| 词或词组 | 中文 | 英文解释中文解释 |
|---|---|---|
| Machine screw | 机械螺丝 |
A countersunk, slotted screw with machined threads such as are found on bolts. A relatively small screw, usually less than 20 mm in diameter, with the thread running along the whole length up to the head, intended to be screwed into threaded holes. If inserted through plain holes in assembled parts and held together by a nut, an undesirable contact surface of threads bearing against the surface of a hole results. 带有机加工螺纹的沉头开槽螺钉，如螺栓上的螺纹。一种相对较小的螺钉，直径通常小于20毫米，螺纹沿整个长度一直延伸到头部，用于拧入螺纹孔中。如果通过装配零件上的平孔插入并用螺母固定在一起，则会导致螺纹与孔表面接触不良。 |
| Engineering strain (e) | 工程应变（e） |
A term sometimes used for average linear strain or conventional strain in order to differentiate it from true strain. In tension testing it is calculated by dividing the change in the gage length by the original gage length. 一个术语，有时用于平均线性应变或常规应变，以便将其与真实应变区分开来。在张力测试中，通过将标距变化除以原始标距来计算。 |
| Roughness | 粗糙度 |
The deviations from the wavy surface itself, caused by geometry of the cutting tool and its wear, machining conditions, microstructure of the workpiece, vibrations in the system, and so on. Surface roughness changes as a surface goes through the wearing-in process, but may then stabilize. 由刀具的几何形状及其磨损、加工条件、工件的微观结构、系统中的振动等引起的与波状表面本身的偏差。表面粗糙度随着表面经过磨合过程而变化，但随后可能会稳定下来。 |
| Auxiliary power unit (APU) | 辅助动力装置（APU） |
In aircraft–gas–turbine applications, a small gas turbine used to provide start-up power, electrical and hydraulic power, and compressed air for cabin ventilation. In other applications, an APU may be a gas turbine or internal-combustion engine used to provide emergency power. 在飞机-燃气轮机应用中，小型燃气轮机用于提供启动动力、电力和液压动力以及用于机舱通风的压缩空气。在其他应用中，APU可以是用于提供应急动力的燃气轮机或内燃机。 |
| Compression member | 压缩构件 |
A structural component, the major loading on which is compressive. 一种结构部件，其上的主要载荷是压缩的。 |
| Maximum allowable operating pressure (Unit Pa) | 最大允许使用压力（单位Pa） |
The highest pressure at which any pressure system may be operated, usually 10 to 20% below the maximum allowable working pressure. 任何压力系统可运行的最高压力，通常比最大允许工作压力低10%至20%。 |
| Absolute rating | 绝对标称值 |
A theoretical size designation which is an estimation of the largest particle, by length, that can pass through a filter with a specific 一个理论尺寸名称，它是按长度估算的最大颗粒，它可以通过具有特定过滤器的过滤器 |
| Median fatigue strength at N cycles | N次循环的中位疲劳强度 |
An estimate of the stress level at which 50% of the population would survive N cycles. The estimate is derived from a particular point of the fatigue life distribution, because there is no test procedure by which a frequency distribution of fatigue strengths at Ncycles can be directly observed. 估计50%的量在N个周期内生存的压力水平。该估计值来自疲劳寿命分布的一个特定点，因为没有试验程序可以直接观察N次循环疲劳强度的频率分布。 |
| Alloying element | 合金元素 |
Component added deliberately with the aim of improving the properties of an alloy. Alloying elements can affect the existence range of equilibrium phases present in an unalloyed material, or lead to the occurrence of new phases, or both. In addition, alloying elements strongly affect the kinetics of phase transformations and thus the microstructure formation in alloyed materials. 为改善合金性能而有意添加的成分。合金元素可以影响非合金材料中存在的平衡相的存在范围，或导致新相的出现，或两者兼而有之。此外，合金元素强烈影响相变动力学，从而影响合金材料的微观结构形成。 |
| International Bureau of Weights and Measures | 国际度量衡局IBWM |
(BIPM, Bureau International des Poids et Mesures) The intergovernmental organization which has the mandate to provide the basis for a single, coherent system of measurements, traceable to the International System of Units. （BIPM，国际计量局）政府间组织，其任务是为可追溯到国际单位制的单一、一致的计量系统提供基础。 |
| Tightness | 紧密度 |
A measure of the mass leak rate from a gasketed joint. 垫圈接头质量泄漏率的测量值。 |
| Turn-of-nut | 转动螺母 |
Sometimes used to describe the general rotation of the nut (or bolt head) as the fastener is tightened. More often used to define a particular tightening procedure in which a fastener is first tightened with a preselected torque, and is then tightened further by giving the nut an additional, measured, turn such as ‘‘three flats’’ (180°). 有时用于描述紧固件拧紧时螺母（或螺栓头）的总体旋转。更常用于定义一种特定的紧固程序，在该程序中，首先以预选扭矩拧紧紧固件，然后通过使螺母额外转动，如“三平面”（180°）进一步拧紧。 |
| Vacuum carburizing | 真空渗碳 |
A high-temperature gas carburizing process using furnace pressures between 7 and 55 kPa during the carburizing portion of the cycle. 在循环的渗碳部分期间使用7至55kPa之间的炉压的高温气体渗碳工艺。 |
| Tangential load (Unit N) | 切向荷载（单位：N） |
The component of load applied to an object, such as a gear, that tends to cause or resist rotation. 旋转力施加在物体上的载荷分量，如齿轮，倾向于引起或阻止旋转。 |
| Ferritic decarburization | 铁素体脱碳 |
Decarburization with sufficient loss of carbon to cause a lighter shade of tempered martensite and a significantly lower hardness than that of the adjacent base metal, with the presence of ferrite grains or grain boundary network under metallographic examination. 脱碳，碳损失充分，导致回火马氏体颜色较浅，硬度明显低于相邻母材，金相检查时存在铁素体晶粒或晶界网络。 |
| Serrations | 锯齿 |
A row of notches or tooth-like projections on an edge or surface. On an engineering drawing, serrations on the surface of a circular component are shown over about 60° of arc. 边缘或表面上的一排凹口或齿状突起。在工程图纸上，圆形部件表面的锯齿超过约60°的圆弧。 |
| U-bend | U形管 |
U-bend A 180° bend in a pipe. 180°弯曲的管道。 |
| Shear fracture | 剪切断裂 |
A ductile fracture in which a crystal (or a polycrystalline mass)has separated by sliding or tearing under the action of shear stresses. Contrast with cleavage fracture. 在剪切应力作用下，晶体（或多晶块）通过滑动或撕裂而分离的韧性断裂。与解理断裂形成对比。 |
| Equation, short form | 方程式，简写形式 |
An empirical equation which relates the torque applied to the bolt to the preload created in it, and which depends mainly on an experimentally derived factor called the Nut factor. 一个经验公式，将施加在螺栓上的扭矩与螺栓中产生的预载荷联系起来，主要取决于一个称为螺母系数的实验得出的系数。 |
| Fastener | 紧固件 |
A fastener is a mechanical device for holding two or more bodies in definite positions with respect to each other. 紧固件是一种机械装置，用于将两个或多个物体相对于彼此固定在确定的位置。 |
| Sizing | 颗粒化 |
1. A finishing operation to ensure the specified dimensions and tolerances for a component are met. 2. (size classification) Separating an aggregate of mixed particles into groups according to size using a series of screens. 1.精加工操作，以确保满足部件的规定尺寸和公差。2.（粒度分类）使用一系列筛网根据粒度将混合颗粒的聚集体分成组。 |
| Graphitization | 石墨化 |
Formation of graphite in iron or steel. Where graphite is formed during solidification, the phenomenon is called primary graphitization; where formed later by heat treatment, secondary graphitization. 在铁或钢中形成石墨。在凝固过程中形成石墨的现象称为一次石墨化；后来通过热处理，形成二次石墨化。 |
| Heat capacity (C) (Unit J/K) | 热容量（C）（单位J/K） |
The energy required to raise the temperature of a body by 1K without change of phase. Heat capacity is an extensive thermodynamic property dependent on temperature and pressure. 在不发生相变的情况下将物体的温度提高1K所需的能量。热容量是一种广泛的热力学性质，取决于温度和压力。 |
| Initial preload | 初始预载 |
The tension created in a single bolt as it is tightened. Will usually be modified by subsequent assembly operations or by in-service loads and conditions. 拧紧单个螺栓时产生的张力。通常会通过后续的装配操作或在役负载和条件进行修改。 |
| Induction tempering | 感应回火 |
Tempering of steel using low-frequency electrical induction heating. 钢的回火采用低频电感应加热。 |
| Nanotechnology | 纳米技术 |
The science and engineering of materials that have been structured on length scales of 1–100 nm, resulting in modified physical properties owing to changes in the ratio of surface area to volume (atoms on surfaces having different symmetry from those in the bulk) and because many of the fundamental physical processes that underpin the properties of materials have a characteristic length scale of a few nm, so that alteration of microstructure at the nm level alters the bulk properties. 材料科学与工程，其结构长度为1-100nm，由于表面积与体积之比的变化（表面上的原子与体中的原子具有不同的对称性），并且支撑材料性质的许多基本物理过程具有几纳米的特征长度尺度，因此改变纳米级微观结构会改变体性质。 |
| Fatigue | 疲劳 |
The phenomenon leading to fracture under repeated or fluctuating stresses having a maximum value less than the ultimate tensile strength of the material. Fatigue failure generally occurs at loads that, applied statically, would produce little perceptible effect. Fatigue fractures are progressive, beginning as minute cracks that grow under the action of the fluctuating stress. A term referring, in components and structures subjected to either random or cyclic periodically-varying loads, to a progressive reduction in strength leading to failure at stresses lower than those that cause failure under monotonic loading. Variable loads arise from outof-balance machinery and other vibration sources, wind gusts, etc., and a large proportion of service failures is caused by fatigue. Fatigue results from the initiation and slow propagation of cracks. In manufactured components, crack initiation usually occurs at a point of stress concentration. After a period, often of millions of stress cycles, the crack reaches a critical length at which the next peak load causes sudden brittle or ductile fracture. Fracture surfaces resulting from fatigue display characteristic striations or progression marks emanating from the crack initiation site during the slow crack growth period, with a different surface appearance for the final fracture. 在最大值小于材料极限抗拉强度的重复或波动应力下导致断裂的现象。疲劳失效通常发生在静态施加的载荷下，不会产生明显影响。疲劳断裂是渐进性的，从在波动应力作用下生长的微小裂纹开始。在承受随机或周期性变化载荷的部件和结构中，指强度逐渐降低，导致在低于单调载荷下导致失效的应力下发生失效的术语。可变负载由失衡的机械和其他振动源、阵风等引起，大部分故障是由疲劳引起的。疲劳是裂纹萌生和缓慢扩展的结果。在制造部件中，裂纹萌生通常发生在应力集中点。在一段时间（通常是数百万次应力循环）后，裂纹达到临界长度，此时下一个峰值载荷会导致突然脆性或韧性断裂。疲劳产生的断裂表面在缓慢裂纹扩展期间显示出从裂纹萌生部位发出的特征条纹或进展标记，最终断裂的表面外观不同。 |
| Safety valve (safety-relief valve) | 安全阀（安全泄压阀） |
A mechanical valve, fitted by law to all pressure vessels (e.g. steam boilers), which opens to prevent the internal pressure exceeding the maximum design value for that vessel. The valve closes again once the pressure reduces to a safe level. 根据法律安装在所有压力容器（如蒸汽锅炉）上的机械阀，其打开以防止内部压力超过该容器的最大设计值。一旦压力降至安全水平，阀门将再次关闭。 |
| Shear strain | 剪切应变 |
The tangent of the angular change, as a response to force, between two lines originally perpendicular to each other through a point in a body. Also known as shearing strain. 角变化的切线，作为对力的响应，在两条原本通过物体中的一个点相互垂直的线之间。也称为剪切应变。 |
| Feather key | 滑键 |
A parallel key fastened in either the shaft or in the hub of a member sliding on it. When fastened in the shaft, it must be long enough to hold or drive the sliding member in any of its positions on the shaft. When in the sliding member the key need only be as long as the hub. 一种平行键，固定在轴上或在其上滑动的构件的轮毂上。当固定在轴上时，其长度必须足以将滑动构件固定或驱动在轴上的任何位置。当处于滑动构件中时，键只需与轮毂一样长。 |
| Congruent melting point (Unit K) | 全等熔点（单位K） |
congruent melting point (Unit K) The temperature at which a solid substance at a specified pressure changes phase to a liquid of identical composition. 一致的熔点（单位K）固体物质在特定压力下相变为具有相同成分的液体时的温度。 |
| Rockwell hardness number (HR) | 洛氏硬度值（HR） |
A number derived from the net increase in the depth of impression in a Rockwell hardness test as the load on an indenter is increased from a fixed minor load to a major load and then returned to the minor load. Rockwell hardness numbers are always quoted with a scale symbol representing the penetrator, load, and dial used. 当压头上的载荷从固定的小载荷增加到大载荷，然后返回到小载荷时，洛氏硬度试验中压痕深度的净增加值。洛氏硬度值总是用刻度符号引用，表示所用的穿透器、载荷和刻度盘。 |
| Vector | 矢量 |
Any physical quantity, such as velocity, acceleration, force, or momentum, that is specified in terms of both its magnitude and its direction. The convention of printing vector quantities in boldface was introduced by the physicist Josiah Willard Gibbs. 任何物理量，如速度、加速度、力或动量，以其大小和方向来表示。用黑体印刷矢量量的惯例是由物理学家约西亚·威拉德·吉布斯提出的。 |
| Nipple | 喷嘴 |
A device containing a non-return valve screwed into a lubrication point through which grease may be introduced, for example into a bearing. 一种包含止回阀的装置，该止回阀拧入润滑点，通过该润滑点可以将润滑脂引入，例如轴承中。 |
| Engine emissions | 发动机排放 |
(exhaust emissions) The pollutants contained in the exhaust gases from an internal-combustion engine. （废气排放）内燃机废气中所含的污染物。 |
| Grain coarsening | 晶粒粗化 |
A heat treatment that produces excessively large austenitic grains. 产生过大奥氏体晶粒的热处理。 |
| Tolerance limits | 公差极限 |
The extreme values (upper and lower) that define the range of permissible variation in size or other quality characteristic of a part. 定义零件尺寸或其他质量特性允许偏差范围的极值（上限和下限）。 |
| Transmission | 传输 |
The system that transmits power and torque from a power source; for example a shaft, belts and pulleys, or a gear train. In the case of a motor vehicle, it includes the gearbox, clutch, propeller shaft, differential and final drive shafts. 从动力源传输功率和扭矩的系统；例如轴、皮带和滑轮或齿轮系。对于机动车辆，包括变速箱、离合器、传动轴、差速器和终传动轴。 |
| Sound pressure (Unit μPa) | 声压（单位：μPa） |
The instantaneous deviation of pressure from the ambient pressure caused by the passage of a sound wave, which can be measured by a microphone in air and a hydrophone in water. 声波传播引起的压力与环境压力的瞬时偏差，可通过空气中的麦克风和水中的水听器测量。 |
| Calorizing | 热化 |
Imparting resistance to oxidation to an iron or steel surface by heating in aluminum powder at 800 to 1000 °C (1470 to 1830 °F). 通过在800至1000°C（1470至1830°F）下加热铝粉，赋予铁或钢表面抗氧化性。 |
| Single-shear test | 单剪试验 |
(1) A shear test similar to the double-shear test used for round-bar specimens, but that uses only one stationary shear blade. (2) A shear test that uses a sheet or thin-plate specimen. （1）一种剪切试验，类似于用于圆棒试样的双剪切试验，但仅使用一个固定剪切刀片。（2）使用薄板或薄板试样的剪切试验。 |
| Stabilizing treatment | 稳定化处理 |
(1) Before finishing to final dimensions, repeatedly heating a ferrous or nonferrous part to or slightly above its normal operating temperature and then cooling to room temperature to ensure dimensional stability in service. (2) Transforming retained austenite in quenched hardenable steels, usually by cold treatment. (3) Heating a solution-treated stabilized grade of austenitic stainless steel to 870 to 900 °C (1600 to 1650 °F) to precipitate all carbon as TiC, NbC, or TaC so that sensitization is avoided on subsequent exposure to elevated temperature. （1）在精加工至最终尺寸之前，反复加热含铁或非铁零件至或略高于其正常工作温度，然后冷却至室温，以确保使用中的尺寸稳定性。（2）在淬火可淬硬钢中转变残余奥氏体，通常通过冷处理。（3）将固溶处理的稳定等级奥氏体不锈钢加热至870至900°C（1600至1650°F），使所有碳沉淀为TiC、NbC或TaC，从而避免在随后暴露于高温时敏化。 |
| Fretting corrosion | 微动腐蚀 |
(1) The accelerated deterioration at the interface between contacting surfaces as the result of corrosion and slight oscillatory movement between the two surfaces. (2) A form of fretting in which chemical reaction predominates. Fretting corrosion is often characterized by the removal of particles and subsequent formation of oxides, which are often abrasive and so increase the wear. Fretting corrosion can involve other chemical reaction products, which may not be abrasive. （1）由于两个表面之间的腐蚀和轻微振荡运动，接触表面之间的界面加速劣化。（2）一种以化学反应为主的微动磨损形式。微动腐蚀通常以颗粒的去除和随后形成的氧化物为特征，这些氧化物通常具有研磨性，因此会增加磨损。微动腐蚀可能涉及其他化学反应产物，这些化学反应产物可能不是磨料。 |
| Atmospheric pressure | 气压 |
The downward force exerted by the atmosphere because of its weight, (gravitational attraction to the Earth), measured by barometers, and usually expressed in units of millibars. Standard atmospheric pressure at sea level is 1013.25 mb.expressed in units of millibars. Standard atmospheric pressure at sea level is 1013.25 mb. 大气由于其重量（对地球的引力）而施加的向下的力，用气压计测量，通常以毫巴为单位表示。海平面的标准大气压为1013.25mb。以毫巴为单位表示。海平面的标准大气压为1013.25mb。 |
| Contact strength (Unit N) | 接触强度（单位N） |
The maximum allowable load between contacting bodies converted into a stress. 换算成应力的接触体之间的最大允许载荷。 |
| Submerged-electrode furnace | 浸入式电极炉 |
A furnace used for liquid carburizing of parts by heating molten salt baths with the use of electrodes submerged in the ceramic lining. 一种通过使用浸入陶瓷衬里中的电极加热熔融盐浴对零件进行液体渗碳的炉。 |
| Three-quarters hard | 四分之三硬度 |
A temper of nonferrous alloys and some ferrous alloys characterized by tensile strength and hardness about midway between those of half hard and full hard tempers. 一种非铁合金和一些铁合金的回火，其特征是抗拉强度和硬度介于半硬回火和全硬回火之间。 |
| Bypass ratio | 旁路比 |
In a turbofan engine, the ratio of the mass flow rate of the bypass stream to the mass flow rate through the core of the engine. 在涡扇发动机中，旁通流的质量流量与通过发动机核心的质量流量之比。 |
| Stress amplitude | 应力幅值 |
One-half the algebraic difference between the maximum and minimum stress in one cycle of a repetitively varying stress. 重复变化应力的一个循环中最大和最小应力之间代数差的一半。 |
| Plug | 螺塞 |
1. An object, usually tapered, used to block a hole to prevent fluid from escaping or flowing. 2. The central moveable part of a valve. 3. In the flow of a yield-stress fluid through a pipe or duct, the central region is often assumed to take the form of a plug with uniform axial velocity. 4. In thermoforming, a shaping tool that forces a heated plastic sheet into a female mould. 1.一种物体，通常为锥形，用于堵塞孔以防止流体逸出或流动。2.阀门的中心可移动部分。3.在屈服应力流体通过管道或管道的流动中，中心区域通常假定为具有均匀轴向速度的塞子形式。4.在热成型技术中，一种成型工具，将加热的塑料板压入阴模中。 |
| Intergranular cracking | 沿晶断裂 |
Cracking or fracturing that occurs between the grains or crystals in a polycrystalline aggregate. Also called intercrystalline cracking. 多晶聚集体中的晶粒或晶体之间发生的开裂或断裂。也称为晶间断裂。 |
| Micrometer | 千分尺 |
(micrometer gauge) A mechanical-contact device for the accurate measurement of the length, width, diameter, etc. of an object, the depth of a hole, the height of a step, etc. The usual arrangement is a spindle that is moved by rotation of a thimble, the distance then being read off a vernier scale. （千分尺）一种机械接触装置，用于精确测量物体的长度、宽度、直径等、孔的深度、台阶的高度等。通常的布置是通过顶针的旋转移动主轴，然后通过游标尺读取距离。 |
| Concurrent engineering | 并行工程 |
The integration of the procedures for product design, material selection and manufacturing method to include life-cycle analysis. 产品设计、材料选择和制造方法程序的整合，包括生命周期分析。 |
| Coalescence | 聚结 |
Growth of grains at the expense of the remainder by absorption or the growth of a phase or particle at the expense of the remainder by absorption or reprecipitation. 通过吸收以牺牲剩余为代价的晶粒的生长或以通过吸收或再沉淀为代价的以剩余为代价的相或颗粒的生长。 |
| Turbocharging | 涡轮增压 |
A method of supercharging in which the hot exhaust gas from a piston engine is used to drive a turbine which powers the supercharging compressor. A turbocharger is the turbine/compressor combination. The compressor is usually of radial outflow design while radial, axial, and mixed-flow turbines are all in use. The wastegate is a valve that reduces the flow of exhaust gas into the turbine to limit the boost produced or overspeeding. Not shown in the diagram are bearings, oil passages, etc. 一种增压方法，其中活塞发动机的热废气用于驱动涡轮，涡轮为增压压缩机提供动力。涡轮增压器是涡轮/压缩机组合。压缩机通常为径向流出设计，而径向、轴向和混流式涡轮机都在使用。废气旁通阀是一种减少进入涡轮的废气流量以限制产生的增压或超速的阀。 |
| Mechanical units | 机械单位 |
The units of physical quantities, the dimensions of which includemass, length, and time. 物理量的单位，其量纲包括质量、长度和时间。 |
| Precipitation heat treatment | 沉淀热处理 |
Artificial aging in which a constituent precipitates from a supersaturated solid solution. 成分从过饱和固溶体沉淀的人工时效。 |
| Two-dimensional flow | 二维流 |
A fluid flow in which the velocity at any time depends upon two spatial coordinates, such as the radial and axial locations in developing pipe flow. 一种流体流动，其中任何时候的速度取决于两个空间坐标，如发展中的管道流中的径向和轴向位置。 |
| Pitch-circle diameter (Unit m) | 节圆直径（单位：m） |
The diameter of the circle (the pitch circle) centred on a component’s axis, around which holes or bolts are equally spaced. 以部件轴为中心的圆（节圆）的直径，孔或螺栓围绕其等距分布。 |
| Scragging machine | 刮擦机 |
1. A machine to test springs by impulsive loading 2. A machine to increase the service life of coil springs by compressing them to their minimum solid length before use, thereby inducing favourable residual stresses. 1.一种通过冲击载荷测试弹簧的机器2.一种在使用前将螺旋弹簧压缩至其最小实心长度以提高其使用寿命的机器，从而产生有利的残余应力。 |
| Creep modulus (Unit Pa) | 蠕变模量（单位Pa） |
The ratio of stress/strain at a chosen strain level obtained from creep tests, often plotted against time to show changes in stiffness. 从蠕变测试中获得的选定应变水平下的应力/应变比，通常随时间绘制以显示刚度的变化。 |
| Endurance | 耐力 |
The capacity of a material to withstand repeated application of stress. 材料承受反复施加应力的能力。 |
| Lockbolt | 锁紧螺栓 |
A fastener which bears a superficial resemblance to a bolt, but which engages a collar (instead of a nut) with annular grooves (instead of threads). The collar is swaged over the grooves on the male fastener to develop preload. 表面上类似于螺栓的紧固件，但与环槽（而不是螺纹）接合的轴环（而不是螺母）。套环在阳紧固件上的凹槽上锻造，以产生预紧力。 |
| Abelian group | 阿贝尔群 |
Property of a group of elements associated with a binary operation. In an Abelian group, the group elements commute under the binary operation. If a and b are any two group elements and if the (+) sign denotes the binary operation, then, for an Abelian group, 与二元运算相关的一组元素的属性。在阿贝尔群中，群元素在二元运算下交换。如果a和b是任意两个群元素并且（+）符号表示二元运算 |
| Stress wave | 应力波 |
An unbalanced force, such as an impact, applied at one location in a body sets the material there into vibration that is transmitted to adjacent elements and ultimately to all parts of the body in the form of stress waves or wave packets. 施加在物体某个位置的不平衡力（如冲击力）会使物体中的材料产生振动，并以应力波或波包的形式传递到相邻元件，最终传递到物体的所有部位。 |
| Significance level | 显着性水平 |
The stated probability (risk) that a given test of significance will reject the hypothesis that a specified effect is absent when the hypothesis is true. 当假设为真时，给定的显著性检验将拒绝特定效应不存在的假设的所述概率（风险）。 |
| Oxidizing agent | 氧化剂 |
A compound that causes oxidation, thereby itself becoming reduced. 一种引起氧化从而自身被还原的化合物。 |
| Bearing stress | 承受应力 |
The force per unit of bearing area. 每单位承载面积的力。 |
| Teeth | 齿 |
The projecting elements on gears, cutting tools, etc. 齿轮、刀具等上的突出元件。 |
| Caustic cracking | 苛性开裂 |
A form of stress-corrosion cracking most frequently encountered in carbon steels or iron-chromiumnickel alloys that are exposed to concentrated hydroxide solutions at temperatures of 200 to 250 °C (400 to 480 °F). Also known as caustic embrittlement. 在200至250°C（400至480°F）的温度下暴露于浓氢氧化物溶液中的碳钢或铁铬镍合金中最常遇到的一种应力腐蚀开裂形式。也称为碱脆。 |
| Young’s modulus | 杨氏模量 |
A term used synonymously with modulus of elasticity. The ratio of tensile or compressive stresses to the resulting strain. 与弹性模量同义的术语。拉伸或压缩应力与产生应变的比率。 |
| Quarter hard | （1/4H）低硬（回火） |
A temper of nonferrous alloys and some ferrous alloys characterized by tensile strength aboutmidway between that of dead soft and half hard tempers. 非铁合金和某些铁合金的一种回火，其特点是抗拉强度介于软态和半硬态之间。 |
| Abradant | 研磨剂 |
The differently sized grits of hard materials such as emery employed for grinding, polishing, etc. The abrasive grade is determined by the grit size (grit number) originally related to the hole sizes in wire sieves. 用于研磨、抛光等的硬质材料（例如金刚砂）的不同尺寸粒度。磨料等级由最初与金属丝筛孔尺寸相关的粒度（粒度数）决定。 |
| Shore hardness | 肖氏硬度 |
A measure of the hardness of materials such as elastomers, plastics, and rubbers determined using a Shore durometer which measures the penetration depth of a hardened steel rod (the indenter) 1.1–1.4 mm in diameter into the test material for a given force applied rapidly with a calibrated spring. There are two main indenter designs: type A (for softer materials) for which the end of the rod is a truncated 35° cone tapering to a diameter of 0.79 mm, and type D (harder materials) for which the end is a 30° cone with a 0.1 mm radius tip. The spring force is 8.05 N for type A and 44.45 N for type D. The hardness value is related to the penetration depth (limited to a maximum of 2.5 mm) such that for zero penetration the hardness is 100 and for maximum penetration the hardness is zero. The relevant standards are ISO 48-1, 48-4, and 48-7. Shore hardness values of selected materials are as follows: ABS 100, cellulose acetate 50–95, high-density polyethylene 60–70, low density polyethylene 40–50, polymethylmethacrylate 90–99, PTFE 50–65, and plasticized PVC 15–70. 使用肖氏硬度计测量弹性体、塑料和橡胶等材料的硬度，肖氏硬度仪测量直径为1.1–1.4mm的硬化钢棒（压头）在用校准弹簧快速施加的给定力下渗入试验材料的深度。有两种主要的压头设计：A型（适用于较软的材料），其杆端为截头35°锥形，逐渐变细至直径0.79 mm；D型（较硬的材料），端部为30°锥形，尖端半径为0.1mm。A型的弹簧力为8.05N，D型为44.45N。硬度值与渗透深度相关（最大限制为2.5mm），因此，对于零渗透，硬度为100，对于最大渗透，硬度是零。相关标准为ISO 48-1、48-4和48-7。所选材料的肖氏硬度值如下：ABS100、醋酸纤维素50-95、高密度聚乙烯60-70、低密度聚乙烯40-50、聚甲基丙烯酸甲酯90-99、PTFE50-65和塑化PVC15-70。 |
| Nano machining | 纳米加工 |
The machining of silicon chips typically less than 1 nm thick. 硅芯片的加工通常小于1nm厚。 |
| Coefficient of discharge (CD) | 流量系数（CD） |
For flow through a nozzle or orifice plate, the ratio of the actual mass flow rate to the theoretical mass flow rate calculated assuming the flow to be isentropic. The coefficient of velocity (velocity coefficient) is the corresponding ratio of the actual average velocity to the theoretical value. For incompressible flow, the theoretical flow rate and velocity can be calculated using Bernoulli’s equation. 对于通过喷嘴或孔板的流量，实际质量流量与假设流量为等熵计算的理论质量流量之比。速度系数（速度系数）是实际平均速度与理论值的对应比。对于不可压缩流，可以使用伯努利方程计算理论流量和速度。 |
| Pitch | 沥青节距 |
The nominal distance between two adjacent thread roots or crests. In screw threads, the distance from a point on one thread to a corresponding point on the next thread measured parallel to the axis. In the case of spur gears, indicates the size of the gear teeth and is correctly called diametral pitch. 两个相邻螺纹根部或顶部之间的标称距离。在螺纹中，从一根螺纹上的一点到下一根螺纹对应点的距离，平行于轴线测量。对于正齿轮，表示齿轮齿的尺寸，正确地称为径向节距。 |
| Ratchet marks | 棘轮痕 |
Lines on a fatigue fracture surface that result from the intersection and connection of fatigue fractures propagating from multiple origins. Ratchet marks are parallel to the overall direction of crack propagation and are visible to the unaided eye or at low magnification. 疲劳断裂面上由从多个源头传播的疲劳断裂的交叉和连接产生的线。棘轮标记与裂纹扩展的整个方向平行，肉眼或低倍镜下均可看到。 |
| Mechanical energy (Unit J) | 机械能（单位J） |
The sum of kinetic energy and potential energy for an object or a mechanical system, including the energy stored in springs, etc. 物体或机械系统的动能和势能之和，包括储存在弹簧等中的能量。 |
| Fin neck carriage bolt | 翼颈圆头方颈螺栓 |
A plain, circular, oval head bolt with two oppositely located fins to prevent rotation. 一种普通的圆形椭圆头螺栓，有两个相对的翼片以防止旋转。 |
| Hypereutectic alloy | 过共晶合金 |
In an alloy system exhibiting a eutectic, any alloy whose composition has an excess of alloying element compared with the eutectic composition, and whose equilibrium microstructure contains some eutectic structure. 在呈现共晶的合金系统中，任何合金，其组成与共晶组成相比具有过量的合金元素，并且其平衡微观结构包含一些共晶结构。 |
| Water-jet cutting | 水射流切割 |
Cutting of materials such as rock by means of a high-speed jet of water containing abrasive particles. 通过含有磨料颗粒的高速水射流切割岩石等材料。 |
| Compression pressure (Unit Pa) | 压缩压力（单位Pa） |
The pressure produced in a cylinder of a piston engine by compression of air in the absence of fuel. 在没有燃料的情况下通过压缩空气在活塞发动机的气缸中产生的压力。 |
| Inspection gauge | 检验规 |
Any of various gauges used in manufacturing and quality control to check dimensions, finish, etc. 任何用于制造和质量控制的各种量规，以检查尺寸、光洁度等。 |
| Relaxed stress | 松弛应力 |
The initial stress minus the remaining stress at a given time during a stress-relaxation test. 在应力松弛试验期间，初始应力减去给定时间的剩余应力。 |
| Stress-intensity calibration | 应力强度校准 |
A mathematical expression, based on empirical or analytical results, that relates the stress-intensity factor to load and crack length for a specific specimen planar geometry. Also known as Kcalibration. 基于经验或分析结果的数学表达式，该表达式将特定试样平面几何形状的应力强度因子与载荷和裂纹长度联系起来。也称为K校准。 |
| Maraging steels | 马氏体时效钢 |
Very high-strength iron alloys named after ‘martensitic’ and ‘aging’. They contain nickel, chromium, cobalt, and molybdenum, and form martensite on air cooling with a strength of about 1 GPa. When reheated to about 500°C and aged for some hours, a room-temperature strength of some 2.4 GPa is reached. 以“马氏体”和“时效”命名的超高强度铁合金。它们含有镍、铬、钴和钼，在空气冷却下形成强度约为1GPa的马氏体。当再加热至约500°C并老化数小时时，室温强度达到约2.4GPa。 |
| Physical properties | 物理性质 |
Properties of a material the determination of which does not involve the deformation or destruction of the specimen—for example, density, electrical conductivity, coefficient of thermal expansion, magnetic permeability, and lattice parameter. Does not include chemical reactivity or the properties more appropriately regarded as mechanical properties. 不涉及试样变形或破坏的材料特性，例如密度、电导率、热膨胀系数、磁导率和晶格参数。不包括化学反应性或更适当地视为机械的性质。 |
| Mechanical efficiency (η) | 机械效率（η） |
1. In general for a machine, the ratio of output work to input work. 2. For a compressor, the ratio of indicated power to shaft power; for a reciprocating engine or an expander, the ratio of shaft power to indicated power. 1.一般而言，机器的输出功与输入功之比。2.对于压缩机，指示功率与轴功率之比；对于往复式发动机或膨胀机，轴功率与指示功率之比。 |
| Compound pendulum | 复摆 |
A rigid body free to swing about an axis. 可绕轴自由摆动的刚体。 |
| Magnetic materials | 磁性材料 |
Materials in which the magnetic moment of adjacent atoms can adopt either parallel or antiparallel alignment. Ferromagnetism occurs when the magnetic moments adopt parallel alignment. When adjacent magnetic moments cancel due to antiparallel alignment, the material exhibits antiferromagnetism and has no overall magnetic moment. Examples of the latter include ferrous oxide and manganese oxide. The phenomenon of ferrimagnetism occurs when adjacent magnetic moments adopt antiparallel alignment but have unequal magnitude. The region of ferromagnetic or ferrimagnetic material in which the magnetic moments are aligned is known as a magnetic domain and adjacent regions are separated by domain walls. Diamagnetic and paramagnetic materials exhibit weak forms of magnetism that results from independent (uncoupled) alignment of magnetic atomic dipoles induced by an applied magnetic field. Ferromagnetic and ferrimagnetic materials can acquire high degrees of magnetization in relatively weak magnetic fields. They have different hysteresis characteristics and are classified as either hard magnets or soft magnets. Hard magnets retain large magnetization in the absence of an applied magnetic field and are used as permanent magnets. Conventional materials include magnet steels alloyed with tungsten or cobalt. Rare-earth magnets made from alloys of rare-earth elements produce significantly stronger magnetic fields. The most common of these are samarium-cobalt and neodymiumiron-boron permanent magnets. Their strength allows them to be small and used in numerous applications, including cordless tools, disk drives, headphones, toys, and motors for automotive components such as wipers, fans, washers, and windows. Soft magnets may be magnetized and demagnetized relatively easily. When subjected to an alternating magnetic field the energy loss due to hysteresis is small. Common materials include iron-silicon alloys (known as electrical steels), nickel-iron alloys (permalloy), soft ferrites, and amorphous nanocrystalline alloys, the last of which can be produced in the form of tape by meltspinning. Soft magnets are used to enhance the magnetic flux produced by an electric current. 相邻原子的磁矩可以采用平行或反平行排列的材料。当磁矩采用平行排列时，会产生铁磁性。当相邻磁矩因反平行排列而抵消时，材料表现出反铁磁性，没有总磁矩。后者的实例包括氧化亚铁和氧化锰。当相邻磁矩采用反平行排列但大小不等时，就会出现铁磁现象。磁矩对齐的铁磁或铁磁材料区域称为磁畴，相邻区域由磁畴壁分隔。抗磁和顺磁材料表现出弱磁性形式，这是由外加磁场诱导的磁原子偶极子的独立（非耦合）排列引起的。铁磁性和铁磁性材料可以在相对弱的磁场中获得高磁化度。它们具有不同的磁滞特性，分为硬磁铁和软磁铁。硬磁铁在没有外加磁场的情况下保持较大的磁化强度，用作永磁体。常规材料包括与钨或钴合金化的磁钢。由稀土元素合金制成的稀土磁体产生明显更强的磁场。其中最常见的是钐钴和钕硼永磁体。它们的强度使其体积小，可用于多种应用，包括无绳工具、磁盘驱动器、耳机、玩具和汽车部件（如雨刷、风扇、洗衣机和车窗）的电机。软磁体可以相对容易地磁化和退磁。当受到交变磁场时，由于磁滞引起的能量损失很小。常见材料包括铁硅合金（称为电工钢）、镍铁合金（坡莫合金）、软铁氧体和非晶纳米晶合金，最后一种可以通过熔钉以胶带的形式生产。软磁铁用于增强电流产生的磁通量。 |
| mechanical engineering | 机械工业 |
That branch of engineering concerned with energy conversion, stress analysis, vibration, dynamics, and kinematics, especially applied to design (machine design, mechanical-engineering design). 与能量转换、应力分析、振动、动力学和运动学有关的工程分支，尤其适用于设计（机器设计、机械工程设计）。 |
| Yielding | 屈服 |
Evidence of plastic deformation in structural materials. Also known as plastic flow or creep. 结构材料塑性变形的证据。也称为塑性流动或蠕变。 |
| Pump | 泵 |
A machine designed to cause a liquid, gas, vapour, or slurry to flow due to the reciprocating motion of pistons, rotation of vanes, or rotation of an impeller. 通过活塞的往复运动、叶片的旋转或叶轮的旋转而使液体、气体、蒸汽或泥浆流动的机器。 |
| Torsional angle (ϕ) | 扭转角（ψ） |
(Unit ° or rad) The angular deflexion between two locations on a straight bar subjected to a torque. （单位为°或rad）受扭矩作用的直杆上两个位置之间的角偏转。 |
| Preheating | 预热 |
Heating before some further thermal or mechanical treatment. For tool steel, heating to an intermediate temperature immediately before final austenitizing. For some nonferrous alloys, heating to a high temperature for a long time, to homogenize the structure before working. In welding and related processes, heating to an intermediate temperature for a short time immediately before welding, brazing, soldering, cutting, or thermal spraying. 在进一步热处理或机械处理之前加热。对于工具钢，在最终奥氏体化之前立即加热至中间温度。对于一些非铁合金，在工作前长时间加热到高温，以使结构均匀化。在焊接和相关工艺中，在焊接、钎焊、钎焊、切割或热喷涂之前，立即加热到中间温度。 |
| Sawing | 锯切 |
Sawing is the process of cutting a workpiece with power band saws, hacksaws, and circular saws. Each of these methods is used in cutoff operations (cutting pieces to a required length), although band sawing also provides a method of cutting contours. 锯切是用带锯、钢锯和圆锯切割工件的过程。这些方法中的每一种都用于切割操作（将工件切割到所需长度），尽管带锯也提供了一种切割轮廓的方法。 |
| Shoulder joint | 轴肩关节 |
The second joint on an articulated robot, which has a horizontal axis and is analogous to the human shoulder. 关节机器人上的第二个关节，具有水平轴，类似于人的肩膀。 |
| Stretch ratio (extension ratio, λ) | 拉伸比（拉伸比，λ） |
A measure, used for highly-extensible materials such as rubber, of the extensional or normal strain of a component subjected to tension and defined as the ratio of the final length l, for a given load, to the initial or gauge length l0, where the coordinate axes are those of principal strain. It is related to the engineering strain e by λ = 1 + e. 用于高度可延展材料（如橡胶）的一种测量方法，用于测量受拉构件的拉伸或法向应变，定义为给定载荷下的最终长度l与初始或标距长度l0之比，其中坐标轴为主应变轴。它与工程应变e的关系为λ=1+e。 |
| Mean diameter (Unit m) | 平均直径（单位米） |
The average of the inside and outside diameters for a helical spring or hollow circular cylinder or sphere 螺旋弹簧或空心圆柱体或球体的内径和外径的平均值 |
| Coefficient of restitution (e) | 回弹系数（e） |
The ratio of the relative velocity of two colliding bodies after collision to that before. In perfectly elastic collisions e = 1; when all the impact energy is dissipated, e = 0. 两个碰撞体在碰撞后与碰撞前的相对速度之比。在完全弹性碰撞中e=1；当所有的冲击能量都消散时，e=0。 |
| Mohs hardness test | 莫氏硬度测试 |
A scratch hardness test for determining comparative hardness using 10 standard minerals—from talc (the softest) to diamond (the hardest). 刮擦硬度测试，用于使用从滑石（最软）到钻石（最硬）的10种标准矿物测定比较硬度。 |
| Transducer | 传感器 |
A device which converts one form of energy into another. An ultrasonic transducer, for example, converts electrical energy into acoustic energy (at ultrasonic frequencies) and vice versa. 将一种形式的能量转换为另一种形式能量的装置。例如，超声换能器将电能转换为声能（在超声频率下），反之亦然。 |
| Grain | 晶粒 |
1. An individual crystal in a polycrystalline solid. Most engineering materials such as metals and ceramics are used in polycrystalline form. 2. (gr) A non-SI unit of mass. The conversion to SI is 1 gr = 6.479 891 × 10−5 kg. 1.多晶固体中的单个晶体。大多数工程材料，如金属和陶瓷，都以多晶形式使用。2.（gr）非国际单位制的质量单位。转换为SI为1gr=6.479891×10-5kg。 |
| Hooke’s law | 胡克定律 |
Within the limit of proportionality, the extension of a material is proportional to the applied force. Approximately, it is the relationship between stress and strain in an elastic material when it is stretched. The law states that the stress (force per unit area) is proportional to the strain (a change in dimensions). The law, which holds only approximately and over a limited range, was discovered in 1676 by Robert Hooke. 在比例极限内，材料的延伸与所施加的力成比例。近似地说，它是弹性材料拉伸时应力和应变之间的关系。该定律指出，应力（单位面积的力）与应变（尺寸变化）成比例。该定律仅适用于有限的范围，由罗伯特·胡克于1676年发现。 |
| Vent | 发泄 |
A small valve that allows the release of pressurized fluid from a pipe, pressure vessel, etc., often to the atmosphere. 一种小阀门，允许将加压流体从管道、压力容器等中释放到大气中。 |
| British thermal unit (BTU, Btu) | 英热单位（BTU，Btu） |
An obsolete (non-SI) imperial unit of energy defined as the energy required to raise the temperature of one pound of pure water at 68°F by 1°F. The conversion to SI is 1 Btu = 1.055 056 × 103 J. 一种已被淘汰的（非SI）英制能量单位，定义为将68°F的一磅纯水的温度升高1°F所需的能量。转换为SI为1Btu=1.055056×103J。 |
| Residual preload | 残余预载荷 |
The tension which remains in an unloaded bolted joint after Relaxation. 松弛后未加载螺栓连接中保持的张力。 |
| Constant-velocity universal joint | 等速万向节 |
(CV joint, homokinetic joint) A connexion that transmits constant angular velocity between two shafts that are neither necessarily in line nor whose axial position is necessarily fixed. （CV关节，匀速关节）在两个轴之间传递恒定角速度的连接，这两个轴既不必在一条直线上，也不必固定其轴向位置。 |
| Freezing point | 冰点 |
The temperature at which a substance changes phase (or state) from liquid to solid. The freezing point for most substances increases as pressure increases. The reverse process, from solid to liquid, is melting; melting point is the same as freezing point. 物质从液态变为固态的温度。大多数物质的冰点随着压力的增加而增加。从固体到液体的逆过程是熔化；熔点与凝固点相同。 |
| Ideal gas laws | 理想气体定律 |
The law relating pressure, temperature and volume of an ideal (perfect) gas pV = mRT, where R is the gas constant. The law implies that at constant temperature T, the product of pressure p and volume V is constant (Boyle’s law), and at constant pressure, the volume is proportional to the temperature (Charles’ law). 与理想（完美）气体的压力、温度和体积相关的定律pV=mRT，其中R是气体常数。该定律意味着在恒定温度T下，压力p和体积V的乘积是恒定的（波义耳定律），而在恒定压力下，体积与温度成正比（查尔斯定律）。 |
| Median fatigue life | 中位疲劳寿命 |
The middle value when all of the observed fatigue life values of the individual specimens in a group tested under identical conditions are arranged in order of magnitude. When an even number of specimens are tested, the average of the two middlemost values is used. Use of the sample median rather than the arithmetic mean (that is, the average) is usually preferred. 当在相同条件下测试的一组中单个试样的所有观察疲劳寿命值按数量级排列时的中间值。当测试偶数个试样时，使用两个中间值的平均值。通常优选使用样本中值而不是算术平均值（即平均值）。 |
| Dead space | 死区 |
(dead volume) (Unit m³) That volume of a gas-filled thermometer in which the gas is not at the same temperature as that being measured. （死容）（单位m³）充气温度计的体积，其中气体的温度与被测温度不同。 |
| Fracture stress | 断裂应力 |
The true normal stress on the minimum cross-sectional area at the beginning of fracture. This term usually applies to tension tests of unnotched specimens. 断裂开始时最小横截面积上的真实正应力。该术语通常适用于无缺口试样的拉伸试验。 |
| Angle of friction | 摩擦角 |
(friction angle, β) (Unit °) For a body in contact with a plane surface, the angle between the normal to the surface and the resultant force between the body and the surface. If the friction force is F and normal force is N, β is given by F/N = μ = tan β where μ is the coefficient of friction. （摩擦角，β）（单位°）对于与平面接触的物体，表面法线与物体与表面之间的合力之间的夹角。如果摩擦力为F，法向力为N，则β由F/N=μ=tanβ给出，其中μ是摩擦系数。 |
| Sample variance (s²) | 样本方差（s²） |
The sum of the squares of the differences between each observed value and the sample average divided by the sample size minus one. It is a point estimate of the population variance. 每个观测值与样本平均值之差的平方和除以样本大小减1。它是总体方差的点估计。 |
| Pascal (Pa) | 帕斯卡（Pa） |
The SI unit of pressure, 1 Pa = 1 N/m². 压力的国际单位制，1Pa=1N/m²。 |
| Torque (T) (Unit N.m) | 扭矩（T）（单位：N.m） |
The twisting moment, product of force and wrench length, applied to a nut or bolt (for example). The twisting moment of a force or couple about an axis which results in torsion. 施加在螺母或螺栓（例如）上的扭矩，是力和扳手长度的乘积。力或力偶绕轴产生扭转的力矩。 |
| Tensile strength (Unit Pa) | 抗拉强度（单位Pa） |
In tension testing, the ratio of maximum load to original cross-sectional area. Also known as ultimate strength. The resistance that a material offers to tensile stress. It is defined as the smallest tensile stress required to break the body. (ultimate strength, ultimate tensile strength, UTS, Rm, Rm) The nominal or engineering stress given by the maximum load in a tension test divided by the original cross-sectional area of the specimen. The maximum load could be the fracture load for a brittle material, but for a ductile material it is usually taken as the load at which necking begins, beyond which the load falls. 在拉伸试验中，最大载荷与原始横截面积之比。也称为极限强度。材料对拉伸应力的抵抗力。它被定义为破坏主体所需的最小拉伸应力。（极限强度、极限抗拉强度、UTS、Rm、Rm）拉伸试验中最大载荷除以试样原始横截面积得出的标称或工程应力。对于脆性材料，最大载荷可以是断裂载荷，但对于韧性材料，最大荷载通常被视为颈缩开始时的载荷，超过该载荷时，载荷下降。 |
| Allowable stress | 许用应力 |
The maximum stress a designer can assume that the parts will stand. It is always less than the minimum strength of the material. For example, the ASME Boiler and Pressure Vessel Code typically specifies an allowable stress that is one-quarter of the service temperature yield strength of the material. This introduces a four-to-one safety factor into the design process and is intended to compensate for uncertainties in estimates of strength, service loads, etc. 设计师可以假设零件能够承受的最大应力。它总是小于材料的最小强度。例如，ASME锅炉和压力容器规范通常指定允许应力为材料使用温度屈服强度的四分之一。这在设计过程中引入了四比一的安全系数，旨在补偿强度、服务载荷等估计的不确定性。 |
| Elastic recovery | 弹性恢复 |
Amount the dimension of a stressed elastic material returns to its original (unstressed) dimension on release of an applied load. In hardness testing, the shortening of the original dimensions of the indentation upon release of the applied load. 在释放施加的载荷时，受应力弹性材料的尺寸恢复到其原始（无应力）尺寸的量。在硬度测试中，当释放所施加的载荷时，压痕的原始尺寸缩短。 |
| Materials selection | 材料选择 |
The process of selecting the most suitable material for a particular application. In the case of solid materials, it involves assessment of candidate materials in terms of their physical properties (density, elastic moduli, fracture toughness, yield strength, hardness, fatigue resistance, coefficient of thermal expansion, thermal conductivity, resistance to thermal shock, creep resistance, corrosion resistance, radiation resistance, etc), and such factors as the function of the final product, its shape, method of manufacture, required tolerances, number to be made, ease of inspection and quality control, cost, and design methodology employed. 为特定应用选择最合适材料的过程。对于固体材料，它涉及根据其物理特性（密度、弹性模量、断裂韧性、屈服强度、硬度、抗疲劳性、热膨胀系数、导热系数、抗热冲击性、抗蠕变性、耐腐蚀性、抗辐射性等）评估候选材料，以及诸如最终产品的功能、其形状、制造方法、所需公差、制造数量、检查和质量控制的容易程度、成本和采用的设计方法等因素。 |
| Free machining | 易切削 |
The property that makes machining easy because of the forming of small chips, a characteristic imparted to steel by sulfur, etc. 由于形成小切屑而使加工变得容易的特性，比如硫赋予钢的特性，等等。 |
| Coated abrasive | 涂附磨具 |
An abrasive tool consisting of a flexible backing material, such as a woven cloth, paper or vulcanized fibre, a bond material, such as a glue or synthetic resin, and grit. 一种研磨工具，由柔性背衬材料（例如编织布、纸或硫化纤维）、粘合材料（例如胶水或合成树脂）和砂砾组成。 |
| Quick coupling | 快速接头 |
(quick disconnect, fast coupling) A hose connection allowing rapid assembly or disassembly and comprising a socket and a plug incorporating a springloaded locking mechanism. （快速断开、快速连接）一种软管连接，允许快速组装或拆卸，包括插座和带有弹簧加载锁定机构的插头。 |
| Torsional stress | 扭转应力 |
The shear stress on a transverse cross section resulting from a twisting action. 扭转作用在横截面上产生的剪切应力。 |
| Nut factor | 螺母系数 |
An experimental constant used to evaluate or describe the ratio between the torque applied to a fastener and the Preload achieved as a result. 用于评估或描述施加在紧固件上的扭矩与由此获得的预载之间的比率的实验常数。 |
| Wind pressure (Unit Pa) | 风压（单位Pa） |
The dynamic pressure associated with the wind. The static pressure of the wind is the atmospheric pressure. 与风相关的动态压力。风的静压是大气压。 |
| Case hardening | 表面硬化 |
A generic term covering several processes applicable to steel that change the chemical composition of the surface layer by absorption of carbon, nitrogen, or a mixture of the two and, by diffusion, create a concentration gradient. The processes commonly used are carburizing and quench hardening; cyaniding; nitriding; and carbonitriding. The use of the applicable specific process name is preferred. 一个通用术语，涵盖适用于钢的几种工艺，这些工艺通过吸收碳、氮或二者的混合物改变表层的化学成分，并通过扩散形成浓度梯度。常用的工艺有渗碳和淬火硬化，氰化，氮化以及碳氮共渗。优选使用适用的特定工艺名称。 |
| Quench hardening | 淬火硬化 |
(1) Hardening suitable alpha-beta alloys (most often certain copper to titanium alloys) by solution treating and quenching to develop a martensitic-like structure. (2) In ferrous alloys, hardening by austenitizing and then cooling at a rate such that a substantial amount of austenite transforms to martensite. （1）通过固溶处理和淬火硬化合适的α-β合金（通常是某些铜-钛合金），以形成类似马氏体的结构。（2）在铁合金中，通过奥氏体化硬化，然后以一定速度冷却，使大量奥氏体转变为马氏体。 |
| Thermal reactor | 热反应器 |
An enlarged exhaust manifold bolted directly to the cylinder head of a piston engine, in which the oxidation of carbon monoxide and unburned hydrocarbons in the exhaust gas is enhanced. 一种扩大的排气歧管，直接用螺栓固定在活塞式发动机的气缸盖上，其中一氧化碳和未燃烧碳氢化合物的氧化作用增强。 |
| Vane engine (vane motor) | 叶片发动机（叶片马达） |
A rotary engine in which high-pressure hydraulic fluid in the spaces between spring-loaded sliding vanes held in an offset rotor acts on the vanes, causing the rotor to revolve within a cylinder. The design is much like a sliding-vane compressor, as is that of a vane pump, used to pump liquids. 一种旋转式发动机，其中偏置转子中装有弹簧的滑动叶片之间的高压液压流体作用在叶片上，使转子在气缸内旋转。这种设计很像滑动叶片压缩机，就像用于泵送液体的叶片泵一样。 |
| Hydraulics | 液压系统 |
The study of water flow in open channels (including canals, rivers, etc.), water-supply, drainage, and irrigation systems. 研究明渠（包括运河、河流等）、供水、排水和灌溉系统中的水流。 |
| Forced-air quench | 强制空气淬火 |
A quench utilizing blasts of compressed air against relatively small parts such as a gear. 利用压缩空气冲击相对较小的零件（例如齿轮）进行的淬火。 |
| Decalescence | 退色 |
A phenomenon, associated with the transformation of alpha iron to gamma iron on the heating (superheating) of iron or steel, revealed by the darkening of the metal surface owing to the sudden decrease in temperature caused by the fast absorption of the latent heat of transformation. 一种现象，与铁或钢加热（过热）时α铁向γ铁的转变有关，由于转变潜热的快速吸收导致温度突然降低，金属表面变黑。 |
| Radiosity (J) (Unit W/m²) | 辐射度（J）（单位W/m²） |
The total radiation leaving a given surface per unit area, including emitted, reflected, and transmitted radiation. 每单位面积离开给定表面的总辐射，包括发射、反射和透射辐射。 |
| Set pressure (Unit Pa) | 设定压力（单位Pa） |
The pressure at which a relief valve or safety valve is set to open, corresponding to the relevant code or standard which applies to the pressure vessel being protected. 安全阀或安全阀开启时的压力，对应于适用于受保护压力容器的相关规范或标准。 |
| Relative humidity (ϕ) | 相对湿度（ψ） |
The ratio or percentage of the actual mass of moisture in a given volume of air at a given temperature to the maximum possible mass of moisture at the same temperature. 给定温度下给定体积空气中的实际水分质量与相同温度下的最大可能水分质量的比率或百分比。 |
| Typical basis | 典型基础 |
The typical property value is an average value. No statistical assurance is associated with this basis. 典型的属性值是平均值。没有与此基础相关的统计保证。 |
| Vapour-pressure thermometer | 蒸汽压力温度计 |
(vapour-filled thermometer) A type of fluidexpansion thermometer in which the working fluid is a volatile liquid. （蒸汽填充温度计）一种流体膨胀温度计，其中工作流体为挥发性液体。 |
| Embedment | 嵌入 |
Localized plastic deformation in heavily loaded fasteners allows one part to sink into, or smooth the surface of, a softer or more heavily loaded second part. Nuts embed themselves in joint surfaces. Bolt threads embed themselves in nut threads, etc. 重载紧固件中的局部塑性变形允许一个零件陷入较软或更重载的第二零件中，或使其表面光滑。螺母嵌入接合面中。例如螺栓螺纹嵌入螺母螺纹等。 |
| Impact strength | 冲击强度 |
The resiliency or toughness of a solid as measured by impact energy. 用冲击能量测量的固体的弹性或韧性。 |
| Cohesive strength | 内聚强度 |
(Unit Pa) A theoretical fracture strength for solids based on interatomic forces, approximately equal to E/10 where E is Young’s modulus. （单位Pa）基于原子间力的固体理论断裂强度，大约等于E/10，其中E是杨氏模量。 |
| Screw | 螺钉 |
Threaded fastener designed to be used in a tapped or untapped (e.g., wood screw) hole, but not with a nut. A fastener with a screw thread cut or rolled into its cylindrical or conical shank, intended either to cut its own thread (as in a wood screw) or engage in a threaded hole. A self-tapping screw (sheet-metal screw, tapping screw) has a sufficiently hard thread that it cuts an internal thread in thin sheet or a component made of soft material when driven into a hole in the sheet or component. The screw head is the part of a screw used to apply torque to the screw. Common screw-head designs are circular in cross section with a diametral slot or cross, or hexagonal and recessed with a cross or hexagon. A screw thread is one or more continuous helical grooves of uniform section along either the exterior surface (male thread) or the interior surface (female thread) of a cylindrical or conical body. The three-dimensional shape that results when the thread cross section is rotated and axially advanced along an axis is called a helicoid, the angle that the thread makes when projected on to the axis being called the angle of inclination. Threads are employed in fasteners such as bolts, nuts, and screws; location and measuring instruments; in power drives; in some electrical fittings (Edison thread); and on the ends of crankshafts to suppress oil leakage (thrower thread). Parallel threads are formed on cylinders; tapered threads on cones, typically with a taper rate of 1:16. A screw with a righthanded thread appears to move away from the observer when turned clockwise. All standard screws, bolts and nuts have right-hand threads, but left-handed threads are sometimes employed. The axial distance between corresponding points on adjacent threads is called the screw pitch or screw rate and, for a single continuous helical groove (a single-start thread), is the same as the change in axial distance (the lead) between a nut and the head of a bolt during one revolution, the number of thread forms per mm then being the reciprocal of the pitch. For the same screw diameter, coarse threads have fewer threads per mm than fine threads. A multiple-start screw thread (usually coarse, see later) consists of two or more identical threads running simultaneously along its axis so as to provide greater bearing area and greater velocity ratio. The starts are separated by 180° (double start), 120° (triple start), 90° (quadruple start) etc., depending upon the number of threads. Thus, in double-start threads, the lead is twice the pitch; and so on. The axial distance between corresponding points on two adjacent threads in a multiple start thread is called the divided pitch. The position on a screw thread where there is equal distance between the flanks on the solid part of the thread and in the space between the threads is the pitch point, the associated diameter of which is termed the pitch diameter. The basic nomenclature for threads, some of which is common with that for toothed gearing, is shown in the diagrams. A helix formed or cut on a cylindrical surface which may advance along the axis to the right or left. The helix may be single or multiple. 一种螺纹紧固件，设计用于攻丝或未攻丝（如木螺钉）孔，但不与螺母配合使用。其螺纹被切割或卷成圆柱形或锥形柄，用于切割自身螺纹（如木螺钉）或嵌入螺纹孔。自攻螺钉（钣金螺钉、自攻螺钉）具有足够硬的螺纹，当打入薄板或部件中的孔时，它会在薄板或软材料部件中切割内螺纹。螺钉头是螺钉的一部分，用于向螺钉施加扭矩。常见的螺钉头设计为横截面为圆形，带有直径槽或十字，或为六边形，并带有十字或六边形凹槽。螺纹是沿圆柱形或锥形体的外表面（外螺纹）或内表面（内螺纹）具有均匀截面的一个或多个连续螺旋槽。当螺纹横截面旋转并沿轴轴向前进时产生的三维形状称为螺旋面，螺纹投影到轴上时形成的角度称为倾角。螺纹用于紧固件，如螺栓、螺母和螺钉；定位和测量仪器；在动力驱动中；在一些电气配件中（爱迪生螺纹）；并安装在曲轴端部，以抑制漏油（抛掷器螺纹）。在圆柱体上形成平行螺纹；圆锥上的锥形螺纹，通常具有1:16的锥形率。当顺时针旋转时，具有右手螺纹的螺钉似乎会远离观察者。所有标准螺钉、螺栓和螺母都有右手螺纹，但有时使用左手螺纹。相邻螺纹上对应点之间的轴向距离称为螺距或螺纹率，对于单个连续螺旋槽（单个起始螺纹），与螺母和螺栓头之间的轴向间距（导程）在一周内的变化相同，每mm的螺纹形式数为螺距的倒数。对于相同的螺钉直径，粗螺纹的每毫米螺纹数少于细螺纹。多头螺纹（通常为粗螺纹，见下文）由两个或多个沿其轴线同时延伸的相同螺纹组成，以提供更大的承载面积和更大的速比。根据螺纹的数量，起点之间的间隔为180°（双起点）、120°（三起点）、90°（四起点）等。因此，在双起始螺纹中，导程是螺距的两倍；多起点螺纹中两个相邻螺纹上对应点之间的轴向距离称为分割螺距。螺纹上的位置，即螺纹实体部分的侧面和螺纹之间的空间之间的距离相等，即节点，其相关直径称为节径。图中显示了螺纹的基本术语，其中一些与齿轮传动的基本术语相同。在圆柱面上形成或切割的螺旋线，可沿轴线向右或向左前进。螺旋可以是单个或多个。 |
| Creep rupture strength (Unit Pa) | 蠕变断裂强度（单位Pa） |
The fracture stress at the end of a creep test in metals and polymers, often plotted against time to give a stress-rupture curve. 金属和聚合物蠕变试验结束时的断裂应力，通常与时间作图以给出应力-断裂曲线。 |
| Tap | 旋塞 |
1. A threaded hard metal plug for cutting screw threads in holes. It has longitudinal grooves for the clearance of chips while cutting. Progressive cutting is achieved by using three taps in succession: taper, second, and plug. First and second taps have tapers to help start the thread along the axis of the hole; the plug tap has no taper and is used on the final cut in a blind hole. 2. A valve in, or at the end of, a pipeline. 1.一种用于在孔中切割螺纹的螺纹硬金属塞。它具有纵向凹槽，用于在切割时清除切屑。渐进式切割通过连续使用三个丝锥实现：锥度、二次和塞。第一和第二丝锥具有锥度，以帮助沿孔的轴线开始螺纹；塞式丝锥没有锥度，用于盲孔的最终切割。2.管道中或管道末端的阀门。 |
| Screw pair | 螺旋副 |
Two links connected together to form a kinematic pair, in which the contacting surfaces are screw threads, so that their relative motion consists of rotation and sliding. 两个连杆连接在一起形成运动副，其中接触面为螺纹，因此它们的相对运动包括旋转和滑动。 |
| Testing machine | 试验机 |
A machine used to apply either a steady or oscillatory or impact load to a testpiece. The load may be tensile, compressive, shear, bending, or torsional. 用于向试件施加稳定或振荡或冲击载荷的机器。载荷可以是拉伸的、压缩的、剪切的、弯曲的或扭转的。 |
| Working section | 工作区 |
That part of a wind tunnel in which models are placed for testing, or where detailed measurements are performed. 风洞中放置模型进行测试或进行详细测量的部分。 |
| Slenderness ratio | 长细比 |
The effective unsupported length of a uniform column divided by the least radius of gyration of the cross-sectional area. 均匀柱的有效无支撑长度除以横截面积的最小回转半径。 |
| Centrifugal | 离心式 |
Acting or moving in a direction away from the axis of rotation of a rotating body. 沿远离旋转体的旋转轴的方向作用或移动。 |
| Angularity | 角度 |
The underfaces of the nut and the bolt head should be exactly perpendicular to the thread or shank axes. If the angle between the face and the axis is, for example, 868 or 948, the fastener is said to have an angularity of 48 (sometimes called Perpendicularity). 螺母和螺栓头的底面应与螺纹或柄轴完全垂直。例如，如果面和轴之间的角度为868或948，则称紧固件的角度为48（有时称为垂直度）。 |
| Freezing range | 冻融范围 |
That temperature range between liquidus and solidus temperatures in which molten and solid constituents coexist. 熔融和固体成分共存的液相线和固相线温度之间的温度范围。 |
| Vacuum relief valve | 真空安全阀 |
A valve that admits gas to a system under vacuum, should the degree of vacuum become excessive. 如果真空度过高，允许气体在真空下进入系统的阀门。 |
| Radial marks | 径向标记 |
Lines on a fracture surface that radiate from the fracture origin and are visible to the unaided eye or at low magnification. Radial lines result from the intersection and connection of brittle fractures propagating at different levels. Also known as shear ledges. 断裂表面上的线，从断裂起点辐射，肉眼可见或在低放大率下可见。径向线是在不同层面上传播的脆性断裂相交和连接的结果。也称为剪切壁架。 |
| International System of Units | 国际单位制 |
(SI system of units, Le Système international d’unités) The standard system of units now used almost universally in science and engineering except in the United States. The definitive reference on the SI is a booklet published by the International Bureau of Weights and Measures, often referred to as the BIPM SI Brochure. There are seven base units: metre (symbol m) for length; kilogram (kg) for mass; mole (mol) for amount of substance; second (s) for time; kelvin (K) for temperature; ampere (A) for electric current; and candela (cd) for luminous intensity. New SI unit definitions, based upon the values of the universal constants of nature (also termed the fundamental physical constants: the Avogadro constant, the Boltzmann constant, and the Planck constant), came into effect on 20 May 2019. Minor adjustments were also made to the values of these constants. In addition to the base units, there are 22 coherent derived units, including radian (rad) for plane angle, steradian (sr) for solid angle, hertz (Hz) for frequency, newton (N) for force, pascal (Pa) for pressure, joule (J) for energy, work, and amount of heat, and watt (W) for power and radiant flux. Recommended practice is to avoid combinations such as N/mm², MN/m² being preferred.(kg) for mass; mole (mol) for amount of substance; second (s) for time; kelvin (K) for temperature; ampere (A) for electric current; and candela (cd) for luminous intensity. New SI unit definitions, based upon the values of the universal constants of nature (also termed the fundamental physical constants: the Avogadro constant, the Boltzmann constant, and the Planck constant), came into effect on 20 May 2019. Minor adjustments were also made to the values of these constants. In addition to the base units, there are 22 coherent derived units, including radian (rad) for plane angle, steradian (sr) for solid angle, hertz (Hz) for frequency, newton (N) for force, pascal (Pa) for pressure, joule (J) for energy, work, and amount of heat, and watt (W) for power and radiant flux. Recommended practice is to avoid combinations such as N/mm², MN/m² being preferred. （国际单位制，Le Système international d\\\'unités）目前美国除外，在科学和工程中几乎是普遍使用的标准单位制。SI的最终参考是国际度量衡局出版的小册子，通常称为BIPM SI小册子。有七个基本单位：米（符号m）表示长度；质量为千克（kg）；物质量的摩尔（mol）；时间为秒；开尔文（K）表示温度；电流为安培（A）；而坎德拉（cd）表示发光强度。新的国际单位制定义于2019年5月20日生效，该定义基于自然界的普遍常数（也称为基本物理常数：阿伏伽德罗常数、玻尔兹曼常数和普朗克常数）。这些常数的值也进行了少量调整。除了基本单位外，还有22个相干导出单位，包括平面角的弧度（rad）、立体角的斯特拉迪安（sr）、频率的赫兹（Hz）、力的牛顿（N）、压力的帕斯卡（Pa）、能量、功和热量的焦耳（J）以及功率和辐射通量的瓦特（W）。建议的做法是避免N/mm²、MN/m²等组合。 |
| Graham’s laws | 格雷厄姆定律 |
The laws stating that the rates of diffusion and effusion of a gas are inversely proportional to the square root of its density. 规定气体的扩散和渗出速率与其密度的平方根成反比的定律。 |
| Slug wrench | 缓动扳手 |
A box wrench with an anvil on the end of the handle. Torque is produced by striking the anvil with a sledge hammer. 柄端有铁砧的套筒扳手。扭矩是通过用大锤敲击铁砧产生的。 |
| Bright annealing | 光亮退火 |
Annealing in a protective medium to prevent discoloration of the bright surface. 在保护介质中退火以防止光亮表面变色。 |
| Load and resistance factor design | 负载和阻力系数设计 |
A design procedure developed for the AISC by the Research Council on Structural Connections. Assigns uncertainties in the strength of (i.e., resistance of) and in the service loads to be placed on a shear joint to estimate the probable strength of the joint. It is a recently defined alternative to the Allowable stress design procedure. 结构连接研究委员会为AISC制定的设计程序。分配剪切接头的强度（即阻力）和工作荷载的不确定性，以估计接头的可能强度。它是最近定义的容许应力设计程序的替代方案。 |
| Breaking stress | 断裂应力 |
The stress at failure. Also known as rupture stress. 失效时的应力。也称为破裂应力。 |
| Blank nitriding | 空白渗氮 |
Simulating the nitriding operation without introducing nitrogen. This is usually accomplished by using an inert material in place of the nitriding agent or by applying a suitable protective coating to the ferrous alloy. 在不引入氮气的情况下模拟氮化操作。这通常通过使用惰性材料代替氮化剂或通过在铁合金上施加合适的保护涂层来实现。 |
| Valve spring | 气门弹簧 |
The spring that restores a valve to its closed position after having been opened, and is also intended to prevent valve bounce. 在阀门打开后将其恢复到关闭位置的弹簧，也用于防止阀门反弹。 |
| Modulus of elasticity (E) | 弹性模量（E） |
The measure of rigidity or stiffness of a metal; the ratio of stress, below the proportional limit, to the corresponding strain. In terms of the stress-strain diagram, the modulus of elasticity is the slope of the stress-strain curve in the range of linear proportionality of stress to strain. 金属的刚度或刚度的量度；低于比例极限的应力与相应应变之比。根据应力应变图，弹性模量是应力应变曲线在应力应变线性比例范围内的斜率。 |
| Carbon steels | 碳钢 |
(plain carbon steels) Steels in which carbon is the principal alloying element, and the amount of manganese does not exceed 1.65% and the copper and silicon contents are less than 0.60%. There are three main types: low-carbon steels (0.08–0.35% carbon); medium-carbon steels (0.35–0.50% carbon); and high-carbon steels (0.50–2.0% carbon). （普通碳钢）以碳为主要合金元素，锰含量不超过1.65%，铜和硅含量低于0.60%的钢。主要有三种类型：低碳钢（0.08-0.35%碳）；中碳钢（0.35–0.50%碳）；和高碳钢（0.50–2.0%碳）。 |
| Atomizing humidifier | 雾化加湿器 |
A humidifier that functions by spraying fine droplets of water into an airstream. 一种加湿器，通过将细小的水滴喷射到气流中来发挥作用。 |
| Two-phase flow | 两相流 |
A flow in which two phases are present, for example gas bubbles in a liquid, liquid bubbles in another liquid with which it is immiscible, solid particles in a liquid or gas. 两相流动，例如液体中的气泡、与之不混溶的另一种液体中的液体气泡、液体或气体中的固体颗粒。 |
| Thermoelectric converter | 热电转换器 |
(thermoelectric generator) A device consisting of series-connected alternate n- and p-type semiconductor elements sandwiched between two ceramic plates. Due to the Seebeck effect, electrical power is generated when a temperature difference is maintained across the plates. Due to the Peltier effect, a thermoelectric converter can act as either a thermoelectric heater or a thermoelectric cooler (thermoelectric refrigerator) by passing an electrical current through it. The thermoelectric figure of merit (Z), with unit 1/K, is a dimensional parameter on which the efficiency of a thermoelectric device is primarily dependent, defined by Z = σα2/k where α is the Seebeck coefficient, σ is the electrical conductivity, and k is the thermal conductivity. The product of Z and a temperature is non-dimensional. （热电发生器）由串联连接的交替的n型和p型半导体元件夹在两块陶瓷板之间组成的装置。由于塞贝克效应，当板之间保持温差时，就会产生电能。由于珀尔帖效应，热电转换器可以通过使电流通过而充当热电加热器或热电冷却器（热电制冷机）。热电优值（Z）和第一单元/K是一个尺寸参数，热电装置的效率主要取决于此，由Z=σα2/K定义，其中α是塞贝克系数，σ是电导率，K是热导率。Z和温度的乘积是无量纲的。 |
| Blanking shear test | 落料剪力试验 |
A method used to determine the through-thickness shear strength of sheet material that involves blanking a disk out of flat strip using a simple punch-and-die method. Alson known as punching shear test. 一种用于确定板材全厚度剪切强度的方法，包括使用简单的冲模方法从扁平带材中冲裁出圆盘。也称为冲切试验。 |
| Temper embrittlement | 回火脆化 |
Brittleness that results when certain steels are held within, or are cooled slowly through, a certain range of temperature below the transformation range. The brittleness is manifested as an upward shift in ductile-to-brittle transition temperature but only rarely produces a low value of reduction in area in a smooth-bar tension test of the embrittled material. The anomalous reduction in toughness of martensitic stainless steels when tempered in the range 370–600°C. Embrittlement of alloy steels caused by holding within or cooling slowly through a temperature range just below the transformation range. Embrittlement is the result of the segregation at grain boundaries of impurities such as arsenic, antimony, phosphorus, and tin; it is usually manifested as an upward shift in ductile-to-brittle transition temperature. Temper embrittlement can be reversed by retempering above the critical temperature range, then cooling rapidly. 当某些钢保持在低于转变范围的某一温度范围内或缓慢冷却时产生的脆性。脆性表现为延性到脆性转变温度的向上移动，但在脆性材料的平滑棒材拉伸试验中，很少产生较小的面积减小值。马氏体不锈钢在370–600°C范围内回火时的韧性异常降低。合金钢的脆化是由于在低于转变范围的温度范围内保持或缓慢冷却而引起的。脆化是杂质（如砷、锑、磷和锡）在晶界处偏析的结果；它通常表现为韧脆转变温度的上升。回火脆化可以通过在临界温度范围以上重新回火，然后快速冷却来逆转。 |
| Yield strength | 屈服强度 |
That stress level which will create a permanent deformation of 0.2% or 0.5% or some other small, preselected, amount in a body. Approximately equal to the elastic and proportional limits of the material; a little higher than the proof strength of a bolt. The stress at which a material exhibits a specified deviation from proportionality of stress and strain. An offset of 0.2% is used for many metals. 该应力水平将在物体中产生0.2%或0.5%的永久变形，或其他一些小的、预先选定的量。近似等于材料的弹性和比例极限；略高于螺栓的强度。材料表现出与应力和应变比例的特定偏差的应力。许多金属使用0.2%的偏移量。 |
| Zone melting (zone refining) | 区域熔炼（区域精炼） |
A process of purification of materials in which a narrow molten zone is moved along the length of the material, resulting in impurities being segregated at one end. 一种净化材料的过程，其中一个狭窄的熔融区沿材料长度移动，导致杂质在一端分离。 |
| Standard hole | 标准孔 |
A hole in a workpiece bored to a specified tolerance where clearance with a shaft is accomplished by allowance on the shaft. A standard shaft is machined to a specified tolerance where clearance with a hole is accomplished by allowance on the hole. 工件上的孔，钻孔至规定公差，其中与轴的间隙通过轴上的余量来实现。标准轴加工至规定公差，其中与孔的间隙通过孔上的公差实现。 |
| Safe working load (Unit N) | 安全工作负荷（单位：N） |
The steady or unsteady load against which a component or structure is designed for normal operation. It is lower than that which would cause failure by buckling, fracture, or yielding, so as to accommodate uncertainty, possible fault or accident conditions. 部件或结构设计用于正常运行的稳定或不稳定荷载。该值低于因屈曲、断裂或屈服而导致失效的值，以适应不确定性、可能的故障或事故条件。 |
| Crank angle (Unit °) | 曲柄角度（单位°） |
The angle between the crank of a slider-crank mechanism and a line from the crankshaft centreline to the piston axis. 曲柄滑块机构的曲柄与曲轴中心线到活塞轴线的直线之间的角度。 |
| Elasticity | 弹性 |
The property of a material by virtue of which deformation caused by stress disappears on removal of the stress. A perfectly elastic body completely recovers its original shape and dimensions after release of stress. 一种材料的特性，通过这种特性，由应力引起的变形在去除应力后消失。完全弹性体在应力释放后完全恢复其原始形状和尺寸。 |
| Carbonization | 碳化 |
Conversion of an organic substance into elemental carbon. 将有机物质转化为元素碳。 |
| Spring temper | 弹簧回火 |
A temper of nonferrous alloys and some ferrous alloys characterized by tensile strength and hardness about two-thirds of the way from full hard to extra spring temper. 非铁合金和一些铁合金的一种回火，其特点是抗拉强度和硬度约为全硬回火到超弹性回火的三分之二。 |
| Strain gage | 应变计 |
A device for measuring small amounts of strain produced during tensile and similar tests on metal. A coil of fine wire is mounted on a piece of paper, plastic, or similar carrier matrix (backing material), which is rectangular in shape and usually about 25 mm (1.0 in.) long. This is glued to a portion of metal under test. As the coil extends with the specimen, its electrical resistance increases in direct proportion. This is known as bonded resistance-strain gage. Other types of gages measure the actual deformation. Mechanical, optical, or electronic devices are sometimes used to magnify the strain for easier reading. 一种测量金属拉伸和类似试验中产生的少量应变的装置。将一卷细线安装在一张纸、塑料或类似载体基质（背衬材料）上，该载体基质呈矩形，通常约25mm（1.0in.）长，这是粘在测试金属的一部分。随着线圈随试样延伸，其电阻成正比增加，这被称为粘结电阻应变计。其他类型的量规测量实际变形。机械、光学或电子设备有时用于放大应变以便于读取。 |
| Pressure ratio | 压力比 |
One pressure divided by another which may be a reference pressure. In many flow and thermodynamic processes, the pressure ratio is more important than the absolute pressure levels. For example, in compressible gas flow the Mach number is determined by the ratio of the stagnation pressure to the static pressure. 一个压力除以另一个压力，该压力可以是参考压力。在许多流动和热力学过程中，压力比比绝对压力水平更重要。例如，在可压缩气流中，马赫数由停滞压力与静压之比决定。 |
| Toughening mechanisms | 增韧机理 |
Various methods of increasing the resistance to crack initiation and propagation in materials. They include transformation toughening, in which the microstructure around the crack tip alters so as to slow down or arrest cracks; deflexion of cracks; various ways of de-sharpening crack tips; fibre bridging of cracks; and fibre pull-out. 增加材料中裂纹萌生和扩展阻力的各种方法。它们包括相变增韧，其中裂纹尖端周围的微观结构发生变化，以减缓或阻止裂纹；裂纹偏转；消除裂纹尖端锐化的各种方法；纤维桥接裂纹；和纤维拉出。 |
| Initial stress | 初始应力 |
The stress produced by strain in a specimen immediately on achieving the given constant-strain conditions in a stress-relaxation test before stress-relaxation occurs. Sometimes referred to as instantaneous stress. 在应力松弛发生之前，在应力松弛试验中达到给定的恒定应变条件时，试样立即应变所产生的应力。有时称为瞬时压力。 |
| Carburizing flame | 渗碳火焰 |
A gas flame that will introduce carbon into some heated metals, as during a gas welding operation. A carburizing flame is a reducing flame, but a reducing flame is not necessarily a carburizing flame. 一种气体火焰，会在气焊操作中将碳引入一些加热的金属中。渗碳火焰是还原火焰，但还原火焰不一定是渗碳火焰。 |
| Gasket m-factor | 垫片m系数 |
For a gasketed joint of area A in which the clamping force is F, the factor m is defined by F ≥ mpA where p is the pressure that would separate the two halves of the joint and m > 1. 对于面积为A且夹紧力为F的垫片接头，系数m由F≥mpA定义，其中p是分离接头两半的压力，m>1。 |
| Chafing fatigue | 磨损疲劳 |
Fatigue damage initiated in a surface damaged by rubbing against another body. 因与另一个物体摩擦而损坏的表面引起的疲劳损坏。 |
| Diffusion | 扩散 |
(1) Spreading of a constituent in a gas, liquid, or solid, tending to make the composition of all parts uniform. (2) The spontaneous movement of atoms or molecules to new sites within a material. （1） 一种成分在气体、液体或固体中的扩散，趋于使所有部分的成分均匀。（2） 原子或分子自发运动到材料内的新位置。 |
| Vapour | 蒸气 |
The gas-like phase of a substance at a temperature below its critical point. A vapour can be condensed to a liquid or a solid by increasing its pressure or reducing its temperature. 温度低于临界点的物质的类气相。蒸汽可以通过增加压力或降低温度冷凝成液体或固体。 |
| Friction loss (Unit J) | 摩擦损失（单位J） |
The conversion of mechanical energy to heat due to friction within a machine, mechanism, linkage, etc. 由于机器、机构、连杆等内部的摩擦而将机械能转化为热能。 |
| Deflection temperature under load (DTUL) | 负载变形温度（DTUL） |
The temperature at which a simple cantilever beam deflects a given amount under load. Formerly called heat distortion temperature. 简单悬臂梁在负载下偏转给定量的温度。以前称为热变形温度。 |
| Elastic interactions | 弹性相互作用 |
When a bolt is tightened it partially compresses the joint members ‘‘in its own neighborhood.’’ When nearby bolts are tightened later, they further compress the joint in this region. This allows the first bolt to relax a little (lose a little preload). Tightening bolts on the opposite side of the joint, however, might increase preload in some of the earlier bolts tightened on the near side. These shifts and changes in the elastic energy stored in individual bolts, during assembly, are called elastic interactions. 当螺栓拧紧时，它会“在其自身附近”部分压缩接头构件稍后拧紧附近的螺栓时，进一步压缩该区域的接头。这允许第一个螺栓稍微松弛（失去一点预载）。但拧紧接头另一侧的螺栓可能会增加早期在近侧拧紧的一些螺栓的预载。在装配过程中，储存在单个螺栓中的弹性能量的这些位移和变化称为弹性相互作用。 |
| Age hardening | 时效硬化 |
Raising the strength and hardness of an alloy by heating a supersaturated solid solution at a relatively low temperature to induce precipitation of a finely dispersed second phase. Also known as aging or precipitation hardening. Hardening by aging, usually after rapid cooling or cold working. 通过在相对较低的温度下加热过饱和固溶体以诱导细分散的第二相沉淀来提高合金的强度和硬度。也称为时效或沉淀硬化。通常在快速冷却或冷加工后。 |
| Izod test | 悬臂梁试验 |
A type of impact test in which a V-notched specimen, mounted vertically, is subjected to a sudden blow delivered by the weight at the end of a pendulum arm. The energy required to break off the free end is a measure of the impact strength or toughness of the material. 一种冲击试验，其中垂直安装的V形切口试样受到摆臂末端重量的突然冲击。断开自由端所需的能量是材料冲击强度或韧性的量度。 |
| Standard deviation (σ) | 标准偏差（σ） |
A statistical term used to quantify the Scatter in a set of data points. If the standard deviation is small, most of the data points are ‘‘nearly equal.’’ A large deviation means less agreement. The most usual measure of the dispersion of observed values or results expressed as the positive square root of the variance. The square root of variance, a measure of the spread of data about the mean value. 用于量化一组数据点中分散度的统计术语。如果标准偏差很小，则大多数数据点“几乎相等”大的偏差意味着更少的一致性。观测值或结果离散度的最常用度量，表示为方差的正平方根。方差的平方根，衡量平均值的数据分布。 |
| Flame annealing | 火焰退火 |
Annealing in which the heat is applied directly by a flame. 通过火焰直接加热的退火。 |
| Intergranular fracture | 沿晶破裂 |
Brittle fracture of a metal in which the fracture is between the grains, or crystals, that form the metal. Also called intercrystalline fracture. 金属的脆性断裂，断裂位于形成金属的晶粒或晶体之间。又称晶间破裂。 |
| Screw pump | 螺杆泵 |
A positive-displacement pump that uses one or more helical rotors rotating within a casing to transfer liquids or slurries. 一种容积式泵，使用一个或多个在外壳内旋转的螺旋转子输送液体或泥浆。 |
| Ackerman linkage | 阿克曼装置 |
A steering linkage on a motor vehicle that approximately gives rolling without slipping of both wheels about the turning point. This is achieved by having the inner stub axle (on the inside of the turning curve) move through a greater angle than the outer stub axle. 机动车辆上的一种转向联动装置，在转向点附近两个车轮几乎不会打滑。这是通过使内短轴（在转弯曲线的内侧）比外短轴移动更大的角度来实现的。 |
| Swept volume (Unit m³) | 扫描体（单位m³) |
In the cylinder of a piston engine or other device, the volume between top and bottom dead centre positions of a piston; equal to πR2S where R is the piston radius and S is the stroke. 在活塞发动机或其他装置的气缸中，活塞上止点和下止点位置之间的体积；等于πR2S，其中R是活塞半径，S是冲程。 |
| Accelerated testing | 加速测试 |
A type of testing, for rates of wear, fatigue, corrosion etc., in which failure times are reduced by employing greater loads, more frequent power cycling, higher vibration levels, higher humidity, higher temperatures, greater potential differences etc. than would be encountered in normal operation. 一种测试类型，用于测试磨损率、疲劳率、腐蚀率等，通过采用比正常运行中更大的负载、更频繁的功率循环、更高的振动水平、更高湿度、更高温度、更大的电位差等，减少故障时间。 |
| Absolute specific gravity | 绝对比重 |
The ratio of the weight of any volume of a substance to the weight of an equal volume of a reference substance at the same temperature, often water at 4°C, both measured in a vacuum to avoid any effect of buoyancy. 在相同温度下，任何体积的物质的重量与等体积的参考物质的重量之比，通常是4°C的水，两者都是在真空中测量的，以避免任何浮力的影响。 |
| Stretch forming | 拉伸成型 |
A manufacturing process in which sheet-metal components are physically stretched over a forming die using a press, punch, or edge clamps. Stretching combined with bending reduces springback. 一种制造工艺，其中使用压力机、冲头或边缘夹具在成形模上物理拉伸金属板部件。拉伸与弯曲相结合可减少回弹。 |
| Surface treatment | 表面处理 |
Any process, including chemical, electrochemical, mechanical, and thermal, designed to protect a surface against corrosion and wear or to alter its mechanical properties. 任何旨在保护表面免受腐蚀和磨损或改变其机械性能的工艺，包括化学、电化学、机械和热处理。 |
| Preload adjustments | 预载调整 |
Preloads may be applied directly by axial loading or indirectly by turning of the nut or bolt. When preload is applied by turning of nuts or bolts, a torsion load component is added to the desired axial bolt load. 预载荷可通过轴向载荷直接施加，或通过转动螺母或螺栓间接施加。当通过转动螺母或螺栓施加预载荷时，扭转载荷分量被添加到所需的轴向螺栓载荷中。 |
| Precipitation-hardenable stainless steels | 沉淀硬化不锈钢 |
Precipitation-hardenable stainless steels contain typically 11–18% chromium, 3–10% nickel, 0.05–0.2% carbon, and small additions of manganese, silicon, aluminium, molybdenum, niobium and titanium. These steels can be supplied in a solution-treated condition, which is readily fabricated or machined, and then hardened by an ageing treatment that produces a fine dispersion of second-phase precipitates. They are available in austenitic, semi-austenitic, and martensitic grades. Uses include springs, knives, and pressure vessels. 沉淀硬化不锈钢通常含有11-18%的铬、3-10%的镍、0.05-0.2%的碳以及少量添加的锰、硅、铝、钼、铌和钛。这些钢可在固溶处理条件下供应，该条件易于制造或机加工，然后通过时效处理硬化，从而产生细小的第二相沉淀。它们有奥氏体、半奥氏体和马氏体等级。用途包括弹簧、刀具和压力容器。 |
| Nut thickness | 螺母厚度 |
The nut thickness shall be the overall distance measured parallel to the axis of nut, from the top of the nut to the bearing surface, and shall include the thickness of the washer face where provided. 螺母厚度应为平行于螺母轴线测量的从螺母顶部到轴承表面的总距离，还应包括垫圈表面的厚度。 |
| Total head (hT) (Unit m) | 总水头（hT）（单位：m） |
Total pressure pT expressed in terms of the vertical height of a column of liquid, typically water or mercury, i.e. hT = pT/ρg where g is the acceleration due to gravity and ρ is the liquid density. 总压力pT以液体柱（通常为水或汞）的垂直高度表示，即hT=pT/ρg，其中g为重力加速度，ρ为液体密度。 |
| Fillister head | 槽头 |
Similar to a pan head but with a smaller head diameter and a taller head, with higher vertical sides. 类似于盘头，但头部直径较小，头部较高，垂直边较高。 |
| Impact extrusion | 冲击挤压 |
The extrusion of separate components of soft metals whose properties permit the action to be performed quickly. 挤压单独的软金属组件，其特性允许快速执行操作。 |
| Zirconia-toughened alumina composites | 氧化锆增韧氧化铝复合材料 |
(ZTA composites) Ceramic composites based on aluminium oxide to which zirconium oxide is added, resulting in improved fracture toughness. （ZTA复合材料）基于氧化铝的陶瓷复合材料，其中添加了氧化锆，从而提高了断裂韧性。 |
| Steady pin | 定位销 |
A dowel, key, or pin that prevents a pulley from turning on its shaft. 防止滑轮在其轴上转动的销钉、键或销。 |
| Brake fluid | 制动液 |
The hydraulic fluid used to transmit force to the pistons in disc brakes or the wheel cylinders in drum brakes. Requirements include a high boiling point and low hygroscopy. 用于将力传递到盘式制动器中的活塞或鼓式制动器中的轮缸的液压油。要求包括高沸点和低吸湿性。 |
| Brittle fracture | 脆性断裂 |
The fracture of a component or structure in the globally-elastic range of loading, so that the broken pieces may be refitted to regain the original article. Separation of a solid accompanied by little or no macroscopic plastic deformation. Typically, brittle fracture occurs by rapid crack propagation with less expenditure of energy than for ductile fracture. 部件或结构在全局弹性载荷范围内的断裂，以便可以将破碎的碎片重新装配以恢复原始物品。固体的分离伴随着很少或没有宏观塑性变形。通常，脆性断裂通过快速裂纹扩展发生，能量消耗比韧性断裂少。 |
| Concentrated load | 集中负荷 |
A load on a component which is distributed over a very small area, idealized as the line load of a wedge or knife edge, and the point load of a cone. 分布在非常小的区域上的部件上的载荷，理想化为楔形或刀刃的线载荷和锥体的点载荷。 |
| Lead screw | 丝杠 |
The master screw running along the length of the bed of a lathe from which all screws threads on that machine are cut. Master screw used for cutting a screw thread in a lathe. 沿车床床身长度方向运行的主螺钉，该机床上的所有螺钉和螺纹都从主螺钉上切割下来。用于在车床上切削螺纹的主螺钉。 |
| Coil spring | 螺旋弹簧 |
A spiral (‘clockwork’) or helical (cylindrical) spring. A spring steel wire wound in a spiral pattern. 螺旋（“发条”）或螺旋（圆柱形）弹簧。以螺旋状缠绕的弹簧钢丝。 |
| Mechanical metallurgy | 机械冶金 |
The science and technology dealing with the behavior of metals when subjected to applied forces. 处理金属在外力作用下的行为的科学技术。 |
| Thermal fatigue | 热疲劳 |
Fatigue resulting from the presence of temperature gradients that vary with time in such a manner as to produce cyclic stresses in a structure. 由于温度梯度的存在而产生的疲劳，温度梯度随时间变化，从而在结构中产生循环应力。 |
| Overaging | 过时效 |
Aging under conditions of time and temperature greater than those required to obtain maximum change in a certain property, so that the property is altered in the direction of the initial value. 在时间和温度条件下的时效大于获得某一特性最大变化所需的时间和温度，从而使该特性沿初始值的方向发生变化。 |
| Bond strength (Unit Pa) | 结合强度（单位Pa） |
The tensile, compressive or shear stress at which joints fail, e.g. by fracture or excessive deformation. 接头失效的拉伸、压缩或剪切应力，例如断裂或过度变形。 |
| Metallurgy | 冶金 |
The study of the atomic, crystallographic, microstructural, mechanical, and physical properties of metallic elements and alloys and their applications. 研究金属元素和合金的原子、晶体学、微观结构、机械和物理特性及其应用。 |
| Outside diameter (Unit m) | 外径（单位：m） |
(external diameter, OD) The diameter of a circular cylindrical tube or a sphere measured between opposite points on the external surface. （外径，OD）在外表面上的相对点之间测量的圆柱管或球体的直径。 |
| Computational domain | 计算域 |
In CFD, FEM, and other numerical methods, the area or volume within which calculations are performed and on the periphery of which the boundary conditions are specified. 在CFD、FEM和其他数值方法中，执行计算的区域或体积以及在其外围指定边界条件的区域或体积。 |
| Uniform strain | 均匀应变 |
The strain occurring prior to the beginning of localization of strain (necking); the strain to maximum load in the tension test. 在应变局部化（颈缩）开始之前发生的应变；拉伸试验中最大载荷的应变。 |
| Oxidized surface (on steel) | 氧化表面（在钢上） |
Surface having a thin, tightly adhering, oxidized skin (from straw to blue in color), extending in from the edge of a coil or sheet. Sometimes called annealing border. 表面具有薄的、紧密粘附的氧化皮（从稻草色到蓝色），从线圈或薄片的边缘延伸。有时称为退火边界。 |
| Reverse engineering | 逆向工程 |
The disassembly of a machine, mechanism, system or device, measurement of its component parts, and identification of the materials used so that if required, a functioning replica can be produced. 拆卸机器、机构、系统或装置，测量其组成部分，并识别所用材料，以便在需要时可以生产出功能正常的复制品。 |
| Ratchet coupling | 棘轮联轴器 |
A joint employing a ratchet system between two shafts, so that not only does the driven shaft run in one direction only, but also the driven shaft can, if necessary, run more quickly than the driving shaft. 在两个轴之间采用棘轮系统的接头，这样不仅从动轴只能在一个方向上运行，而且在必要时，从动轴可以比驱动轴运行得更快。 |
| Torsion | 扭矩 |
A twisting deformation of a solid body about an axis in which lines that were initially parallel to the axis become helices. The twisting of an object about an axis due to an applied couple (torque). 一种固体绕轴的扭转变形，在该变形中，最初平行于轴的线变成螺旋线。由于施加的力偶（扭矩），物体绕轴扭曲。 |
| Captive nut | 松脱螺母 |
A nut attached loosely or rigidly to a sheet member that is too thin to thread and which engages with a cap screw. 松脱地或刚性地连接到薄板构件上的螺母，该螺母太薄而无法拧入，并与带帽螺钉接合。 |
| Torsion test | 扭力测试 |
A test designed to provide data for the calculation of the shear modulus, modulus of rupture in torsion, and yield strength in shear. 为计算剪切模量、扭转断裂模量和剪切屈服强度而设计的试验。 |
| Induction hardening | 感应淬火 |
A surface-hardening process in which only the surface layer of a suitable ferrous workpiece is heated by electromagnetic induction to above the upper critical temperature and immediately quenched. 一种表面硬化工艺，在该工艺中，只有合适的含铁工件的表面层通过电磁感应加热到高于上临界温度，并立即淬火。 |
| Guided-bend test | 导向弯曲试验 |
A test in which the specimen is bent to a definite shape by means of a punch (mandrel) and a bottom block. 用冲头（心轴）和底块将试样弯曲成一定形状的试验。 |
| Cathode | 阴极 |
That electrode in a battery or corrosion cell which attracts electrons. 电池或腐蚀电池中吸引电子的电极。 |
| Gearbox | 变速箱 |
A mechanism consisting of meshing gears which transmit power and torque to an output shaft from an input shaft directly connected to an engine. The mechanism is normally contained within a casing filled with lubricating oil. The diagram shows a simple four-speed sliding-mesh gearbox in which gears with different numbers of teeth are slid along parallel splined shafts within the gearbox to mesh with each other and change the ratio of output to input speed (gear ratio). 一种由啮合齿轮组成的机构，将动力和扭矩从直接连接到发动机的输入轴传递到输出轴。该机构通常包含在充满润滑油的外壳内。示例一个简单的四速滑动啮合齿轮箱，其中具有不同齿数的齿轮沿着齿轮箱内的平行花键轴滑动，以相互啮合并改变输出与输入速度的比率（齿轮比）。 |
| Following flank | 跟随侧翼 |
The flank of a thread opposite to the leading flank. 与前牙面相对的螺纹牙面。 |
| Liquation temperature | 液化温度 |
The lowest temperature at which partial melting can occur in an alloy that exhibits the greatest possible degree of segregation. 偏析程度最高的合金发生部分熔融的最低温度。 |
| Hot dipping | 热浸 |
(hot-dip galvanizing) A process of coating an iron, steel, or aluminium object with a thin layer of zinc by passing it through a bath of molten zinc at a temperature of about 460°C. （热浸镀锌）通过使铁、钢或铝物体通过温度约为460°C的熔融锌浴，在铁、钢或铝物体上镀上一层薄薄的锌层的工艺。 |
| Tab washer (lock washer) | 止动垫圈（锁紧垫圈） |
A washer with one or more protruding tabs which can be bent in such a way that a nut or bolt head is prevented from becoming loose. 一种垫圈，具有一个或多个突出凸耳，可弯曲以防止螺母或螺栓头松动。 |
| B-basis | B-基础 |
Mechanical property value above which at least 90% of the population of values is expected to fall, with a confidence of 95%. 机械性能值超过该值时，至少90%的值预计会下降，置信度为95%。 |
| Eyebolt (eyescrew) | 吊环螺栓（眼螺丝） |
A bolt threaded at one end and bent to a loop at the other end. A bolt or screw with a closed loop in place of a head. 一端有螺纹，另一端弯曲成环的螺栓。带有闭合环代替头部的螺栓或螺钉。 |
| Amontons friction | 阿蒙顿摩擦 |
(Coulomb friction) Friction between surfaces where the ratio of the frictional force F to the normal force N is constant and independent of the area in contact. （库仑摩擦）摩擦力F与法向力N之比恒定且与接触面积无关的表面之间的摩擦。 |
| Tension testing | 张力测试 |
A method of determining the behavior of materials subjected to uniaxial loading, which tends to stretch the metal. A longitudinal specimen of known length and diameter is gripped at both ends and stretched at a slow, controlled rate until rupture occurs. Also known as tensile testing. 一种确定材料在单轴载荷下的行为的方法，这种载荷倾向于拉伸金属。将已知长度和直径的纵向试样夹持在两端，并以缓慢、受控的速率拉伸，直到发生断裂。也称为拉伸测试。 |
| High strength low alloy steels | 高强度低合金钢 |
(HSLA steels) Steels with various micro-alloying elements such as copper, nickel, chromium, molybdenum, niobium, titanium, and vanadium in small quantities that give improved strength (as high as 900 MPa) and corrosion properties compared with plain carbon steels. Improvements are due to grain refinement and precipitation hardening, better control of the chemistry during steel making, and accurate rolling temperatures. （HSLA钢）是含有各种微合金元素的钢，如少量的铜、镍、铬、钼、铌、钛和钒，与普通碳钢相比，具有更好的强度（高达900MPa）和腐蚀性能。这些改进归功于晶粒细化和沉淀硬化、炼钢过程中更好的化学控制以及精确的轧制温度。 |
| Load ratio, R | 负载比R |
In fatigue, the algebraic ratio of the minimum to maximum load in a fatigue cycle, that is, R = Pmin/Pmax. Also known as stress ratio. 在疲劳中，疲劳循环中最小载荷与最大载荷的代数比，即 R= Pmin/Pmax。也称为应力比。 |
| Vickers hardness number | 维氏硬度值 |
(diamond hardness number, DHN, VHN, VPN) (Unit kg/mm² originally, sometimes now Pa) Indentation hardness given by load divided by the surface area of the permanent impression obtained when the indenter is in the form of a square pyramid whose opposite faces make an angle of 136° with one another. The mean length d of the diagonals of the indentation is determined, from which VPN = 0.927(2W/d2) where W is the load, since the base of the pyramid has an area equal to 0.927 times the surface area. （金刚石硬度值，DHN，VHN，VPN）（最初单位为kg/mm²，有时为Pa）压痕硬度，由载荷除以永久压痕的表面积得出，当压头呈方形棱锥体形式时，其相对面彼此成136°角。确定压痕对角线的平均长度d，其中VPN=0.927（2W/d2），其中W是载荷，因为棱锥底部的面积等于表面积的0.92七倍。 |
| Ultrasonic extensometer | 超声波伸长计 |
An electronic instrument which measures the change in length of a fastener ultrasonically as, or before and after, the fastener is tightened. 一种电子仪器，可在紧固件拧紧时或前后通过超声波测量紧固件长度的变化。 |
| Working stress (Unit Pa) | 工作应力（单位Pa） |
The stress under which a component or structure is designed to operate under normal conditions. 部件或结构设计为在正常条件下运行的应力。 |
| Strain hardening | 应变硬化 |
An increase in hardness and strengthcaused by plastic deformation at temperatures below the recrystallization range. Also known as work hardening. (workhardening) The increase in stress above the initial yield stress required to deform a metal to greater strains in the plastic range at temperatures below the recrystallization range (cold working). Unloading after some strain or work input gives a harder and stronger material. 在低于再结晶范围的温度下，塑性变形导致硬度和强度的增加。也称为加工硬化。（加工硬化）在低于再结晶范围（冷加工）的温度下，使金属在塑性范围内变形至更大应变所需的高于初始屈服应力的应力增加。在一定的应变或功输入后卸载，会得到更硬、更强的材料。 |
| Temperature factor | 温度系数 |
A calibration constant used in ultrasonic measurement of bolt stress or strain. Accounts for the effects of thermal expansion and the temperature-induced change in the velocity of sound. 用于螺栓应力或应变超声波测量的校准常数。说明了热膨胀和温度引起的声速变化的影响。 |
| Condenser vacuum | 冷凝器真空 |
The sub-atmospheric pressure imposed on the condenser of a steam-power plant which leads to an appreciable increase in overall efficiency. 施加在蒸汽发电厂冷凝器上的低于大气压的压力导致整体效率显着提高。 |
| Air classifier | 空气分级机 |
(air elutriator) A device in which an airstream, which may be swirling, sorts particles by a combination of size, shape, and mass. （空气淘析器）一种装置，在该装置中，气流（可能是漩涡）根据大小、形状和质量的组合对颗粒进行分类。 |
| Calorie | 卡路里 |
(cal, gram calorie, small calorie) An obsolete (i.e. non-SI) unit of energy equal to 4.186 8 J. It is the amount of energy needed to raise the temperature of 1 gram of pure airfree water from 14.5°C to 15.5°C at standard atmospheric pressure. （卡，克热量，小热量）一种已被淘汰的（即非SI）能量单位，等于4.1868J。它是在标准大气压力下将1克纯无空气水的温度从14.5℃升高到15.5℃所需的能量。 |
| Vibration-testing machine (vibrator) | 振动试验机（振动器） |
Any machine that subjects components or systems to vibration at known amplitudes and frequencies in order to determine the response. vibratory equipment Vibrating process equipment, such as shakers, used to separate small and large particles, or feeders to supply particulate or granular material that may otherwise clog. 使部件或系统以已知振幅和频率振动以确定响应的任何机器。振动设备振动工艺设备，如用于分离小颗粒和大颗粒的振动筛，或用于供应可能堵塞的颗粒或粒状材料的给料机。 |
| Delamination | 分层 |
A mode of failure of composite materials, including radial-ply tyres, in which the layers separate due to repeated cyclic loading, impact, or weak bonding. 复合材料的一种失效模式，包括子午线轮胎，其中层由于重复的循环载荷、冲击或弱粘合而分离。 |
| Scuffing | 擦伤 |
A form of adhesive wear that produces superficial scratches or a high polish on the rubbing surfaces. It is observed most often on inadequately lubricated parts. 粘着磨损的一种形式，在摩擦表面上产生表面划痕或高度抛光。通常在润滑不足的零件上观察到。 |
| Threshold stress for stress-corrosion cracking (σth) | 应力腐蚀开裂阈值应力（σth） |
An experimentally determined critical gross-section stress below which stress-corrosion cracking will not occur under specified test conditions. 实验确定的临界总截面应力，低于该应力，在规定的试验条件下不会发生应力腐蚀开裂。 |
| Rockwell superficial hardness test | 洛氏表面硬度试验 |
Same as Rockwell hardness test, except that smaller minor and major loads are used. 与洛氏硬度测试相同，只是使用较小的次要载荷和主要载荷。 |
| Positive-displacement compressor | 容积式压缩机 |
Any type of compressor, including piston and rotary-screw types, that delivers a fixed volume of gas at high pressure per unit time. A positive-displacement pump delivers a fixed volume of fluid, usually a liquid, per unit time. 任何类型的压缩机，包括活塞式和旋转螺杆式，在单位时间内以高压输送固定体积的气体。容积泵每单位时间输送固定体积的流体，通常为液体。 |
| Shim | 垫片 |
A thin piece of material, such as metal of accurately-known thickness, placed between two surfaces to ensure they are the correct distance apart. A thin piece of material placed between two surfaces to obtain a proper fit, adjustment, or alignment. The piece can also be analyzed to measure furnace carbon potential (that is, because while in the furnace it will quickly carburize to a level equal to the furnace carbon potential). 一块薄的材料，如厚度精确已知的金属，放置在两个表面之间，以确保它们之间的距离正确。放置在两个表面之间以获得适当配合、调整或对齐的一块薄材料。还可以对工件进行分析，以测量熔炉碳势（也就是说，在熔炉中，工件将快速渗碳至与熔炉碳势能相等的水平）。 |
| Nominal size | 公称尺寸 |
The intended size of a component. The actual size will depend on manufacturing tolerances. 组件的预期尺寸。实际尺寸取决于制造公差。 |
| Metre (m) | 米（m） |
The base unit of length in the SI system. It is equal to the distance travelled by light in vacuum in 1/299 792 458 seconds. SI系统中长度的基本单位。它等于光在真空中在1/299792458秒内传播的距离。 |
| Corrosion | 腐蚀 |
The deterioration of an exposed metal surface due to electrochemical oxidation with its surroundings. In the oxidation reaction, metal atoms give up electrons which are transferred to form another chemical species by a reduction reaction, usually with hydrogen and/or oxygen. A common example is the formation of the iron oxide rust Fe(OH)3 on iron or steel in moist air or water. Rust breaks away easily, exposing fresh iron to the atmosphere, whereas the corrosion product of some metals forms an adherent layer that prevents further oxidation reaction at fresh metal, an effect known as passivation. Examples include aluminium oxide on aluminium, chromium oxide on chromium, chromium oxide on alloys containing chromium such as stainless steels, and the patina formed on copper and zinc. Corrosion protection takes many forms. Good design to avoid crevices and stress is important. In some situations, substances known as inhibitors may be added to the environment to decrease its corrosiveness. The electrochemical nature of corrosion results in some metals having a greater tendency for oxidation than others. Zinc has a stronger tendency than iron and this is made use of in galvanizing. This is one example of cathodic protection, in which one metal is connected electrically to a more reactive metal, called a sacrificial anode, that oxidizes by giving up electrons and so protects the first metal. Coatings may be used to resist corrosion. Paints, plating, and diffusion coatings are the most common and the electrochemical process of anodizing is used to deliberately form a passive layer of oxide on aluminium alloys. Material selection plays a major role. For example, stainless steels with their high chromium content are widely used in corrosive environments. 暴露的金属表面由于与周围环境的电化学氧化而劣化。在氧化反应中，金属原子放弃电子，这些电子通过还原反应（通常与氢和/或氧）转移形成另一种化学物质。一个常见的例子是在潮湿的空气或水中在铁或钢上形成氧化铁锈Fe(OH)3。铁锈很容易脱落，将新鲜铁暴露在大气中，而一些金属的腐蚀产物形成一层粘附层，防止新鲜金属发生进一步的氧化反应，这种效果称为钝化。实例包括铝上的氧化铝、铬上的氧化铬、含铬合金上的氧化铬如不锈钢，以及铜和锌上形成的铜绿。腐蚀防护有多种形式。避免裂缝和应力的良好设计非常重要。在某些情况下，可以向环境中添加称为抑制剂的物质，以降低其腐蚀性。腐蚀的电化学性质导致一些金属比其他金属具有更大的氧化倾向。锌比铁具有更强的倾向性，这可用于镀锌。这是阴极保护的一个例子，其中一种金属与活性更强的金属（称为牺牲阳极）电连接，牺牲阳极通过释放电子进行氧化，从而保护第一种金属。涂层可用于抗腐蚀。油漆、电镀和扩散涂层是最常见的，阳极氧化的电化学过程用于有意在铝合金上形成一层钝化氧化物。材料选择起着重要作用。例如，铬含量高的不锈钢广泛用于腐蚀性环境。 |
| Tribology | 摩擦学 |
The science and technology concerned with interacting surfaces in relative motion. 与相对运动中相互作用的表面有关的科学和技术。 |
| Constant life diagram | 恒定寿命图 |
A plot of experimentally derived fatigue-life data; perhaps the most complex and complete of the popular charts used to represent such data. 实验得出的疲劳寿命数据图；可能是用于表示此类数据的最复杂和最完整的流行图表。 |
| Vickers hardness test | 维氏硬度测试 |
An indentation hardness test employing a 136° diamond pyramid indenter (Vickers) and variable loads, enabling the use of one hardness scale for all ranges of hardness—from very soft lead to tungsten carbide. Also know as diamond pyramid hardness test. 采用136°金刚石棱锥压头（维氏硬度计）和可变载荷的压痕硬度测试，能够对从极软铅到碳化钨的所有硬度范围使用一个硬度标度。也称为钻石金字塔硬度测试。 |
| Kilogram (kg) | 千克（kg） |
The base unit of mass in the SI system. It was previously defined as being equal to the mass of the International Prototype Kilogram, a right cylinder of height and diameter 39.17 mm made of an alloy of 90% (by mass) platinum and 10% iridium. From 20 May 2019 it has been defined by taking the fixed numerical value of the Planck constant h to be 6.626 070 150 × 10−34 when expressed in the unit J.s, which is equal to kg.m².s. 国际单位制中的基本质量单位。它以前被定义为等于国际原型千克的质量，一个高度和直径为39.17毫米的右圆柱体，由90%（质量）的铂和10%的铱合金制成。从2019年5月20日起，普朗克常数h的固定数值被定义为6.626070150×10−34当以单位J.s表示时，和kg.m².s一样。 |
| Lock nut | 锁紧螺母 |
A type of nut that is prevented from loosening under vibration. The locking action is accomplished by squeezing, gripping or jamming against the bolt threads. A nut which provides extra resistance to vibration loosening (beyond that produced by proper Preload ), either by providing some form of Prevailing torque, or, in free-spinning lock nuts, by deforming, cramping, or biting into mating parts when fully tightened. 1. A thin auxiliary nut tightened against another nut to prevent loosening. 2. A single nut with special features that prevent loosening. 一种在振动下防止松动的螺母。锁定动作通过挤压、夹紧或卡住螺栓螺纹来完成。通过提供某种形式的主要扭矩，或在自由旋转锁紧螺母中，通过完全拧紧时变形、夹紧或咬入配合零件，提供额外的抗振动松动能力（超出适当预载产生的能力）。1.一个薄的辅助螺母，拧紧到另一个螺母上以防止松动。2.具有防止松动的特殊功能的单个螺母。 |
| Specific weight (γ) (Unit N/m³) | 比重（γ）（单位：N/m³） |
The weight per unit volume of a substance: if W is the weight of a volume of the substance, ρ is its density, and g is the acceleration due to gravity, γ = W/ = ρg. 物质单位体积的重量：W是物质体积的重量，ρ是其密度，g是重力引起的加速度，γ=W/=ρg。 |
| Left hand screw | 左螺旋 |
One that screws into the mating part or advances when turned to the left or counter clockwise. 旋入配合部分或向左或逆时针旋转时前进的螺钉。 |
| Profiling machine | 仿形机 |
(profile milling machine) A milling machine in which the cutter is guided by the contour of a pattern having the required shape. （仿形铣床）铣刀由具有所需形状的图案轮廓引导的铣床。 |
| Tracking problem | 跟踪问题 |
A control problem where the set point changes with time and thus the plant output must follow the changing set point. The opposite of a regulator problem. 一种控制问题，其中设定值随时间变化，因此设备输出必须遵循变化的设定值。与调节器问题相反。 |
| Rupture stress | 断裂应力 |
The stress at failure. Also known as breaking stress. 失效时的应力。也称为破裂应力。 |
| Fatigue life (N) | 疲劳寿命（N） |
The number of cycles of stress or strain of a specified character that a given specimen sustains before failure occurs. 给定试样在失效发生之前所承受的特定特征的应力或应变的循环次数。 |
| Structural analysis | 结构分析 |
The determination of the forces, displacements, stresses, and strains in a given structure. 确定给定结构中的力、位移、应力和应变。 |
| Absorption dynamometer | 吸收式测功机 |
A dynamometer in which input work or power is dissipated by mechanical friction, electrical resistance, hydraulic resistance, etc. 通过机械摩擦、电阻、液压阻力等耗散输入功或功率的测功机。 |
| Normality | 常态 |
The principle that the vector sum of plastic strain increments is perpendicular to the yield surface. 塑性应变增量矢量和垂直于屈服面的原理。 |
| Cooling curve | 冷却曲线 |
A curve showing the relation between time and temperature during the cooling of a material. 显示材料冷却过程中时间和温度之间关系的曲线。 |
| Zero-gravity | 零重力 |
The situation in which there is no force of gravity (i.e. weightlessness). 没有重力的情况（即失重）。 |
| Shrink ring | 预紧环 |
A ring, which is expanded by heating, is placed around an assembly of parts, and then contracts upon cooling to hold the assembly in place. 通过加热膨胀的环被放置在零件组件周围，然后在冷却时收缩以将组件固定到位。 |
| Scatter | 分散 |
Data points or calculations are said to be scattered when they are not all the same. A ‘‘lot of scatter in preload’’ means wide variation in the preloads found in individual bolts. 当数据点或计算不尽相同时，它们被称为分散的。“预载的大量分散”意味着单个螺栓中的预载差异很大。 |
| Allowable stress design | 许用应力设计 |
A design procedure developed for the AISC by the Research Council on Structural Connections. Purposely underestimates the strengths of bolts and joint materials to introduce safety factors into the design of structural steel joints. It is an alternative to the more recently defined load and resistance factor design procedure. 结构连接研究委员会为AISC制定的设计程序。故意低估螺栓和接头材料的强度，以便在结构钢接头的设计中引入安全系数。它是最近定义的荷载和阻力系数设计程序的替代方法。 |
| Snap temper | 快速回火 |
A precautionary interim stress-relieving treatment applied to high-hardenability steels immediately after quenching to prevent cracking because of delay in tempering them at the prescribed higher temperature. 在淬火后立即对高淬透性钢进行预防性临时应力消除处理，以防止因在规定的更高温度下回火延迟而开裂。 |
| Artificial aging | 人工时效 |
Aging above room temperature. 在室温以上的时效。 |
| Joule | 焦耳 |
The SI unit of energy. One joule is the work done by a force of one newton acting over a distance of one metre. The symbol is J, where 1 J = 1 N m. 国际单位制能量单位。一焦耳是一牛顿的力在一米的距离上所做的功。符号为J，其中1j=1m。 |
| Observed value | 观测值 |
The particular value of a characteristic determined as a result of a test or measurement. 作为测试或测量结果确定的特性的特定值。 |
| Venturi | 文丘里管 |
A convergent–divergent flow nozzle, usually circular in cross section, with a relatively short convergent section (the confuser) upstream of a throat followed by a gradually diverging section (the diffuser). Such nozzles usually have flanges at either end for installation in a pipeline. Applications include flow meters and ejectors. When a fluid flows through a convergent duct at subsonic speed, there is an increase in velocity accompanied by a decrease in pressure (Venturi effect). 收敛-发散流喷嘴，横截面通常为圆形，喉部上游具有相对较短的收敛段（扰流器），然后是逐渐发散段（扩散器）。这种喷嘴通常在两端都有法兰，以便安装在管道中。应用包括流量计和喷射器。当流体以亚音速流过收敛管道时，速度增加，压力降低（文丘里效应）。 |
| Impact testing | 冲击测试 |
Determination of the mechanical properties of materials under high-rate conditions. Often determined from the behaviour of a testpiece when struck by a pendulum or a weight falling from a known height, or when sandwiched between two Hopkinson bars. 在高速条件下测定材料的机械性能。通常根据测试件在被钟摆撞击或从已知高度坠落的重物或夹在两个霍普金森棒之间时的行为来确定。 |
| Work ratio | 工作比 |
The ratio of the net work out to the actual work out for a thermodynamic cycle. 热力学循环的净功与实际功之比。 |
| O-ring (O-ring seal) | O形圈（O形密封圈） |
A toroidal ring of synthetic rubber seated in a groove machined into a flat or cylindrical surface to act as a seal. 一种环形合成橡胶环，位于加工成平面或圆柱表面的凹槽中，起密封作用。 |
| Screw feeder | 螺旋给料机 |
A mechanism for handling bulk materials in which a rotating helicoidal screw moves the material axially forward. Similar to a screw conveyor, but required to discharge material at a controlled rate very accurately. It operates with the screw completely full. 一种用于处理散装物料的机构，其中旋转的螺旋螺杆使物料轴向向前移动。类似于螺旋输送机，但需要以受控速率非常精确地排出物料。它在螺杆完全充满的情况下运行。 |
| Dilatometer | 膨胀计 |
An instrument for measuring length or volume changes in a solid during heating and subsequent cooling or isothermal holding. · An instrument for measuring the linear expansion or contraction in a metal resulting from changes in such factors as temperature and allotropy. 一种在加热和随后的冷却或等温保持过程中测量固体长度或体积变化，测量金属因温度和同素异形体等因素的变化而引起的线性膨胀或收缩的仪器。 |
| Strength of materials | 材料强度 |
A confusing name for what is really stress analysis, reflecting older engineering design based upon elasticity and ‘theories of strength’ for different materials, without regard to cracks. 对于真正的应力分析，这是一个具有迷惑性的名称，反映了基于弹性和不同材料的“强度理论”的旧工程设计，而不考虑断裂。 |
| Vibration isolation | 隔振 |
The prevention of transmission of vibration from one component of a system to another part of the same system, such as a building or other structure. Isolation may be achieved using dampers (vibration damping) or by active feedback-control methods. Mechanical vibration is often attenuated by means of components immersed in oil such as in dashpots (viscous damping). Vibration suppression can be achieved (a) using dampers and absorbers tuned to a particular frequency to suppress vibratory forces in structures and other systems (passive suppression) or (b) by the measurement of vibration at key locations in a structure and the application of cancellation forces (active suppression). 防止振动从系统的一个部件传递到同一系统的另一部分，如建筑物或其他结构。可以使用阻尼器（减振）或主动反馈控制方法实现隔离。机械振动通常通过浸入油中的部件来衰减，例如缓冲罐（粘性阻尼）。可以通过（a）使用调谐到特定频率的阻尼器和吸收器来抑制结构和其他系统中的振动力（被动抑制），或（b）通过测量结构中关键位置的振动并施加抵消力（主动抑制），实现振动抑制。 |
| Cap nut | 盖型螺母 |
A nut with a blind threaded hole, for example a dome nut to cover the end of a bolt. 带有盲螺纹孔的螺母，例如用于覆盖螺栓末端的圆顶螺母。 |
| Hot pressing | 热压 |
1. Sintering of metal or ceramic powder at high temperature. 2. Formation of components from fibre-reinforced composite material in which bonding is ensured through application of pressure and temperature, often against a mould to give the required shape. 1、金属或陶瓷粉末的高温烧结。2. 由纤维增强复合材料形成部件，其中通过施加压力和温度来确保粘合，通常靠在模具上以形成所需的形状。 |
| Atomization | 雾化 |
The production of a spray of fine droplets from a liquid, such as diesel oil or petrol, by injection through a nozzle (an atomizer). 通过喷嘴（雾化器）喷射从液体（例如柴油或汽油）中产生细小液滴喷雾。 |
| Angström (Å) | 昂斯特罗姆（Å） |
An obsolete (non-SI) unit of length, sometimes still employed for atomic and crystallographic measurements. The conversion to SI is 1 Å = 10−10 m. 一种已被淘汰的（非SI）长度单位，有时仍用于原子和晶体学测量。转换为SI为1Å=10-10m。 |
| Normal temperature and pressure (NTP) | 常温常压（NTP） |
Reference conditions defined by NIST as 20°C and 1 atm. NIST定义的参考条件为20°C和1atm。 |
| Stress relieving | 应力消除 |
Heating to a suitable temperature, holding long enough to reduce residual stresses, and then cooling slowly enough to minimize the development of new residual stresses. 加热到合适的温度，保持足够长的时间以减少残余应力，然后缓慢冷却以尽量减少新残余应力的产生。 |
| Blue brittleness | 蓝色脆性 |
Anomalous loss of ductility when quenched steels are tempered in the range 250–350°C (temperatures that produce blue tints on the surface of components). Brittleness exhibited by some steels after being heated to some temperature within the range of about 205 to 370 °C (400 to 700 °F), particularly if the steel is worked at the elevated temperature. Killed steels are virtually free of this kind of brittleness. 当淬火钢在250–350°C范围内回火（在部件表面产生蓝色色调的温度）时，延展性异常损失。某些钢在加热到约205至370°C（400至700°F）范围内的某个温度后表现出脆性，特别是在高温下加工钢时。镇静钢几乎没有这种脆性。 |
| Fibreglass | 玻璃纤维 |
Fibreglass is used in studs and nuts for applications when the fastener should be non-corrosive, low in conductivity, or transparent to electromagnetic waves. 当紧固件应无腐蚀性、低导电性或对电磁波透明时，玻璃纤维用于螺柱和螺母中。 |
| Ferritizing anneal | 铁素体化退火 |
A treatment given as-cast gray or ductile (nodular) iron to produce an essentially ferritic matrix. For the term to be meaningful, the final microstructure desired or the time-temperature cycle used must be specified. 给予铸态灰铁或球墨铸铁以产生基本铁素体基体的处理。为了使该术语有意义，必须指定所需的最终微观结构或使用的时间-温度循环。 |
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