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词或词组	中文	英文解释中文解释
Physical testing	物理测试	Methods used to determine the entire range of physical properties of a material. In addition to density and thermal, electrical, and magnetic properties, physical testing methods can be used to assess simple fundamental physical properties such as color, crystalline form, and melting point. 用于确定材料整个物理特性范围的方法。除了密度和热、电、磁特性外，物理测试方法还可用于评估简单的基本物理特性，如颜色、结晶形式和熔点。
Dew point	压力露点	The temperature and pressure at which a gas begins to condense to a liquid. 气体开始凝结成液体的温度和压力。
Radial marks	径向标记	Lines on a fracture surface that radiate from the fracture origin and are visible to the unaided eye or at low magnification. Radial lines result from the intersection and connection of brittle fractures propagating at different levels. Also known as shear ledges. 断裂表面上的线，从断裂起点辐射，肉眼可见或在低放大率下可见。径向线是在不同层面上传播的脆性断裂相交和连接的结果。也称为剪切壁架。
Free carbon	游离碳	The part of the total carbon in steel or cast iron that is present in elemental form as graphite or temper carbon. Contrast with combined carbon. 钢或铸铁中总碳中以石墨或回火碳等元素形式存在的部分。与结合碳形成对比。
Stress-intensity calibration	应力强度校准	A mathematical expression, based on empirical or analytical results, that relates the stress-intensity factor to load and crack length for a specific specimen planar geometry. Also known as Kcalibration. 基于经验或分析结果的数学表达式，该表达式将特定试样平面几何形状的应力强度因子与载荷和裂纹长度联系起来。也称为K校准。
Stress-strain diagram	应力-应变图	A graph in which corresponding values of stress and strain are plotted against each other. Values of stress are usually plotted vertically(ordinates or y-axis) and values of strain horizontally (abscissas or xaxis). Also known as deformation curve and stress-strain curve. 对应的应力和应变值相对绘制的图表。应力值通常垂直绘制（纵坐标或y轴），应变值水平绘制（横坐标或X轴）。也称为变形曲线和应力-应变曲线。
Compression member	压缩构件	A structural component, the major loading on which is compressive. 一种结构部件，其上的主要载荷是压缩的。
Oxidative wear	氧化磨损	A type of wear resulting from the sliding action between two metallic components that generates oxide films on the metal surfaces. These oxide films prevent the formation of a metallic bond between the sliding surfaces, resulting in fine wear debris and low wear rates. 由两个金属部件之间的滑动作用导致的一种磨损，在金属表面上产生氧化膜。这些氧化膜防止在滑动表面之间形成金属结合，导致细磨屑和低磨损率。
Fatigue limit for p % survival	p%存活率的疲劳极限	The limiting value of fatigue strength for p%survival as the number of stress cycles becomes very large; pmay be any number, such as 95, 90, etc. 随着应力循环次数的增加，p%存活率的疲劳强度极限值变得非常大；p可以是任何数字，例如95、90等。
Intense quenching	强烈淬火	Quenching in which the quenching medium is cooling the part at a rate at least two and a half times faster than still water. 淬火，其中淬火介质以比静水快至少两倍半的速度冷却零件。
Crank angle (Unit °)	曲柄角度（单位°）	The angle between the crank of a slider-crank mechanism and a line from the crankshaft centreline to the piston axis. 曲柄滑块机构的曲柄与曲轴中心线到活塞轴线的直线之间的角度。
Crack-extension force (G)	裂纹扩展力（G）	The elastic energy per unit of new separation area that would be made available at the front of an ideal crack in an elastic solid during a virtual increment of forward crack extension. 在向前裂纹扩展的虚拟增量期间，在弹性固体中理想裂纹的前端可获得的每单位新分离面积的弹性能量。
Mass flow rate (ṁ) (Unit kg/s)	质量流量（ṁ）（单位kg/s）	The mass of a material, usually a fluid or powder, that flows across a surface or through a pipe or other duct per unit time. The corresponding mass flux (ṁ″), with unit kg/s.m², is the mass flow across a real surface or through a duct, divided by the surface or cross-sectional area A, i.e. ṁ″ = ṁ/A or ṁ″ = ρV where ρ is the material density and V is its velocity normal to the surface. 单位时间内流过表面或通过管道或其他管道的材料质量，通常是流体或粉末。相应的质量通量（ṁ″），单位为kg/s.m²，是通过真实表面或通过管道的质量流量除以表面或横截面积A，即ṁ″=ṁ/A或ṁ″=ρV，其中ρ是材料密度，V是其垂直于表面的速度。
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。
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。
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。
Sawing	锯切	Sawing is the process of cutting a workpiece with power band saws, hacksaws, and circular saws. Each of these methods is used in cutoff operations (cutting pieces to a required length), although band sawing also provides a method of cutting contours. 锯切是用带锯、钢锯和圆锯切割工件的过程。这些方法中的每一种都用于切割操作（将工件切割到所需长度），尽管带锯也提供了一种切割轮廓的方法。
Shoulder joint	轴肩关节	The second joint on an articulated robot, which has a horizontal axis and is analogous to the human shoulder. 关节机器人上的第二个关节，具有水平轴，类似于人的肩膀。
Heat tinting	热着色	Coloration of a metal surface through oxidation by heating to reveal details of the microstructure. 通过加热氧化使金属表面着色，以揭示微观结构的细节。
Superheating	过热	Heating above the temperature at which an equilibrium phase transformation should occur without actually obtaining the transformation. 在不实际获得相变的情况下，加热到应发生平衡相变的温度以上。
Standard gauge	标准量规	A highly-accurate reference gauge against which to check working gauges. 一种高精度的基准量规，用于检查工作量规。
Thermodynamics laws	热力学定律	The zeroth, first, second, and third laws of thermodynamics. 热力学第零、第一、第二和第三定律。
Dimensional stability	尺寸稳定性	Ability of a plastic part to retain the precise shape in which it was molded, fabricated, or cast. 塑料零件保持其成型、制造或铸造时的精确形状的能力。
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。
Torque arm	扭力臂	A bar fixed at one end used to resist torque applied at the other, for example by an electric drill. 固定在一端的杆，用于抵抗施加在另一端的扭矩，如电钻。
Anode	阳极	That electrode in a battery or corrosion cell which produces electrons. It is the electrode which is destroyed (corrodes). 电池或腐蚀电池中产生电子的电极。被破坏（腐蚀）的是电极。
Destructive testing	破坏性测试	Measurement of the mechanical properties of a material, component, or structure, by increased loading until the sample fails by fracture, collapse, or buckling. 通过增加载荷测量材料、部件或结构的机械性能，直到样品因断裂、塌陷或屈曲而失效。
Indentation hardness	压痕硬度	The resistance of a material to indentation as determined by hardness testing. The indenter, which may be spherical or diamond shaped, is pressed into the surface of a metal under specified load for a given time. (Unit Pa or, non-SI, kgf/mm²) A measurement of hardness taken by means of an indenter, pressed into a material by a load, which makes a permanent impression. The hardness is given by the load divided by the projected (sometimes surface) area of the indentation. Plasticity theory shows that the hardness is about 2.5–3 times the uniaxial yield stress. 通过硬度测试确定的材料抗压痕的能力。压头可以是球形或菱形，在规定的载荷下压入金属表面一段时间。（单位Pa或，非国际单位制，kgf/mm²）通过压头测量硬度，压入材料，形成永久压痕。硬度由载荷除以压痕的投影（有时是表面）面积得出。塑性理论表明，硬度约为单轴屈服应力的2.5–3倍。
Initial stress	初始应力	The stress produced by strain in a specimen immediately on achieving the given constant-strain conditions in a stress-relaxation test before stress-relaxation occurs. Sometimes referred to as instantaneous stress. 在应力松弛发生之前，在应力松弛试验中达到给定的恒定应变条件时，试样立即应变所产生的应力。有时称为瞬时压力。
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。
Shim	垫片	A thin piece of material, such as metal of accurately-known thickness, placed between two surfaces to ensure they are the correct distance apart. A thin piece of material placed between two surfaces to obtain a proper fit, adjustment, or alignment. The piece can also be analyzed to measure furnace carbon potential (that is, because while in the furnace it will quickly carburize to a level equal to the furnace carbon potential). 一块薄的材料，如厚度精确已知的金属，放置在两个表面之间，以确保它们之间的距离正确。放置在两个表面之间以获得适当配合、调整或对齐的一块薄材料。还可以对工件进行分析，以测量熔炉碳势（也就是说，在熔炉中，工件将快速渗碳至与熔炉碳势能相等的水平）。
Sample average	样本平均值	The sum of all the observed values in a sample divided by the sample size. It is a point estimate of the population mean. Also known as arithmetic mean. 样本中所有观察值的总和除以样本大小。它是总体平均值的点估计。也称为算术平均值。
Binary vapour cycle	二元蒸气循环	A power cycle which combines a steam cycle at relatively low temperature (the bottoming cycle) with a higher temperature cycle (the topping cycle) in which a working fluid such as mercury, sodium or potassium is used. 一种动力循环，它将相对低温的蒸汽循环（底部循环）与高温循环（顶部循环）相结合，其中使用了诸如汞、钠或钾之类的工作流体。
Preload accuracy	预载精度	A measure of the precision with which a given tool or procedure creates preload in a bolt when the bolt is tightened. A common torque wrench, for example, is said to produce preload with an accuracy of +30%. The mean preload, however, may not be that which the designer intended, or may not be what he should have intended. Accuracy as used here, in other words, is synonymous with Scatter. 当螺栓拧紧时，给定工具或程序在螺栓中产生预紧力的精度度量。例如，一个普通的扭矩扳手据说可以产生精度为+30%的预载。然而，平均预载可能不是设计者预期的。这里使用的准确度是分散度的同义词。
Compression stroke	压缩冲程	The stroke in a reciprocating compressor or engine during which the working fluid is compressed. 往复式压缩机或发动机中工作流体被压缩的冲程。
Breaking load	断裂载荷	The maximum load (or force) applied to a test specimen or structural member loaded to rupture. 施加到加载到破裂的试样或结构构件上的最大载荷（或力）。
Absolute humidity	绝对湿度	The weight of water vapor in a gadwater vapor mixture per unit volume of space occupied, expressed, for example, in grains or pounds per cubic foot. 单位体积空间占用的水蒸气混合物中水蒸气的重量，例如，以谷物或磅/立方英尺表示。
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。
Effective crack size (ae)	有效裂纹尺寸（ae）	The physical crack size augmented for the effects of cracking plastic deformation. Sometimes the effective crack size is calculated from a measured value of a physical crack size plus a calculated value of a plastic-zone adjustment. A preferred method for calculation of effective crack size compares compliance from the secant of a load-deflection trace with the elastic compliance from a calibration for the type of specimen. 由于裂纹塑性变形的影响，物理裂纹尺寸增大。有时，根据物理裂纹尺寸的测量值加上塑性区调整的计算值来计算有效裂纹尺寸。计算有效裂纹尺寸的首选方法是将载荷-挠度轨迹正割的柔度与试样类型校准的弹性柔度进行比较。
Proof strength  (Unit Pa)	验证强度（单位Pa）	(proof stress, Rp, Rp,) The yield strength (offset yield strength) at some fixed value of the permanent strain given by the intersection of a line offset from, but parallel to, the elastic loading line and the engineering stress-engineering strain curve. The offset is arbitrary but is usually 0.1, 0.2, or 0.5% permanent strain (the proof strain). Used for materials which do not exhibit a sharply defined yield point. The notation Rp0.2 or Rp0.2 is employed for the 0.2% proof stress. （验证应力，Rp）在永久应变的某个固定值下的屈服强度（偏移屈服强度），由偏离但平行于弹性加载线的线与工程应力-工程应变曲线的交点给出。偏移是任意的，但通常为0.1、0.2或0.5%的永久应变（验证应变）。用于没有明确定义屈服点的材料。对于0.2%的验证应力，采用符号Rp0.2。
Ductile crack propagation	延性裂纹扩展	Slow crack propagation that is accompanied by noticeable plastic deformation and requires energy to be supplied from outside the body. 缓慢的裂纹扩展，伴随着明显的塑性变形，需要从外部提供能量。
Load and resistance factor design	负载和阻力系数设计	A design procedure developed for the AISC by the Research Council on Structural Connections. Assigns uncertainties in the strength of (i.e., resistance of) and in the service loads to be placed on a shear joint to estimate the probable strength of the joint. It is a recently defined alternative to the Allowable stress design procedure. 结构连接研究委员会为AISC制定的设计程序。分配剪切接头的强度（即阻力）和工作荷载的不确定性，以估计接头的可能强度。它是最近定义的容许应力设计程序的替代方案。
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。
Atmosphere	大气	1. (atm) An obsolete (non-SI) unit of pressure equal to 101 325 Pa or 1.013 25 bar and approximately equal to the atmospheric pressure (barometric pressure) measured at mean sea level. 1.（atm）一种已被淘汰的（非SI）压力单位，等于101325Pa或1.01325bar，大约等于在平均海平面测量的大气压力（大气压）。
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。
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。
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。
Columnar structure	柱状结构	A coarse structure of parallel elongated grains formed by unidirectional growth, most often observed in castings, but sometimes in structures resulting from diffusional growth accompanied by a solid-state transformation. 由单向生长形成的平行细长晶粒的粗略结构，最常见于铸件中，但有时也出现在伴随固态转变的扩散生长产生的结构中。
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。
Anneal to temper	退火回火	A final partial anneal that softens a cold worked nonferrous alloy to a specified level of hardness or tensile strength. 将冷加工的有色金属合金软化到规定的硬度或抗拉强度水平的最终局部退火。
Hoseclip	软管夹	(hose clamp) A circular metal band, one end of which has a screw mechanism through which passes the other end such that the screw engages with indentations in the band, allowing the clip to be tightened or loosened. Used to hold a hose on to a pipe such as a water outlet. （软管夹）一种圆形金属带，其一端有一个螺钉组织，另一端穿过该螺钉组织，使螺钉与带子上的凹口啮合，从而可以拧紧或松开夹子。用于将软管固定在管道上，例如出水口。
Gauge	测量	1. Any instrument for measuring or checking dimensions, including adjustable gauges such as a micrometer and non-adjustable gauges such as go/no-go limit gauges that indicate the maximum and minimum dimensions allowable in a component during manufacture. 2. A term often used to mean an instrument, e.g. pressure gauge. 3. The diameter of a wire or thickness of a sheet according to a standard. 4. The distance between the rails of a railway track. 1. 任何用于测量或检查尺寸的仪器，包括可调节量规（例如千分尺）和不可调节量规（例如指示制造过程中组件允许的最大和最小尺寸的通过/不通过限制量规）。2. 常用于表示仪器的术语，例如压力表。3.根据标准的线材直径或片材厚度。4.铁路轨道的钢轨之间的距离。
Plug gauge	塞规	A steel gauge used to determine the dimension or dimensions of a hole. It may be straight or tapered, and is typically circular, but in principle can have any cross section. 用于确定孔的尺寸的钢制量规。它可以是直的或锥形的，通常是圆形的，原则上可以有任何横截面。
Cohesive strength	内聚强度	(Unit Pa) A theoretical fracture strength for solids based on interatomic forces, approximately equal to E/10 where E is Young’s modulus. （单位Pa）基于原子间力的固体理论断裂强度，大约等于E/10，其中E是杨氏模量。
Positive-displacement compressor	容积式压缩机	Any type of compressor, including piston and rotary-screw types, that delivers a fixed volume of gas at high pressure per unit time. A positive-displacement pump delivers a fixed volume of fluid, usually a liquid, per unit time. 任何类型的压缩机，包括活塞式和旋转螺杆式，在单位时间内以高压输送固定体积的气体。容积泵每单位时间输送固定体积的流体，通常为液体。
Acoustic pyrometer	声学高温计	A non-intrusive pyrometer based on the principle that the sound speed in a gas is proportional to the square root of its absolute temperature. 一种非侵入式高温计，其原理是气体中的声速与其绝对温度的平方根成正比。
Screw pair	螺旋副	Two links connected together to form a kinematic pair, in which the contacting surfaces are screw threads, so that their relative motion consists of rotation and sliding. 两个连杆连接在一起形成运动副，其中接触面为螺纹，因此它们的相对运动包括旋转和滑动。
Heat-capacity rate (c) (Unit W/K)	热容率（c）（单位W/K）	For fluid flow in a duct with mass flow rate ṁ, the product ṁC where C is the specific-heat capacity, at constant pressure (CP) in the case of a gas. 对于质量流量为ṁ的管道中的流体流动，乘积ṁC其中C是比热容，在气体的情况下为恒定压力（CP）。
Taper pins	圆锥销	A pin or peg of circular cross section that tapers along its length. Steel pins used for locating and holding the machine parts in position on a shaft. 沿其长度逐渐变细的圆形横截面的销钉或销钉。用于在轴上定位和固定机器零件的钢销。
Melting point (Unit K or °C)	熔点（单位K或°C）	The temperature at which a solid material undergoes the phase change to a liquid at a specified pressure, usually 1 atm. Pure metals and eutectics have single-valued melting points, while alloys with other compositions melt over a range of temperature such that there is a well-defined start and end to the melting process, but there are states in between where solid and liquid are both present. 在特定压力下，固体材料发生相变为液体的温度，通常为1大气压。纯金属和共晶具有单值熔点，而具有其他成分的合金在一定温度范围内熔化，熔化过程有一个明确的起点和终点，但其间存在固态和液态并存的状态。
Laser sintering	激光烧结	A manufacturing technique by which parts are built layer by layer (each typically 20 μm thick) from plastic or metal (Direct Metal Laser Sintering, DMLS) material in powder form, each layer being sintered by a scanning laser. 一种制造技术，通过这种制造技术，零件由粉末形式的塑料或金属（直接金属激光烧结，DMLS）材料逐层（每个厚度通常为 20 微米）构建，每一层都由扫描激光烧结。
Snap temper	快速回火	A precautionary interim stress-relieving treatment applied to high-hardenability steels immediately after quenching to prevent cracking because of delay in tempering them at the prescribed higher temperature. 在淬火后立即对高淬透性钢进行预防性临时应力消除处理，以防止因在规定的更高温度下回火延迟而开裂。
Wrist	腕关节	The final three joints on a robot which simulate rotations provided by the human wrist and thus allow orientation of the end effector to which it is attached by the wrist socket. 机器人上的最后三个关节，模拟人类手腕提供的旋转，从而允许其通过手腕插座连接到的末端执行器的方向。
Radiator	散热器	A heat exchanger used to transfer thermal energy from one fluid to another for heating or cooling purposes. Despite the name, the principal mode of heat transfer is convection rather than radiation. In motor vehicles, water circulated through the engine block is cooled as it flows through the tubes of an air-cooled heat exchanger. In domestic radiators, hot water from a boiler is circulated through a heat exchanger with a large surface area which transfers heat to the surrounding air. 一种热交换器，用于将热能从一种流体传递到另一种流体，用于加热或冷却。尽管有这个名字，但热传递的主要方式是对流而不是辐射。在机动车辆中，通过发动机缸体循环的水在流经风冷热交换器的管道时被冷却。在家用散热器中，来自锅炉的热水通过具有大表面积的热交换器循环，该热交换器将热量传递给周围的空气。
Sinter (sintering)	烧结	A solid-state diffusion densification process for the production of objects, particularly porous objects, from raw material in powder, granular, mesh, perforatedsheet, or fibre form by heating to a temperature below the melting point until the constituents bond together. It is used for ceramic materials and metals. Applications of sintered materials include filtration, separation, flow control, fluidization, and noise reduction. The bonding of adjacent surfaces in a mass of particles by molecular or atomic attraction on heating at high temperatures below the melting temperature of any constituent in the material. Sintering strengthens a powder mass and normally produces densification and, in powdered metals, recrystallization. 一种固态扩散致密化工艺，用于从粉末、粒状、网状、穿孔片或纤维形式的原材料中生产物体，尤其是多孔物体，方法是加热至低于熔点的温度，直到成分结合在一起。它用于陶瓷材料和金属。烧结材料的应用包括过滤、分离、流量控制、流化和降噪。在低于材料中任何成分熔化温度的高温下加热时，通过分子或原子引力将大量颗粒的相邻表面结合起来。烧结增强了粉末质量，通常会产生致密化，在粉末金属中还会产生再结晶。
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。
Cathode	阴极	That electrode in a battery or corrosion cell which attracts electrons. 电池或腐蚀电池中吸引电子的电极。
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。
Verification	检验	Checking or testing an instrument to ensure conformance with a specification. 检查或测试仪器以确保符合规范。
Pitch	沥青节距	The nominal distance between two adjacent thread roots or crests. In screw threads, the distance from a point on one thread to a corresponding point on the next thread measured parallel to the axis. In the case of spur gears, indicates the size of the gear teeth and is correctly called diametral pitch. 两个相邻螺纹根部或顶部之间的标称距离。在螺纹中，从一根螺纹上的一点到下一根螺纹对应点的距离，平行于轴线测量。对于正齿轮，表示齿轮齿的尺寸，正确地称为径向节距。
Steady loads	稳定负载	Loads that do not change in intensity or that change so slowly they may be regarded as steady. 强度不变或变化缓慢的荷载可视为稳定荷载。
Flattening test	压扁试验	This term as applied to tubing refers to a method of testing a section of tubing by flattening it until the inside walls are parallel and separated by a given distanceusually equal to three times the wall thickness for seamless tubes and five times the wall thickness for lap-welded tubes. Boiler tubes subjected to this test should show no cracks or flaws. The flattening test applied to rivets, consists in flattening a rivet head while hot to a diameter equal to 21⁄2 times the diameter of the shank or body of the rivet. Good rivet steel must not crack at the edges of the flattened head. 该术语适用于管材，是指通过压扁管材直至内壁平行并隔开给定距离（通常等于无缝钢管壁厚的三倍，搭接焊管壁厚的五倍）来测试管材截面的方法。进行该试验的锅炉管应无裂纹或缺陷。适用于铆钉的压扁试验包括在热态下压扁铆钉头，使其直径等于铆钉柄或铆钉体直径的21⁄2倍。良好的铆钉钢不得在扁平头部边缘开裂。
Millimetre of mercury	毫米汞柱	A non-SI unit of pressure equal to the pressure exerted by a vertical column of mercury 1 mm high. Approximately equal to 133.3 Pa or 1 torr. 一种非SI压力单位，等于1毫米高的垂直水银柱施加的压力。大约等于133.3Pa或1托。
Cementite	渗碳体	A compound of iron and carbon, known chemically as iron carbide and having the approximate chemical formula Fe3C. It is characterized by an orthorhombic crystal structure. When it occurs as a phase in steel, the chemical composition will be altered by the presence of manganese and other carbide-forming elements. 碳化铁一种铁和碳的化合物，化学上称为碳化铁，化学式近似为Fe3C。其特征在于正交晶体结构。当它在钢中以相形式出现时，锰和其他碳化物形成元素的存在将改变其化学成分。
Abrasion	磨损	The removal of surface material by the scratching action of hard particles, either deliberately (abrasive papers, abrasive cleaning, abrasive machining) or as a consequence of operation (wear). 通过硬质颗粒的刮擦作用去除表面材料，可以是故意的（砂纸、研磨清洁、研磨加工），也可以是操作的结果（磨损）。
Butterfly valve	蝶阀	A valve in which a disc rotates on a shaft at right angles to the axis of a pipe to regulate flow. When open, the disc is edge-on to the flow and offers limited resistance. When closed, the disc is pressed against a seat in the valve body. 阀瓣在与管道轴线成直角的轴上旋转以调节流量的阀门。当打开时，圆盘与水流边缘并提供有限的阻力。关闭时，阀瓣被压在阀体内的阀座上。
Grinding	研磨	1. A process of high-speed multiple scratching of surfaces by a wheel formed from hard grits and a binder which are progressively exposed as the binder wears away. It is a process of micromachining employed particularly in accurate finishing operations on hard materials. 2. A form of comminution. 1.一种通过由硬砂砾和粘合剂形成的轮对表面进行高速多次刮擦的方法，所述硬砂砾和粘结剂随着粘合剂的磨损而逐渐暴露。这是一种微机械加工工艺，特别适用于硬材料的精确精加工操作。2.一种粉碎形式。
Materials science	材料科学	The study of the properties, behaviour, and application of solid substances such as metals, ceramics, glasses, polymers, composites, biomaterials, and semiconductors, at all scales from the atomic to the macroscopic. The topic has its origins in metallurgy. 研究金属、陶瓷、玻璃、聚合物、复合材料、生物材料和半导体等固体物质的特性、行为和应用，涵盖从原子到宏观的所有范围。起源于冶金学。
Time quenching	时间淬火	A term used to describe a quench in which the cooling rate of the part being quenched must be changed abruptly at some time during the cooling cycle. 用于描述淬火的术语，其中被淬火零件的冷却速率必须在冷却循环的某个时间突然改变。
Transition metals	过渡金属	Metallic elements from groups (columns) 3 to 12 of the periodic table. They include important metals such as titanium, vanadium, chromium, manganese, iron, cobalt, zirconium, niobium, molybdenum, tantalum, tungsten, and the noble metals. They have either body-centred cubic, face-centred cubic, or hexagonal close-packed crystal structure at room temperature and have a wide range of mechanical and physical properties. 元素周期表第3组至第12组（列）中的金属元素。它们包括重要的金属，如钛、钒、铬、锰、铁、钴、锆、铌、钼、钽、钨和贵金属。它们在室温下具有体心立方、面心立方或六方密排晶体结构，并具有广泛的机械和物理性能。
Bánki turbine	班基涡轮机	A cross-flow, impulse-type water turbine for very low heads in which a jet of water in the form of a flat sheet passes transversely through the turbine, so going through the runner twice. The thin runner blades which run horizontally across the turbine parallel to the axis of rotation are profiled in cross section. 一种用于非常低水头的横流脉冲式水轮机，其中平板形式的水射流横向穿过涡轮机，因此穿过转轮两次。平行于旋转轴水平穿过涡轮机的薄转轮叶片在横截面上具有轮廓。
Zone melting (zone refining)	区域熔炼（区域精炼）	A process of purification of materials in which a narrow molten zone is moved along the length of the material, resulting in impurities being segregated at one end. 一种净化材料的过程，其中一个狭窄的熔融区沿材料长度移动，导致杂质在一端分离。
Observed value	观测值	The particular value of a characteristic determined as a result of a test or measurement. 作为测试或测量结果确定的特性的特定值。
Dead centre	止点	The point at which, in a crank mechanism, the piston connecting rod and crank are all in line so that there can be no driving moment. 在曲柄机构中，活塞连杆和曲柄都在一条线上，因此不会有驱动力矩。
Frequency	频率	(temporal frequency, f) (Unit Hz) The number of cycles per second in an oscillation or the repetition rate for a cyclic process. （时间频率，f）（单位Hz）振荡中每秒的周期数或循环过程的重复率。
Turboblower	涡轮鼓风机	A centrifugal or axial compressor or fan. 离心式或轴流式压缩机或风扇。
Single thread	单头螺纹	A screw thread cut around a cylinder having a single start in which the lead is equal to the pitch. 一种螺纹，在一个圆柱体上切割而成，具有一个单一的起点，在这个起点上，导程等于螺距。
Absolute viscosity	绝对粘度	A measure of the internal shear properties of fluids, expressed as the tangential force per unit area at either of two horizontal planes separated by one unit thickness of a given fluid, one of the planes being fixed and the other moving with unit velocity. 流体内部剪切特性的量度，表示为两个水平面中的任何一个上的单位面积切向力，两个水平面被给定流体的一个单位厚度隔开，其中一个平面固定，另一个以单位速度移动。
Wind pump	风泵	A pump driven directly by a windmill on a tower. Widely used in remote locations. 由塔上的风车直接驱动的泵。广泛应用于偏远地区。
Failure of the bolt	螺栓失效	Term implying that the bolt has broken or the threads have stripped. There can be many reasons for this. 表示螺栓断裂或螺纹脱落的术语。原因可能有很多种。
Martempering	淬火	(1) A hardening procedure in which an austenitized ferrous workpiece is quenched into an appropriate medium whose temperature is maintained substantially at the Ms of the workpiece, held in the medium until its temperature is uniform throughout–but not long enough to permit bainite to form–and then cooled in air. The treatment is frequently followed by tempering. (2) When the process is applied to carburized material, the controlling Ms temperature is that of the case. This variation of the process is frequently called marquenching. （1）一种淬火工艺，将奥氏体化铁质工件淬火到适当的介质中，该介质的温度基本保持在工件的Ms，保持在该介质中直到其温度在整个过程中均匀，但不足以形成贝氏体，然后在空气中冷却。处理后经常进行回火。（2） 当该工艺应用于渗碳材料时，控制Ms温度与实际情况相同。这个过程的变化经常被称为淬火。
Length of engagement	啮合长度	It is the axial measurement within which the external and internal threads have theoretical contact. 它是外螺纹和内螺纹具有理论接触的轴向测量。
Crankshaft	曲轴	The main shaft, of which the cranks are a part, of a reciprocating single-or multi-cylinder machine. Crankshafts may be built up in sections or forged as a single component. In an engine, the reciprocating motion of the pistons transmits power to the crankshaft and causes it to rotate, whereas in a pump the crankshaft is driven and its rotation causes the pistons to reciprocate. 曲柄是往复式单缸或多缸机器主轴的一部分。曲轴可以分段组装或作为单个部件锻造。在发动机中，活塞的往复运动将动力传递给曲轴并使其旋转，而在泵中，曲轴被驱动，其旋转使活塞往复运动。
Composite property	复合属性	In thermodynamics, a property defined in terms of the properties of a closed system and its surroundings, such as the non-flow exergy function. 在热力学中，根据封闭系统及其周围环境的性质定义的性质，例如非流动火用函数。
Hot stamping	热冲压	Hot forging of brass and bronze alloys. 黄铜和青铜合金的热锻。
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。
Computational domain	计算域	In CFD, FEM, and other numerical methods, the area or volume within which calculations are performed and on the periphery of which the boundary conditions are specified. 在CFD、FEM和其他数值方法中，执行计算的区域或体积以及在其外围指定边界条件的区域或体积。
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。
Strength (Unit Pa)	强度（单位Pa）	The maximum stress, in tension, compression, shear, or combinations thereof, that may be monotonically applied to a material, component, or structure before failure (defined as fracture, yielding, buckling, etc. as appropriate). 在破坏前（视情况定义为断裂、屈服、屈曲等），材料、部件或结构在拉伸、压缩、剪切或其组合中可能单调施加的最大应力。
Diffusion coating	扩散涂层	Coating on metal for corrosion- and/or oxidation-resistance. Coatings are produced by heating a metal in contact with an alloy in powder, liquid, or gaseous form at elevated temperature such that atoms of the coating diffuse into the substrate. Examples include chromium, aluminium, or silicon on substrates such as nickel-based superalloys, steels, and refractory metals. 金属上的防腐和/或抗氧化涂层。涂层是通过在高温下加热与粉末、液体或气体形式的合金接触的金属，从而使涂层的原子扩散到基体中而产生的。实例包括基底上的铬、铝或硅，如镍基高温合金、钢和耐火金属。
Spring load (Unit N)	弹簧载荷（单位：N）	A load exerted on a component by bending, compressing, extending, or twisting an attached spring. Mechanical energy stored in the spring can be released if any constraints on the component are removed. 通过弯曲、压缩、延伸或扭转连接的弹簧而施加在部件上的载荷。如果部件上的任何约束被移除，则可以释放弹簧中存储的机械能。
Forge	锻造	To shape metal while holt and plastic by a hammering or forcing process. Dies used in process. 通过锤击或强制过程使金属成型，同时保持塑料成型。过程会使用模具。
Available draught (Unit Pa)	可用通风量（单位Pa）	The reduced pressure of combustion gases in a furnace or boiler, either forced or due to the buoyancy of hot gases, which is used to draw in combustion air and remove products of combustion. 炉子或锅炉中燃烧气体的压力降低，无论是强制还是由于热气体的浮力，用于吸入燃烧空气并去除燃烧产物。
Mechanical efficiency (η)	机械效率（η）	1. In general for a machine, the ratio of output work to input work. 2. For a compressor, the ratio of indicated power to shaft power; for a reciprocating engine or an expander, the ratio of shaft power to indicated power. 1.一般而言，机器的输出功与输入功之比。2.对于压缩机，指示功率与轴功率之比；对于往复式发动机或膨胀机，轴功率与指示功率之比。
Degradation failure	退化失效	Failure of a system, component, or structure owing to material degradation. 由于材料退化导致的系统、组件或结构失效。
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。
Elastic recovery	弹性恢复	Amount the dimension of a stressed elastic material returns to its original (unstressed) dimension on release of an applied load. In hardness testing, the shortening of the original dimensions of the indentation upon release of the applied load. 在释放施加的载荷时，受应力弹性材料的尺寸恢复到其原始（无应力）尺寸的量。在硬度测试中，当释放所施加的载荷时，压痕的原始尺寸缩短。
Quench aging	淬火时效	Aging induced by rapid cooling after solution heat treatment. 固溶热处理后快速冷却引起的时效。
Impact loads	冲击载荷	Especially severe shock loads such as those caused by instantaneous arrest of a falling mass, shock meeting of two parts (in a mechanical hammer, for example), or by explosive impact, in which there can be an exceptionally rapid build-up of stress. 特别严重的冲击载荷，例如由下落质量的瞬时停止、两部分的冲击碰撞（例如在机械锤中）或爆炸性冲击引起的冲击载荷，其中可能会出现异常快速的应力积聚。
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。
Differential heating	差动加热	Heating that intentionally produces a temperature gradient within an object such that, after cooling, a desired stress distribution or variation in properties is present within the object. 加热有意在物体内产生温度梯度，从而在冷却后，在物体内出现所需的应力分布或特性变化。
Span (Unit m)	跨度（单位：m）	A dimension measured between the extremities of a body or structure, such as between the tips of a wing or the supports of a bridge. 在身体或结构的末端之间测量的尺寸，如机翼尖端或桥梁支架之间。
Crystalline defects	结晶缺陷	The deviations from a perfect three-dimensional atomic packing that are responsible for much of the structure-sensitive properties of the materials. Crystal defects can be point defects (dislocations) or surface defects (vacancies), line defects (dislocations), or surface defects (grain boundaries). 与完美的三维原子堆积的偏差是造成材料的大部分结构敏感特性的原因。晶体缺陷可以是点缺陷（位错）或表面缺陷（空位）、线缺陷（位错）或表面缺陷（晶界）。
Compressive strength	抗压强度	Maximum compressive stress a material is capable of developing. With a brittle material that fails in compression by fracturing, the compressive strength has a definite value. For ductile, malleable, or semiviscous materials (which do not fail in compression by a shattering fracture), the value obtained for compressive strength is an arbitrary value dependent on the degree of distortion that is regarded as effective failure of the material. 材料能够产生的最大压缩应力。如果脆性材料因破裂而无法压缩，则抗压强度具有一定值。对于韧性、可锻性或半粘性材料（不会因破裂而导致压缩失效），获得的抗压强度值是一个任意值，取决于被视为材料有效失效的变形程度。
Range of stress (Sr)	应力范围（Sr）	The algebraic difference between the maximum and minimum stress in one cycle—that is, Sr = Smax – Smin 一个循环中最大和最小应力之间的代数差，即Sr=Smax–Smin
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。
Widmanstätten structure	魏氏组织	A structure characterized by a geometrical pattern resulting from the formation of a new phase along certain crystallographic planes of the parent solid solution. The orientation of the lattice in the new phase is related crystallographically to the orientation of the lattice in the parent phase. The structure is readily produced in many alloys by appropriate heat treatment. 一种结构，其特征是沿母体固溶体的某些晶体学平面形成新相而形成的几何图案。新相中晶格的取向在晶体学上与母相中晶格的定向相关。通过适当的热处理，在许多合金中容易产生这种结构。
Tear strength (Unit N/m)	撕裂强度（单位：N/m）	The tensile force divided by the sheet thickness required to tear a pre-split sheet material at a specified rate. Particularly used for plastics, rubber, fabrics, and elastomers. Since the units are not those of stress but equivalent to J/m², the units of toughness, the term ‘strength’ is strictly incorrect. 按规定速率撕裂预裂片材所需的张力除以片材厚度。特别用于塑料、橡胶、织物和弹性体。由于单位不是应力单位，而是相当于J/m²，韧性单位，“强度”一词是完全错误的。
Grip length	夹紧长度	Combined thickness of all the things clamped together by the bolt and nut, including washers, gaskets, and joint members. 由螺栓和螺母夹紧在一起的所有部件的总厚度，包括垫圈、垫圈和接头构件。
Mechanical vibration	机械振动	The motion of a particle or body which oscillates about a position of equilibrium. 围绕平衡位置摆动的粒子或物体的运动。
Normality	常态	The principle that the vector sum of plastic strain increments is perpendicular to the yield surface. 塑性应变增量矢量和垂直于屈服面的原理。
Selective heating	局部加热	Intentionally heating only certain portions of a workpiece. 有意仅加热工件的某些部分。
Turning	车削	Turning is a machining process for generating external surfaces of revolution by the action of a cutting tool on a rotating workpiece, usually in a lathe. The rotation of a workpiece held against a cutting tool in a lathe to produce components with a circular cross section. 车削是一种机械加工过程，通常在车床上，通过刀具对旋转工件的作用产生旋转外表面。在车床中，工件靠着刀具旋转，以生产具有圆形横截面的部件。
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。
Variance	方差	A measure of the squared dispersion of observed values or measurements expressed as a function of the sum of the squared deviations from the population mean or sample average. 观测值或测量值的平方离散度的度量，表示为总体平均值或样本平均值的平方偏差之和的函数。
Mechanical energy (Unit J)	机械能（单位J）	The sum of kinetic energy and potential energy for an object or a mechanical system, including the energy stored in springs, etc. 物体或机械系统的动能和势能之和，包括储存在弹簧等中的能量。
Tightness	紧密度	A measure of the mass leak rate from a gasketed joint. 垫圈接头质量泄漏率的测量值。
Oil hardening	油回火	The formation of martensite before tempering by quenching suitable steels in oil at lower cooling rates than given by water quenching, thus reducing the likelihood of component fracture or severe residual stresses. Quench-hardening treatment involving cooling in oil. 通过在油中以低于水淬的冷却速率淬火合适的钢，在回火前形成马氏体，从而降低部件断裂或严重残余应力的可能性。是一种淬火硬化处理，包括在油中冷却。
Nanoparticles	纳米颗粒	Particles with dimensions of order 1 nm which have either been introduced into microstructures for reinforcement or are present as impurities. 尺寸为1nm级的颗粒，其已被引入微结构中用于增强或作为杂质存在。
Creep rupture strength (Unit Pa)	蠕变断裂强度（单位Pa）	The fracture stress at the end of a creep test in metals and polymers, often plotted against time to give a stress-rupture curve. 金属和聚合物蠕变试验结束时的断裂应力，通常与时间作图以给出应力-断裂曲线。
Shear stress (Unit Pa)	剪应力（单位Pa）	(1) A stress that exists when parallel planes in metal crystals slide across each other. (2) The stress component tangential to the plane on which the forces act. Also known as tangential stress. (shearing stress, tangential stress, τ) 1. The stress which acts parallel to any plane within a solid material. It can arise due to a bending moment, a shear force, or torque applied to the body. 2. The stress corresponding to velocity gradients within a flowing viscous fluid. （剪应力，切向应力，τ）（1）当金属晶体中的平行平面彼此滑动时存在的应力。（2）与力作用平面相切的应力分量。也称为切向应力。1.平行于固体材料内任何平面的应力。它可能是由于施加在身体上的弯矩、剪力或扭矩引起的。2.对应于流动粘性流体内的速度梯度的应力。
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。
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。
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。
Nut factor	螺母系数	An experimental constant used to evaluate or describe the ratio between the torque applied to a fastener and the Preload achieved as a result. 用于评估或描述施加在紧固件上的扭矩与由此获得的预载之间的比率的实验常数。
Inclusions	夹杂物	Small pieces of nonmetallic impurities trapped within the base metal of. 存在于金属基体中的小块非金属杂质。
Slip line	滑移线	The trace of the slip plane on a viewing surface; the trace is usually observable only if the surface has been polished before deformation. The usual observation on metal crystals (under the light microscope) is of a cluster of slip lines known as a slip band. 滑动平面在观察表面上的轨迹；只有在变形前对表面进行抛光，才能观察到痕迹。通常对金属晶体的观察（在光学显微镜下）是一组称为滑移带的滑移线。
Reverse pitch (Unit °)	反向螺距（单位°）	The pitch of a variable-pitch propeller that produces negative thrust. 产生负推力的变桨距螺旋桨的桨距。
Pressure regulator	压力调节器	(pressure-regulating valve) A device installed in a pneumatic or gas system to maintain the downstream pressure at the required level. （压力调节阀）安装在气动或气体系统中以将下游压力保持在所需水平的装置。
Equation, long form	方程，长格式	An equation which relates the torque applied to a bolt to the preload created in it, and involves fastener geometry and the coefficient of friction between mating surfaces. A theoretical equation based on rigid body mechanics and the assumption that the geometry of the fastener is perfectly described by blueprint dimensions. 将施加在螺栓上的扭矩与螺栓中产生的预载荷联系起来的方程，该方程涉及紧固件几何形状和配合面之间的摩擦系数。基于刚体力学和紧固件几何结构由蓝图尺寸完美描述的假设的理论方程。
Chafing fatigue	磨损疲劳	Fatigue damage initiated in a surface damaged by rubbing against another body. 因与另一个物体摩擦而损坏的表面引起的疲劳损坏。
Coefficient of friction (μ)	摩擦系数（μ）	(coefficient of kinetic friction, coefficient of sliding friction, friction coefficient, μ) The ratio of the frictional force F to the normal force N between two surfaces in contact, i.e. μ = F/N. Static friction is when there is no relative sliding; kinetic friction when there is. For structural components sliding on one another, the coefficient of friction is the ratio of the force causing the sliding to the force perpendicular to the sliding component surfaces. The coefficient of friction is dimensionless with values between zero and one. The number characterising the force necessary to slide or roll one material along the€surface of another. If an object has a weight N and the coefficient of friction is μ, then the force F necessary to move it without acceleration along a level surface is F = μN. The coefficient of static friction determines the force necessary to initiate movement; the coefficient of kinetic friction determines the force necessary to maintain movement. Kinetic friction is usually smaller than static friction. （动摩擦系数、滑动摩擦系数、摩擦系数，μ）两个接触表面之间摩擦力F与法向力N的比值，即μ=F/N。静摩擦是指没有相对滑动时；有摩擦时的动摩擦。对于相互滑动的结构部件，摩擦系数是引起滑动的力与垂直于滑动部件表面的力的比值。摩擦系数是无量纲的，其值介于0和1之间。代表一种材料沿另一种材料的表面滑动或滚动所需的力的数字。如果一个物体的重量为N并且摩擦系数为μ，那么在没有加速度的情况下沿水平表面移动它所需的力F为F=μN。静摩擦系数决定了启动运动所需的力；动摩擦系数决定了保持运动所需的力。动摩擦通常小于静摩擦。两个物体之间的力（F）与将这些物体压在一起的法向力（N）的无量纲比：μ（或f）=（F/N）。
Cold working	冷加工	The plastic deformation of a metal, by rolling (cold rolling), drawing, forging (cold forging), etc. at a temperature well below its recrystallization temperature, which results not only in permanent shape change but also increase in strength and loss of ductility owing to work-hardening. 金属在远低于其再结晶温度的温度下通过轧制（冷轧）、拉拔、锻造（冷锻）等方式发生塑性变形，这不仅会导致永久的形状变化，还会增加强度并降低延展性由于加工硬化。
Compressed liquid	压缩液体	A liquid subjected to a pressure greater than the saturation pressure corresponding to its temperature. 承受大于与其温度对应的饱和压力的压力的液体。
Torsion test	扭力测试	A test designed to provide data for the calculation of the shear modulus, modulus of rupture in torsion, and yield strength in shear. 为计算剪切模量、扭转断裂模量和剪切屈服强度而设计的试验。
Bearing area	承载面积	The product of the pin (or hole) diameter and specimen thickness in a bearing test. (bearing surface) (Unit m²) The projected area of a hole, such as a rivet hole, that carries a transverse load. 轴承测试中销（或孔）直径和试样厚度的乘积。（承载面）（单位m²）承载横向载荷的孔（例如铆钉孔）的投影面积。
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。
Crest clearance (Unit m)	顶隙（单位米）	For screw threads and gearing, the radial clearance between the crest of a thread (or gear) and the root of the engaging thread (or gear). 对于螺纹和齿轮，螺纹（或齿轮）的顶部与啮合螺纹（或齿轮）的根部之间的径向间隙。
Semi-rotary pump	半回转泵	A form of self-priming pump, often hand-operated, suitable for pumping water and light oils such as diesel oil and petrol. As shown in the diagram, liquid is sucked into one side of the pump through flap valves and simultaneously ejected from the other side on one stroke. The sequence is reversed on each successive stroke. 一种自吸泵，通常是手动的，适用于泵送水和轻油，如柴油和汽油。液体通过翻板阀吸入泵的一侧，同时在一个冲程中从另一侧排出。在每个连续冲程上，顺序颠倒。
Galilean transformation	伽利略变换	In steady fluid flow, the addition or subtraction of a constant velocity to the entire flowfield, e.g. so that flow can be considered relative to a moving object or flow feature, such as a shock wave. 在稳定的流体流动中，对整个流场增加或减少恒定速度，例如，可以考虑相对于移动物体或流动特征（例如冲击波）流动。
Initial strain	初始应变	The strain in a specimen immediately upon achieving the given loading conditions in a creep test (before creep occurs). Sometimes referred to as instantaneous strain. 在蠕变试验中（蠕变发生之前）达到给定载荷条件后，试样立即产生的应变。有时称为瞬时应变。
Combustion chamber	炉膛	1. In a piston engine, the volume between the head of an individual cylinder and the crown of the piston in which the fuel–air mixture burns during each power stroke of the engine. 2. (combustor) In a gas-turbine engine, a ramjet, an afterburner, or a rocket motor, the component, often cylindrical or annular in shape, in which the fuel–air mixture burns in a continuous-flow process. 1.在活塞式发动机中，在发动机的每个动力冲程中，燃料-空气混合物燃烧的单个气缸盖和活塞顶之间的体积。2.（燃烧室）在燃气涡轮发动机、冲压发动机、加力燃烧室或火箭发动机中，燃料-空气混合物在连续流动过程中燃烧的部件，通常为圆柱形或环形。
Barcol hardness test	巴氏硬度测试	An indentation test, similar to the Shore hardness test but using a pointed indentor with a flat tip, used to determine the hardness of such materials as rigid plastics and composites. 一种压痕测试，类似于肖氏硬度测试，但使用带有扁平尖端的尖头压头，用于确定硬质塑料和复合材料等材料的硬度。
Velocity ratio	速度比	1. The ratio between the input velocity to a machine, train of gears, etc. and the output velocity. 2. The ratio between the displacement of an applied force at one part of a mechanism and the movement of the load at a different part. 1.机器、齿轮系等的输入速度与输出速度之间的比率。2.在机构的一个部分处施加的力的位移与在不同部分处的载荷的移动之间的比率。
Radiation pressure (Unit μPa)	辐射压力（单位：μPa）	The pressure exerted on a surface exposed to any form of electromagnetic radiation. If the radiation is absorbed, it is equal to the power-flux density divided by the speed of light. 施加在暴露于任何形式电磁辐射的表面上的压力。如果辐射被吸收，它等于功率通量密度除以光速。
Ductility	延展性	The ability of a material to deform plastically before fracturing. Measured by elongation or reduction in area in a tensile test, by height of cupping in a cupping test, or by the radius or angle of bend in a bend test. 材料在断裂前发生塑性变形的能力。通过拉伸试验中的伸长率或面积减少量、杯突试验中的杯突高度或弯曲试验中的弯曲半径或角度来测量。
Structural analysis	结构分析	The determination of the forces, displacements, stresses, and strains in a given structure. 确定给定结构中的力、位移、应力和应变。
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。
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。
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。
Vickers hardness test	维氏硬度测试	An indentation hardness test employing a 136° diamond pyramid indenter (Vickers) and variable loads, enabling the use of one hardness scale for all ranges of hardness—from very soft lead to tungsten carbide. Also know as diamond pyramid hardness test. 采用136°金刚石棱锥压头（维氏硬度计）和可变载荷的压痕硬度测试，能够对从极软铅到碳化钨的所有硬度范围使用一个硬度标度。也称为钻石金字塔硬度测试。
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。
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。
Composite material	复合材料	(composite structure) A general term used of two or more materials or structures acting in combination (e.g. concrete, reinforced concrete, filamentreinforced polymers, laminated materials, particulate-reinforced materials, flitched beams), resulting in values of strength, stiffness, or toughness greater than the base matrix material alone. （复合结构）用于组合作用的两种或多种材料或结构的通用术语（例如混凝土、钢筋混凝土、纤维增强聚合物、层压材料、颗粒增强材料、切割梁），从而产生强度、刚度或韧性值大于单独的基体材料。
Tangent screw	微动螺旋	A worm screw used to adjust measuring instruments such as sextants and vernier callipers. 用于调整六分仪和游标卡尺等测量仪器的蜗杆。
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。
Refractory materials	耐火材料	Metals or ceramics that do not melt when exposed to temperature above about 1 500°C or deteriorate rapidly in a continuous temperature above about 550°C. 当暴露于高于约1500°C的温度时不熔化或在高于约550°C的连续温度下快速劣化的金属或陶瓷。
Acoustic droplet ejection	声液滴喷射	The ejection of small droplets from the surface of a liquid that results from focusing high-intensity ultrasound near the surface. 由于在表面附近聚焦高强度超声波而从液体表面喷射出小液滴。
Turn-of-nut method	螺母转动法	It applies preload by turning a nut through an angle that corresponds to a given elongation. 它通过将螺母旋转一个与给定伸长率相对应的角度来施加预载荷。
Design load (Unit N)	设计荷载（单位N）	The greatest load that a component or structure is expected to experience under normal operating conditions. 部件或结构在正常运行条件下预期承受的最大负载。
Stress–strain curve	应力-应变曲线	(stress–strain diagram) A plot of stress vs strain for a solid material obtained from a test in which a specimen is loaded in tension, compression, shear, or combinations thereof. Diagrams of true stress vs true strain deviate from those of nominal stress vs nominal strain only at large strains where appreciable changes in cross section of testpieces occur. （应力-应变图）从试验中获得的固体材料的应力与应变图，其中试样在拉伸、压缩、剪切或其组合中加载。只有在试件横截面发生明显变化的大应变下，真实应力与真实应变图与标称应力与标称应变图不同。
O-ring (O-ring seal)	O形圈（O形密封圈）	A toroidal ring of synthetic rubber seated in a groove machined into a flat or cylindrical surface to act as a seal. 一种环形合成橡胶环，位于加工成平面或圆柱表面的凹槽中，起密封作用。
Steel-wire rope	钢丝绳	A rope or cable made up of many steel strands wrapped helically about an axis, each strand being made of metal wires twisted together like a helix. 一种绳索或缆绳，由许多绕轴螺旋缠绕的钢绞线组成，每根钢绞线由金属丝缠绕在一起形成螺旋。
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。
Austenite	奥氏体	A solid solution of one or more elements in face-centered cubic iron. Unless otherwise designated (such as nickel austenite), the solute is generally assumed to be carbon. Solid solution of alloying elements and/or carbon in γ-Fe. It is named after British metallurgist W. C. Roberts-Austen. 一种或多种元素在面心立方铁中的固溶体。除非另有说明（如镍奥氏体），溶质通常假定为碳。合金元素和/或碳在γ-Fe中的固溶体。它以英国冶金学家WCRoberts-Austen的名字命名。
Clamping force	夹紧力	The equal and opposite forces which exist at the interface between two joint members. The clamping force is created by tightening the bolts, but is not always equal to the combined tension in the bolts. Hole interference problems, for example, can create a difference between clamping force and bolt loads. 存在于两个连接构件之间的界面处的相等和相反的力。夹紧力是通过拧紧螺栓产生的，但并不总是等于螺栓中的组合张力。例如，孔干涉问题可能会在夹紧力和螺栓载荷之间产生差异。
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。
Wedge	楔子	A short triangular prism whose major surfaces subtend an acute angle, that can be driven between two objects or parts of an object to split, tighten, or secure them, or to widen an opening or raise a heavy object. The acute angle gives a high mechanical advantage. 一种短的三棱镜，其主面对着一个锐角，可在两个物体或物体的一部分之间驱动，以将它们分开、拧紧或固定，或加宽开口或举起重物。锐角具有很高的机械优势。
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。
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。
Finishing temperature	终轧温度	The temperature at which hot working is completed. 完成热加工的温度。
Spinner	旋转器	A co-axial streamlined fairing enclosing the hub of a propeller and rotating with it. 一种同轴流线型整流罩，包围螺旋桨毂并随其旋转。
Forging cracks	锻造裂纹	This may occur during fastener manufacturing at the cutting or forging operations and are located on the top of the head or on the raised periphery of indented head bolts. 这可能发生在紧固件制造过程中的切削或锻造操作中，并且位于头部的顶部或带锯齿的头部螺栓的凸起周边上。
Head height	头部高度	The head height shall be that overall distance measured parallel to the axis of the product from the top of the head to the bearing surface and shall include the thickness of the washer face. Raised grade and manufacturer’s identification are excluded from head height. 头部高度应为平行于产品轴线从封头顶部到支承面测量的总距离，并应包括垫圈表面的厚度。提升等级和制造商标识不包括在头部高度中。
Crushing strain	压应变	The supposed single strain that results in comminution of a brittle material. The corresponding stress is termed the crushing strength. Neither quantity can be a material constant as they must obey the laws of fracture mechanics and will depend on the type of testpiece, method of loading etc. 导致脆性材料粉碎的假定单应变。相应的应力称为抗压强度。这两个量都不能是材料常数，因为它们必须遵守断裂力学定律，并取决于试件类型、加载方法等。
Angström (Å)	昂斯特罗姆（Å）	An obsolete (non-SI) unit of length, sometimes still employed for atomic and crystallographic measurements. The conversion to SI is 1 Å = 10−10 m. 一种已被淘汰的（非SI）长度单位，有时仍用于原子和晶体学测量。转换为SI为1Å=10-10m。
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。
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。
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。
Precision	精确	The closeness of agreement between the results of individual replicated measurements or tests. The standard deviation of the error of measurement may be used as a measure of “imprecision.” 单个重复测量或测试结果之间的一致性。测量误差的标准偏差可用作“不精确性”的度量
Gravity	重力	The attractive force by which bodies are drawn towards the centre of Earth or other celestial object. Its intensity is measured by the acceleration produced. The gravitational force of attraction at the surface of a planet or other celestial body. The Earth’s gravity produces an acceleration of around 9.8m/s² for any unsupported body. 物体被拉向地球中心或其他天体的吸引力，行星或其他天体表面的引力。它的强度是通过产生的加速度来衡量的，对于任何无支撑的物体，地球的重力都会产生大约9.8m/s²的加速度。
Workspace (Unit m³)	工作空间（单位m³）	(working-space volume) The volume around the base frame of a robot, defined by the reach of the robot. The robot can thus only perform tasks within this volume. （工作空间体积）机器人基架周围的体积，由机器人的可达范围定义。因此，机器人只能执行该体积内的任务。
constitutive equation	本构方程	(constitutive relation) 1. In solid mechanics or fluid mechanics, an algebraic or numerical relation for the dependency of stress on deformation, strain, strain rate, temperature, etc. in a material. In solid mechanics such a relation is sometimes called an equation of state. Simple linear examples include Hooke’s law and Newton’s viscosity law. 2. In heat transfer, a relation, such as Fourier’s law of heat conduction, connecting heat flux with temperature gradient. （本构关系）1.在固体力学或流体力学中，应力与材料的变形、应变、应变率、温度等之间的代数或数值关系。在固体力学中，这种关系有时称为状态方程。简单的线性例子包括胡克定律和牛顿粘度定律。2.在传热学中，将热流与温度梯度联系起来的一种关系，如傅立叶热传导定律。
Actual power	实际功率	(actual horsepower) (Unit W or hp) The power delivered at the output shaft of an engine, before subsequent transmission through a gearbox etc. （实际马力）（单位W或hp）在随后通过变速箱等传输之前，在发动机输出轴上传递的功率。
Springback	回弹	The extent to which metal tends to return to its original shape or contour after undergoing a forming operation. 金属在经历成形操作后趋于恢复其原始形状或轮廓的程度。
Bearing strength	承载强度	The maximum bearing stress that a material is capable of sustaining. 材料能够承受的最大承载应力。
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。
Computer-aided design (CAD)	计算机辅助设计（CAD）	Generally, design and calculations performed by computer; more specifically, the use of computer graphics and models to communicate design concepts. Computer-aided design and computer-aided manufacturing (CAD/CAM) is where component dimensions resulting from CAD are passed by electronic means directly to machines for manufacture. 一般由计算机进行设计和计算，更具体地说，使用计算机图形和模型来传达设计概念。计算机辅助设计和计算机辅助制造（CAD/CAM）是由CAD产生的组件尺寸通过电子方式直接传递到机器进行制造。
Elasticity	弹性	The property of a material by virtue of which deformation caused by stress disappears on removal of the stress. A perfectly elastic body completely recovers its original shape and dimensions after release of stress. 一种材料的特性，通过这种特性，由应力引起的变形在去除应力后消失。完全弹性体在应力释放后完全恢复其原始形状和尺寸。
Martensitic stainless steels	马氏体不锈钢	Martensitic stainless steels are hardenable magnetic stainless steels that contain 9–18% chromium, 0.06–1.25% carbon, and typically up to about 2.5% in total of manganese, silicon, nickel, and molybdenum. They can be heat-treated such that martensite is the prime microconstituent, and are usually available in the annealed or quenched-and-tempered condition. They have excellent strength and high hardness, and good corrosion resistance. Uses include cutlery, surgical instruments, rifle barrels, steam turbine tubing and blading, jet engine components, hand tools, machine parts, fasteners, valves, springs, bearings, pump shafts, nozzles, mining equipment, and wear-resistant parts. 马氏体不锈钢是一种可硬化的磁性不锈钢，其铬含量为9-18%，碳含量为0.06-1.25%，锰、硅、镍和钼的总含量通常高达约2.5%。它们可以进行热处理，使马氏体成为主要的微组分，通常可在退火或淬火回火条件下获得。它们具有优异的强度和高硬度，以及良好的耐腐蚀性。用途包括餐具、外科器械、步枪枪管、蒸汽轮机管道和叶片、喷气发动机部件、手动工具、机械零件、紧固件、阀门、弹簧、轴承、泵轴、喷嘴、采矿设备和耐磨零件。
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。
Galvanic protection	电流保护	The coating on a fastener is said to provide galvanic protection if it is more anodic than the fastener and will, therefore, be destroyed instead of the fastener. Zinc plate (galvanizing) provides galvanic protection to steel fasteners, for example. 如果紧固件上的涂层比紧固件更具阳极性，则据说它可以提供电流保护，将会因此被破坏而不是紧固。例如，锌板（镀锌）为钢紧固件提供电流保护。
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。
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。
Wrap-around bend	环绕弯曲	The bend obtained when a specimen is wrapped in a closed helix around a cylindrical mandrel. This term is sometimes applied to a semiguided bend of 180° or less. 当试样缠绕在圆柱形心轴周围的闭合螺旋中时获得的弯曲。该术语有时适用于180°或更小的半导弯曲。
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。
Thermodynamic state	热力学状态	The condition of a system or working fluid according to its properties. 系统或工作流体根据其性质的状态。
Tightness, acceptable	密封性，可接受的	Wholly leak-free joints are impossible, at least if the contained fluid is a gas, so it has been proposed that the design of a gasketed joint should start with the selection of an ‘‘acceptable’’ leak rate. The designer would dimension bolts and joint members so that the actual leak rate would never exceed this. Three standard levels of tightness have been proposed as well. 至少在所含流体为气体的情况下，完全无泄漏的接头是不可能的，因此有人建议，垫圈接头的设计应从选择“可接受”的泄漏率开始。设计师将确定螺栓和接头构件的尺寸，以便实际泄漏率永远不会超过此值。还提出了三种标准的密封性等级。
Elongation	伸张率	A term used in mechanical testing to describe the amount of extension of a test piece when stressed. 机械测试中使用的术语，用于描述试样在受力时的延伸量。
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。
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。
Full-size fastener	全尺寸紧固件	Finished fastener with a shank diameter of ds ≈ d or ds > d, or screw threaded to the head, or fully threaded stud. 柄径为ds≈d或ds>d的紧固件，或螺纹连接到头部，或全螺纹螺柱。
Young’s modulus	杨氏模量	A term used synonymously with modulus of elasticity. The ratio of tensile or compressive stresses to the resulting strain. 与弹性模量同义的术语。拉伸或压缩应力与产生应变的比率。
Effective radius of nut, bolt head, or threads	螺母、螺栓头或螺纹的有效半径	Distance between the geometric center of the part and the circle of points through which the resultant contact forces between mating parts passes. Must be determined by integration. 零件几何中心与配合零件之间的合力通过的点圆之间的距离。必须通过积分来确定。
Absorptance	吸收率	(absorptivity, absorption coefficient, α) The fraction of radiant flux incident on a surface that is absorbed by the surface. The term also applies to absorption of radiation by a volume of fluid. For a semi-transparent surface, α + ρ + τ = 1, where ρ is the reflectance and τ is the transmittance. （吸收率，吸收系数，α）入射到表面的辐射通量被表面吸收的部分。该术语也适用于一定体积的流体对辐射的吸收。对于半透明表面，α+ρ+τ=1，其中ρ是反射率，τ是透射率。
Clearance	间距	(Unit m or μm) 1. The distance (if any) between mating components in an assembly. 2. The distance between two moving parts, or a moving part and stationary part, in a machine (e.g. the gap between a piston and a cylinder head). 3. With threads, the major clearance is the distance between the design form at the root of an internal thread and the crest of its mating external thread; the minor clearance is the corresponding dimension between the crest of an internal thread and the root of the external thread. （单位m或μm）1.装配体中配合组件之间的距离（如果有）。2.机器中两个运动部件之间的距离，或运动部件和静止部件之间的距离（例如活塞和气缸盖之间的间隙）。3.带螺纹时，主要间隙是内螺纹根部的设计形状与其配合的外螺纹牙顶之间的距离；小间隙是内螺纹牙顶和外螺纹牙根之间的对应尺寸。
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。
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。
Cavitation damage	气蚀损坏	Erosion of a solid surface through the formation and collapse of cavities or bubbles in an adjacent liquid that contains vapor and/or gas. 通过在包含蒸汽和/或气体的相邻液体中形成空穴或气泡并破坏固体表面。
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。
Seal	密封件	A component which controls or prevents leakage of fluids into or out of parts of a machine. 控制或防止流体流入或流出机器部件的部件。
Induction heating	感应加热	Heating by combined electrical resistance and hysteresis losses induced by subjecting a metal to the varying magnetic field surrounding a coil carrying alternating current. 通过将金属置于承载交流电的线圈周围的变化磁场中而引起的电阻和磁滞损耗的组合加热。
Crack-growth rate	裂纹增长速度	Rate of propagation of a crack through a material due to statically or dynamically applied load. 由于静态或动态施加的载荷，裂纹在材料中的扩展速率。
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。
Fatigue	疲劳	The phenomenon leading to fracture under repeated or fluctuating stresses having a maximum value less than the ultimate tensile strength of the material. Fatigue failure generally occurs at loads that, applied statically, would produce little perceptible effect. Fatigue fractures are progressive, beginning as minute cracks that grow under the action of the fluctuating stress. A term referring, in components and structures subjected to either random or cyclic periodically-varying loads, to a progressive reduction in strength leading to failure at stresses lower than those that cause failure under monotonic loading. Variable loads arise from outof-balance machinery and other vibration sources, wind gusts, etc., and a large proportion of service failures is caused by fatigue. Fatigue results from the initiation and slow propagation of cracks. In manufactured components, crack initiation usually occurs at a point of stress concentration. After a period, often of millions of stress cycles, the crack reaches a critical length at which the next peak load causes sudden brittle or ductile fracture. Fracture surfaces resulting from fatigue display characteristic striations or progression marks emanating from the crack initiation site during the slow crack growth period, with a different surface appearance for the final fracture. 在最大值小于材料极限抗拉强度的重复或波动应力下导致断裂的现象。疲劳失效通常发生在静态施加的载荷下，不会产生明显影响。疲劳断裂是渐进性的，从在波动应力作用下生长的微小裂纹开始。在承受随机或周期性变化载荷的部件和结构中，指强度逐渐降低，导致在低于单调载荷下导致失效的应力下发生失效的术语。可变负载由失衡的机械和其他振动源、阵风等引起，大部分故障是由疲劳引起的。疲劳是裂纹萌生和缓慢扩展的结果。在制造部件中，裂纹萌生通常发生在应力集中点。在一段时间（通常是数百万次应力循环）后，裂纹达到临界长度，此时下一个峰值载荷会导致突然脆性或韧性断裂。疲劳产生的断裂表面在缓慢裂纹扩展期间显示出从裂纹萌生部位发出的特征条纹或进展标记，最终断裂的表面外观不同。
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。
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）。
Recrystallization annealing	再结晶退火	Annealing cold-worked metal to produce a new grain structure without phase change. 退火冷加工金属以产生新的晶粒结构而不发生相变。
Initial preload	初始预载	The tension created in a single bolt as it is tightened. Will usually be modified by subsequent assembly operations or by in-service loads and conditions. 拧紧单个螺栓时产生的张力。通常会通过后续的装配操作或在役负载和条件进行修改。
Nut	螺母	A metal fastener of square, hexagon or other shape, having an internal thread which screws onto a bolt, stud or arbor. An internally-threaded fastener used with externally-threaded bolts. Usually hexagonal in shape but there is a multitude of other geometries, such as square, for special purposes and different gripping tools. 一种方形、六角形或其他形状的金属紧固件，具有内螺纹，可拧在螺栓、螺柱或心轴上。与外螺纹螺栓一起使用的内螺纹紧固件。通常为六边形，但也有许多其他几何形状，如方形，用于特殊用途和不同的夹持工具。
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。
Half nut	半螺母	A mechanism attached to the apron of a lathe and operated by a lever. The lever opens and closes a nut that has been split lengthwise so that the two halves of the nut can be closed upon the lead screw when threads are being cut. Also called Split Nut. 固定在车床裙板上并由杠杆操作的机械装置，杠杆打开和关闭纵向分开的螺母，以便在切割螺纹时，螺母的两半可以在丝杠上闭合。也称为剖分螺母。
Compressor bleed	压缩机排气	The removal of air before the final stage of a multistage compressor operating below design speed, to prevent the final stage from choking. 在低于设计速度运行的多级压缩机的末级之前去除空气，以防止末级阻塞。
Transducer	传感器	A device which converts one form of energy into another. An ultrasonic transducer, for example, converts electrical energy into acoustic energy (at ultrasonic frequencies) and vice versa. 将一种形式的能量转换为另一种形式能量的装置。例如，超声换能器将电能转换为声能（在超声频率下），反之亦然。
Stress ratio (A or R)	应力比（A或R）	The algebraic ratio of two specified stress values in a stress cycle. Two commonly used stress ratios are the ratio of the alternating stress amplitude to the mean stress, A = Sa/Sm, and the ratio of the minimum stress to the maximum stress, R = Smin/Smax. 应力循环中两个指定应力值的代数比。两种常用的应力比是交变应力振幅与平均应力之比，A=Sa/Sm，以及最小应力与最大应力之比R=Smin/Smax。
Friction loss (Unit J)	摩擦损失（单位J）	The conversion of mechanical energy to heat due to friction within a machine, mechanism, linkage, etc. 由于机器、机构、连杆等内部的摩擦而将机械能转化为热能。
Effective yield strength	有效屈服强度	An assumed value of uniaxial yield strength that represents the influence of plastic yielding on fracture test parameters. 单轴屈服强度的假设值，代表塑性屈服对断裂试验参数的影响。
Modulus of resilience	回弹系数	The amount of energy stored in a material when loaded to its elastic limit. It is determined by measuring the area under the stress-strain curve up to the elastic limit. 当加载到其弹性极限时，材料中储存的能量量。通过测量应力-应变曲线下直至弹性极限的面积来确定。
Vacuum pump	真空泵	A pump for exhausting air and non-condensable gases from a vessel to be maintained at sub-atmospheric pressure. The pirani and thermal-conductivity gauges are vacuum gauges used to measure the absolute pressure within a vacuum system (vacuum level), usually expressed in torr or Pa. 用于从容器中排出空气和不凝性气体以保持在亚大气压的泵。皮拉尼和热导率计是用于测量真空系统内绝对压力（真空水平）的真空计，通常用托或帕表示。
Cavity radiator	空腔辐射器	A heated chamber having a small hole through which radiation, approximating blackbody radiation, passes out. 具有小孔的加热室，近似于黑体辐射的辐射通过该小孔传递出去。
Hot-wire analyzer	热电阻丝型分析仪	An electrical atmosphere analysis device that is based on the fact that the electrical resistivity of steel is a linear function of carbon content over a range from 0.05% C to saturation. The device measures the carbon potential of furnace atmospheres (typically). This term is not to be confused with the hot-wire test which measures heat extraction rates. 一种基于以下事实的电气氛分析设备：钢的电阻率是从0.05%C到饱和范围内的碳含量的线性函数。该设备测量炉内气氛的碳势（通常）。不要将此术语与测量热提取率的热线测试相混淆。
British thermal unit (BTU, Btu)	英热单位（BTU，Btu）	An obsolete (non-SI) imperial unit of energy defined as the energy required to raise the temperature of one pound of pure water at 68°F by 1°F. The conversion to SI is 1 Btu = 1.055 056 × 103 J. 一种已被淘汰的（非SI）英制能量单位，定义为将68°F的一磅纯水的温度升高1°F所需的能量。转换为SI为1Btu=1.055056×103J。
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。
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。
Working stress (Unit Pa)	工作应力（单位Pa）	The stress under which a component or structure is designed to operate under normal conditions. 部件或结构设计为在正常条件下运行的应力。
Welding	焊接	In tribology, the bonding between metallic surfaces in direct contact, at any temperature. A joining process in which the mating surfaces are at least softened, or more usually melted, unlike soldering and brazing. In solid-state (non-melting) welding, similar or dissimilar metals or thermoplastics may be joined by applying pressure to hot interfaces. In forge welding, joining is achieved by compression across the join between pre-heated workpieces. In friction welding (spin welding) one of the contacting surfaces is rotated rapidly before being loaded against the other. On contact, heat generated by friction softens the materials and permits severe plastic deformation that seals the joint. In friction stir welding, a wear-resistant tool is rotated rapidly, indents the surfaces and is traversed to form a join line. Resistance welding involves simultaneous pressure and electrically-generated heat, as in spot welding where a heavy electric current is passed for a short time through metal sheets which are pressed together between electrodes. 在摩擦学中，在任何温度下直接接触的金属表面之间的结合。与钎焊和钎焊不同，接合面至少软化或更通常熔化的接合工艺。在固态（非熔化）焊接中，相似或不同的金属或热塑性塑料可通过向热界面施加压力来连接。在锻造焊接中，通过压缩预热工件之间的连接来实现连接。在摩擦焊接（旋转焊接）中，一个接触表面在被加载到另一个表面之前快速旋转。接触时，摩擦产生的热量使材料软化，并允许密封接头的严重塑性变形。在搅拌摩擦焊中，耐磨工具快速旋转，使表面凹陷，并横穿形成连接线。电阻焊涉及同时产生的压力和电产生的热量，如点焊，在点焊中，大电流短时间通过电极之间压在一起的金属板。
Wing	翼	A relatively long and thin body with a cross section designed to produce lift when there is motion relative to a fluid. The principal applications are to aircraft and highperformance motor vehicles. 一种相对长而薄的物体，其横截面设计用于在相对于流体运动时产生升力。主要应用于飞机和高性能机动车辆。
Minor diameter	螺纹小径	On a straight thread, the diameter of the imaginary cylinder which just touches the root of an external thread or the crest of an internal thread. 在直螺纹上，仅接触外螺纹根部或内螺纹顶部的假想圆柱体的直径。
Biomechanics	生物力学	The application of mechanical-engineering principles, including thermodynamics, fluid mechanics, and solid mechanics together with materials engineering, to biological systems. 机械工程原理（包括热力学、流体力学和固体力学以及材料工程）在生物系统中的应用。
Profilometer	轮廓仪	An instrument used to quantify the roughness of a surface. For a contact profilometer, a diamond stylus sweeps across the surface along a series of parallel lines. Noncontact profilometers use optical techniques to map the surface irregularities. 用于量化表面粗糙度的仪器。对于接触式轮廓仪，钻石触针沿一系列平行线扫过表面。非接触式轮廓仪使用光学技术绘制表面不规则。
Rotor	转子	A part of a machine that rotates on a shaft (rotor shaft) about its own axis, such as the blade-carrying discs of a turbine, the blades of a helicopter, or the rotating parts of a Roots blower. 绕轴（转子轴）绕其自身轴线旋转的机器部件，如涡轮叶片、直升机叶片或罗茨鼓风机的旋转部件。
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。
Pin or mandrel	销或心轴	In bend testing, the plunger or tool used in making semiguided, guided, or wrap-around tests to apply the bending force to the inside surface of the bend. In free bends or semiguided bends to an angle of180°, a shim or block of the proper thickness may be placed between the legs of the specimen as bending is completed. This shim or block is also referred to as a pin or mandrel. 在弯曲测试中，用于进行半导向、导向或环绕测试以将弯曲力施加到弯曲内表面的柱塞或工具。在180°角的自由弯曲或半导向弯曲中，弯曲完成后，可在试样支腿之间放置适当厚度的垫片或垫块。该垫片或垫块也称为销或心轴。
Hysteresis	滞后	The phenomenon of permanently absorbed or lost energy that occurs during any cycle of loading or unloading when a material is subjected to repeated loading. 当材料经受重复加载时，在任何加载或卸载循环期间发生的永久吸收或损失能量的现象。
Intergranular fracture	沿晶破裂	Brittle fracture of a metal in which the fracture is between the grains, or crystals, that form the metal. Also called intercrystalline fracture. 金属的脆性断裂，断裂位于形成金属的晶粒或晶体之间。又称晶间破裂。
Starting torque (Unit N.m)	起动扭矩（单位：N.m）	The torque developed by a motor at zero rotational speed in order to initiate rotation of the applied load. 电机在零转速下产生的扭矩，以启动所施加负载的旋转。
Nanomanufacturing	纳米制造	1. The manufacture of nanoscale materials. 2. The manufacture of components or devices that have critical dimensions of order 1 nm. 1.纳米材料的制造。2.具有1nm级临界尺寸的部件或装置的制造。
Stress corrosion cracking (SCC)	应力腐蚀开裂（SCC）	A common form of Stress cracking in which an Electrolyte encourages the growth of a crack in a highly stressed bolt. Only a tiny quantity of electrolyte need be present, at the tip or face of the crack. A time-dependent process in which a metallurgically susceptible material fractures prematurely under conditions of simultaneous corrosion and sustained loading at lower stress levels than would be required in the absence of a corrosive environment. Tensile stress is required at the metal surface and may be a residual stress resulting from heat treatment or fabrication of the metal or the result of external loading. Cracking may be intergranular or transgranular, depending on the combination of alloy and environment. 一种常见的应力开裂形式，其中电解液促使高应力螺栓中的裂纹扩展。在裂纹尖端或表面，只需存在少量电解质。一种随时间变化的过程，其中冶金敏感材料在同时腐蚀和持续加载的条件下过早断裂，其应力水平低于无腐蚀环境时的要求。在金属表面需要拉应力，拉应力可以是金属的热处理或制造或外部负载产生的残余应力。裂纹可能是沿晶开裂或穿晶开裂，这取决于合金和环境的组合。
Coarsening	粗粒化	An increase in the grain size, usually, but not necessarily, by grain growth. 晶粒尺寸的增加，通常但不一定是晶粒变大。
Radial engine	径向发动机	A piston engine in which the cylinders are arranged radially around the crankshaft, a design commonly used in early aircraft engines. 气缸沿径向围绕曲轴布置的活塞式发动机，这种设计通常用于早期飞机发动机。
AISC	AISC	The American Institute of Steel Construction. 美国钢结构学会。
Tensile strength (Unit Pa)	抗拉强度（单位Pa）	In tension testing, the ratio of maximum load to original cross-sectional area. Also known as ultimate strength. The resistance that a material offers to tensile stress. It is defined as the smallest tensile stress required to break the body.  (ultimate strength, ultimate tensile strength, UTS, Rm, Rm) The nominal or engineering stress given by the maximum load in a tension test divided by the original cross-sectional area of the specimen. The maximum load could be the fracture load for a brittle material, but for a ductile material it is usually taken as the load at which necking begins, beyond which the load falls. 在拉伸试验中，最大载荷与原始横截面积之比。也称为极限强度。材料对拉伸应力的抵抗力。它被定义为破坏主体所需的最小拉伸应力。（极限强度、极限抗拉强度、UTS、Rm、Rm）拉伸试验中最大载荷除以试样原始横截面积得出的标称或工程应力。对于脆性材料，最大载荷可以是断裂载荷，但对于韧性材料，最大荷载通常被视为颈缩开始时的载荷，超过该载荷时，载荷下降。
Bimetallic strip	双金属片	A strip formed by welding, riveting or brazing together two metals having different coefficients of expansion, which causes the strip to curl when its temperature changes. Typical combinations are steel and copper or steel and brass. 将两种膨胀系数不同的金属焊接、铆接或钎焊在一起形成的带材，当温度变化时，带材会卷曲。典型的组合是钢和铜或钢和黄铜。
Archimedes screw	阿基米德螺旋泵	A machine which comprises a rotating helical blade inside a closefitting tube, which may be used to pump liquids, slurries (such as sewage), granular materials, etc. If water flows into the top of an inclined or vertical Archimedes screw, the screw will rotate and can be used to drive an electrical generator. 一种机器，它在紧密的管子内包含一个旋转的螺旋叶片，可用于泵送液体、泥浆（如污水）、颗粒材料等。如果水流入倾斜或垂直的阿基米德螺杆的顶部，螺杆将旋转，可用于驱动发电机。
Coil spring	螺旋弹簧	A spiral (‘clockwork’) or helical (cylindrical) spring. A spring steel wire wound in a spiral pattern. 螺旋（“发条”）或螺旋（圆柱形）弹簧。以螺旋状缠绕的弹簧钢丝。
Nano machining	纳米加工	The machining of silicon chips typically less than 1 nm thick. 硅芯片的加工通常小于1nm厚。
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。
Starting valve (regulator)	起动阀（调节器）	A valve which admits steam from the boiler to the cylinder(s) of a steam engine. 将蒸汽从锅炉送入蒸汽机汽缸的阀门。
Pressure recovery (Unit Pa)	压力恢复（单位Pa）	The progressive increase in static pressure for unseparated flow through a diverging nozzle or diffuser. 通过发散喷嘴或扩散器的未分离流的静压逐渐增加。
Vibration isolation	隔振	The prevention of transmission of vibration from one component of a system to another part of the same system, such as a building or other structure. Isolation may be achieved using dampers (vibration damping) or by active feedback-control methods. Mechanical vibration is often attenuated by means of components immersed in oil such as in dashpots (viscous damping). Vibration suppression can be achieved (a) using dampers and absorbers tuned to a particular frequency to suppress vibratory forces in structures and other systems (passive suppression) or (b) by the measurement of vibration at key locations in a structure and the application of  cancellation forces (active suppression). 防止振动从系统的一个部件传递到同一系统的另一部分，如建筑物或其他结构。可以使用阻尼器（减振）或主动反馈控制方法实现隔离。机械振动通常通过浸入油中的部件来衰减，例如缓冲罐（粘性阻尼）。可以通过（a）使用调谐到特定频率的阻尼器和吸收器来抑制结构和其他系统中的振动力（被动抑制），或（b）通过测量结构中关键位置的振动并施加抵消力（主动抑制），实现振动抑制。
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。
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。
Vibration	振动	1. A periodic change with time of the displacements of elements making up a component or structure. 2. The study of the oscillatory motion of bodies and systems and the frequencies, amplitudes, and forces associated with them. 1.组成部件或结构的元件位移随时间的周期性变化。2.研究物体和系统的振荡运动以及与之相关的频率、振幅和力的学科。
Ferritizing anneal	铁素体化退火	A treatment given as-cast gray or ductile (nodular) iron to produce an essentially ferritic matrix. For the term to be meaningful, the final microstructure desired or the time-temperature cycle used must be specified. 给予铸态灰铁或球墨铸铁以产生基本铁素体基体的处理。为了使该术语有意义，必须指定所需的最终微观结构或使用的时间-温度循环。
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。
Effective length of a bolt	螺栓的有效长度	The grip length plus some portion of the bolt (often one-half of the thickness of the nuts) which lies within the nut(s) plus some portion (often one-half the thickness) of the head. 握持长度加上位于螺母内的螺栓的某些部分（通常是螺母厚度的二分之一）加上头部的某些部分（通常是厚度的二分之一）。
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。
Thermomechanical working	热机械加工	A general term covering a variety of processes combining controlled thermal and deformation treatments to obtain specific properties. Same as thermal-mechanical treatment. 一个通用术语，涵盖结合受控热处理和变形处理以获得特定性能的各种工艺。与热机械处理相同。
Hot shortness	热脆性	The reduction of ductility in steels at high temperatures caused by melting of sulfides that wet grain boundaries and spread along them. 高温下钢的延展性降低，这是由于硫化物的熔化润湿晶界并沿晶界扩散而引起的。
Strength of materials	材料强度	A confusing name for what is really stress analysis, reflecting older engineering design based upon elasticity and ‘theories of strength’ for different materials, without regard to cracks. 对于真正的应力分析，这是一个具有迷惑性的名称，反映了基于弹性和不同材料的“强度理论”的旧工程设计，而不考虑断裂。
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。
Base metal hardness	母材硬度	Hardness closest to the surface (when traversing from core to outside diameter) just before an increase or decrease occurs, denoting, respectively, carburization or decarburization. 在发生增加或减少之前最接近表面的硬度（从芯部到外径时），分别表示渗碳或脱碳。
Safe working load (Unit N)	安全工作负荷（单位：N）	The steady or unsteady load against which a component or structure is designed for normal operation. It is lower than that which would cause failure by buckling, fracture, or yielding, so as to accommodate uncertainty, possible fault or accident conditions. 部件或结构设计用于正常运行的稳定或不稳定荷载。该值低于因屈曲、断裂或屈服而导致失效的值，以适应不确定性、可能的故障或事故条件。
Air classifier	空气分级机	(air elutriator) A device in which an airstream, which may be swirling, sorts particles by a combination of size, shape, and mass. （空气淘析器）一种装置，在该装置中，气流（可能是漩涡）根据大小、形状和质量的组合对颗粒进行分类。
Poisson’s ratio (ν)	泊松比（ν）	The absolute value of the ratio of transverse (lateral) strain to the corresponding axial strain resulting from uniformly distributed axial stress below the proportional limit of the material. 横向（侧向）应变与相应轴向应变之比的绝对值，该比值由低于材料比例极限的均匀分布的轴向应力产生。
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。
Vacuum carburizing	真空渗碳	A high-temperature gas carburizing process using furnace pressures between 7 and 55 kPa during the carburizing portion of the cycle. 在循环的渗碳部分期间使用7至55kPa之间的炉压的高温气体渗碳工艺。
Slot	狭槽	A groove machined into a component, e.g. to allow for thermal expansion, or in which the tongue or tip of another component can fit or slide. 在部件上加工的凹槽，例如，允许热膨胀，或另一部件的榫舌或尖端可在其中安装或滑动。
Vibrograph	示振器	An instrument that records vibrations in a system over time. 记录系统随时间变化的振动的仪器。
Spring constant	弹簧常数	The ratio between the forces exerted on a spring (or a bolt) and the deflection thereof. Has the dimensions of force per unit change in length (e.g., lb=in.). Also called Stiffness. 施加在弹簧（或螺栓）上的力与其挠度之间的比率。具有每单位长度变化的力的尺寸（例如lb=in.）。也称为刚度。
Proportional limit	比例极限	The greatest stress a material is capable of developing without a deviation from straight-line proportionality between stress and strain. 材料能够产生的最大应力不偏离应力和应变之间的直线比例。
Minute (min)	分钟（min）	A non-SI unit of time. The conversion to SI is 1 min = 60 s. 非SI时间单位。转换为1分钟=60秒。
Selective quenching	局部淬火	Quenching only certain portions of an object. 仅淬火工件的某些部分。
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。
Regenerative pump	涡流泵	(regenerative turbine pump, peripheral pump) A pump with a double-sided impeller having a large number of radial blades. The pressure of the pumped liquid increases progressively over several revolutions of the impeller. It is  particularly suited to producing large heads at small flow rates without cavitation. （再生涡轮泵，外围泵）具有具有大量径向叶片的双面叶轮的泵。泵送液体的压力在叶轮的几圈内逐渐增加。它特别适合于在小流速下产生大水头且不产生气穴。
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。
Form of thread	螺纹形式	The profile of a thread in an axial plane for a length of one pitch. 一个螺距长度的螺纹在轴向平面中的轮廓。
Band clutch	带式离合器	A friction clutch in which drive is achieved by a band contracting on to the rim of the clutch. 一种摩擦离合器，其驱动是通过一条带在离合器边缘上收缩来实现的。
Blank carburizing	毛坯渗碳	Simulating the carburizing operation without introducing carbon. This is usually accomplished by using an inert material in place of the carburizing agent, or by applying a suitable protective coating to the ferrous alloy. 在不引入碳的情况下模拟渗碳操作。这通常通过使用惰性材料代替渗碳剂或通过在铁合金上施加合适的保护涂层来实现。
Densimeter	密度计	An instrument used to determine the density or relative density of a solid or liquid. 用于测定固体或液体的密度或相对密度的仪器。
Vent	发泄	A small valve that allows the release of pressurized fluid from a pipe, pressure vessel, etc., often to the atmosphere. 一种小阀门，允许将加压流体从管道、压力容器等中释放到大气中。
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