扭曲和变形。有时候我们也称这个过程叫做退火。

热处理的原因钢的热处理经常是为了完善如下几个方面:

消除在冷却过程中产生的应力和消除热金属处理中的应力。

细化晶粒组织,钢可能在热加工过后会产生粗大的晶粒。

获得稳定的适当的晶粒结构

降低硬度,提高塑性。

增加硬度以提高抗磨损能力或者使金属能够承受更多条件环境。、

增加韧性,这样一来,可以使钢同时拥有高拉伸性和好的延展性,使它能承受高程度的碰撞。

提高切削性能。

提高导电性。

改变钢的磁性。

热处理对于任何一种钢而言,最困难的是获得马氏体。由于硬度和强度有直接关系,钢由百分之百的马氏体组成时它处于最大强度状态。然而,强度并不是钢在应用中唯一考虑的性质,延展性同样重要。

回火可塑性是指金属在其破裂前改变形状的能力。马氏体本身具有很高硬度但延展性不高,而且易碎。回火是被用作使马氏体具有良好的可塑性,往往是牺牲了一小部分的强度。此外,回火处理大大增加了马氏体抵抗冲击负荷的能力。

机械毕业设计英文外文翻译50材料的热处理

外文资料 HEAT TREATMENT OF METALS The understanding of heat treatment is embrace by the broader study of metallurgy .Metallurgy is the physics, chemistry , and engineering related to metals from ore extraction to the final product . Heat treatment is the operation do heating and cooling a metal in its solid state to change its physical properties. According to the procedure used, steel can be hardened to resist cutting action and abrasion , or it can be softened to permit machining .With the proper heat treatment internal ductile interior . The analysis of the steel must be known because small percentages of certain elements,notably carbon , greatly affect the physical properties . Alloy steels owe their properties to the presence of one or more elements other than carbon, namely nickel, chromium , manganese , molybdenum , tungsten ,silicon , vanadium , and copper . Because of their improved physical properties they are used commercially in many ways not possible with carbon steels. The following discussion applies principally to the heat treatment of ordinary commercial steel known as plain-carbon steels .With this proves the rate of cooling is the controlling factor, produces the opposite effect . A SIMPLIFIED IRON-CARBON DAGRAM If we focus only on the materials normally known as steels, a simplified diagram is often used . Those portions of the iron-carbon diagram near the delta region and those above 2% carbon content are of little importance to the engineer and are deleted. A simplified diagram, such as the one in Fig . 2.1 focuses on the eutectoid region and is quite useful in understanding the properties and processing of steel.

流体力学中英文对照外文翻译文献

中英文对照外文翻译(文档含英文原文和中文翻译)

14选择的材料取决于于高流动速度 降解或材料由于疲劳,腐蚀,磨损和气蚀故障糜烂一次又一次导致泵运营商成本高昂的问题。这可能通过仔细选择材料的性能以避免在大多数情况下发生。一两个原因便可能导致错误的材料选择:(1)泵输送的腐蚀性液体的性质没有清楚地指定(或未知),或(2),由于成本的原因(竞争压力),使用最便宜的材料。 泵部件的疲劳,磨损,空化攻击的严重性和侵蚀腐蚀与流速以指数方式增加,但应用程序各种材料的限制,不容易确定。它们依赖于流速度以及对介质的腐蚀性泵送和浓度夹带的固体颗粒,如果有的话。另外,交变应力诱导通过压力脉动和转子/定子相互作用力(RSI)真的不能进行量化。这就是为什么厚度的叶片,整流罩和叶片通常从经验和工程判断选择。 材料的本讨论集中在流之间的相互作用现象和物质的行为。为此,在某些背景信息腐蚀和经常使用的材料,被认为是必要的,但是一个综合指南材料的选择显然是超出了本文的范围。在这一章中方法开发出促进系统和一致方法选择材料和分析材料的问题领域。四个标准有关,用于选择材料暴露于高流动速度: 1.疲劳强度(通常在腐蚀环境),由于高的速度在泵本身与高压脉动,转子/定子的相互作用力和交变应力。 2.腐蚀诱导高的速度,特别是侵蚀腐蚀。 3.气蚀,由于已广泛在章讨论。 4.磨耗金属损失造成的流体夹带的固体颗粒。 磨损和汽蚀主要是机械磨损机制,它可以在次,被腐蚀的钢筋。与此相反,腐蚀是一种化学金属,泵送的介质,氧和化学试剂之间的反应。该反应始终存在- 即使它是几乎察觉。最后,该叶轮尖端速度可以通过液压力或振动和噪声的限制。 14.1叶轮和扩散的疲劳性骨折 可避免的叶轮叶片,整流罩或扩散器叶片的疲劳断裂施加领域的状态;它们很少观察到。在高负荷的泵,无视基本设计规则或生产应用不足的医疗服务时,这种类型的伤害仍然是有时会遇到。的主要原因在静脉或罩骨折包括: ?过小的距离(间隙B或比D3*= D3/ D2)叶轮叶片之间扩散器叶片(表10.2)。 ?不足寿衣厚度。 ?不足质量:叶片和护罩之间的圆角半径缺失或过于引起的小,铸造缺陷,脆性材料(韧性不足)热处理不足。 ?可能地,过度的压力脉动引起的泵或系统,第一章。10.3。 ?用液压或声叶轮的固有模式之间共振激发。也可能有之间的一个流体- 结构交互叶轮的侧板,并在叶轮侧壁间隙流动.. 转子/定子的互动和压力脉动章中讨论。10产生交替在叶轮叶片的压力和所述整流罩以及在扩散器叶片。这些应力的准确的分析几乎是不可能的(甚至虽然各组分能很好通过有限元程序进行分析),因为叶轮由不稳定压力分布的水力负荷不能定义。它不仅取决于流在叶轮,集电极和侧壁的差距,同时也对声学现象,并可能在脉动系统(也指章。10.3)。为了开发一致的实证过程评估装载叶轮和扩散器,用于选择叶片和护罩厚度或对所述的损伤的分析中,可以使用下一个均匀的负荷的简单梁的模型作为起点。因此,封闭的叶轮或扩散器的叶片是通过夹紧在两端的梁建模。开式叶轮或扩散器的描述由光束夹紧在一端,但游离在其他。根据表14.1和14.2的计算是基于以下assumptions1: 1.考虑叶片的最后部分中,在所述叶轮出口处的束夹在两者的宽度为X =5×e和跨度L = B2(E =标称叶片端厚度没有可能配置文件)。如果刀片是异形,平均叶片厚度青霉用于确

金属材料与热处理教案

绪论 引入: 材料金属材料 机械行业本课程得重要性 主要内容:金属材料得基本知识(晶格结构及变性) 金属得性能(力学及工艺性能) 金属学基础知识(铁碳相图、组织) 热处理(退火、正火、淬火、回火) 学习方法:三个主线 重要概念 ①掌握 基本理论 ②成分 组织性能用途热处理 ③理论联系实际 引入:内部结构决定金属性能 内部结构? 第一章:金属得结构与结晶 §1-1金属得晶体结构 ★学习目得:了解金属得晶体结构 ★重点:有关金属结构得基本概念:晶面、晶向、晶体、晶格、单晶

体、晶体,金属晶格得三种常见类型. ★难点:金属得晶体缺陷及其对金属性能得影响. 一、晶体与非晶体 1、晶体:原子在空间呈规则排列得固体物质称为“晶体"。(晶体内得原子之所以在空间就是规则排列,主要就是由于各原子之间得相互吸引力与排斥力相平衡得结晶。) 规则几何形状 性能特点: 熔点一定 各向异性 2、非晶体:非晶体得原子则就是无规则、无次序得堆积在一起得(如普通玻璃、松香、树脂等)。 二、金属晶格得类型 1、晶格与晶胞 晶格:把点阵中得结点假象用一序列平行直线连接起来构成空间格子称为晶格. 晶胞:构成晶格得最基本单元 2、晶面与晶向 晶面:点阵中得结点所构成得平面。 晶向:点阵中得结点所组成得直线 由于晶体中原子排列得规律性,可以用晶胞来描述其排列特征。(阵点(结点):把原子(离子或分子)抽象为规则排列于空间得几何点,称为阵点或结点。点阵:阵点(或结点)在空间得排列方式称

晶体。) 晶胞晶面晶向 3、金属晶格得类型就是指金属中原子排列得规律。 7个晶系 14种类型 最常见:体心立方晶格、面心立方晶格、密排六方晶格 (1)、体心立方晶格:(体心立方晶格得晶胞就是由八个原子构成得立方体,并且在立方体得体中心还有一个原子)。 属于这种晶格得金属有:铬Cr、钒V、钨W、钼Mo、及α—铁α-Fe 所含原子数 1/8×8+1=2(个) (2)、面心立方晶格:面心立方晶格得晶胞也就是由八个原子构成得立方体,但在立方体得每个面上还各有一个原子。 属于这种晶格得金属有:Al、Cu、Ni、Pb(γ-Fe)等 所含原子数1/8×8+6×1/2=4(个) (3)、密排六方晶格:由12个原子构成得简单六方晶体,且在上下两个六方面心还各有一个原子,而且简单六方体中心还有3个原子。 属于这种晶格得金属有铍(Be)、Mg、Zn、镉(Cd)等。 所含原子数 1/6×6×2+1/2×2+3=6(个) 三、单晶体与多晶体 金属就是由很多大小、外形与晶格排列方向均不相同得小晶体组成得,

毕业设计外文翻译附原文

外文翻译 专业机械设计制造及其自动化学生姓名刘链柱 班级机制111 学号1110101102 指导教师葛友华

外文资料名称: Design and performance evaluation of vacuum cleaners using cyclone technology 外文资料出处:Korean J. Chem. Eng., 23(6), (用外文写) 925-930 (2006) 附件: 1.外文资料翻译译文 2.外文原文

应用旋风技术真空吸尘器的设计和性能介绍 吉尔泰金,洪城铱昌,宰瑾李, 刘链柱译 摘要:旋风型分离器技术用于真空吸尘器 - 轴向进流旋风和切向进气道流旋风有效地收集粉尘和降低压力降已被实验研究。优化设计等因素作为集尘效率,压降,并切成尺寸被粒度对应于分级收集的50%的效率进行了研究。颗粒切成大小降低入口面积,体直径,减小涡取景器直径的旋风。切向入口的双流量气旋具有良好的性能考虑的350毫米汞柱的低压降和为1.5μm的质量中位直径在1米3的流量的截止尺寸。一使用切向入口的双流量旋风吸尘器示出了势是一种有效的方法,用于收集在家庭中产生的粉尘。 摘要及关键词:吸尘器; 粉尘; 旋风分离器 引言 我们这个时代的很大一部分都花在了房子,工作场所,或其他建筑,因此,室内空间应该是既舒适情绪和卫生。但室内空气中含有超过室外空气因气密性的二次污染物,毒物,食品气味。这是通过使用产生在建筑中的新材料和设备。真空吸尘器为代表的家电去除有害物质从地板到地毯所用的商用真空吸尘器房子由纸过滤,预过滤器和排气过滤器通过洁净的空气排放到大气中。虽然真空吸尘器是方便在使用中,吸入压力下降说唱空转成比例地清洗的时间,以及纸过滤器也应定期更换,由于压力下降,气味和细菌通过纸过滤器内的残留粉尘。 图1示出了大气气溶胶的粒度分布通常是双峰形,在粗颗粒(>2.0微米)模式为主要的外部来源,如风吹尘,海盐喷雾,火山,从工厂直接排放和车辆废气排放,以及那些在细颗粒模式包括燃烧或光化学反应。表1显示模式,典型的大气航空的直径和质量浓度溶胶被许多研究者测量。精细模式在0.18?0.36 在5.7到25微米尺寸范围微米尺寸范围。质量浓度为2?205微克,可直接在大气气溶胶和 3.85至36.3μg/m3柴油气溶胶。

冲压模具技术外文翻译(含外文文献)

前言 在目前激烈的市场竞争中,产品投入市场的迟早往往是成败的关键。模具是高质量、高效率的产品生产工具,模具开发周期占整个产品开发周期的主要部分。因此客户对模具开发周期要求越来越短,不少客户把模具的交货期放在第一位置,然后才是质量和价格。因此,如何在保证质量、控制成本的前提下加工模具是值得认真考虑的问题。模具加工工艺是一项先进的制造工艺,已成为重要发展方向,在航空航天、汽车、机械等各行业得到越来越广泛的应用。模具加工技术,可以提高制造业的综合效益和竞争力。研究和建立模具工艺数据库,为生产企业提供迫切需要的高速切削加工数据,对推广高速切削加工技术具有非常重要的意义。本文的主要目标就是构建一个冲压模具工艺过程,将模具制造企业在实际生产中结合刀具、工件、机床与企业自身的实际情况积累得高速切削加工实例、工艺参数和经验等数据有选择地存储到高速切削数据库中,不但可以节省大量的人力、物力、财力,而且可以指导高速加工生产实践,达到提高加工效率,降低刀具费用,获得更高的经济效益。 1.冲压的概念、特点及应用 冲压是利用安装在冲压设备(主要是压力机)上的模具对材料施加压力,使其产生分离或塑性变形,从而获得所需零件(俗称冲压或冲压件)的一种压力加工方法。冲压通常是在常温下对材料进行冷变形加工,且主要采用板料来加工成所需零件,所以也叫冷冲压或板料冲压。冲压是材料压力加工或塑性加工的主要方法之一,隶属于材料成型工程术。 冲压所使用的模具称为冲压模具,简称冲模。冲模是将材料(金属或非金属)批量加工成所需冲件的专用工具。冲模在冲压中至关重要,没有符合要求的冲模,批量冲压生产就难以进行;没有先进的冲模,先进的冲压工艺就无法实现。冲压工艺与模具、冲压设备和冲压材料构成冲压加工的三要素,只有它们相互结合才能得出冲压件。 与机械加工及塑性加工的其它方法相比,冲压加工无论在技术方面还是经济方面都具有许多独特的优点,主要表现如下; (1) 冲压加工的生产效率高,且操作方便,易于实现机械化与自动化。这是

R180柴油机曲轴工艺及夹具外文文献翻译、中英文翻译、外文翻译

中国地质大学长城学院 本科毕业设计外文资料翻译 系别:工程技术系 专业:机械设计制造及其自动化 姓名:刘庆鹏 学号: 05211602 年月日

外文资料翻译原文 R180柴油机曲轴工艺设计及夹具设计 一、研究目的及意义 曲轴是柴油机的关键零部件之一,主要用于往复运动的机械中,与连杆配合将作用在活塞上的气体压力变为旋转的动力。而随着机械化生产逐渐成为当今主流,传统的制造工艺已经不能满足人们的需求。结合实际进行理论分析,在保证产品质量,提高生产效率,降低生产成本的的前提下,对R180柴油机曲轴工艺进行优化设计。 二、R180曲轴工艺现状 从目前的整体水平来看,R180柴油机曲轴基本都是两种材质:一是钢锻曲轴;二是球墨铸铁曲轴。根据材质选择的不同,其生产方式也不同。为了保证生产精度,铸造方式生产的曲轴已经广泛运用于R180柴油机的运行。球墨铸铁具有良好的切削性能,并且可以进行各种热处理以及表面强化处理,故球墨铸铁被广泛运用于曲轴的生产。但是,曲轴毛坯的铸造工艺生产效率低下,工艺装备参差不齐,性能不够稳定、精度低、报废率高居不下,这一系列的问题都需要优化。 从目前整体水平来看, 毛坯的铸造工艺存在生产效率低,工艺装备落后,毛坯机械性能不稳定、精度低、废品率高等问题。从以下几个工艺环节采取措施对提高曲轴质量具有普遍意义。①熔炼国内外一致认为,高温低硫纯净铁水的获得是生产高质量球铁的关键所在。为获得高温低硫磷的纯净铁水,可用冲天炉熔化铁水,经炉外脱硫,然后在感应电炉中升温并调整成分。②球化处理③孕育处理冲天炉熔化球铁原铁水,对铜钼合金球铁采用二次孕育。这对于防止孕育衰退,改善石墨形态,细化石墨及保证高强度球铁机械性能具有重要作用。④合金化配合好铜和钼的比例对形成珠光体组织十分有利,可提高球铁的强度,而且铜和钼还可大大降低球铁件对壁厚的敏感性。⑤造型工艺气流冲击造型工艺优于粘土砂造型工艺,可获得高精度的曲轴铸件,该工艺制作的砂型具有无反弹变形量的特点,这对于多拐曲轴尤为重要。⑥浇注冷却工艺采用立浇—立冷,斜浇—斜冷、斜浇—反斜冷三种浇注方式较为理想,其中后一种最好。斜浇—反斜冷的优点是:型腔排气充分,铁水充型平稳,浇注系统撇渣效果好,冒口对铸件的补缩效果好,适应大批量流水线生产。 目前,国内大部分专业厂家普遍采用普通机床和专用组合机床组成的流水线生产,生产效率、自动化程度较低。曲轴的关键技术项目仍与国外相差1~2个数量级。国外的机加工工艺大致可归纳为如下几个特点。①广泛采用数控技术和

金属材料与热处理课后习题答案

第1章金属的结构与结晶 一、填空: 1、原子呈无序堆积状态的物体叫,原子呈有序、有规则排列的物体称为。一般固态金属都属于。 2、在晶体中由一系列原子组成的平面,称为。通过两个或两个以上原子中心的直线,可代表晶格空间排列的的直线,称为。 3、常见的金属晶格类型有、和三种。铬属于晶格,铜属于晶格,锌属于晶格。 4、金属晶体结构的缺陷主要有、、、、、和 等。晶体缺陷的存在都会造成,使增大,从而使金属的提高。 5、金属的结晶是指由原子排列的转变为原子排列的过程。 6、纯金属的冷却曲线是用法测定的。冷却曲线的纵坐标表示,横坐标表示。 7、与之差称为过冷度。过冷度的大小与有关, 越快,金属的实际结晶温度越,过冷度也就越大。 8、金属的结晶过程是由和两个基本过程组成的。 9、细化晶粒的根本途径是控制结晶时的及。 10、金属在下,随温度的改变,由转变为的现象称为

同素异构转变。 二、判断: 1、金属材料的力学性能差异是由其内部组织结构所决定的。() 2、非晶体具有各向同性的特点。() 3、体心立方晶格的原子位于立方体的八个顶角及立方体六个平面的中心。() 4、金属的实际结晶温度均低于理论结晶温度。() 5、金属结晶时过冷度越大,结晶后晶粒越粗。() 6、一般说,晶粒越细小,金属材料的力学性能越好。() 7、多晶体中各晶粒的位向是完全相同的。() 8、单晶体具有各向异性的特点。() 9、在任何情况下,铁及其合金都是体心立方晶格。() 10、同素异构转变过程也遵循晶核形成与晶核长大的规律。() 11、金属发生同素异构转变时要放出热量,转变是在恒温下进行的。() 三、选择 1、α—Fe是具有()晶格的铁。 A、体心立方 B、面心立方 C、密排六方 2、纯铁在1450℃时为()晶格,在1000℃时为()晶格,在600℃时为 ()晶格。A、体心立方 B、面心立方 C、密排六方 3、纯铁在700℃时称为(),在1000℃时称为(),在1500℃时称为()。

智能照明系统的外文文献原稿和译文

智能照明系统的外文文献原稿和译文

Introduction Introduction With the continuous development of our economy, rapidly rising living standards, people working and living environment have become increasingly demanding, while the lighting system requirements have become more sophisticated, the traditional lighting technology has been a strong blow. On the one hand because of information technology and computer technology changes in lighting technology, providing technical support; the other hand, due to energy shortage, the state more and more attention on energysaving lighting, new lighting control technology to develop rapidly to meet with By energy conservation, comfort, convenience requirements. Lighting control lighting control from the traditional manual method, automated lighting control to today's intelligent lighting control. Intelligent lighting control system is based on computercontrolled alldigital platform, modular, distributed bus control system, the central processor modules communicate directly through the network bus, the bus makes use of lighting, dimming, blinds, scene control to achieve intelligent, and become a complete bus system. Can be based on changes in the external environment in the device automatically adjust the status of the bus to reach safety, energy conservation, human effects, and can use in the future, in accordance with the requirements of users through the computer Way to increase or modify the system's functionality, without having to relaying of cables, intelligent lighting control system, high reliability, flexible control, lighting control is the traditional way can not be done. The basic components and monitoring the contents of the system System The basic components and monitoring the contents of the system System components Intelligent lighting control system is usually dimmer module, switch module, input module, the control panel, liquid crystal display touch screen, smart sensors, PC interface, time management module, handheld programmer, monitoring computer (need to bridge a large network connection) and other components composition.

金属材料及热处理中英文专业词汇表

《金属材料及热处理》课程中英文专业词汇表 (第二部分) 刘国权辑录整理 主要来源:全国材料科学名词委员会与中国材料研究学会组编的《材料科学名词》文稿; 国家标准GB/T 7232-1999 “金属热处理工艺术语”等。 材料热处理基础术语 热处理 heat treatment 采用适当的方式对材料或工件进行加热、保温和冷却以获得预期的组织结构与性能的工艺。 化学热处理 chemical heat treatment 将工件置于适当的活性介质中加热、保温,使一种或几种元素渗入它的表层,以改变其化学成分、组织和性能的热处理。 表面热处理 surface heat treatment 为改变工件表面的组织和性能,仅对其表面进行热处理的工艺。 局部热处理local heat treatment, partial heat treatment 仅对工件的某一部位或几个部位进行热处理的工艺。 预备热处理 conditioning heat treatment 为调整原始组织,以保证工件最终热处理或(和)切削加工质量,预先进行热处理的工艺。 真空热处理vacuum heat treatment, low pressure heat treatment在低于1×105Pa(通常是10-1~10-3Pa)的环境中进行的热处理工艺。 光亮热处理 bright heat treatment 工件在热处理过程中基本不氧化,表面保持光亮的热处理。磁场热处理 magnetic heat treatment 为改善某些铁磁性材料的磁性能而在磁场中进行的热处理。 可控气氛热处理controlled atmosphere heat treatment 将工件置于可控制其化学特性的气相氛围中进行的热处理。如无氧化、无脱碳、无增碳(氮)的热处理。 保护气氛热处理heat treatment in protective gases 在工件表面不氧化的气氛或惰性气体中进行的热处理。 离子轰击热处理plasma heat treatment, ion bombardment, glow discharge heat treatment 在低于1×105Pa(通常是10-1~10-3Pa)的特定气氛中利用工件(阴极)和阳极之 间等离子体辉光放电进行的热处理。 流态床热处理heat treatment in fluidized beds 工件由气流和悬浮其中的固体粉粒构成的流态层中进行的热处理。 高能束热处理high energy heat treatment 利用激光、电子束、等离子弧、感应涡流或火焰等高功率密度能源加热工件的热处理工艺总称。 稳定化热处理stabilizing treatment, stabilizing 为使工件在长期服役的条件下形状、尺寸、组织与性能变化能够保持在规定范围内的热处理。 形变热处理 thermomachanical treatment 将形变强化与相变强化相结合,以提高工件综合力学性能的一种复合强韧化工艺。 热处理工艺周期 thermal cycle 通过加热、保温、冷却,完成一种热处理工艺过程的周期。预热 preheating 在工件加热至最终温度前进行的一次或数次阶段性保温的过程。 奥氏体化 austenitizing工件加热至相变临界温度以上,以全部或部分获得奥氏体组织的操作。工件进行奥氏体化的保温温度和保温时间分别称为奥氏体化温度和奥氏体化 时间。

外文翻译原文

204/JOURNAL OF BRIDGE ENGINEERING/AUGUST1999

JOURNAL OF BRIDGE ENGINEERING /AUGUST 1999/205 ends.The stress state in each cylindrical strip was determined from the total potential energy of a nonlinear arch model using the Rayleigh-Ritz method. It was emphasized that the membrane stresses in the com-pression region of the curved models were less than those predicted by linear theory and that there was an accompanying increase in ?ange resultant force.The maximum web bending stress was shown to occur at 0.20h from the compression ?ange for the simple support stiffness condition and 0.24h for the ?xed condition,where h is the height of the analytical panel.It was noted that 0.20h would be the optimum position for longitudinal stiffeners in curved girders,which is the same as for straight girders based on stability requirements.From the ?xed condition cases it was determined that there was no signi?cant change in the membrane stresses (from free to ?xed)but that there was a signi?cant effect on the web bend-ing stresses.Numerical results were generated for the reduc-tion in effective moment required to produce initial yield in the ?anges based on curvature and web slenderness for a panel aspect ratio of 1.0and a web-to-?ange area ratio of 2.0.From the results,a maximum reduction of about 13%was noted for a /R =0.167and about 8%for a /R =0.10(h /t w =150),both of which would correspond to extreme curvature,where a is the length of the analytical panel (modeling the distance be-tween transverse stiffeners)and R is the radius of curvature.To apply the parametric results to developing design criteria for practical curved girders,the de?ections and web bending stresses that would occur for girders with a curvature corre-sponding to the initial imperfection out-of-?atness limit of D /120was used.It was noted that,for a panel with an aspect ratio of 1.0,this would correspond to a curvature of a /R =0.067.The values of moment reduction using this approach were compared with those presented by Basler (Basler and Thurlimann 1961;Vincent 1969).Numerical results based on this limit were generated,and the following web-slenderness requirement was derived: 2 D 36,500a a =1?8.6?34 (1) ? ??? t R R F w ?y where D =unsupported distance between ?anges;and F y =yield stress in psi. An extension of this work was published a year later,when Culver et al.(1973)checked the accuracy of the isolated elas-tically supported cylindrical strips by treating the panel as a unit two-way shell rather than as individual strips.The ?ange/web boundaries were modeled as ?xed,and the boundaries at the transverse stiffeners were modeled as ?xed and simple.Longitudinal stiffeners were modeled with moments of inertias as multiples of the AASHO (Standard 1969)values for straight https://www.360docs.net/doc/a89740328.html,ing analytical results obtained for the slenderness required to limit the plate bending stresses in the curved panel to those of a ?at panel with the maximum allowed out-of-?atness (a /R =0.067)and with D /t w =330,the following equa-tion was developed for curved plate girder web slenderness with one longitudinal stiffener: D 46,000a a =1?2.9 ?2.2 (2) ? ? ? t R f R w ?b where the calculated bending stress,f b ,is in psi.It was further concluded that if longitudinal stiffeners are located in both the tension and compression regions,the reduction in D /t w will not be required.For the case of two stiffeners,web bending in both regions is reduced and the web slenderness could be de-signed as a straight girder panel.Eq.(1)is currently used in the ‘‘Load Factor Design’’portion of the Guide Speci?cations ,and (2)is used in the ‘‘Allowable Stress Design’’portion for girders stiffened with one longitudinal stiffener.This work was continued by Mariani et al.(1973),where the optimum trans-verse stiffener rigidity was determined analytically. During almost the same time,Abdel-Sayed (1973)studied the prebuckling and elastic buckling behavior of curved web panels and proposed approximate conservative equations for estimating the critical load under pure normal loading (stress),pure shear,and combined normal and shear loading.The linear theory of shells was used.The panel was simply supported along all four edges with no torsional rigidity of the ?anges provided.The transverse stiffeners were therefore assumed to be rigid in their directions (no strains could be developed along the edges of the panels).The Galerkin method was used to solve the governing differential equations,and minimum eigenvalues of the critical load were calculated and presented for a wide range of loading conditions (bedding,shear,and combined),aspect ratios,and curvatures.For all cases,it was demonstrated that the critical load is higher for curved panels over the comparable ?at panel and increases with an increase in curvature. In 1980,Daniels et al.summarized the Lehigh University ?ve-year experimental research program on the fatigue behav-ior of horizontally curved bridges and concluded that the slen-derness limits suggested by Culver were too severe.Equations for ‘‘Load Factor Design’’and for ‘‘Allowable Stress Design’’were developed (respectively)as D 36,500a =1?4?192(3)? ?t R F w ?y D 23,000a =1?4 ?170 (4) ? ? t R f w ?b The latter equation is currently used in the ‘‘Allowable Stress Design’’portion of the Guide Speci?cations for girders not stiffened longitudinally. Numerous analytical and experimental works on the subject have also been published by Japanese researchers since the end of the CURT project.Mikami and colleagues presented work in Japanese journals (Mikami et al.1980;Mikami and Furunishi 1981)and later in the ASCE Journal of Engineering Mechanics (Mikami and Furunishi 1984)on the nonlinear be-havior of cylindrical web panels under bending and combined bending and shear.They analyzed the cylindrical panels based on Washizu’s (1975)nonlinear theory of shells.The governing nonlinear differential equations were solved numerically by the ?nite-difference method.Simple support boundary condi-tions were assumed along the curved boundaries (top and bot-tom at the ?ange locations)and both simple and ?xed support conditions were used at the straight (vertical)boundaries.The large displacement behavior was demonstrated by Mi-kami and Furunishi for a range of geometric properties.Nu-merical values of the load,de?ection,membrane stress,bend-ing stress,and torsional stress were obtained,but no equations for design use were presented.Signi?cant conclusions include that:(1)the compressive membrane stress in the circumfer-ential direction decreases with an increase in curvature;(2)the panel under combined bending and shear exhibits a lower level of the circumferential membrane stress as compared with the panel under pure bending,and as a result,the bending moment carried by the web panel is reduced;and (3)the plate bending stress under combined bending and shear is larger than that under pure bending.No formulations or recommendations for direct design use were made. Kuranishi and Hiwatashi (1981,1983)used the ?nite-ele-ment method to demonstrate the elastic ?nite displacement be-havior of curved I-girder webs under bending using models with and without ?ange rigidities.Rotation was not allowed (?xed condition)about the vertical axis at the ends of the panel (transverse stiffener locations).Again,the nonlinear distribu-

相关文档
最新文档