| 词或词组 | 中文 | 英文解释中文解释 |
|---|---|---|
| Speed of rotation (N) | 转速（N） |
(Unit rps or rpm) For an object rotating about a fixed axis, the speed of rotation is the number of turns (revolutions) of the object per unit time. It is equal to the angular velocity Ω (or ω) (unit rad/s) divided by 2π. （单位rps或rpm）对于绕固定轴旋转的物体，旋转速度是物体每单位时间的转数。它等于角速度Ω（或ω）（单位rad/s）除以2π。 |
| Collar | 圈、箍 |
A ring secured to, or integral with, a shaft to give axial location. 固定在轴上或与轴成一体以提供轴向位置的环。 |
| Conduit | 导管 |
A hollow object, of metal, plastic, glass, ceramic, etc., which is relatively long compared with its lateral dimensions and through which there is fluid flow. 由金属、塑料、玻璃、陶瓷等制成的中空物体，与其横向尺寸相比相对较长，并且有流体流过。 |
| Compression ratio | 压缩率 |
The volume of a combustion chamber with the piston at the top of its stroke as a proportion of the total volume of the cylinder with the piston at the bottom of its stroke. For a piston engine, if the swept volume is SW and the clearance volume is CL, the compression ratio is given by ( SW + CL)/CL, i.e. it is a volume ratio rather than a pressure ratio. 活塞位于其冲程顶部的燃烧室的容积与活塞位于其冲程底部的气缸总体积的比例。对于活塞发动机，如果扫气量为SW，间隙容积为CL，则压缩比由(SW+CL)/CL给出，即它是体积比而不是压力比。 |
| International Practical Temperature Scale (IPTS) | 国际实用温标（IPTS） |
A close approximation to the thermodynamic temperature scale based upon the triple points of hydrogen (13.8 K), neon (24.6 K), oxygen (54.4 K), argon (83.8 K), mercury (234.3 K), and water (273.2 K); the melting point of gallium (302.9 K); and the freezing points of indium (429.7 K), tin (505.1 K), zinc (692.7 K), aluminium (933.5 K), silver (1 234.9 K), gold (1 337.3 K), and copper (1 基于氢（13.8K）、氖（24.6K）、氧（54.4K）、氩（83.8K），汞（234.3K）和水（273.2K）的三相点的热力学温度标度的近似值；镓的熔点（302.9K）；铟（429.7K）、锡（505.1K）、锌（692.7K），铝（933.5K）、银（1234.9K）、金（1337.3K）和铜等。 |
| Oxidizing flame | 氧化焰 |
A gas flame produced with excess oxygen in the inner flame. 在内部火焰中过量氧气产生的气体火焰。 |
| Set screw | 紧定螺钉（平头螺钉、紧定螺栓） |
Usually a hardened steel screw having either no head or a square head and with various degrees of points or ends to lock or tighten adjustable machine parts in position on a shaft. A short, headless screw with a recess at one end to receive a screwdriver or key, the other end being pointed, square, or otherwise shaped. Typically used to secure a pulley, gear, or other component on a shaft. 通常是一种硬化钢螺钉，无头或方头，具有不同程度的点或端部，用于将可调机械部件锁定或拧紧在轴上的适当位置。一端有凹槽，用来装螺丝刀或钥匙，另一端是尖的、方形的或其他形状的。通常用于将皮带轮、齿轮或其他部件固定在轴上。 |
| Fillet | 圆角 |
Transition region between bolt head and shank, or between other changes in diameter. 螺栓头和螺栓杆之间的过渡区域，或其他直径变化之间的过渡区域。 |
| 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。 |
| Embrittlement | 脆化 |
The loss of ductility or fracture toughness of materials, either during processing or in service. The severe loss of ductility or toughness or both, of a material, usually a metal or alloy. Many forms of embrittlement can lead to brittle fracture. Many forms can occur during thermal treatment or elevated-temperature service (thermally induced embrittlement). Some of these forms of embrittlement, which affect steels, include blue brittleness, 885 °F (475 °C) embrittlement, quench-age embrittlement, sigma-phase embrittlement, strain-age embrittlement, temper embrittlement, tempered martensite embrittlement, and thermal embrittlement. In addition, steels and other metals and alloys can be embrittled by environmental conditions (environmentally assisted embrittlement). The forms of environmental embrittlement include acid embrittlement, caustic embrittlement, corrosion embrittlement, creep-rupture embrittlement, hydrogen embrittlement, liquid metal embrittlement, neutron embrittlement, solder embrittlement, solid metal embrittlement, and stress-corrosion cracking. 材料在加工或使用过程中的延展性或断裂韧性损失。通常是金属或合金的延展性或韧性或两者的严重损失。多种形式的脆化可导致脆性断裂。在热处理或高温服务期间，可能会出现多种形式（热致脆化）。影响钢的一些脆化形式包括蓝脆、885°F（475°C）脆化、淬火时效脆化、西格玛相脆化、应变时效脆化，回火脆化、回火马氏体脆化和热脆化。此外，钢和其他金属和合金可能因环境条件而脆化（环境辅助脆化）。环境脆化的形式包括酸脆化、碱脆化、腐蚀脆化、蠕变断裂脆化、氢脆化、液态金属脆化、中子脆化、焊料脆化、固态金属脆化和应力腐蚀开裂。 |
| Accommodation | 适应能力 |
The ability of a robot to respond to changes in the environment. 机器人对环境变化做出反应的能力。 |
| Steam gauge | 汽压表 |
A pressure gauge used to measure gauge pressure in a line, boiler, cylinder, or other device operating with steam. 一种压力表，用于测量管道、锅炉、汽缸或其他与蒸汽一起工作的装置中的表压。 |
| Combustion deposit | 燃烧沉积物 |
Ash, carbon, and other incombustible solids, often due to impurities in the fuel, that build up on any surfaces exposed to products of combustion. They can lead to corrosion, reduced heat transfer and so higher flue-gas temperatures and reduced efficiency. 灰、碳和其他不燃固体，通常是由于燃料中的杂质，在暴露于燃烧产物的任何表面上堆积。它们会导致腐蚀、传热降低，从而导致烟气温度升高和效率降低。 |
| Temper color | 回火颜色 |
A thin, tightly adhering oxide skin that forms when steel is tempered at a low temperature, or for a short time, in air or a mildly oxidizing atmosphere. The color, which ranges from straw to blue depending on the thickness of the oxide skin, varies with both tempering time and temperature. 一种薄的、紧密粘附的氧化皮，当钢在低温或短时间内在空气或轻度氧化气氛中回火时形成。颜色范围从稻草色到蓝色，取决于氧化皮的厚度，随回火时间和温度而变化。 |
| Vehicle | 车辆 |
A means of conveyance for transporting goods and people, generally with wheels powered by a petrol, diesel, or steam engine, or by an electric motor, or by a hybrid combination of an electric motor and a diesel or petrol engine. 一种运输货物和人员的交通工具，通常由汽油机、柴油机或蒸汽机、电动机或电动机与柴油机或汽油机的混合动力驱动。 |
| U-bolt | U型螺栓 |
A rod threaded at both ends and bent into a U-shape. It is used for clamping. An externally threaded fastener bent in the shape of the letter U and with both ends threaded. 两端有螺纹并弯曲成U形的杆。用于夹紧。一种外螺纹紧固件，弯曲成字母U的形状，两端带有螺纹。 |
| Ablative materials | 烧蚀材料 |
Materials, especially coating materials, designed to provide thermal protection to a body in a fluid stream through the loss of mass. 材料，尤其是涂层材料，旨在通过质量损失为流体流中的物体提供热保护。 |
| Circlip | 卡簧 |
(snap ring) An external or internal retaining ring that locates parts of circular cross section in an axial direction. It consists of an incomplete ring, with holes on either side of the gap, that may be expanded by a plier-like tool to pass into a groove in a shaft or contracted to pass into a groove in a bore. （卡环）在轴向定位圆形横截面部分的外部或内部保持环。它由一个不完整的环组成，在间隙的任一侧都有孔，可以通过钳形工具将其扩展以进入轴中的凹槽或收缩以进入孔中的凹槽。 |
| Auxetic materials | 拉胀材料 |
Those man-made materials for which Poisson’s ratio is negative, so that the cross section expands when subjected to a longitudinal tensile stress and contracts when subjected to a longitudinal compressive stress. 泊松比为负的人造材料，其横截面在受到纵向拉应力时会膨胀，在受到纵向压应力时会收缩。 |
| Pressure gauge | 压力表 |
An instrument used to measure absolute or gauge pressure. The sensing element may be a tube which deflects when pressurized, as in a Bourdon gauge, a bellows as in an aneroid barometer, a piezoelectric crystal, a piezoresistive element, etc. 测量绝对压力或表压的仪器。传感元件可以是加压时会偏转的管，如波登压力表、无液气压计中的波纹管、压电晶体、压阻元件等。 |
| Fastener quality | 紧固件质量 |
A fastener’s adherence to its specification for dimensional tolerances, mechanical properties, and other requirements stated under applicable standards. 紧固件对尺寸公差、机械性能和适用标准规定的其他要求的规范的遵守情况。 |
| Normalizing | 正火 |
Heating a ferrous alloy to a suitable temperature above the transformation range and then cooling in air to a temperature substantially below the transformation range. 将铁合金加热至高于转变范围的合适温度，然后在空气中冷却至基本低于转变范围的温度。 |
| Residual stress (Unit Pa) | 残余应力（单位Pa） |
Stresses that remain within a body as the result of thermal or mechanical treatment or both. (internal stress) An internal-stress system found in components that have experienced elastic unloading from non-uniform plastic-strain fields during manufacture. 由于热处理或机械处理或两者兼而有之而留在物体内的应力。（内应力）在制造期间从非均匀塑性应变场经历弹性卸载的部件中发现的内应力系统。 |
| 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。 |
| Static fatigue | 静态疲劳 |
A term referring to a time-dependent reduction in strength with a static (noncyclic) load. The term may refer to hydrogen-induced delayed cracking or the effect of creep on the strength of plastics. Delayed fracture caused by environmental effects under dead-weight loading of materials such as glass. The name is unfortunate, as cyclic loads are not involved and glass is not susceptible to fatigue. 指静态（非循环）载荷下强度随时间变化的降低。该术语可指氢致延迟开裂或蠕变对塑料强度的影响。在玻璃等材料的自重荷载下，由环境影响引起的延迟断裂。 |
| Quench-age embrittlement | 淬火时效脆化 |
Embrittlement of low-carbon steels resulting from precipitation of solute carbon at existing dislocations and from precipitation hardening of the steel caused by differences in ferrite at different temperatures. Quenchage embrittlement usually is caused by rapid cooling of the steel from temperatures slightly below Ac1 (the temperature at which austenite begins to form), and can be minimized by quenching from lower temperatures. 低碳钢的脆化是由于溶质碳在现有位错处的沉淀和铁素体在不同温度下的差异导致的钢沉淀硬化造成的。淬火脆性通常是由钢从略低于Ac1的温度（奥氏体开始形成的温度）快速冷却引起的，可以通过从较低温度淬火来最小化。 |
| Design stress (Unit Pa) | 设计应力（单位Pa） |
The greatest allowable stress in a component or structure that will not result in failure under normal operating conditions. 在正常操作条件下不会导致失效的部件或结构中的最大许用应力。 |
| 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。 |
| Angle of contact | 接触角 |
(Unit °) The angle subtended at the centre of a pulley or sprocket wheel by the circumferential contact of a belt or chain. （单位°）皮带或链条的圆周接触在皮带轮或链轮的中心所对的角度。 |
| Combustion efficiency | 燃烧效率 |
(source efficiency, ηCOMB) A performance measure for combustion equipment defined by ηCOMB = amount of heat released during combustion/(calorific value of the fuel burned). （源效率，ηCOMB）燃烧设备的性能度量，定义为ηCOMB=燃烧过程中释放的热量/（燃烧燃料的热值）。 |
| 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。 |
| Maximum allowable working pressure (Unit Pa) | 最大允许工作压力（单位Pa） |
The pressure on which the design of a pressure system is based and the highest pressure at which relief valves should be set. The lowest-rated component in the system typically has a design safety factor of 4. 压力系统设计所依据的压力和应设置安全阀的最高压力。系统中最低额定部件的设计安全系数通常为4。 |
| 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。 |
| Thermal compressor | 热压缩机 |
1. (thermocompressor) A jet compressor used to boost the pressure of low-pressure waste or exhaust steam. 2. A device consisting of an absorber, a generator, a pump, and a throttling device, used instead of a mechanical vapour compressor in an absorption-cooling refrigeration system. 1.（热压缩机）用于提升低压废蒸汽或排气压力的喷射压缩机。2.一种由吸收器、发电机、泵和节流装置组成的装置，用于替代吸收冷却制冷系统中的机械蒸汽压缩机。 |
| Wear | 磨损 |
Damage to a solid surface, generally involving progressive loss of material, due to relative motion between that surface and a contacting surface or substance. The deterioration of a component or structure with time and usage, often impairing the function for which it was designed, owing to abrasion, corrosion, fatigue, friction, etc. during relative motion of parts. The wear factor (K), with unit mm³/N.m, is an empirical dimensional factor that quantifies surface wear due to mechanical frictional contact, and defined by K = /Fs where is the worn volume (in mm³), F is the contact load (in N), and s is the sliding distance (in m). 由于固体表面与接触表面或物质之间的相对运动，对固体表面的损坏，通常涉及材料的渐进损失。部件或结构随时间和使用而劣化，通常由于部件相对运动过程中的磨损、腐蚀、疲劳、摩擦等而损害其设计功能。磨损系数（K），单位为mm³/N.m、 是量化机械摩擦接触导致的表面磨损的经验尺寸因子，由K=/Fs定义，其中是磨损体积（单位：mm³），F是接触载荷（单位：N），s是滑动距离（单位：m）。 |
| 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。 |
| Grain size | 晶粒大小 |
A measure of the areas or volumes of grains in a polycrystalline metal, usually expressed as an average when the individual sizes are fairly uniform. In metals containing two or more phases, the grain size refers to that of the matrix unless otherwise specified. For metals, a measure of the areas or volumes of grains in a polycrystalline material, usually expressed as an average when the individual sizes are fairly uniform. In metals containing two or more phases, the grain size refers to that of the matrix unless otherwise specified. Grain sizes are reported in terms of number of grains per unit area or volume, average diameter, or as a grainsize number derived from area measurements. 多晶金属中晶粒的面积或体积的量度，通常表示为单个尺寸相当均匀时的平均值。在含有两相或多相的金属中，除非另有说明，晶粒尺寸是指基体的晶粒尺寸。多晶材料中晶粒的面积或体积的量度，通常表示为单个尺寸相当均匀时的平均值。在含有两相或多相的金属中，除非另有说明，晶粒尺寸是指基体的晶粒尺寸。晶粒尺寸以每单位面积或体积的晶粒数、平均直径或从面积测量得出的晶粒尺寸数来报告。 |
| Machine tool | 机床工具 |
A powered machine, such as a borer, grinder, lathe, milling machine or planer, used for cutting and shaping metal, plastics, composites, etc. (machining). A machining centre is a CNC machine tool working about several axes, having a stock of tools and automatic tool changing ability, which is capable of diverse machining operations under automated control. 一种动力机器，如钻孔机、磨床、车床、铣床或刨床，用于切割和成形金属、塑料、复合材料等（机加工）。加工中心是围绕多个轴工作的CNC机床，具有刀具库存和自动换刀能力，能够在自动化控制下进行各种加工操作。 |
| Absolute expansion | 绝对扩张 |
The true volumetric expansion of a liquid with temperature, after account is taken of any expansion of the container in which it is held. 考虑到容纳液体的容器的任何膨胀后，液体随温度的真实体积膨胀。 |
| Root diameter (Unit m) | 根部直径（单位：m） |
The diameter of the circle passing through the roots of teeth in gear teeth or screw threads. 穿过齿轮齿或螺纹中齿根的圆的直径。 |
| Permanent set | 永久变形 |
The deformation or strain remaining in a previously stressed body after release of load. 释放荷载后，先前受力物体中剩余的变形或应变。 |
| 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。 |
| J-integral | J-积分 |
A mathematical expression describing a line or surface integral that encloses the crack front from one crack surface to the other, used to characterize the fracture toughness of a material having appreciable plasticity before fracture. The J-integral eliminates the need to describe the behavior of the material near the crack tip by considering the local stress-strain field around the crack front; JIc is the critical value of the J-integral required to initiate crack extension from a preexisting crack. 描述从一个裂纹表面到另一个裂纹正面的线或表面积分的数学表达式，用于表征断裂前具有可观塑性的材料的断裂韧性。J积分通过考虑裂纹前缘周围的局部应力应变场，无需描述裂纹尖端附近材料的行为；JIc是从先前存在的裂纹开始裂纹扩展所需的J积分的临界值。 |
| 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。 |
| Tensometer | 拉力计 |
A bench-top device, used to perform tension and compression tests. 用于进行拉伸和压缩试验的台式装置。 |
| Inch-pound force/inch² | 英寸磅力/英寸² |
A non-SI unit for the specific work of fracture (fracture toughness). The conversion to SI is 1 in.lbf/in² = 1.751 268 × 102 J/m². 用于特定断裂功（断裂韧性）的非国际单位制单位。到SI的转换为1英寸。lbf/in²=1.751268×102J/m²。 |
| Rpm (N) | 转速（N） |
An abbreviation for revolutions per minute. It is a widely used non-SI unit for rotational speed. The corresponding angular velocity ω in rad/s is given by πN/30. Rps (revolutions per second) is also used, the angular velocity then being 2πN. 每分钟转数的缩写。它是一种广泛使用的转速非SI单位。相应的角速度ω，单位为rad/s，由πN/30给出。还使用Rps（每秒转数），此时角速度为2πN。 |
| Piston pump | 活塞泵 |
A positive-displacement pump in the basic configuration of which a piston reciprocates in a cylinder. On the suction stroke, fluid is drawn into a chamber through the inlet valve, which is then open while the outlet valve is closed. On the delivery stroke the fluid is forced out of the chamber through the outlet valve, which then opens while the inlet valve is closed. Both axial and radial configurations are common. 活塞在气缸中往复运动的一种容积泵。在吸入冲程，流体通过入口阀吸入腔室，然后在出口阀关闭时打开。在输送冲程中，流体通过出口阀被迫流出腔室，然后出口阀打开，同时入口阀关闭。轴向和径向配置都很常见。 |
| Degrees of freedom | 自由度 |
The number of independent variables (such as temperature, pressure, or concentration within the phases present) that may be altered at will without causing a phase change in an alloy system at equilibrium; or the number of such variables that must be fixed arbitrarily to define the system completely. 可以随意改变而不引起平衡时合金系统相变的自变量的数量（例如存在的相内的温度、压力或浓度）；或必须任意固定以完全定义系统的此类变量的数量。 |
| Roots blower | 罗茨鼓风机 |
(rotary-piston blower) A positive-displacement gas compressor with two meshing lobed rotors that rotate within a close-fitting casing. Commonly used as a supercharger. （旋转活塞鼓风机）一种容积式气体压缩机，具有两个啮合的凸角转子，在紧密配合的外壳内旋转。通常用作增压器。 |
| Acid rain | 酸雨 |
Any form of precipitation, including rain, snow, sleet, fog, dew, and particulates, which contains higher than normal levels of sulfuric and nitric acids. These acids result from natural and man-made emissions of sulfur dioxide and oxides of nitrogen, respectively. Acid soot consists of unburned carbon particles, typically larger than 10 μm, in the atmosphere contaminated with sulfuric acid. The particles result from poor combustion of fossil fuels. 任何形式的降水，包括雨、雪、雨夹雪、雾、露水和颗粒物，其中含有高于正常水平的硫酸和硝酸。这些酸分别来自二氧化硫和氮氧化物的自然排放和人为排放。酸烟灰由未燃烧的碳颗粒组成，通常大于10微米，在被硫酸污染的大气中。这些颗粒是化石燃料燃烧不良造成的。 |
| 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。 |
| Compressive stress | 压缩应力 |
A stress that causes an elastic body to deform (shorten) in the direction of the applied load. Contrast with tensile stress. 使弹性体沿施加载荷方向变形（缩短）的应力。与拉应力对比。 |
| Rolled thread | 滚制螺纹 |
A thread formed by plastically deforming the surface of the blank rather than by cutting operations. Increases fatigue life and thread strength, but is not possible (or perhaps economical) on larger sizes. 通过塑性变形坯料表面而不是通过切割操作形成的螺纹。增加疲劳寿命和螺纹强度，但不太可能（或者说是经济上不太可能）用于较大的尺寸。 |
| Low-E coating | 低辐射涂层 |
(low-emittance coating) A thin metallic or metal-oxide coating on a glass sheet to absorb and reflect infrared radiation. The coating is applied either by a pyrolytic chemical vapour-deposition process (hard coat), or by sputtering (soft coat). （低辐射涂层）玻璃板上的薄金属或金属氧化物涂层，用于吸收和反射红外辐射。通过热解化学气相沉积工艺（硬涂层）或溅射（软涂层）施加涂层。 |
| Torque multiplier | 扭矩放大器 |
A gearbox used to multiply the torque produced by a small hand wrench (usually a Torque wrench). The output of the multiplier drives the nut or bolt with a torque that is higher, and a speed that is lower, than input torque and speed. There is no torque gage or readout on the multiplier. 一种齿轮箱，用于增加小手动扳手（通常是扭矩扳手）产生的扭矩。倍增器的输出以比输入扭矩和速度更高的扭矩和更低的速度驱动螺母或螺栓。倍增器上没有扭矩计或读数。 |
| 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。 |
| 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。 |
| 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。 |
| Stress cycle | 应力循环 |
The smallest segment of the stress-time function that is repeated periodically. 周期性重复的应力时间函数的最小段。 |
| Cellular materials | 蜂窝材料 |
There are three broad classes of materials that have a sponge-like structure containing many small closed or open (interlinked) pores or cells. Natural cellular materials include bone, cork, sponge, and wood, and have numerous well-known uses. Wide ranges of cellular plastics are produced using blowing or foaming agents, such as air, ammonium carbonate, sodium bicarbonate, etc., to create pores during the processing of thermoplastic or thermosetting polymers. Rigid foams have moderate compressive strength and can be moulded and machined. 有三大类材料具有海绵状结构，包含许多小的封闭或开放（互连）孔或细胞。天然多孔材料包括骨骼、软木、海绵和木材，有许多众所周知的用途。使用发泡剂或发泡剂（如空气、碳酸铵、碳酸氢钠等）生产各种泡沫塑料，以在热塑性或热固性聚合物加工过程中产生孔隙。硬质泡沫具有中等抗压强度，可模制和机加工。 |
| Torque coefficient | 扭矩系数 |
1. (KT) For a propeller of diameter D, a non-dimensional parameter defined by KT = T/ρΩ2D5 where Ω is the rotational speed (in rad/s) and ρ is the fluid density. 2. (CT) An alternative to (1) for a wind turbine, defined by CT = 2T/ρV2AR where V is the wind speed, A is the swept area of the blades, and R is the blade radius. 3. (K) An empirical coefficient used to calculate the torque T required to achieve an axial load F in a bolt according to T = KFd where d is the nominal bolt diameter. 1.（KT）对于直径为D的螺旋桨，由KT=T/ρΩ2D5定义的无量纲参数，其中Ω是转速（单位为rad/s），ρ是流体密度。2.（CT）对于风力涡轮机（1）的替代方案，由CT=2T/ρV2AR定义，其中V是风速，a是叶片的扫掠面积，R是叶片半径。3.（K）经验系数，用于根据T=KFd计算螺栓中实现轴向载荷F所需的扭矩T，其中d是螺栓标称直径。 |
| Connecting rod | 连杆 |
(con rod) A link that transmits power from one system to another, often changing linear to rotary motion, as in the rod connecting the piston to the crankshaft in a reciprocating compressor or pump or to the crankshaft in an internal-combustion engine, as in the diagram. The big end (bottom end) is the larger end that connects to the bearing on one of the crankpins of the crankshaft. The little end (small end) is joined by a gudgeon pin to the piston. （连杆）将动力从一个系统传递到另一个系统的连杆，通常由线性运动变为旋转运动，如图所示，连杆将活塞连接到往复式压缩机或泵的曲轴或内燃机的曲轴上。大端（底端）是连接到曲轴一个曲柄销上轴承的大端。小端（小端）通过活塞销连接到活塞上。 |
| Lock-nut pipe thread | 锁紧螺母管螺纹 |
The lock-nut pipe thread is a straight thread of the largest diameter which can be cut on a pipe. Its form is identical with that of the American or Briggs standard taper pipe thread. In general, “Go” gages only are required. These consist of a straight-threaded plug representing the minimum female lock-nut thread, and a straight-threaded ring representing the maximum male lock-nut thread. This thread is used only to hold parts together, or to retain a collar on the pipe. It is never used where a tight threaded joint is required. 锁紧螺母管螺纹是最大直径的直螺纹，可在管道上切割。其形式与美国或布里格斯标准锥管螺纹相同。一般情况下，只需要通规。它们由一个表示最小内螺纹锁紧螺母螺纹的直螺纹塞和一个表示最大外螺纹锁紧螺帽螺纹的直形螺纹环组成。该螺纹仅用于将零件固定在一起，或用于将轴环固定在管道上。切勿使用于需要紧密螺纹接头的情况下。 |
| Air-cooled engine | 风冷发动机 |
An internal-combustion engine directly cooled by airflow, rather than by water flowing through the engine block being cooled by a radiator. 一种由气流直接冷却的内燃机，而不是通过流经发动机缸体的水被散热器冷却。 |
| 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。 |
| Tensile test (tension test) | 拉伸试验（拉力试验） |
A test in which a precisely-machined tensile specimen (tensile testpiece), typically circular or rectangular in cross section with large end sections that are gripped in the testing machine, is subjected to an increasing tensile load, usually to the point of fracture, to produce a stress–strain curve from which such material properties as modulus of elasticity, limit of proportionality, proof stress, yield point, and ultimate tensile stress can be determined. The relevant standard is ISO 6892-1. 一种试验，在这种试验中，精密加工的拉伸试样（拉伸试件）的横截面通常为圆形或矩形，具有在试验机中夹紧的大端部，受到越来越大的拉伸载荷，通常达到断裂点，以产生应力-应变曲线，从中可以看出弹性模量、比例极限等材料特性，可以确定验证应力、屈服点和极限拉伸应力。相关标准为ISO 6892-1。 |
| Secant modulus | 割线模量 |
The slope of the secant drawn from the origin to any specified point on a stress-strain curve. Compare with chord modulus. 从原点到应力应变曲线上任何指定点的割线斜率。与弦模量进行比较。 |
| 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。 |
| Flange bolt | 法兰螺栓 |
A bolt with a built in washer-like flange just below the head. 在头部下方带有内置垫圈状法兰的螺栓。 |
| 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。 |
| 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。 |
| Interrupted quenching | 间断淬火 |
A quenching procedure in which the workpiece is removed from the first quench at a temperature substantially higher than that of the quenchant and is then subjected to a second quenching system having a different cooling rate than the first. 在该淬火过程中，工件在显著高于淬火剂的温度下从第一次淬火中取出，然后经受具有不同于第一次淬火的冷却速率的第二次淬火系统。 |
| Flange rotation | 法兰转角 |
Angular distortion of a flange under the influence of bolt and reaction forces. Measured with respect to the center of the cross section of the flange. 法兰在螺栓和反作用力影响下的角度变形。相对于法兰横截面的中心测量。 |
| Die | 模具 |
1. A tool having an appropriately-shaped hole through which material may be extruded or drawn. 2. A tool employed in forging. 3. A block having the male or female shape employed in stamping operations. 4. A thick circular disc, driven by a die wrench, with internally-threaded cutting edges for producing a screw thread. A die wrench (die stock) holds a screw-cutting die and has two projecting arms for applying the torque necessary to cut the thread. A die having a hexagonal or square shape (die nut), driven by a spanner, is used in confined spaces where a die wrench cannot be rotated through a full circle. 1.一种具有适当形状的孔的工具，通过该孔可以挤压或拉伸材料。2.一种用于锻造的工具。3.一种用于冲压操作的具有阳或阴形状的块体。4.一种由模具扳手驱动的厚圆盘，具有用于产生螺纹的内螺纹切削刃。冲模扳手（冲模）装有一个螺旋切割模，并有两个突出臂，用于施加切割螺纹所需的扭矩。由扳手驱动的六边形或方形模具（模具螺母）用于模具扳手无法旋转一整圈的受限空间。 |
| Dimensioning | 尺寸标注 |
The specification on an engineering drawing of the size (e.g. length, radius, angle, or spacing) and the relative location (e.g. angular position) of each feature of a component. The numerical values often include the tolerances. There should be no more dimensions than are necessary to manufacture the component. 工程图纸上对部件每个特征的尺寸（例如长度、半径、角度或间距）和相对位置（例如角位置）的规范。数值通常包括公差。尺寸不应超过制造组件所需的尺寸。 |
| Turbine pump (turbopump) | 涡轮泵 |
An axial or centrifugal pump driven by a turbine. Typically used to supply fuel to the combustion chamber of a rocket engine such as on the space shuttle. 由涡轮驱动的轴向或离心泵。通常用于向火箭发动机（如航天飞机）的燃烧室供应燃料。 |
| Angle of torsion | 扭转角 |
(angle of twist) (Unit ° or rad) The angle relative to a chosen section, normal to the axis of twist, through which another part of a component rotates when subjected to a torque. （扭转角）（单位°或弧度）相对于选定截面的角度，垂直于扭转轴，部件的另一部分在受到扭矩时通过该角度旋转。 |
| 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。 |
| Liquid nitriding | 液体氮化 |
A method of surface hardening in which molten nitrogen-bearing, fused-salt baths containing both cyanides and cyanates are exposed to parts at subcritical temperatures. 一种表面硬化方法，其中含有氰化物和氰酸盐的熔融含氮熔盐浴在亚临界温度下暴露于零件。 |
| 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。 |
| Concentrated solar power plant (CSP plant) | 聚光太阳能发电厂（CSP发电厂） |
A power plant in which solar radiation is concentrated using mirrors or lenses, typically using parabolic trough mirrors which focus solar radiation on to receiver tubes along the trough’s focal line. In an alternative arrangement molten salt, heated by solar receivers mounted on a tower, is circulated through a steam generator. 使用镜子或透镜集中太阳辐射的发电厂，通常使用抛物面槽镜，将太阳辐射沿着槽的焦线聚焦到接收管上。在另一种布置中，由安装在塔上的太阳能接收器加热的熔盐通过蒸汽发生器循环。 |
| Fatigue striations | 疲劳条纹 |
Parallel lines frequently observed in electron microscope fractographs or fatigue-fracture surfaces. The lines are transverse to the direction of local crack propagation; the distance between successive lines represents the advance of the crack front during the one cycle of stress variation. 在电子显微镜断口图或疲劳断口表面中经常观察到平行线。这些线横向于局部裂纹扩展方向；连续线之间的距离表示在一个应力变化周期内裂纹前沿的前进。 |
| Radius of bend | 弯曲半径 |
The radius of the cylindrical surface of the pin or mandrel that comes in contact with the inside surface of the bend during bending. For free or semiguided bends to 180° in which a shim or block is used, the radius of bend is one-half the thickness of the shim or block. 在弯曲过程中与弯曲内表面接触的销或心轴的圆柱面半径。对于使用垫片或垫块的180°自由弯曲或半导向弯曲，弯曲半径为垫片或垫板厚度的一半。 |
| Flange | 法兰 |
Flange refers to a head style for bolts where there is a circular ‘flange’ under the head that acts like a washer to distribute a load. A flange is a projected flat rim or collar. 1. Annular rims at the ends of pipes (flanged pipe) or shafts by which they may be coupled together using bolts that pass through holes in the flanges (flange coupling, flange union), or by toggle clamps around the periphery. 2. An extended rim on a wheel that positions it laterally on a track. Commonly used for railway rolling stock. 3. The top and bottom parts of an I-beam. 法兰是指螺栓的头部样式，其中头部下方有一个圆形“法兰”，其作用类似于垫圈以分配载荷。凸缘是凸出的平轮辋或凸缘。1.管道（法兰管）或轴端部的环形边缘，通过这些边缘，可以使用穿过法兰孔的螺栓（法兰联轴器、法兰接头）或通过周边的肘节夹将管道连接在一起。2.车轮上的延伸轮辋，将其横向定位在轨道上。通常用于铁路车辆。3.工字梁的顶部和底部。 |
| Hardening | 硬化 |
Increasing hardness by suitable treatment, usually involving heating and cooling. When applicable, the following more specific terms should be used: age hardening, flame hardening, induction hardening, laser hardening, precipitation hardening, and quench hardening. 通过适当的处理增加硬度，通常包括加热和冷却。适用时，应使用以下更具体的术语：时效硬化、火焰硬化、感应硬化、激光硬化、沉淀硬化和淬火硬化。 |
| Critical diameter | 临界直径 |
(D) Diameter of the bar that can be fully hardened with 50% martensite at its center. （D）中心有50%马氏体可完全硬化的棒材直径。 |
| Altitude chamber | 高空舱 |
(hypobaric chamber) A chamber in which conditions at different altitudes are simulated by a combination of appropriate pressures, temperatures and relative humidity. （低压舱）通过适当的压力、温度和相对湿度的组合来模拟不同高度条件的舱室。 |
| 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。 |
| 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。 |
| Annealing carbon | 退火碳 |
Fine, apparently amorphous carbon particles formed in white cast iron and certain steels during prolonged annealing. Also called temper carbon. 白口铸铁和某些钢在长时间退火过程中形成的细小、明显的无定形碳颗粒。也称为回火碳。 |
| Applied thermodynamics | 应用热力学 |
(engineering thermodynamics, thermodynamics) The science of the relationship between heat, work and the properties of systems and the ways in which heat energy from fuels can be converted into mechanical work. It involves the study of all aspects of energy use and energy transformation, including power generation, refrigeration, the relevant properties of the substances involved and the relationships between them. The principle of conservation of energy is a fundamental law of nature. （工程热力学、热力学）热、功和系统特性之间关系的科学，以及燃料中的热能可以转化为机械功的方式。它涉及能源使用和能源转换的各个方面的研究，包括发电、制冷、所涉及物质的相关特性以及它们之间的关系。能量守恒定律是自然的基本规律。 |
| 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。 |
| Starting friction | 起动摩擦 |
(limiting friction, static friction, stiction) (Unit N) The force required to initiate movement between two bodies in contact. （极限摩擦力、静摩擦力、粘滞）（单位N）在两个接触物体之间启动运动所需的力。 |
| Pneumatic control valve | 气动控制阀 |
(pneumatic valve) A valve in which the position of the valve stem, which varies the open area, is determined by the net force generated by compressed air acting on a diaphragm operating against the force of a compression spring. Depending upon the arrangement of the spring, in the event of air-supply failure, the valve may open or close. （气动阀）一种阀门，其中阀杆的位置随开口面积的变化而变化，由压缩空气作用在隔膜上产生的净力决定，隔膜克服压缩弹簧的力进行操作。根据弹簧的布置，在供气故障的情况下，阀门可以打开或关闭。 |
| 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。 |
| Bulk velocity | 体积速度 |
(average velocity, V) (Unit m/s) For fluid flow in a pipe or duct, the average flow velocity, given by V = ṁ/ρA where ṁ is the mass flow rate, ρ is the fluid density, and A is the duct cross-sectional area. （平均速度，V）（单位m/s）对于管道或管道中的流体流动，平均流速，由V=ṁ/ρA给出，其中ṁ是质量流量，ρ是流体密度，A是管道截面积。 |
| Car furnace | 车炉 |
A batch-type furnace using a car on rails to enter and leave the furnace area. Car furnaces are used for lower stress relieving ranges. 一种间歇式炉，使用轨道上的小车进出炉区。汽车炉用于较低的应力消除范围。 |
| 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。 |
| Maximum stress (Smax) | 最大应力（Smax） |
The stress having the highest algebraic value in the stress cycle, tensile stress being considered positive and compressive stress negative. The nominal stress is used most commonly. 在应力循环中具有最高代数值的应力，拉应力被认为是正的，压应力被认为是负的。名义应力是最常用的。 |
| Active accommodation | 主动适应能力 |
The use of information from sensors, for example, in a vision system, that allows a robot to show accommodation to the environment. 使用来自传感器的信息，例如在视觉系统中，允许机器人显示对环境的适应。 |
| True strain | 真应变 |
(1) The ratio of the change in dimension, resulting from a given load increment, to the magnitude of the dimension immediately prior to applying the load increment. (2) In a body subjected to axial force, the natural logarithm of the ratio of the gage length at the moment of observation to the original gage length. Also known as natural strain. Compare with engineering strain. （1）给定载荷增量导致的尺寸变化与施加载荷增量之前尺寸大小的比率。（2）在承受轴向力的物体中，观察时刻标距与原始标距之比的自然对数。也称为自然应变。与工程应变相比。 |
| Minimum stress (Smin) | 最小应力（Smin） |
In fatigue, the stress having the lowest algebraic value in the cycle, tensile stress being considered positive and compressive stress negative. 在疲劳中，循环中代数值最低的应力，拉应力被视为正应力，压应力为负应力。 |
| 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。 |
| Working pressure (Unit Pa) | 工作压力（单位Pa） |
The pressure at which a pressure vessel, such as a boiler, is designed to operate under normal conditions. 压力容器（如锅炉）设计用于在正常条件下运行的压力。 |
| Complete decarburization | 完全脱碳 |
Decarburization with sufficient carbon loss to show only clearly defined ferrite grains under metallographic examination. 脱碳，具有足够的碳损失，以在金相检查下仅显示清晰定义的铁素体晶粒。 |
| Fatigue crack growth rate (da/dN) | 疲劳裂纹扩展率（da/dN） |
The rate of crack extension caused by constant-amplitude fatigue loading, expressed in terms of crack extension per cycle of load application. 恒幅疲劳荷载引起的裂纹扩展速率，以每次荷载施加循环的裂纹扩展表示。 |
| Density | 密度 |
The mass per unit volume of a solid material. (mass density, ρ) (Unit kg/m³) The mass per unit volume of a substance that satisfies the continuum assumption. The reciprocal of specific volume. 固体材料每单位体积的质量。（质量密度，ρ）（单位kg/m³）满足连续统假设的物质每单位体积的质量。和比容相关联。 |
| Tensioner | 张紧器 |
A hydraulic tool used to tighten a fastener by stretching it rather than by applying a substantial torque to the nut. After the tension has stretched the bolt or stud, the nut is run down against the joint with a modest torque, and the tensioner is disengaged from the fastener. The nut holds the stretch produced by the tensioner. 一种液压工具，用于通过拉伸紧固件而不是对螺母施加较大扭矩来拧紧紧固件。张力拉伸螺栓或螺柱后，以适当的扭矩将螺母向下压靠接头，张紧器与紧固件分离。螺母保持张紧器产生的拉伸。 |
| Bypass flow meter | 旁通流量计 |
(shunt flow meter) A flow meter installed in a pipework bypass which may itself be part of the flow meter. An orifice plate is used to ensure a fraction of the main flow passes through the bypass. （分流流量计）安装在管道旁路中的流量计，它本身可能是流量计的一部分。孔板用于确保一部分主流通过旁路。 |
| 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。 |
| Activation energy | 活化能 |
(Ea, U) (Unit kJ/mol) The minimum energy for a chemical reaction to occur or for processes such as diffusion to take place in crystals. （Ea, U）（单位kJ/mol）发生化学反应或在晶体中发生扩散等过程的最小能量。 |
| Impact strength 1. (Unit Pa) | 冲击强度1.（单位Pa） |
The stress to cause failure (by yielding or fracture) under conditions of high strain rate. 2. (Unit J) A term sometimes used to describe the energy required to fracture a specimen in a Charpy or Izod impact test even though the unit is not that of strength. 在高应变率条件下导致失效（通过屈服或断裂）的应力。2.（单位J）有时用于描述在夏比或悬臂梁式冲击试验中使样品断裂所需的能量，即使单位不是强度单位。 |
| Hypoeutectoid alloy | 亚共析合金 |
In an alloy system exhibiting a eutectoid, any alloy whose composition has an excess of base metal compared with the eutectoid composition, and whose equilibrium microstructure contains some eutectoid structure. 在呈现共析的合金系统中，与共析成分相比，其成分具有过量母材的任何合金，并且其平衡微观结构包含一些共析结构。 |
| Vernier | 游标 |
A short auxiliary scale that slides along the main instrument scale to permit more accurate fractional reading of the least main division of the main scale. 一种短辅助刻度，沿主仪表刻度滑动，以便更准确地读取主刻度的最小主刻度。 |
| Rosette | 玫瑰形的结 |
Strain gages arranged to indicate, at a single position, strain in three different directions. 应变计布置成在单个位置指示三个不同方向的应变。 |
| Stress cycles endured (N) | 承受的应力循环（N） |
The number of cycles of a specified character (that produce fluctuating stress and strain) that a specimen has endured at any time in its stress history. 试样在其应力历史中任何时间所经受的特定特征（产生波动应力和应变）的循环次数。 |
| GGas turbine | G燃气轮机 |
An engine in which air, compressed by a multi-stage axial compressor and/or one or more centrifugal compressors, flows into a combustion chamber (or chambers) where fuel is burned and the hot gases then drive an axial turbine which powers the compressor. 由多级轴流压缩机和/或一个或多个离心压缩机压缩的空气流入燃烧室（或多个燃烧室），在燃烧室中燃烧燃料，然后热气体驱动轴流涡轮，为压缩机提供动力。 |
| Air composition | 空气成分 |
The sea-level composition (in per cent by volume) of air at a temperature of 15°C and a pressure of 1 atm is mainly 78.084% nitrogen, 20.947% oxygen and 0.934% argon. The remaining 0.035% consists of carbon dioxide, neon, helium, methane, krypton, hydrogen, oxides of nitrogen, xenon, ozone, iodine, carbon monoxide, and ammonia. Different sources give slightly different figures for the composition. Not included are water vapour (typically 0.4%) and pollutants such as sulfur dioxide. 在15°C的温度和1个大气压的压力下，空气的海平面成分（体积百分比）主要是78.084%的氮气、20.947%的氧气和0.934%的氩气。剩余的0.035%由二氧化碳、氖、氦、甲烷、氪、氢、氮的氧化物、氙、臭氧、碘、一氧化碳和氨组成。不同的来源给出的组成略有不同。不包括水蒸气（通常为0.4%）和二氧化硫等污染物。 |
| Tempered martensite embrittlement | 回火马氏体脆化 |
Embrittlement of ultrahigh-strength steels caused by tempering in the temperature range of 205 to 400 °C (400 to 750 °F); also called 350 °C or 500 °F embrittlement. Tempered martensite embrittlement is thought to result from the combined effects of cementite precipitation on prioraustenite grain boundaries or interlath boundaries and the segregation of impurities at prioraustenite grain boundaries. 超高强度钢在205至400°C（400至750°F）温度范围内回火引起的脆化；也称为350°C或500°F脆化。回火马氏体脆化被认为是由于渗碳体沉淀在原奥氏体晶界或层间晶界上以及杂质在原奥氏体晶粒边界处偏析的综合影响。 |
| Stud | 螺柱 |
A rod having thread on both ends. A headless threaded fastener, threaded on both ends, with an unthreaded body in the middle section, or threaded from end to end. Used with two nuts, or with one nut and a tapped hole. A plain cylindrical piece having a threaded portion of suitable length at each end or a continuous thread over the entire length. One end is screwed into a machine or workpiece after which a second part is placed over the stud and held in place by a nut. 两端都有螺纹的杆。无头螺纹紧固件，两端有螺纹，中间部分有无螺纹主体，或从一端到另一端有螺纹。与两个螺母或一个螺母和一个螺纹孔一起使用。一种普通的圆柱形部件，其两端具有适当长度的螺纹部分，或在整个长度上具有连续螺纹。一端拧入机器或工件，然后将第二部分放在螺柱上，并用螺母固定到位。 |
| Clutch | 离合器 |
A device for connecting and disconnecting rotating shafts, for example between an engine and a gearbox. 一种用于连接和断开旋转轴的装置，例如在发动机和变速箱之间。 |
| Edge distance ratio | 边距比 |
The ratio of the edge distance to the pin diameter in a bearing test. 轴承测试中边缘距离与销直径的比值。 |
| 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。 |
| Compressometer | 压力计 |
Instrument for measuring change in length over a given gage length caused by application or removal of a force. Commonly used in compression testing of metal specimens. 用于测量在给定标距上由施加或移除力引起的长度变化的仪器。常用于金属试样的压缩试验。 |
| 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。 |
| Impact energy (Unit J) | 冲击能量（单位J） |
The amount of energy required to fracture a material, usually measured by means of an Izod test or Charpy test.The type of specimen and test conditions affect the values and therefore should be specified. 1. The sum of the kinetic energies of all the bodies involved at the instant of collision of two or more moving bodies. 2. The energy required to fracture a specimen in a Charpy or Izod impact test. 使材料断裂所需的能量，通常通过悬臂梁式试验或夏比试验测量。试样类型和试验条件会影响数值，因此应加以说明。1.两个或多个运动物体碰撞瞬间所有物体的动能之和。2.夏比或悬臂冲击试验中断裂试样所需的能量。 |
| Flame straightening | 火焰矫直 |
Correcting distortion in metal structures by localized heating with a gas flame. 通过使用气体火焰进行局部加热来纠正金属结构的变形。 |
| 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%。 |
| 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。 |
| 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。 |
| Vacuum servo | 真空服务器 |
A vacuum-operated servomotor which is used in a motor vehicle to provide a brake effort greater than the capability of the driver. 一种真空操作的伺服电机，用于机动车中，以提供大于驾驶员能力的制动力。 |
| Butt joint | 对接接头 |
The end-to-end joining of two plates either by welding or by overlapping plates that are bolted or riveted. 通过焊接或通过螺栓或铆接的重叠板将两块板端对端连接。 |
| Lobe | 凸轮 |
The projecting part such as rotor lobe or the cam lobe. 转子凸角或凸轮凸角等突出部分。 |
| Caustic quenching | 苛性淬火 |
Quenching with aqueous solutions of 5 to 10% sodium hydroxide (NaOH). 用5%至10%氢氧化钠（NaOH）水溶液淬灭。 |
| Closed system | 封闭系统 |
A closed thermodynamic system consists of a fixed amount of mass. No mass can cross its boundary although energy can, in the form of work or heat, and its volume can change. 一个封闭的热力学系统由一定量的质量组成。能量可以以功或热的形式存在，其体积可以改变，但没有质量可以越过它的边界。 |
| Air compressor | 空气压缩机 |
A turbomachine that draws in air and delivers it at higher pressure, temperature, and density. It can be of axial, fan, reciprocating, or rotary design. 一种涡轮机，它吸入空气并以更高的压力、温度和密度输送空气。它可以是轴流式、风扇式、往复式或旋转式设计。 |
| Fluid mechanics | 流体力学 |
The study of fluids in motion (fluid dynamics) or fluid statics where there is no relative motion between fluid particles. Fluid statics concerns primarily the variation of pressure with altitude or depth; it includes aerostatics and hydrostatics. Fluid dynamics includes the topics of aerodynamics, gas dynamics, hydraulics, hydrodynamics and many aspects of acoustics, chemical engineering, flight, lubrication, meteorology, non-Newtonian fluid flow, oceanography, power-plant technology, propulsion, and turbomachinery. 研究运动中的流体（流体动力学）或流体静力学，其中流体粒子之间没有相对运动。流体静力学主要关注压力随高度或深度的变化；它包括空气静力学和流体静力学。流体动力学包括空气动力学、气体动力学、水力学、流体动力学以及声学、化学工程、飞行、润滑、气象学、非牛顿流体流动、海洋学、发电厂技术、推进和涡轮机械的许多方面。 |
| Mode of failure | 故障模式 |
The various ways in which a material can fail when subjected to loading, surface damage, chemical attack, heating, cooling, or radiation, in either isolation or combination. The failure modes include fracture, fatigue, creep, corrosion, erosion, and embrittlement. 材料在受到载荷、表面损伤、化学侵蚀、加热、冷却或辐射时，可能发生失效的各种方式，无论是单独还是组合。失效模式包括断裂、疲劳、蠕变、腐蚀、侵蚀和脆化。 |
| Barometer | 气压计 |
An instrument used to measure atmospheric pressure. An instrument for measuring atmospheric pressure. There are two main types – the mercury barometer, and the aneroid barometer. 用于测量大气压力的仪器。有两种主要类型——水银气压计和无液气压计。 |
| 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。 |
| Zero initial conditions | 零初始条件 |
The assumption normally made in control engineering that up to a start time defined as t = 0, all variables have zero value. 在控制工程中通常作出的假设，即在定义为t=0的开始时间内，所有变量均为零值。 |
| Flat head | 平头 |
Flat top surface and a conical bearing surface. 平顶表面和锥形轴承表面。 |
| Millimetre of water | 毫米水柱 |
A non-SI unit of pressure equal to the pressure exerted by a vertical column of water 1 mm high. Approximately equal to 9.81 Pa. 一种非SI压力单位，等于1毫米高的垂直水柱施加的压力。大约等于9.81Pa。 |
| 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。 |
| Jack | 杰克装置 |
A lifting device that exerts large forces over small displacements, achieved by mechanical gearing or hydraulics. 通过机械传动或液压装置在小位移上施加大力的提升装置。 |
| Fracture toughness | 断裂韧性 |
A generic term for measures of resistance to extension of a crack. The term is sometimes restricted to results of fracture mechanics tests, which are directly applicable in fracture control. However, the term commonly includes results from simple tests of notched or precracked specimens not based on fracture mechanics analysis. Results from tests of the latter type are often useful for fracture control, based on either service experience or empirical correlations with fracture mechanics tests. 裂纹扩展阻力测量的通用术语。该术语有时仅限于断裂力学试验的结果，这些结果直接适用于断裂控制。该术语通常包括非基于断裂力学分析的切口或预裂纹试样的简单试验结果。基于使用经验或与断裂力学试验的经验相关性，后一类试验的结果通常有助于断裂控制。 |
| 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。 |
| Air cleaner | 空气净化器 |
A device, such as a filter, hydrocyclone, or electrostatic precipitator, that removes particles and aerosols from a flow of air. 一种设备，例如过滤器、水力旋流器或静电除尘器，用于从气流中去除颗粒和气溶胶。 |
| 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。 |
| Uniform elongation | 均匀伸长 |
The elongation at maximum load and immediately preceding the onset of necking in a tension test. 在拉伸试验中，在最大载荷下和颈缩开始之前的伸长率。 |
| Microscopic stresses | 微观应力 |
Residual stresses that vary from tension to compression in a distance (presumably approximating the grain size) that is small compared with the gage length in ordinary strain measurements. They are not detectable by dissection methods, but can sometimes be measured from line shift or line broadening in an x-ray diffraction pattern. 与普通应变测量中的标距相比，从拉伸到压缩的距离（大概接近晶粒尺寸）较小的残余应力。它们无法通过解剖方法检测到，但有时可以通过x射线衍射图案中的线位移或线加宽来测量。 |
| Fitted bolt | 装配螺栓 |
A bolt with a plain unthreaded portion immediately beneath the head. 一种螺栓，其头部正下方有一个普通的无螺纹部分。 |
| Centripetal | 向心力 |
Acting or moving in a direction towards the axis of rotation. 在朝向旋转轴的方向上起作用或移动。 |
| Batch furnace | 间歇式炉 |
A furnace used to heat treat a single load at a time. Batch-type furnaces are necessary for large parts such as heavy forgings and are preferred for complex alloy grades requiring long cycles. 用于一次热处理单个负载的炉子。对于重型锻件等大型零件，间歇式炉是必需的，对于需要长周期的复杂合金牌号来说是首选。 |
| Normal stress (Unit N) | 法向应力（单位：N） |
The stress component perpendicular to a plane on which forces act. Normal stress may be either tensile stress or compressive stress. A stress in a fluid (such as pressure) or a solid, that is perpendicular to the surface on which it acts. The surface may be a real external surface or an imaginary internal one. 垂直于受力平面的应力分量。法向应力可以是拉应力或压应力。流体（如压力）或固体中垂直于其作用表面的应力。该表面可以是真实的外表面或假想的内表面。 |
| Wind velocity (Unit m/s) | 风速（单位：m/s） |
1. In the Earth’s atmosphere, a vector quantity that quantifies both the magnitude of the wind speed and its direction at a given altitude and location, conveniently represented in the hodograph plane. For convenience, the unit kph is often used. It could in principle also include information about large- and small-scale unsteadiness. Spatial variation in wind velocity, either with altitude or in a horizontal plane, is termed wind shear. 2. The airspeed in the working section of a wind tunnel. 1.在地球大气层中，一种矢量量，用于量化给定高度和位置处的风速大小及其方向，方便地用速度计平面表示。为方便起见，通常使用单位kph。原则上，它还可以包括关于大尺度和小尺度不稳定性的信息。风速随高度或水平面的空间变化称为风切变。2.风洞工作段的空速。 |
| Mechatronics | 机电一体化 |
The integration of mechanical engineering, electrical engineering, electronic engineering, and software engineering. 机械工程、电气工程、电子工程和软件工程的集成。 |
| Gasket factors | 垫片系数 |
Experimentally derived ‘‘constants’’ used to define the behavior of a gasket or the assembly and in-service conditions required for acceptable behavior. 实验得出的“常数”用于定义垫圈的行为或可接受行为所需的组件和使用条件。 |
| 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。 |
| Specimen | 样品 |
A test object, often of standard dimensions or configuration, that is used for destructive or nondestructive testing. One or more specimens may be cut from each unit of a sample. 用于破坏性或无损检测的测试对象，通常具有标准尺寸或配置。可以从样品的每个单位切割一个或多个样品。 |
| Displacement | 移位 |
The distance that a chosen measurement point on a cracked specimen displaces normal to the crack plane as the crack grows. 随着裂纹扩展，裂纹试样上选定的测量点垂直于裂纹平面位移的距离。 |
| Pitch diameter | 中径 |
For screw threads, the diameter of an imaginary cylinder, the surface of which would pass through the threads at such points that would make the width of the groove and width of the land equal to one half the pitch. 对于螺纹，指一个假想圆柱体的直径，其表面将在使凹槽宽度和焊盘宽度等于螺距一半的点穿过螺纹。 |
| Stress distribution | 应力分布 |
The manner in which tensile, compressive, and shear stresses are distributed within a loaded body, indicated by loci of constant stress. 拉应力、压应力和剪应力在受载物体内的分布方式，由恒定应力轨迹表示。 |
| Notch brittleness | 缺口脆性 |
Susceptibility of a material to brittle fractureat points of stress concentration. For example, in a notch tensile test, the material is said to be notch brittle if the notch strengthis less than the tensile strength of an unnotched specimen. Otherwise, it is said to be notch ductile. 材料在应力集中点易发生脆性断裂。例如，在缺口拉伸试验中，如果缺口强度小于无缺口试样的抗拉强度，则称材料为缺口脆性材料。否则，称其为缺口韧性。 |
| 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。 |
| Bainitic hardening | 贝氏体硬化 |
Quench-hardening treatment resulting principally in the formation of bainite. 淬火硬化处理主要导致贝氏体的形成。 |
| Impact wrench | 冲击扳手 |
An air- or electric-powered wrench in which multiple blows from tiny hammers are used to produce output torque to tighten fasteners. A pneumatically-or electrically-powered socket wrench used to tighten or loosen nuts through the application of torque in a rapid series of impulses. 一种气动或电动扳手，使用小锤子多次敲击来产生输出扭矩以拧紧紧固件，用于通过在一系列快速脉冲中施加扭矩来拧紧或松开螺母。 |
| Compressible flow | 可压缩流动 |
A gas flow in which the Mach number M is sufficiently high for the gas density to change significantly. For air, this is when M > 0.3. 马赫数M高到足以使气体密度发生显着变化的气流。对于空气，这是当M>0.3时。 |
| Damage | 损伤 |
1. The deterioration of a component or structure in fault or accident conditions, reducing or preventing its ability to perform its intended function. 2. The accumulation of defects or microcracks in the microstructure of a body loaded monotonically or in fatigue, which weakens the body and can lead to crack propagation and failure. 1.部件或结构在故障或事故条件下的劣化，降低或阻止其执行预期功能的能力。2.在承受单调载荷或疲劳载荷的物体的微观结构中累积的缺陷或微裂纹，这会削弱物体，并可能导致裂纹扩展和失效。 |
| Centre line | 中心线 |
1. In an engineering drawing, a line of symmetry. 2. An imaginary line along a pipe, duct, or shaft that defines an axis of symmetry. 3. An imaginary straight line parallel to the intended direction of a surface located such that the areas above and below the line and the real wavy (rough) surface cancel out. 1.在工程图中，对称线。2.沿着管道、管道或竖井定义对称轴的假想线。3.一条平行于表面预期方向的假想直线，该直线上方和下方的区域与真实的波状（粗糙）表面相抵消。 |
| 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。 |
| Adhesive wear | 粘着磨损 |
Wear that develops when two surfaces slide across one another under pressure. The removal or displacement of material from a surface by the welding together and subsequent shearing of minute areas of two surfaces that slide across each other under pressure. In advanced stages, may lead to galling. Contrast with abrasive wear. 当两个表面在压力下相互滑动时产生的磨损。通过焊接在一起并随后剪切在压力下相互滑动的两个表面的微小区域，从表面去除或置换材料。在晚期，可能会导致擦伤。与磨料磨损形成对比。 |
| Thread run-out | 螺纹耗尽 |
That portion of the threads which are not cut or rolled full depth, but which provide the transition between full-depth threads and the body or head. Officially called thread washout or vanish, although the term run-out is more popular. (Run-out is officially reserved for rotational eccentricity, as defined by total indicator readings or the like.) 未全深度切割或轧制的螺纹部分，但提供全深度螺纹与主体或头部之间的过渡。官方称之为螺纹冲蚀或消失，但术语“耗尽”更为流行。（跳动是官方为旋转偏心度保留的，由总指示器读数等定义。） |
| Sigma phase | σ相 |
A hard, brittle, nonmagnetic intermediate phase with a tetragonal crystal structure, containing 30 atoms per unit cell, space group P42/mnm, occurring in many binary and ternary alloys of the transition elements. The composition of this phase in the various systems is not the same, and the phase usually exhibits a wide range in homogeneity. Alloying with a third transition element usually enlarges the field of homogeneity and extends it deep into the ternary section. 一种硬、脆、非磁性中间相，具有四方晶体结构，每单位晶胞含有30个原子，空间群P42/mnm，存在于许多过渡元素的二元和三元合金中。该相在各种系统中的组成不尽相同，并且该相通常表现出宽范围的均匀性。与第三过渡元素的合金化通常会扩大均匀性范围，并将其延伸到三元区。 |
| 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。 |
| U-tube | U型管 |
A device consisting of two vertical tubes connected at either the top or bottom by a length of tubing such that a U-shape is formed. 由两个垂直管组成的装置，在顶部或底部通过一段管子连接，形成U形。 |
| 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。 |
| Combined carbon | 复合碳 |
The part of the total carbon in steel or cast iron that is present as other than free carbon. 钢或铸铁中总碳中除游离碳外的部分。 |
| Bolt length | 螺栓长度 |
The bolt length shall be the distance measured parallel to the axis of the product from the bearing surface of the head to the extreme end of the bolt including point. 螺栓长度应为平行于产品轴线测量的从头部的支承面到包括点在内的螺栓末端的距离。 |
| 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。 |
| Imperial system | 英制单位体系 |
The units of measurement developed in the UK. Formerly known as the fps system, which is an abbreviation for the ‘foot-pound-second system of units. 英国开发的计量单位。以前称为fps系统，是“英尺-磅-秒（foot-pound-second）单位制”的缩写。 |
| Absolute zero | 绝对零度 |
Temperature of -273.16″C or 459.69″F or OK at which molecular motion vanishes and a body has no heat energy. 温度为-273.16″C或459.69″F，此时分子运动消失且物体没有热能。 |
| Thermal efficiency | 热效率 |
The ratio, for a heat engine or thermodynamic cycle, of the net work output to the net heat input into the system. 对于热机或热力循环，净功输出与系统净热输入的比率。 |
| Plane-strain fracture toughness (KIc) | 平面应变断裂韧性（KIc） |
The crack extension resistance under conditions of crack-tip plane strain. 裂纹尖端平面应变条件下的裂纹扩展阻力。 |
| Combustion | 燃烧氧化 |
An exothermic chemical reaction in which a fuel and an oxidant, typically air, react together to release a significant quantity of thermal energy in the presence of a flame. In the case of fluid fuels, ignition may be from an electric spark or compression of the 一种放热化学反应，其中燃料和氧化剂（通常是空气）一起反应，在火焰存在的情况下释放大量热能。 |
| V-belt | 三角带 |
A drive belt having a trapezoidal cross section which runs in pulleys with V-shaped grooves. Higher torques can be transmitted than with a flat belt. 一种具有梯形横截面的传动带，在带V形槽的皮带轮中运行。与平皮带相比，可以传递更高的扭矩。 |
| Active vibration suppression | 主动振动抑制 |
The reduction of undesirable vibration in components by feedback control. 通过反馈控制减少部件中的不良振动。 |
| Thermodynamic process | 热力学过程 |
A change in equilibrium state undergone by a quantity of matter or a system. 一定量的物质或系统所经历的平衡状态的变化。 |
| Slip band | 滑带 |
A group of parallel slip lines so closely spaced as to appear as a single line when observed under an optical microscope. 一组平行滑移线，间距如此之近，以至于在光学显微镜下观察时显示为一条直线。 |
| U-bend | U形管 |
U-bend A 180° bend in a pipe. 180°弯曲的管道。 |
| Net weight (Unit N) | 净重（单位：N） |
The difference between the gross weight of any container including its contents and the tare weight of the empty container. 任何容器（包括其内容物）的毛重与空容器皮重之间的差值。 |
| Fracture | 断裂 |
(rupture) The separation of materials, components, or structures into two or more parts by the propagation of one or more cracks. Cracking may be globally elastic (brittle) or accompanied by varying degrees of plasticity (ductile). （断裂）通过一个或多个裂纹的扩展将材料、部件或结构分离成两个或更多部分。裂纹可能是整体弹性（脆性）或伴有不同程度的塑性（延性）。 |
| Centrifugal clutch | 离心离合器 |
A clutch that engages and disengages at a defined speed of rotation of the driving shaft, as when expanding friction shoes act against the inside of a drum. 一种离合器，以驱动轴规定的旋转速度接合和分离，如当膨胀的摩擦片作用在滚筒内部时。 |
| 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）。 |
| Quench annealing | 淬火退火 |
Annealing an austenitic ferrous alloy by solution heat treatment followed by rapid quenching. 通过固溶热处理然后快速淬火对奥氏体铁合金进行退火。 |
| Fracture strength | 断裂强度 |
(fracture stress) (Unit Pa) The stress at which a material breaks. It is not absolute for a given material, as it depends on the laws of fracture mechanics and is size-dependent. （断裂应力）（单位Pa）材料断裂时的应力。对于给定的材料，它不是绝对的，因为它取决于断裂力学定律，并且取决于尺寸。 |
| Finishing washer | 光制垫圈 |
A washer designed for use with countersunk screws. Used to enhance appearance in some applications. 设计用于沉头螺钉的垫圈。在某些应用中用于增强外观。 |
| Thermal insulation (insulation) | 隔热（绝缘） |
A material that may be a low-conductivity solid, or a porous solid or fabric in which there are voids containing air or another gas, resulting in overall low thermal conductivity. When applied to the surface of a hot or cold object, surface heat transfer is generally reduced. 一种材料，可以是低导电性固体，或多孔固体或织物，其中存在含有空气或其他气体的空隙，从而导致整体低导热性。当应用于热或冷物体的表面时，表面传热通常减少。 |
| Assembly drawing | 装配图纸 |
An engineering drawing that shows how parts are assembled to produce a component or a complete machine. It may include sections to show internal features, dimensions that are critical for assembly, manufacturing information, and part numbers. 显示零件如何组装以生产组件或整机的工程图。它可能包括显示内部特征、对装配至关重要的尺寸、制造信息和零件编号的部分。 |
| 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。 |
| 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。 |
| Collapse load (Unit N) | 毁坏荷载（单位N） |
The applied load at which a structure becomes a mechanism owing to the formation of sufficient plastic hinges for collapse to occur. 由于形成足够的塑性铰链以发生坍塌，结构成为机制的施加载荷。 |
| Absorption | 吸收 |
The process whereby a fluid permeates a porous solid, or a gas is dissolved by a liquid. 流体渗透多孔固体或气体被液体溶解的过程。 |
| Rubber hardness | 橡胶硬度 |
The indentation hardness of rubber-like materials in which the depth of indentation under load is measured. This is a measure of elastic moduli rather than yield stress as with ductile materials, since there is little, if any, permanent impression remaining on unloading rubbery materials. 测量负载下压痕深度的橡胶类材料的压痕硬度。这是对弹性模量的测量，而不是对韧性材料的屈服应力，因为卸载橡胶材料时几乎没有（如果有的话）永久压痕。 |
| 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。 |
| Natural unit system (n.u. system) | 自然单位制（n.u.制） |
A non-SI system of units, based on fundamental constants, used in high-energy and particle physics. The n.u. of speed is the speed of light in a vacuum, c0 = 299 792 458 m/s. 基于基本常数的非国际单位制，用于高能和粒子物理n.u.速度是真空中的光速，c0=299792458m/s。 |
| Bar | 巴（气压单位） |
A widely used (non-SI) unit of pressure approximately equal to normal atmospheric pressure at sea level. The conversion to SI is 1 bar = 105 Pa. Unit of pressure – the pressure created by a column of€mercury 75.006 cm high at 0ºC, or about 33.45 feet of water at 4ºC. It is equal to 105 pascal. Standard atmospheric pressure (at sea level) is 1.01325 bar, or 1013.25 mb. 一种广泛使用的（非SI）压力单位，大约等于海平面上的正常大气压。转换为SI为1bar=105Pa。压力单位——0ºC时75.006厘米高的水银柱或4ºC时约33.45英尺水柱产生的压力。它等于105帕斯卡。标准大气压（海平面）为1.01325bar或1013.25mb。 |
| 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。 |
| Computer-aided manufacturing | 计算机辅助制造 |
(CAM, computer-integrated manufacturing, CIM) The use of computers in all branches of manufacturing, not only to control machines and robots for manufacturing and assembly, but also for process planning, and monitoring progress of materials and components during production, etc. （CAM，计算机集成制造，CIM）在制造的所有分支中使用计算机，不仅可以控制制造和组装的机器和机器人，还可以进行工艺规划，以及在生产过程中监控材料和组件的进度等。 |
| Linear (tensile or compressive) strain | 线性（拉伸或压缩）应变 |
The change per unit length due to force in an original linear dimension. An increase in length is considered positive. 由于原始线性尺寸中的力，每单位长度的变化。长度的增加被认为是正的。 |
| Intermediate annealing | 中间退火 |
Annealing wrought metals at one or more stages during manufacture and before final treatment. 在制造过程中和最终处理之前的一个或多个阶段对锻造金属进行退火。 |
| Microindentation hardness test | 显微压痕硬度测试 |
Hardness test using a calibrated machine to force a diamond indenter of specific geometry, under a test load of 1 to 1000 gramforce, into the surface of the test material and to measure the diagonal or diagonals of the indentation optically. 使用校准机器进行硬度试验，以在1至1000克力的试验载荷下，将特定几何形状的金刚石压头压入试验材料表面，并光学测量压痕的对角线。 |
| Box annealing | 箱式退火 |
Annealing a metal or alloy in a sealed container under conditions that minimize oxidation. In box annealing a ferrous alloy, the charge is usually heated slowly to a temperature below the transformation range, but sometimes above or within it, and is then cooled slowly; this process is also called close annealing or pot annealing. 在使氧化最小化的条件下，在密封容器中对金属或合金进行退火。在对铁合金进行箱式退火时，通常将装料缓慢加热至低于转变范围的温度，但有时会高于或低于转变范围，然后缓慢冷却；这个过程也称为紧密退火或罐式退火。 |
| 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。 |
| Cyaniding | 氰化 |
A case-hardening process in which a ferrous material is heated above the lower transformation range in a molten salt containing cyanide to cause simultaneous absorption of carbon and nitrogen at the surface and, by diffusion, create a concentration gradient. Quench hardening completes the process. 一种表面硬化工艺，将含铁材料在含氰化物的熔融盐中加热至低于较低转变范围，使其表面同时吸收碳和氮，并通过扩散形成浓度梯度。淬火硬化完成该过程。 |
| 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。 |
| Wear rate | 磨损率 |
The rate of material removal or dimensional change due to wear per unit of exposure parameter—for example, quantity of material removed(mass, volume, thickness) in unit distance of sliding or unit time. 由于单位暴露参数的磨损而导致的材料去除率或尺寸变化，例如，单位滑动距离或单位时间内去除的材料数量（质量、体积、厚度）。 |
| 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。 |
| 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。 |
| Prying | 撬动 |
The magnification of an External load by a pseudolever action when that load is an Eccentric tensile load. 当外部荷载为偏心拉伸荷载时，通过伪杠杆作用放大外部荷载。 |
| Hydrogen damage | 氢损伤 |
A general term for the embrittlement, cracking, blistering, and hydride formation that can occur when hydrogen is present in some metals. 当氢存在于某些金属中时可能发生的脆化、开裂、起泡和氢化物形成的总称。 |
| Strain rate | 应变率 |
The time rate of straining for the usual tensile test. Strain as measured directly on the specimen gage length is used for determining strain rate. Because strain is dimensionless, the units of strain rate are reciprocal time. 通常拉伸试验的应变时间速率。直接在试样标距上测量的应变用于确定应变率。因为应变是无因次的，所以应变率的单位是倒数时间。 |
| Total-loss lubrication | 全损耗润滑 |
A system in which the lubricating oil for an internal-combustion engine is burned together with the fuel. 内燃机润滑油与燃料一起燃烧的系统。 |
| 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。 |
| Acceleration-error constant | 加速度误差常数 |
When the reference (demand) input to a control system is parabolic, the output signal will also be parabolic in steady state. The signal that is constant in this situation is the acceleration and thus for a parabolic input the steady-state error, referred to as the acceleration-error constant, is the error in the acceleration. 当控制系统的参考（需求）输入是抛物线时，输出信号在稳定状态下也将是抛物线。在这种情况下恒定的信号是加速度，因此对于抛物线输入，称为加速度误差常数的稳态误差是加速度中的误差。 |
| 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。 |
| 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。 |
| Intercritical annealing | 临界退火 |
Any annealing treatment that involves heating to, and holding at, a temperature between the upper and lower critical temperatures to obtain partial austenitization, followed by either slow cooling or holding at a temperature below the lower critical temperature. 任何退火处理，包括加热至并保持在上临界温度和下临界温度之间的温度，以获得部分奥氏体化，然后缓慢冷却或保持在低于下临界温度的温度。 |
| Carburizing | 渗碳 |
Absorption and diffusion of carbon into solid ferrous alloys by heating, to a temperature usually above Ac3, in contact with a suitable carbonaceous material. A form of case hardening that produces a carbon gradient extending inward from the surface, enabling the surface layer to be hardened either by quenching directly from the carburizing temperature or by cooling to room temperature, then reaustenitizing and quenching. 通过与合适的含碳材料接触加热至通常高于Ac3的温度，将碳吸收和扩散到固体铁合金中。一种表面硬化形式，产生从表面向内延伸的碳梯度，通过直接从渗碳温度淬火或冷却至室温，然后重新奥氏体化和淬火，使表层硬化。 |
| Pressure storage tank | 压力贮存器 |
(pressure vessel) A closed container for storing gases or volatile liquids, such as liquefied gases, at pressures significantly above atmospheric pressure. Such tanks are commonly cylindrical with domed ends, spherical, spheroidal, torispherical or hemispherical. （压力容器）密闭容器：在大气压以上的压力下储存气体或挥发性液体，如液化气体的密闭容器。此类贮存器通常为圆柱形，具有半球形端部、球形、球面或半球形。 |
| 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。 |
| 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。 |
| Secondary hardening | 二次硬化 |
The process whereby some low-alloy steels, quenched to produce martensite, produce fine precipitates when tempered above 550°C, which inhibit dislocation motion and reverse the trend towards lower strength at higher tempering temperatures. 某些低合金钢经淬火产生马氏体，在550°C以上回火时产生细小沉淀的过程，这抑制了位错运动，扭转了在较高回火温度下强度降低的趋势。 |
| 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）。 |
| 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。 |
| 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。 |
| 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。 |
| Torque monitor | 扭矩监测器 |
A torque tool control system which monitors the amount of torque being developed by the tool during use, but does not control the tool or the torque produced. 一种扭矩工具控制系统，监控工具在使用过程中产生的扭矩量，但不控制工具或产生的扭矩。 |
| 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。 |
| Actual value | 实际价值 |
The output of a plant that is being controlled, i.e. the controlled variable. Not directly accessible by the control system, as it can only be measured by a sensor which may distort the measurement. 受控设备的输出，即受控变量。控制系统不能直接访问，因为它只能由可能会扭曲测量结果的传感器测量。 |
| Standard | 标准 |
(standard specification) A set of specifications for components, machines, materials, or processes intended to achieve uniformity, efficiency, and a specified quality. In the UK, standards issued by the British Standards Institution (BSI) are now generally those of the International Organization for Standardization (ISO). （标准规范）为实现一致性、效率和特定质量而制定的一套组件、机器、材料或工艺规范。在英国，英国标准协会（BSI）发布的标准现在基本上是国际标准化组织（ISO）的标准。 |
| Mechanical properties of solid materials | 固体材料的力学性能 |
The strength and stiffness properties of solid materials such as fracture toughness, the moduli of elasticity, percent elongation, 固体材料的强度和刚度特性，例如断裂韧性、弹性模量、伸长率、 |
| Carbon restoration | 碳修复 |
Replacing the carbon lost in the surface layer from previous processing by carburizing this layer to substantially the original carbon level. Sometimes called recarburizing. 通过将该层渗碳到基本上原始的碳水平来替换先前处理中在表面层中损失的碳。有时称为再碳化。 |
| Stead’s brittleness | 斯特德脆性 |
A condition of brittleness that causes transcrystalline fracture in the coarse grain structure that results from prolonged annealing of thin sheets of low-carbon steel previously rolled at a temperature below about 705 °C (1300 °F). The fracture usually occurs at about 45° to the direction of rolling. 一种脆性状态，导致粗晶结构中发生穿晶断裂，这是由于之前在低于约705°C（1300°F）的温度下轧制的低碳钢薄板经过长时间退火造成的。断裂通常发生在与轧制方向约45°处。 |
| Latent heat | 潜热 |
Thermal energy absorbed or released when a substance undergoes a phase change. 物质发生相变时吸收或释放的热能。 |
| Transmission dynamometer | 传动测功机 |
A dynamometer in which the power transmitted by a shaft is obtained from the product of its rotation speed and the torque determined from measured shear strains along the shaft. 一种测功机，其中轴传递的功率由其转速和扭矩的乘积获得，扭矩由沿轴测得的剪切应变确定。 |
| Crack size (a) | 裂纹尺寸（a） |
A lineal measure of a principal planar dimension of a crack. This measure is commonly used in the calculation of quantities descriptive of the stress and displacement fields. In practice, the value of crack size is obtained from procedures for measurement of physical crack size, original crack size, or effective crack size, as appropriate to the situation under consideration. 裂纹主平面尺寸的线性度量。这种测量通常用于计算描述应力场和位移场的量。在实践中，裂纹尺寸的值是通过测量物理裂纹尺寸、原始裂纹尺寸或有效裂纹尺寸的程序获得的，视情况而定。 |
| True stress (σ) (Unit Pa) | 真应力（σ）（单位Pa） |
The value obtained by dividing the load applied to a member at a given instant by the cross-sectional area over which it acts. Compare with engineering stress. The applied load on a test specimen divided by the current cross-section area over which it acts. σ = s expε where s is the engineering stress given by the applied load divided by the original cross-section area over which it acts, and ε is the true strain. 通过将给定时刻施加在构件上的荷载除以其作用的横截面积而获得的值。与工程应力相比。施加在试样上的荷载除以其作用的当前横截面积。σ=s expε，其中s是由施加荷载除以其作用的原始横截面面积得出的工程应力，ε是真实应变。 |
| Bulk density (Unit kg/m³) | 容重（单位kg/m³） |
The average density of a mass of granular or powdered material at ambient conditions. 在环境条件下大量粒状或粉状材料的平均密度。 |
| 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。 |
| Granular fracture | 粒状断裂 |
A type of irregular surface produced when metal is broken that is characterized by a rough, grainlike appearance, rather than a smooth or fibrous one. It can be subclassified as transgranular or intergranular. 金属破碎时产生的一种不规则表面，其特征是粗糙的颗粒状外观，而不是光滑或纤维状的外观。它可以细分为穿晶或晶间。 |
| Ferrite | 铁素体 |
A solid solution of one or more elements in body-centered cubic iron. Unless otherwise designated (for instance, as chromium ferrite), the solute is generally assumed to be carbon. On some equilibrium diagrams, there are two ferrite regions separated by an austenite area. The lower area is alpha ferrite; the upper, delta ferrite. If there is no designation, alpha ferrite is assumed. 一种或多种元素在体心立方铁中的固溶体。除非另有说明（例如，铁酸铬），否则通常假定溶质为碳。在一些平衡图上，有两个铁素体区域被一个奥氏体区域隔开。下部区域为α铁素体；上部，δ铁氧体。如果没有指定，则假定为 α 铁氧体。 |
| Taper key | 楔键 |
A key with parallel sides but tapering cross section along its length. 边平行但横截面沿其长度逐渐变细的键。 |
| Radial wave equation | 径向波动方程 |
A differential equation describing the transmission of a wave in a system with radial symmetry. 描述波在径向对称系统中传输的微分方程。 |
| Rotary pump | 旋转泵 |
A positive-displacement pump that pumps a liquid by rotation of internal components, such as a gear pump, lobe pump (similar to a Roots blower), or progressivecavity pump. 通过内部部件的旋转来泵送液体的容积泵，如齿轮泵、凸轮泵（类似于罗茨鼓风机）或螺杆泵。 |
| Newton (N) | 牛顿（N） |
The basic unit of force in the SI system, defined as the force that results in an acceleration of 1 m/s² when acting on a 1 kg mass. SI国际单位制中力的基本单位，定义为作用于1kg质量时产生1m/s²加速度的力。 |
| Dynamic strain aging | 动态应变时效 |
A behavior in metals in which solute atoms are sufficiently mobile to move toward and interact with dislocations. This results in strengthening over a specific range of elevated temperature and strain rate. 金属的一种特点，其中溶质原子具有足够的移动能力，能够向位错移动并与位错相互作用，会导致在特定的高温和应变速率范围内强化。 |
| Face | 表平面 |
To machine a flat surface perpendicular to the axis at rotation on a lathe. 在车床上加工一个垂直于旋转轴的平面。 |
| Sigma-phase embrittlement | σ相脆化 |
Embrittlement of iron-chromium alloys (most notably austenitic stainless steels) caused by precipitation at grain boundaries of the hard, brittle intermetallic sigma phase during long periods of exposure to temperatures between approximately 565 and 980 °C (1050 and 1800 °F). Sigmaphase embrittlement results in severe loss in toughness and ductility and can make the embrittled material structure susceptible to intergranular corrosion. 铁铬合金（最显著的是奥氏体不锈钢）的脆化是由于在长时间暴露于约565至980°C（1050至1800°F）的温度下，硬脆金属间化合物σ相的晶界处沉淀造成的。σ相脆化导致韧性和延展性的严重损失，可使脆化的材料结构易于发生晶间腐蚀。 |
| Age softening | 时效软化 |
Spontaneous decrease of strength and hardness that takes place at room temperature in certain strain hardened alloys, especially those of aluminum. 某些应变硬化合金，尤其是铝合金，在室温下会发生强度和硬度的自发降低。 |
| Spanner (wrench) | 扳手 |
A tool for applying torque to tighten or loosen a nut, bolt, or screw. Grip is applied by a serrated ring or an open U-shape at the end of the tool. On imperial-size spanners, the BSW and BSF marking refers to the diameter of the screw thread; similarly for BA spanners. Spanners for unified and metric threads are marked with the distance across the flats (‘A/F’) of the nut or head of the bolt. 拧紧或松开螺母、螺栓或螺丝的工具。通过工具端部的锯齿环或开口U形应用夹持。在英制扳手上，BSW和BSF标记是指螺纹的直径；类似于BA扳手。用于统一螺纹和公制螺纹的扳手在螺母或螺栓头的平面（'A/F'）上标记距离。 |
| 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）。 |
| Thread milling | 螺纹铣削 |
Thread milling is a method of cutting screw threads with a milling cutter in a thread mill. Thread milling cutters are either single form or multiple form and are used in either conventional or planetary thread mills. 螺纹铣削是在螺纹铣刀中用铣刀切削螺纹的一种方法。螺纹铣刀为单形或多形，用于传统或行星式螺纹铣刀。 |
| Meyer hardness (Unit Pa) | 迈耶硬度（单位Pa） |
A material hardness similar to the Brinell hardness but based upon the projected area of the impression rather than the surface area. 与布氏硬度相似的材料硬度，但基于印模的投影面积而不是表面面积。 |
| Finished fastener | 精制紧固件 |
Fastener for which all manufacturing steps have been completed, with or without any surface coating and with full or reduced loadability, and which has not been machined into a test piece. 已完成所有制造步骤的紧固件，有或没有任何表面涂层，具有完全或降低的承载能力，并且尚未加工成试件。 |
| Full hard | 全硬化 |
A temper of nonferrous alloys and some ferrous alloys corresponding approximately to a coldworked state beyond which the material can no longer be formed by bending. In specifications, a full hard temper is commonly defined in terms of minimum hardness or minimum tensile strength (or, alternatively, a range of hardness or strength) corresponding to a specific percentage of cold reduction following a full anneal. For aluminum, a full hard temper is equivalent to a reduction of 75% from dead soft ; for austenitic stainless steels, a reduction of about 50 to 55%. 有色金属合金和一些铁合金的回火状态，大致对应于冷加工状态，超过该状态，材料就不能再通过弯曲形成。在规范中，完全硬质回火通常定义为与完全退火后的特定冷压下率百分比相对应的最小硬度或最小抗拉强度（或者，硬度或强度范围）。对于铝来说，完全硬回火相当于从极软状态减少75%；对于奥氏体不锈钢，减少约50%至55%。 |
| Thread insert | 螺纹嵌件 |
(threaded bushing) Either a thin cylinder with an internal thread (and sometimes also an external thread) or a helical coil of wire, pressed or screwed into a hole to accept a bolt or screw. Used in material too soft or a component too thin to be threaded, to change one form of thread to another or to repair a damaged thread. （螺纹衬套）一种带有内螺纹（有时也有外螺纹）的薄圆柱体或螺旋形线圈，压入或拧入孔中以接受螺栓或螺钉。用于材料太软或部件太薄而无法螺纹连接，用于将一种形式的螺纹更换为另一种形式或修复损坏的螺纹。 |
| Humidify | 加湿 |
To add water vapour to air or another gas to increase its humidity. 将水蒸气添加到空气或其他气体中以增加其湿度。 |
| Pre-stress | 预应力 |
To induce stresses into a component or structure before it is subjected to operating loads. 在部件或结构承受操作载荷之前，将应力引入部件或结构。 |
| 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。 |
| Hot-wire test | 热线测试 |
Method used to test heat extraction rates of various quenchants. Faster heat-extracting quenchants will permit more electric current to pass through a standard wire because it is cooled more quickly. Compare with hot-wire analyzer. 用于测试各种淬火剂的热提取率的方法。与热线分析仪相比，更快的热提取淬火剂将允许更多电流通过标准导线，因为标准导线冷却更快。 |
| Terminal velocity (Unit m/s) | 终端速度（单位：m/s） |
The velocity reached by an object in free fall through a fluid when the upward drag and buoyancy forces just balance the object’s weight. For an object with a density lower than that of the fluid, the terminal velocity is vertically upwards. 当向上的阻力和浮力正好平衡物体的重量时，物体自由下落通过流体达到的速度。对于密度低于流体密度的物体，终端速度垂直向上。 |
| Centi (c) | 厘（c） |
An SI unit prefix indicating a multiplier of 0.01; thus centimetre is a unit of length equal to one one-hundredth of a metre or 10 mm. 表示乘数0.01的SI单位前缀；因此厘米是长度单位，等于一米的百分之一或10毫米。 |
| Hardness test | 硬度测试 |
1. Any of various tests in which different hard indenters are forced into the surface of a solid under different loads to give permanent impressions, the pressure to cause which being called the hardness. The Brinell test employs a spherical indenter; the Vickers test a square-based pyramid. The relation between indentation hardness H and uniaxial yield stress Y is approximately H = (2.5 ~ 3.0)Y. Originally hardnesses were given in kg/mm² but now are often given in Pa. 2. The tests for scratch and file hardness relate either to one material being able to mark another (Mohs hardness scale for minerals), or to the size of groove produced by a rigid indenter slid under load across a surface. 3. Rebound hardness concerns the height of rebound of a dropped indenter, or an indenter at the end of a pivoted arm, having struck a surface. 1.任何一种试验，其中不同的硬压头在不同载荷下压入固体表面，以产生永久压痕，所产生的压力称为硬度。布氏试验采用球形压头；维氏硬度测试是一个方形金字塔。压痕硬度H与单轴屈服应力Y之间的关系约为H=（2.5~3.0）Y。最初硬度以kg/mm²为单位，但现在通常在Pa.2中给出。划痕和锉刀硬度测试要么与一种材料能够标记另一种材料（矿物的莫氏硬度标度）有关，要么与刚性压头在表面上滑动产生的凹槽大小有关。3.回弹硬度涉及掉落压头或旋转臂端部压头撞击表面后的回弹高度。 |
| 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。 |
| Erosion | 侵蚀 |
Progressive loss of original material from a solid surface due to mechanical interaction between that surface and a fluid, a multicomponent fluid, or impinging liquid or solid particles. 由于固体表面与流体、多组分流体或撞击液体或固体颗粒之间的机械相互作用，原始材料从固体表面逐渐损失。 |
| Brittle | 脆性材料 |
A brittle material is one that breaks, often suddenly, with no permanent deformation. Examples of brittle materials are some cast irons, glass, concrete, and some plastics. A bolt is said to be brittle if it will break when stretched only a small amount past its yield point. 脆性材料通常会突然断裂，不会产生永久变形。脆性材料的例子有一些铸铁、玻璃、混凝土和一些塑料。如果螺栓在拉伸时仅超过其屈服点一小部分就会断裂，则称其为脆性螺栓。 |
| Design pressure (Unit Pa) | 设计压力（单位Pa） |
The greatest pressure that a closed container is expected to experience under normal operating conditions. 密闭容器在正常操作条件下预期承受的最大压力。 |
| Maximum load (Pmax) | 最大负载（Pmax） |
(1) The load having the highest algebraic value in the load cycle. Tensile loads are considered positive and compressive loads negative. (2)Used to determine the strength of a structural member; the load that can be borne before failure is apparent. （1）负载循环中具有最高代数值的负载。拉伸荷载视为正荷载，压缩荷载视为负荷载。（2）用于确定结构构件的强度；失效前可承受的载荷是明显的。 |
| Graphitizing | 石墨化退火 |
Annealing a ferrous alloy in such a way that some or all of the carbon is precipitated as graphite. 以使部分或全部碳以石墨的形式沉淀的方式对铁合金进行退火。 |
| Annealing | 退火 |
A generic term denoting a treatment, consisting of heating to and holding at a suitable temperature followed by cooling at a suitable rate, used primarily to soften metallic materials, but also to simultaneously produce desired changes in other properties or in microstructure. 一个通用术语，表示一种处理，包括加热并保持在合适的温度，然后以合适的速率冷却，主要用于软化金属材料，但也同时产生其他性能或微观结构的所需变化。 |
| Eutectic carbide | 共晶碳化物 |
Carbide formed during freezing as one of the mutually insoluble phases participating in the eutectic reaction of ferrous alloys. 在冷冻过程中形成的碳化物，是参与铁合金共晶反应的互不溶相之一。 |
| Precipitation hardening | 沉淀硬化 |
Hardening caused by the precipitation of a constituent from a supersaturated solid solution. 因成分从过饱和固溶体沉淀而导致的硬化。 |
| Check valve | 止回阀 |
(clack valve, non-return valve) A mechanical device that allows fluid flow in one direction only. The numerous designs include ball, diaphragm, disc, lift, split disc, and swing check valves. （瓣阀、止回阀）一种仅允许流体单向流动的机械装置。众多设计包括球阀、隔膜阀、盘阀、升降阀、分体盘阀和旋启式止回阀。 |
| Mole (mol) | 摩尔（mol） |
The base unit of the amount of substance in the SI system. It was previously defined as the amount of substance of a system that contains as many elementary entities as there are atoms in 0.012 kg of carbon-12. From 20 May 2019 it has been defined as the amount of substance containing exactly 6.022 140 76 × 1023 elementary entities. SI国际单位制中物质量的基本单位。此前，它被定义为一个系统中的物质量，该系统包含的基本实体数量与0.012千克碳-12中的原子数量相同。从2019年5月20日起，它已被定义为包含6.02214076×1023个基本实体的物质量。 |
| Torque control | 扭矩控制 |
A system of optimizing rotor speed for a variable-speed wind turbine by controlling the torque demands of the generator. 通过控制发电机的扭矩需求来优化变速风力涡轮机的转子速度的系统。 |
| 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。 |
| Union (union joint) | 活接头 |
A threaded pipe fitting that allows two pipes to be connected anddetached without the need for either to be rotated, and without damaging the pipe ends. 一种螺纹管件，允许连接和拆卸两个管道，而无需旋转任何一个管道，且不会损坏管道端部。 |
| Clevis joint | U形接头 |
A joint formed by two parallel cantilever beams pressed upon a component between the beams. 由两个平行悬臂梁压在梁之间的部件上形成的接头。 |
| Kilo (k) | 千（k） |
An SI unit prefix indicating a multiplier of 103; thus kilometre (km) is a unit of length equal to one thousand metres. 表示乘法器103的SI单位前缀；1千米是长度单位，等于1000米。 |
| Mole number (N) | 摩尔数（N） |
The number of moles in a given mass m of a substance, equal to m divided by the molar mass of the substance. 摩尔数物质给定质量m中的摩尔数，等于m除以物质的摩尔质量。 |
| 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）。 |
| 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。 |
| Secondary stresses (Unit Pa) | 二次应力（单位Pa） |
Stresses different from those induced by the major loading but nevertheless resulting from the major loads; for example, the hoop stresses that occur around the circumference of barrelled compression testpieces and forgings. 与主要荷载引起的应力不同，但主要荷载产生的应力；例如，桶装压缩试件和锻件周围产生的环向应力。 |
| 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。 |
| Torsion bar | 扭杆 |
A metal bar designed to act as an elastic spring when torque is applied. 当施加扭矩时用作弹性弹簧的金属棒。 |
| Kelvin (K) | 开尔文（K） |
The SI unit of temperature. The Kelvin temperature scale has a zero point at absolute zero and degree intervals (kelvins) the same size as degrees Celsius. The freezing point of water occurs at 273K (0ºC) and the boiling point at 373 K (100ºC). The base unit of thermodynamic temperature in the SI system. It was previously defined to be the fraction 1/273.16 of the thermodynamic temperature of the triple point of water. From 20 May 2019 it has been defined by taking the fixed numerical value of the Boltzmann constant kB to be 1.380 649 × 10−23 when expressed in the unit J/K, which is equal to kg.m²/(s²K). 国际单位制中热力学温度的基本单位。开尔文温度标度在绝对零度和与摄氏度大小相同的度间隔（开尔文）处有一个零点。水的冰点为273K（0ºC），沸点为373K（100ºC）。它先前被定义为水三相点热力学温度的分数1/273.16。从2019年5月20日起，通过将玻尔兹曼常数kB的固定数值取为1.380649×10来定义−当以等于kg·m²/（s²K）的单位J/K表示时。 |
| Rotary valve (rotating valve) | 旋转阀 |
A cylindrical or conical plug in which there is a transverse hole through which fluid can flow when the hole is aligned with the adjacent piping. 一种圆柱形或锥形塞，其中有一个横向孔，当该孔与相邻管道对齐时，流体可通过该孔流动。 |
| Electrode | 电极 |
The two metallic bodies in a battery or Corrosion cell which give up electrons (the Anode) or which attract them (the Cathode). 电池或腐蚀电池中释放电子（阳极）或吸引电子（阴极）的两个金属体。 |
| Joint diagrams | 接合处关系图 |
Mathematical diagrams which illustrate the forces on and deflections of fasteners and joint members. 说明紧固件和连接件上的力和变形的数学图。 |
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