| 词或词组 | 中文 | 英文解释中文解释 |
|---|---|---|
| Surface treatment | 表面处理 |
Any process, including chemical, electrochemical, mechanical, and thermal, designed to protect a surface against corrosion and wear or to alter its mechanical properties. 任何旨在保护表面免受腐蚀和磨损或改变其机械性能的工艺，包括化学、电化学、机械和热处理。 |
| Boyle’s law | 波义耳定律 |
The product of the pressure of a gas p and its volume is constant at a given absolute temperature T. Together with Charles law, it yields the ideal gas equation p = Mrt where m is the mass of gas and R is the specific gas constant. The volume of a gas at constant temperature is inversely proportional to the pressure. This means that as pressure increases, the volume of a gas decreases. 在给定的绝对温度T下，气体的压力p与其体积的乘积是恒定的。与查尔斯定律一起，它产生了理想的气体方程p=Mrt，其中m是气体的质量，R是特定的气体常数。恒温下气体的体积与压力成反比。这意味着随着压力的增加，气体的体积会减少。 |
| 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。 |
| 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。 |
| Notch strength | 缺口强度 |
The maximum load on a notched tensile-test specimen divided by the minimum cross-sectional area (the area at the root of the notch). Also known as notch tensile strength. 缺口拉伸试样上的最大载荷除以最小横截面积（缺口根部的面积）。也称为缺口抗拉强度。 |
| 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）。 |
| 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。 |
| Water quenching | 水淬 |
A quench in which water is the quenching medium. The major disadvantage of water quenching is its poor efficiency at the beginning or hot stage of the quenching process. 以水为淬火介质的淬火。水淬的主要缺点是在淬火过程的开始或热阶段效率低。 |
| Corrosion | 腐蚀 |
The deterioration of an exposed metal surface due to electrochemical oxidation with its surroundings. In the oxidation reaction, metal atoms give up electrons which are transferred to form another chemical species by a reduction reaction, usually with hydrogen and/or oxygen. A common example is the formation of the iron oxide rust Fe(OH)3 on iron or steel in moist air or water. Rust breaks away easily, exposing fresh iron to the atmosphere, whereas the corrosion product of some metals forms an adherent layer that prevents further oxidation reaction at fresh metal, an effect known as passivation. Examples include aluminium oxide on aluminium, chromium oxide on chromium, chromium oxide on alloys containing chromium such as stainless steels, and the patina formed on copper and zinc. Corrosion protection takes many forms. Good design to avoid crevices and stress is important. In some situations, substances known as inhibitors may be added to the environment to decrease its corrosiveness. The electrochemical nature of corrosion results in some metals having a greater tendency for oxidation than others. Zinc has a stronger tendency than iron and this is made use of in galvanizing. This is one example of cathodic protection, in which one metal is connected electrically to a more reactive metal, called a sacrificial anode, that oxidizes by giving up electrons and so protects the first metal. Coatings may be used to resist corrosion. Paints, plating, and diffusion coatings are the most common and the electrochemical process of anodizing is used to deliberately form a passive layer of oxide on aluminium alloys. Material selection plays a major role. For example, stainless steels with their high chromium content are widely used in corrosive environments. 暴露的金属表面由于与周围环境的电化学氧化而劣化。在氧化反应中，金属原子放弃电子，这些电子通过还原反应（通常与氢和/或氧）转移形成另一种化学物质。一个常见的例子是在潮湿的空气或水中在铁或钢上形成氧化铁锈Fe(OH)3。铁锈很容易脱落，将新鲜铁暴露在大气中，而一些金属的腐蚀产物形成一层粘附层，防止新鲜金属发生进一步的氧化反应，这种效果称为钝化。实例包括铝上的氧化铝、铬上的氧化铬、含铬合金上的氧化铬如不锈钢，以及铜和锌上形成的铜绿。腐蚀防护有多种形式。避免裂缝和应力的良好设计非常重要。在某些情况下，可以向环境中添加称为抑制剂的物质，以降低其腐蚀性。腐蚀的电化学性质导致一些金属比其他金属具有更大的氧化倾向。锌比铁具有更强的倾向性，这可用于镀锌。这是阴极保护的一个例子，其中一种金属与活性更强的金属（称为牺牲阳极）电连接，牺牲阳极通过释放电子进行氧化，从而保护第一种金属。涂层可用于抗腐蚀。油漆、电镀和扩散涂层是最常见的，阳极氧化的电化学过程用于有意在铝合金上形成一层钝化氧化物。材料选择起着重要作用。例如，铬含量高的不锈钢广泛用于腐蚀性环境。 |
| Screw extractor | 螺钉拔 |
A device for removing broken-off screws from threaded holes. It resembles a drill with, for broken right-hand threads, a fast (long-pitch) left-hand thread that is driven into a hole drilled in the broken screw, thus untwisting it. 从螺纹孔中去除断裂螺钉的装置。它类似于一个钻头，对于断裂的右螺纹，一个快速（长螺距）的左螺纹被打入在断裂螺钉上钻的孔中，从而将其松开。 |
| Horsepower | 马力 |
Unit indicating the rate at which work is done. The electrical equivalent of one horsepower is 746 watts. 单位表示完成工作的速率。一马力的电当量为746瓦。 |
| Sample variance (s²) | 样本方差（s²） |
The sum of the squares of the differences between each observed value and the sample average divided by the sample size minus one. It is a point estimate of the population variance. 每个观测值与样本平均值之差的平方和除以样本大小减1。它是总体方差的点估计。 |
| Washer | 垫圈 |
An annular disc of metal, rubber, plastic, ceramic, etc., placed between two surfaces in contact either to spread the load (for example, between a surface and a tightened nut or a bolt head), to provide a seal, or to separate or align components. 由金属、橡胶、塑料、陶瓷等制成的环形圆盘，放置在两个接触面之间，以分散载荷（例如，在一个表面和拧紧的螺母或螺栓头之间），提供密封，或分离或对齐部件。 |
| 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。 |
| 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。 |
| Stress relaxation | 应力松弛 |
The slow decrease in stress level within a part (e.g., a bolt) which is heavily loaded under constant deflection conditions. A ‘‘cousin’’ to creep, which is a slow change in geometry under constant stress conditions. The time-dependent decrease in stress in a solid under constant strain at constant temperature due to creep. The stress-relaxation behavior of a metal is usually shown in a stress-relaxation curve. 在恒定挠曲条件下，零件（如螺栓）内的应力水平缓慢降低，该零件承受重荷载。蠕变的“表亲”，是在恒定应力条件下几何结构的缓慢变化。在恒定温度下，由于蠕变，固体在恒定应变下的应力随时间变化的减小。金属的应力松弛行为通常显示在应力松弛曲线中。 |
| 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。 |
| Fibreglass | 玻璃纤维 |
Fibreglass is used in studs and nuts for applications when the fastener should be non-corrosive, low in conductivity, or transparent to electromagnetic waves. 当紧固件应无腐蚀性、低导电性或对电磁波透明时，玻璃纤维用于螺柱和螺母中。 |
| Relaxation | 松弛 |
The loss of tension, and therefore Clamping force, in a bolt and joint as a result of Embedment, vibration loosening, gasket creep, differential thermal expansion, etc. 由于嵌入、振动松动、垫圈蠕变、热膨胀差等原因，螺栓和接头中的张力损失，因此夹紧力损失。 |
| Compression fitting | 压缩接头 |
A screwed joint for pipework made resistant to leakage by permanent deformation of a closely-fitting ring, called a ferrule or olive, on tightening. 一种用于管道的螺纹接头，通过紧密配合的环（称为套圈或橄榄形）在拧紧时的永久变形来防止泄漏。 |
| 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。 |
| Offset yield strength | 条件屈服强度 |
The stress at which the strain exceeds by a specified amount (the offset) an extension of the initial proportional portion of the stress-strain curve. Expressed in force per unit area. 应变超过应力-应变曲线初始比例部分延伸规定量（偏移）的应力。以每单位面积的力表示。 |
| Apparent area of contact | 表观接触面积 |
In tribology, the area of contact between two solid surfaces defined by the boundaries of their macroscopic interface. 在摩擦学中，两个固体表面之间的接触区域由其宏观界面的边界定义。 |
| 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。 |
| Surface roughness (roughness) | 表面粗糙度 |
The small-scale, irregular peaks and troughs in a solid surface which are quantified using a surface analyser. Roughness may be a consequence of wear and corrosion, or of the manufacturing process. It leads to increased friction in solid– solid contact or fluid flow over a surface. Errors of form and waviness are excluded, but surface texture includes roughness and waviness. Surface topography incorporates the small-scale, three-dimensional geometry of a surface including surface roughness, machined, and etched features, typically at sub-mm scales. 固体表面中的小尺度不规则峰谷，使用表面分析仪进行量化。粗糙度可能是磨损和腐蚀或制造过程的结果。它会导致表面上的固-固接触或流体流动中的摩擦增加。不包括形状和波纹度误差，但表面纹理包括粗糙度和波纹度。表面形貌包括表面的小尺度三维几何结构，包括表面粗糙度、机加工和蚀刻特征，通常为亚毫米尺度。 |
| Zero time | 零时 |
The time when the given loading or constraint conditions are initially obtained in creep or stressrelaxation tests, respectively. 分别在蠕变或应力松弛试验中初始获得给定载荷或约束条件的时间。 |
| Diffusion | 扩散 |
(1) Spreading of a constituent in a gas, liquid, or solid, tending to make the composition of all parts uniform. (2) The spontaneous movement of atoms or molecules to new sites within a material. （1） 一种成分在气体、液体或固体中的扩散，趋于使所有部分的成分均匀。（2） 原子或分子自发运动到材料内的新位置。 |
| 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。 |
| Push rod | 推杆 |
A rod which opens and closes a valve via a valve rocker in an overhead-valve piston engine. The rod is actuated by a camshaft located in the crankcase. 在顶置气门活塞发动机中，通过气门摇臂打开和关闭气门的杆。连杆由曲轴箱中的凸轮轴驱动。 |
| Socket head | 凹头 |
Screw head having a hexagonal or other form of recessed socket in the head so that the screw can be turned with a wrench or key, as a hexagon key. 螺钉头上有六角或其他形式的凹座，可以用扳手或钥匙（如六角钥匙）转动螺钉。 |
| 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。 |
| Alloy | 合金 |
1. A metallic material composed of two or more elements, one of which is usually a metal to which the other elements are added, e.g. iron-carbon or aluminium-copper (binary alloy); nickel-chromium-iron (ternary alloy). 2. A plastic produced as a blend of two or more immiscible polymers. This results in material that cannot be achieved by polymerization. 1.由两种或多种元素组成的金属材料，其中一种通常是添加了其他元素的金属，例如铁碳或铝铜（二元合金）；镍铬铁（三元合金）。2.由两种或多种不混溶聚合物混合而成的塑料。这导致无法通过聚合获得的材料。 |
| Full size body | 全尺寸螺纹杆 |
The body of a bolt or screw which has a diameter between the minimum and maximum limits of the major diameter of the thread. 螺栓或螺钉的主体，其直径介于螺纹大径的最小和最大限制之间。 |
| Shoulder | 轴肩 |
The portion of a shaft, stepped component, or flanged component, where a change in diameter or other dimension occurs. Even for a nominal step change, in practice there will be a radius where shoulder and shaft meet in order to avoid too severe a stress concentration. 轴、阶梯部件或法兰部件的直径或其他尺寸发生变化的部分。即使是名义阶跃变化，在实践中，肩部和轴相交处也会有一个半径，以避免出现过严重的应力集中。 |
| Degradation | 降解 |
The reduction with time of the physical properties of a material. 材料的物理性质随时间的减少。 |
| Load factor (F) | 负载系数（F） |
The ratio between an increase in bolt tension and the external load which has caused the increase. Factors reflecting the probability of an increase in load in a shear joint. Used in load and resistant factor design. 螺栓张力增加与导致增加的外部载荷之间的比率。反映剪切接缝中荷载增加概率的系数。用于载荷和阻力系数设计。 |
| 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。 |
| Anti-freeze | 防冻液 |
A substance such as ethylene glycol added to the cooling system of a watercooled engine to lower the freezing point of the cooling water and also inhibit the formation of rust and other deposits. 一种物质，如乙二醇，添加到水冷发动机的冷却系统中，以降低冷却水的冰点，并抑制生锈和其他沉积物的形成。 |
| Shoulder screw | 轴肩螺钉 |
A screw having two or more diameters or shoulders and commonly used for supporting levers and other machine parts that have to operate freely. 一种具有两个或两个以上直径或轴肩的螺钉，通常用于支撑杠杆和其他必须自由操作的机器部件。 |
| 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。 |
| Barrier protection | 屏障保护 |
The coating on a fastener is said to provide barrier protection if it merely isolates the fastener from the environment. Paint, for example, provides barrier protection. 如果仅将紧固件与环境隔离，则据说紧固件上的涂层可提供屏障保护。例如，油漆提供屏障保护。 |
| Vapour static pressure | 蒸汽静压 |
(Unit Pa or bar) A pressure analogous to hydrostatic pressure, where the fluid is a vapour such as steam. A term used in geothermal applications. （单位Pa或bar）类似于静水压力的压力，其中流体是蒸汽，如蒸汽。地热应用中使用的术语。 |
| Electroplating | 电镀 |
Deposition of one metal on to another using electrolysis. The metal to be plated forms the cathode in an electrolytic cell, and the metal to be deposited forms the anode. 使用电解将一种金属沉积到另一种金属上。待镀金属形成电解池中的阴极，待沉积金属形成阳极。 |
| Mohs hardness test | 莫氏硬度测试 |
A scratch hardness test for determining comparative hardness using 10 standard minerals—from talc (the softest) to diamond (the hardest). 刮擦硬度测试，用于使用从滑石（最软）到钻石（最硬）的10种标准矿物测定比较硬度。 |
| Minimum stress-intensity factor (Kmin) | 最小应力强度因子（Kmin） |
In fatigue, the minimum value of the stress-intensity factor in a cycle. This value corresponds to the minimum loadwhen the load ratio is 0 and is taken to be 0 when the load ratio is ≤0. 在疲劳中，一个循环中应力强度因子的最小值。该值对应于负载比为0时的最小负载，当负载比为≤0 |
| Blue annealing | 蓝色退火 |
Heating hot-rolled ferrous sheet in an open furnace to a temperature within the transformation range and then cooling in air, in order to soften the metal. The formation of a bluish oxide on the surface is incidental. 在开放式炉中将热轧铁板加热到转变范围内的温度，然后在空气中冷却，以软化金属。在表面上形成蓝色氧化物是偶然的。 |
| 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。 |
| Relative humidity (ϕ) | 相对湿度（ψ） |
The ratio or percentage of the actual mass of moisture in a given volume of air at a given temperature to the maximum possible mass of moisture at the same temperature. 给定温度下给定体积空气中的实际水分质量与相同温度下的最大可能水分质量的比率或百分比。 |
| Mohr–Coulomb yield criterion | Mohr–Coulomb屈服准则 |
A pressure-dependent yield criterion, according to which yielding occurs when the stress at a point in a material falls on the envelope created by the Mohr’s stress circles at yielding for various tests such as tension, shear, and compression that have different components of hydrostatic stress. 一种与压力相关的屈服准则，根据该准则，当材料中某一点的应力落在屈服时的莫尔应力圆所形成的包络线上时，即发生屈服，用于各种试验，如具有不同静水应力分量的拉伸、剪切和压缩。 |
| 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。 |
| Strain energy | 应变能 |
A measure of the energy absorption characteristics of a material determined by measuring the area under the stress-strain diagram. 通过测量应力-应变图下的面积确定的材料能量吸收特性的度量。 |
| Gas compressor | 气体压缩机 |
A machine which draws in a gas at low pressure and delivers it at high pressure, usually accompanied by a temperature increase. Compressor designs include axial, centrifugal, diaphragm, reciprocating, and rotary (including the blade compressor). 一种在低压下吸入气体并在高压下输送气体的机器，通常伴随着温度升高。压缩机设计包括轴流式、离心式、隔膜式、往复式和旋转式（包括叶片式压缩机）。 |
| 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。 |
| 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。 |
| Computer numerical control (CNC) | 计算机数控（CNC） |
A term relating to machine tools in which the movements of a tool and/or the workpiece are controlled by computer. 与机床相关的术语，其中工具和/或工件的运动由计算机控制。 |
| Selective quenching | 局部淬火 |
Quenching only certain portions of an object. 仅淬火工件的某些部分。 |
| 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。 |
| 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。 |
| Centrifugal pump | 离心泵 |
A pump into which liquid enters axially through the eye of the casing and is then accelerated through an impeller, thereby increasing both its kinetic energy and pressure before being delivered to a ring diffuser (the volute) that further increases the liquid pressure and from which it leaves. 一种泵，液体通过泵壳的眼轴向进入，然后通过叶轮加速，从而在输送到环形扩散器（蜗壳）之前增加其动能和压力，从而进一步增加液体压力并从中流出树叶。 |
| ANSI | ANSI |
The acronym for American National Standards Institute. 美国国家标准协会的缩写。 |
| Sizing | 颗粒化 |
1. A finishing operation to ensure the specified dimensions and tolerances for a component are met. 2. (size classification) Separating an aggregate of mixed particles into groups according to size using a series of screens. 1.精加工操作，以确保满足部件的规定尺寸和公差。2.（粒度分类）使用一系列筛网根据粒度将混合颗粒的聚集体分成组。 |
| Avogadro constant | 阿伏伽德罗常数 |
(Avogadro number, NA) A fundamental physical constant with the fixed numerical value 6.022 140 76 × 1023 mol−1. The mole contains exactly this number of elementary entities. A minor adjustment to the value of the Avogadro constant was made effective on 20 May 2019. （阿伏伽德罗数，NA）一个固定数值为6.02214076×1023mol的基本物理常数−摩尔正好包含这个数量的基本实体。对阿伏伽德罗常数值的微小调整于2019年5月20日生效。 |
| 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。 |
| 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。 |
| 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。 |
| Turbine | 涡轮 |
A turbomachine in which a rotor (turbine wheel) or impeller is caused to rotate and convert flow energy into shaft power or thrust. 转子（涡轮）或叶轮旋转并将流动能量转换为轴功率或推力的涡轮机。 |
| Process annealing | 中间退火 |
An imprecise term denoting various treatments used to improve workability. For the term to be meaningful, the condition of the material and the time-temperature cycle used must be stated. 一个不精确的术语，表示用于改善可加工性的各种处理方法。为了使术语有意义，必须说明材料的条件和使用的时间-温度循环。 |
| Gage length | 标距 |
The original length of the portion of a specimen over which strain, change of length, or other characteristics are determined. 确定应变、长度变化或其他特性的试样部分的原始长度。 |
| Mohs scale | 莫氏硬度 |
A scale of scratch hardness originally developed for minerals. 最初为矿物开发的划痕硬度标尺。 |
| Partial annealing | 不完全退火 |
An imprecise term used to denote a treatment given cold-worked material to reduce the strength to a controlled level or to effect stress relief. To be meaningful, the type of material, the degree of cold work, and the time-temperature schedule must be stated. 一个不精确的术语，用于表示冷加工材料的处理，以将强度降低到受控水平或消除应力。为了有意义，必须说明材料类型、冷加工程度和时间-温度计划。 |
| 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。 |
| 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。 |
| Pop rivet | 拉钉 |
A hollow rivet that enables a connexion to be made from one side only of an assembly. 一种空心铆钉，使连接只能从组件的一侧进行。 |
| Calorie | 卡路里 |
(cal, gram calorie, small calorie) An obsolete (i.e. non-SI) unit of energy equal to 4.186 8 J. It is the amount of energy needed to raise the temperature of 1 gram of pure airfree water from 14.5°C to 15.5°C at standard atmospheric pressure. （卡，克热量，小热量）一种已被淘汰的（即非SI）能量单位，等于4.1868J。它是在标准大气压力下将1克纯无空气水的温度从14.5℃升高到15.5℃所需的能量。 |
| Valve plug | 阀塞 |
A conical or cylindrical plug, in which there are transverse holes, in a valve, such as a plug valve. Flow through the holes occurs when the plug is rotated. 阀门中的圆锥形或圆柱形阀塞，其中有横向孔，如旋塞阀。旋转阀塞时，会发生通过孔的流动 |
| Curie temperature | 居里温度 |
The temperature of magnetic transformation below which a metal or alloy is ferromagnetic and above which it is paramagnetic. 磁性转变温度，低于此温度金属或合金为铁磁性，高于此温度则为顺磁性。 |
| 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。 |
| 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。 |
| 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。 |
| Mohr–Coulomb fracture criterion | Mohr–Coulomb断裂准则 |
A fracture criterion, primarily for brittle materials, according to which failure occurs when the stress at a point in a material falls outside the envelope created by the Mohr’s circles for uniaxial tensile strength and uniaxial compressive strength. 一种断裂准则，主要适用于脆性材料，根据该准则，当材料中某一点的应力落在单轴抗拉强度和单轴抗压强度的莫尔圆所形成的包络线之外时，就会发生断裂。 |
| Twist drill | 麻花钻 |
A hardened-steel drill bit having one or more helical flutes running from a conical tip to the smooth part of the shank. 一种淬火钢钻头，具有一个或多个螺旋槽，从锥形尖端延伸到柄部的光滑部分。 |
| ABS polymer | ABS聚合物 |
A class of thermoplastic co-polymer consisting of the three monomers acrylonitrile, butadiene and styrene that has improved properties (particularly toughness) over the individual constituents. 一类由丙烯腈、丁二烯和苯乙烯三种单体组成的热塑性共聚物，其性能（特别是韧性）优于单个成分。 |
| Metric ton (tonne, t) | 公制吨（吨，t） |
An SI-accepted, but non-SI, unit of mass defined as 1 t = 103 kg. SI系统可接受但非国际单位制的质量单位，定义为1t=103kg。 |
| 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。 |
| Stroke | 一击 |
1. (stroke length) (Unit m) The linear distance between top dead centre and bottom dead centre of a piston in a reciprocating engine or mechanism. 2. The movement of a piston or plunger in a reciprocating machine to execute a particular function; for example, the exhaust stroke of an engine in which the exhaust gases are expelled from a cylinder. 1.（冲程长度）（单位：m）往复式发动机或机构中活塞上止点和下止点之间的线性距离。2.活塞或柱塞在往复式机器中执行特定功能的运动；例如发动机的排气冲程，其中排气从气缸中排出。 |
| Achme thread | Achme螺纹 |
A screw thread having an included angle of 29° and largely used for feed screws on machine tools. 一种夹角为29°的螺纹，主要用于机床上的进给丝杠。 |
| 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。 |
| Relative density | 相对密度 |
(specific gravity) The ratio of the density of a substance to that of a reference substance, such as water for liquids and solids, and dry air for gases. （比重）物质密度与参考物质密度之比，如液体和固体为水，气体为干燥空气。 |
| Spring materials | 弹簧材料 |
Mainly metals including plain-carbon and corrosion-resisting steels, phosphor bronze, spring brass, beryllium copper and nickel alloys, all of which in their workhardened states permit large reversible elastic strains without permanent deformation. 主要是金属，包括普通碳钢和耐腐蚀钢、磷青铜、弹簧黄铜、铍铜和镍合金，所有这些金属在其加工硬化状态下都允许大的可逆弹性应变而不会产生永久变形。 |
| 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。 |
| Torsion spring | 扭簧 |
1. A spring in the form of a torsion bar. 2. A helical spring to which torque can be applied at the ends. 1.一种扭杆形式的弹簧。2.一种螺旋弹簧，其端部可施加扭矩。 |
| Teeth | 齿 |
The projecting elements on gears, cutting tools, etc. 齿轮、刀具等上的突出元件。 |
| Ideal crack | 理想裂缝 |
A simplified model of a crack used in elastic-stress analysis. In a stress-free body, the crack has two smooth surfaces that are coincident and join within the body along a smooth curve called the crack front; in two-dimensional representations, the crack front is called the crack tip. 用于弹性应力分析的裂纹简化模型。在无应力物体中，裂纹有两个光滑表面，它们在物体内沿称为裂纹前缘的平滑曲线重合并连接；在二维表示中，裂纹前缘称为裂纹尖端。 |
| Fatigue failure | 疲劳失效 |
Failure that occurs when a specimen undergoing fatigue completely fractures into two parts or has softened or been otherwise significantly reduced in stiffness by thermal heating or cracking. 当经历疲劳的试样完全断裂成两部分或因热加热或开裂而软化或刚度显着降低时发生的失效。 |
| Cleavage fracture | 解理断裂 |
A fracture, usually of a polycrystalline metal, in which most of the grains have failed by cleavage, resulting in bright reflecting facets. It is one type of crystalline fracture and is associated with low energy brittle fracture. Contrast with shear fracture. A fracture created by splitting (cleavage), as between layers in materials like slate or mica. In brittle metals, and brittle microconstituents in alloys, cleavage occurs along particular crystal planes. 一种通过分裂（劈裂）产生的裂缝断裂，通常是多晶金属的断裂，其中大部分晶粒因解理而失效，产生明亮的反射面。它是一种结晶性断裂，与低能脆性断裂有关。与剪切断裂相对。如板岩或云母等材料的层之间。在脆性金属和合金中的脆性微量成分中，沿特定晶面发生解理。 |
| Volume flow rate | 体积流率 |
(volumetric flow rate, , ) (Unit m³/s) The volume of a material, usually a fluid or powder, that flows across a surface or through a pipe or other duct per unit time. （体积流量）（单位m³/s）单位时间内流经表面或管道或其他管道的材料体积，通常为流体或粉末。 |
| 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。 |
| Rotary piston flow meter | 旋转活塞流量计 |
A rotary liquid flow meter in which a cylindrical rotor, eccentrically mounted within a cylindrical casing, the axes of the two cylinders being parallel, is caused to rotate by the liquid flow. The flow rate is determined from the number of rotations of the rotor in a given time. 一种旋转式液体流量计，其中偏心安装在圆柱形外壳内的圆柱形转子，两个圆柱体的轴线平行，由液体流引起旋转。流量由转子在给定时间内的转数确定。 |
| Hypereutectic alloy | 过共晶合金 |
In an alloy system exhibiting a eutectic, any alloy whose composition has an excess of alloying element compared with the eutectic composition, and whose equilibrium microstructure contains some eutectic structure. 在呈现共晶的合金系统中，任何合金，其组成与共晶组成相比具有过量的合金元素，并且其平衡微观结构包含一些共晶结构。 |
| 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。 |
| Clearance volume | 余隙容积 |
(Unit m³) The ‘dead’ volume above a piston, including the recess in the cylinder head, in a reciprocating compressor or engine when the piston is at top dead centre. （单位m³）活塞位于上止点时活塞上方的“死区”体积，包括气缸盖中的凹槽，在往复式压缩机或发动机中。 |
| Decarburization | 脱碳 |
Loss of carbon from the surface layer of a carbon-containing alloy due to reaction with one or more chemical substances in a medium that contacts the surface. 由于与接触表面的介质中的一种或多种化学物质发生反应，含碳合金表面层的碳损失。 |
| Pitch (Unit m) | 间距（单位：m） |
1. In a cascade of identical turbine or compressor blades, the distance between successive blades measured parallel to the leading edges. 2. For a screw thread, the distance between adjacent thread forms measured parallel to the thread axis. 3. For an aircraft, the vertical relationship between the nose and the horizon. The pitch axis is an axis in the plane of the wings of an aircraft, perpendicular to the centreline, about which the aircraft rotates. Pitch motion is the corresponding up or down movement of the aircraft nose. Pitch attitude is the angle between the centreline of an aircraft and the horizontal. The angle is positive when the nose is above its position when the centreline is horizontal. 1.在相同涡轮或压缩机叶片的叶栅中，平行于前缘测量的连续叶片之间的距离。2.对于螺纹，平行于螺纹轴线测量的相邻螺纹形状之间的距离。3.对于飞机，机头和水平线之间的垂直关系。俯仰轴是飞机机翼平面内垂直于中心线的轴，飞机绕中心线旋转。俯仰运动是飞机机头的相应向上或向下运动。俯仰姿态是飞机中心线与水平线之间的角度。当中心线水平时，当机头高于其位置时，角度为正。 |
| 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。 |
| Core | 核心 |
In a ferrous alloy prepared for case hardening, that portion of the alloy that is not part of the case . Typically considered to be the portion that (a) appears light on an etched cross section, (b) has an essentially unaltered chemical composition, or (c) has a hardness, after hardening, less than a specified value. 在为表面硬化而制备的铁合金中，合金中不属于表面的那部分。通常被认为是（a）在蚀刻横截面上看起来很轻，（b）化学成分基本不变，或（c）硬化后硬度低于规定值的那部分。 |
| 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。 |
| Slenderness ratio | 长细比 |
The effective unsupported length of a uniform column divided by the least radius of gyration of the cross-sectional area. 均匀柱的有效无支撑长度除以横截面积的最小回转半径。 |
| Brake lining | 制动衬片 |
The replaceable friction material that covers a brake shoe in an internally expanding brake. 在内膨胀制动器中覆盖制动的可更换摩擦材料。 |
| Galling | 磨损 |
An extreme form of adhesive wear, in which large chunks of one part stick to the mating part (during sliding contact). 一种极端形式的粘着磨损，其中一个零件的大块粘在配合零件上（在滑动接触期间）。 |
| Celsius temperature scale | 摄氏温标 |
(centigrade temperature scale) A relative, non-SI, temperature scale now defined in terms of the Kelvin absolute temperature scale as °C = K − 273.15, where °C is the symbol for degrees Celsius. The scale was previously called the centigrade scale, with two fixed points: the melting point of ice (the ice point) as 0°C, and the boiling point of water (the steam point) as 100°C. （摄氏度温度标度）现在以开尔文绝对温度标度定义的相对非国际温度标度为°C=K-273.15，其中°C是摄氏度的符号。该刻度以前称为摄氏度刻度，有两个固定点：冰的熔点（冰点）为0°C，水的沸点（蒸汽点）为100°C。 |
| Caterpillar | 毛虫式履带 |
(crawler vehicle) A vehicle that ‘lays its own road’ by running on endless belts, driven by toothed wheels, on each side. Used on soft ground where spreading of the load reduces contact stress. （履带式车辆）通过在每一侧由齿轮驱动的环形皮带运行来“铺设自己的道路”的车辆。用于负载分散可减少接触应力的松软地面。 |
| Absolute stability | 绝对稳定 |
Condtion of a linear system in which there exists a limiting value of the open-loop gain such that the system is stable for all lower values of that gain, and unstable for all higher values. 线性系统的条件，其中存在开环增益的限制值，使得系统对于该增益的所有较低值都是稳定的，而对于所有较高值来说都是不稳定的。 |
| 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。 |
| Diagonal pitch (Unit m) | 对角线间距（单位米） |
The distance, when components in an assembly are staggered, between the position of a component in one row or column and the position of the corresponding component in the next row or column. The term is applied to rivets, turbine or compressor blades in a cascade, vortex generators on the surface of a wing, etc. 当部件中的零部件交错时，一行或一列中零部件的位置与下一行或下一列中相应零部件的位置之间的距离。该术语适用于铆钉、叶栅中的涡轮或压缩机叶片、机翼表面的涡流发生器等。 |
| Rated load (Unit N) | 额定负荷（单位：N） |
The maximum load that a structure or component has been designed to carry. 结构或部件设计承受的最大荷载。 |
| Transformation toughening | 相变增韧 |
The improvement of fracture toughness of a material by stress-induced transformation of the microstructure. 通过微结构的应力诱导转变来提高材料的断裂韧性。 |
| 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。 |
| 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。 |
| 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。 |
| Thermal electromotive force | 热电动势 |
The electromotive force generated in a circuit containing two dissimilar metals when one junction is at a temperature different from that of the other. 当一个结处于不同于另一个结的温度时，在含有两种不同金属的电路中产生的电动势。 |
| Gauge pressure (Unit Pa) | 表压（单位Pa） |
The level of static pressure above the ambient pressure. 高于环境压力的静压水平。 |
| Axial load (Unit N) | 轴向载荷（单位N） |
In general, a tensile or compressive load directed along the axis of a component. Strictly the load should pass through the centroid of the cross section to avoid inducing bending moments and be perpendicular to the plane of the section. 通常，沿部件的轴定向的拉伸或压缩载荷。严格来说，载荷应通过横截面的质心以避免产生弯矩并垂直于横截面。 |
| 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。 |
| 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。 |
| Impact test | 碰撞测试 |
A test for determining the energy absorbed in fracturing a test piece at high velocity, as distinct from static test. The test may be carried out in tension, bending, or torsion, and the test bar may be notched or unnotched. 测定试件在高速下破裂时吸收的能量的试验，与静态试验不同。测试可以在拉伸、弯曲或扭转条件下进行，测试杆可以有缺口或无缺口。 |
| Modulus of rupture | 断裂模量 |
Nominal stress at fracture in a bend test or torsion test. In bending, modulus of rupture is the bending moment at fracture divided by the section modulus. In torsion, modulus of rupture is the torque at fracture divided by the polar section modulus. 弯曲试验或扭转试验中的标称断裂应力。在弯曲中，断裂模量是断裂时的弯矩除以截面模量。在扭转中，断裂模量是断裂时的扭矩除以极截面模量。 |
| Creep–time relations | 蠕变时间关系 |
Algebraic or numerical relations between creep strain and time at constant stress. 恒定应力下蠕变应变与时间之间的代数或数值关系。 |
| International System of Units | 国际单位制 |
(SI system of units, Le Système international d’unités) The standard system of units now used almost universally in science and engineering except in the United States. The definitive reference on the SI is a booklet published by the International Bureau of Weights and Measures, often referred to as the BIPM SI Brochure. There are seven base units: metre (symbol m) for length; kilogram (kg) for mass; mole (mol) for amount of substance; second (s) for time; kelvin (K) for temperature; ampere (A) for electric current; and candela (cd) for luminous intensity. New SI unit definitions, based upon the values of the universal constants of nature (also termed the fundamental physical constants: the Avogadro constant, the Boltzmann constant, and the Planck constant), came into effect on 20 May 2019. Minor adjustments were also made to the values of these constants. In addition to the base units, there are 22 coherent derived units, including radian (rad) for plane angle, steradian (sr) for solid angle, hertz (Hz) for frequency, newton (N) for force, pascal (Pa) for pressure, joule (J) for energy, work, and amount of heat, and watt (W) for power and radiant flux. Recommended practice is to avoid combinations such as N/mm², MN/m² being preferred.(kg) for mass; mole (mol) for amount of substance; second (s) for time; kelvin (K) for temperature; ampere (A) for electric current; and candela (cd) for luminous intensity. New SI unit definitions, based upon the values of the universal constants of nature (also termed the fundamental physical constants: the Avogadro constant, the Boltzmann constant, and the Planck constant), came into effect on 20 May 2019. Minor adjustments were also made to the values of these constants. In addition to the base units, there are 22 coherent derived units, including radian (rad) for plane angle, steradian (sr) for solid angle, hertz (Hz) for frequency, newton (N) for force, pascal (Pa) for pressure, joule (J) for energy, work, and amount of heat, and watt (W) for power and radiant flux. Recommended practice is to avoid combinations such as N/mm², MN/m² being preferred. （国际单位制，Le Système international d\\\'unités）目前美国除外，在科学和工程中几乎是普遍使用的标准单位制。SI的最终参考是国际度量衡局出版的小册子，通常称为BIPM SI小册子。有七个基本单位：米（符号m）表示长度；质量为千克（kg）；物质量的摩尔（mol）；时间为秒；开尔文（K）表示温度；电流为安培（A）；而坎德拉（cd）表示发光强度。新的国际单位制定义于2019年5月20日生效，该定义基于自然界的普遍常数（也称为基本物理常数：阿伏伽德罗常数、玻尔兹曼常数和普朗克常数）。这些常数的值也进行了少量调整。除了基本单位外，还有22个相干导出单位，包括平面角的弧度（rad）、立体角的斯特拉迪安（sr）、频率的赫兹（Hz）、力的牛顿（N）、压力的帕斯卡（Pa）、能量、功和热量的焦耳（J）以及功率和辐射通量的瓦特（W）。建议的做法是避免N/mm²、MN/m²等组合。 |
| Fatigue wear | 疲劳磨损 |
Wear of a solid surface caused by fracture arising from material fatigue. 由材料疲劳引起的断裂引起的固体表面磨损。 |
| Dilatation (dilation) | 膨胀 |
A change of volume caused by external load, compression, temperature change, chemical action, etc. 由外部载荷、压缩、温度变化、化学作用等引起的体积变化。 |
| 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。 |
| Alloy steels | 合金钢 |
Steels that contain alloying elements such as chromium, nickel, molybdenum, manganese, silicon, tungsten, and vanadium. These are added to improve properties such as the hardenability, toughness, strength, wear resistance, and corrosion resistance compared with those of plain-carbon steel. Low-alloy steels have a total alloy content (including carbon) of less than about 8%. They are hardenable and have strength up to 30% higher than plain-carbon steels. High-alloy steels contain considerably more alloy content and are developed for specific properties such as superior corrosion and chemical resistance. 含有铬、镍、钼、锰、硅、钨和钒等合金元素的钢。添加这些是为了提高与普通碳钢相比的淬透性、韧性、强度、耐磨性和耐腐蚀性等性能。低合金钢的总合金含量（包括碳）小于约8%。它们是可硬化的，强度比普通碳钢高出30%。高合金钢含有相当多的合金含量，并针对特定性能而开发，例如卓越的耐腐蚀性和耐化学性。 |
| 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）。 |
| Oxidation | 氧化 |
(1) A reaction in which there is an increase in valence resulting from a loss of electrons. (2) A corrosion reaction in which the corroded metal forms an oxide; usually applied to reaction with a gas containing elemental oxygen, such as air. （1）因电子损失而导致价态增加的反应。（2）腐蚀反应，其中被腐蚀的金属形成氧化物；通常用于与含有元素氧的气体如空气反应。 |
| Scale effect | 规模效应 |
The change in behaviour with size of a material, component, or structure. For example, cube-square scaling where one element changes with volume and another with area, as in the range of a projectile or ship, droplet formation, and fracture mechanics. 性能随材料、部件或结构尺寸的变化。例如，立方体平方比例，其中一个元素随体积变化，另一个元素因面积变化，如在射弹或飞船的射程、液滴形成和断裂力学中。 |
| Dilatometer | 膨胀计 |
An instrument for measuring length or volume changes in a solid during heating and subsequent cooling or isothermal holding. · An instrument for measuring the linear expansion or contraction in a metal resulting from changes in such factors as temperature and allotropy. 一种在加热和随后的冷却或等温保持过程中测量固体长度或体积变化，测量金属因温度和同素异形体等因素的变化而引起的线性膨胀或收缩的仪器。 |
| 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。 |
| 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。 |
| Temper embrittlement | 回火脆化 |
Brittleness that results when certain steels are held within, or are cooled slowly through, a certain range of temperature below the transformation range. The brittleness is manifested as an upward shift in ductile-to-brittle transition temperature but only rarely produces a low value of reduction in area in a smooth-bar tension test of the embrittled material. The anomalous reduction in toughness of martensitic stainless steels when tempered in the range 370–600°C. Embrittlement of alloy steels caused by holding within or cooling slowly through a temperature range just below the transformation range. Embrittlement is the result of the segregation at grain boundaries of impurities such as arsenic, antimony, phosphorus, and tin; it is usually manifested as an upward shift in ductile-to-brittle transition temperature. Temper embrittlement can be reversed by retempering above the critical temperature range, then cooling rapidly. 当某些钢保持在低于转变范围的某一温度范围内或缓慢冷却时产生的脆性。脆性表现为延性到脆性转变温度的向上移动，但在脆性材料的平滑棒材拉伸试验中，很少产生较小的面积减小值。马氏体不锈钢在370–600°C范围内回火时的韧性异常降低。合金钢的脆化是由于在低于转变范围的温度范围内保持或缓慢冷却而引起的。脆化是杂质（如砷、锑、磷和锡）在晶界处偏析的结果；它通常表现为韧脆转变温度的上升。回火脆化可以通过在临界温度范围以上重新回火，然后快速冷却来逆转。 |
| Thermocouple | 热电偶 |
A device for measuring temperature, consisting of lengths of two dissimilar metals or alloys that are electrically joined at one end and connected to a voltage-measuring instrument at the other end. When one junction is hotter than the other, a thermal electromotive force is produced that is roughly proportional to the difference in temperature between the hot and cold junctions. 一种测量温度的装置，由两种不同的金属或合金组成，一端电连接，另一端与电压测量仪相连。当一个结比另一个结更热时，产生的热电动势大致与热结和冷结之间的温差成比例。 |
| 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。 |
| 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。 |
| 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。 |
| 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。 |
| Plane-stress fracture toughness (Kc) | 平面应力断裂韧性（Kc） |
In linear-elastic fracture mechanics, the value of the crack-extension resistance at the instability condition determined from the tangency between the R-curve and the critical crack-extension force curve of the specimen. 在线弹性断裂力学中，由试样的R曲线和临界裂纹扩展力曲线之间的切线确定的不稳定条件下裂纹扩展阻力的值。 |
| 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。 |
| Yield stress | 屈服应力 |
The stress level of highly ductile materials, such as structural steels, at which large strains take place without further increase in stress. 高韧性材料（如结构钢）的应力水平，在该应力水平下发生大应变而不会进一步增加。 |
| Absorption hygrometer | 吸收式湿度计 |
An instrument that determines the content of water vapour in the atmosphere by it being absorbed into a hygroscopic medium. 通过吸收到吸湿介质中来确定大气中水蒸气含量的仪器。 |
| 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。 |
| Structural engineering | 结构工程 |
A branch of civil engineering concerned with the design of buildings, dams, bridges, and other large structures. 土木工程的一个分支，涉及建筑物、水坝、桥梁和其他大型结构的设计。 |
| 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。 |
| 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。 |
| 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。 |
| Crack | 裂缝 |
A thin fissure-like defect in a component or structure across which material continuity is lost and which reduces the strength of the body. 部件或结构中的细裂缝状缺陷，材料连续性丧失并降低了身体的强度。 |
| Fastener standard | 紧固件标准 |
A document which details the attributes of a finished fastener and includes such characteristics as geometry, material or chemistry, heat treatment, finish, testing lot size, and packaging. 详细说明紧固件属性的文件，包括几何形状、材料或化学、热处理、表面处理、测试批量和包装等特性。 |
| 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。 |
| 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。 |
| Austenite stabilization | 奥氏体稳定化 |
Decrease, in comparison to a continuous cooling, in the amount of martensite occurring from austenite when cooling is interrupted at a temperature between Ms and Mf. This can be explained by the relaxation of stresses induced in the austenite by martensite crystals occurring before the interruption. The relaxation, in turn, leads to the dislocation rearrangement and their interaction with martensite/austenite interfaces, which makes the interfaces immobile. 与连续冷却相比，当在Ms和Mf之间的温度中断冷却时，从奥氏体中产生的马氏体的量减少。这可以通过中断前发生的马氏体晶体在奥氏体中引起的应力松弛来解释。反过来，松弛导致位错重排及其与马氏体/奥氏体界面的相互作用，这使得界面无法移动。 |
| 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。 |
| Austenitic stainless steels | 奥氏体不锈钢 |
Austenitic stainless steels are non-magnetic. They contain significant additions of chromium (16–30%), but have the austenite (FCC) crystal structure, stabilized by the addition of nickel in the composition range 6–20%. Carbon content ranges from about 0.03 to 0.15%. The ‘18–8’ stainless steels containing approximately 18% chromium and 8% nickel are typical of the class. Austenitic stainless steels have high strength and corrosion resistance even at elevated temperatures, good ductility, good low-temperature properties, and good weldability. Used for aircraft and transport equipment, cutlery, chemical and food-processing equipment, surgical instruments, and cryogenic vessels. 奥氏体不锈钢是非磁性的。它们含有显着添加的铬（16–30%），但具有奥氏体（FCC）晶体结构，通过在6–20%的成分范围内添加镍来稳定。碳含量范围约为0.03至0.15%。含有大约18%铬和8%镍的“18-8”不锈钢是该级别的典型不锈钢。奥氏体不锈钢即使在高温下也具有高强度和耐腐蚀性，良好的延展性，良好的低温性能和良好的焊接性。用于飞机和运输设备、餐具、化学和食品加工设备、手术器械和低温容器。 |
| Dew point analyzer | 露点分析仪 |
An atmosphere monitoring device that measures the partial pressure of water vapor in an atmosphere. 一种大气监测装置，用于测量大气中水蒸气的分压。 |
| Cooling stresses | 冷却应力 |
Residual stresses resulting from nonuniform distribution of temperature during cooling. 冷却过程中温度分布不均匀导致的残余应力。 |
| Threshold stress for stress-corrosion cracking (σth) | 应力腐蚀开裂阈值应力（σth） |
An experimentally determined critical gross-section stress below which stress-corrosion cracking will not occur under specified test conditions. 实验确定的临界总截面应力，低于该应力，在规定的试验条件下不会发生应力腐蚀开裂。 |
| Stainless steels | 不锈钢 |
Iron-base alloys that are highly resistant to corrosion in many environments. The predominant alloying element is chromium, which, like iron at room temperature, has BCC crystal structure. Corrosion resistance by passivation is achieved by the formation of chromium oxide on the steel surface. Nickel, which has FCC crystal structure, is another important addition for some steels. Other additions used to enhance properties include manganese, molybdenum, niobium, and titanium. There are several classes of stainless steel. 在许多环境中具有高度耐腐蚀性的铁基合金。主要的合金元素是铬，与室温下的铁一样，铬具有BCC晶体结构。钝化抗腐蚀性是通过在钢表面形成氧化铬来实现的。具有FCC晶体结构的镍是某些钢的另一种重要添加剂。其他用于增强性能的添加剂包括锰、钼、铌和钛。不锈钢的种类有好几种。 |
| 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。 |
| Interrupted aging | 分段时效 |
Aging at two or more temperatures, by steps, and cooling to room temperature after each step. 分为两个或两个以上的温度时效，按顺序并在每个步骤后冷却至室温。 |
| Diesel engine | 柴油发动机 |
(compression–ignition engine) A piston engine operating on the Diesel cycle in which the air is compressed to a temperature above the autoignition temperature of the fuel and combustion is initiated as the fuel is injected into the hot air. Diesel engines operate at higher compression ratios (typically in the range 12 to 24) than petrol engines. Although named after Rudolf Diesel, the inventor, Diesel engine is often spelled with a lower case d, contrary to normal practice. （压燃式发动机）在柴油循环中运行的活塞式发动机，在该循环中，空气被压缩至高于燃料自燃温度的温度，当燃料喷射到热空气中时，燃烧开始。柴油发动机在比汽油发动机更高的压缩比下运行（通常在12到24的范围内）。虽然以发明人鲁道夫·迪塞尔命名，但迪塞尔发动机通常拼写为小写d，这与正常做法相反。 |
| Spring temper | 弹簧回火 |
A temper of nonferrous alloys and some ferrous alloys characterized by tensile strength and hardness about two-thirds of the way from full hard to extra spring temper. 非铁合金和一些铁合金的一种回火，其特点是抗拉强度和硬度约为全硬回火到超弹性回火的三分之二。 |
| 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。 |
| 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。 |
| Allotropy | 同素异形体 |
A near synonym for polymorphism. Allotropy is generally restricted to describing polymorphic behavior in elements, terminal phases, and alloys whose behavior closely parallels that of the predominant constituent element. 多态性的近义词。同素异形体通常仅限于描述元素、终端相和合金中的多晶型行为，其行为与主要组成元素的行为非常相似。 |
| 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。 |
| Typical basis | 典型基础 |
The typical property value is an average value. No statistical assurance is associated with this basis. 典型的属性值是平均值。没有与此基础相关的统计保证。 |
| Sharp-notch strength | 锐缺口强度 |
The notch tensile strength measured using specimens with very small notch root radii (approaching the limit for machining capability); values of sharp-notch strength usually depend on notch root radius. 使用缺口根部半径非常小（接近加工能力极限）的试样测量的缺口抗拉强度；锐缺口强度值通常取决于缺口根部半径。 |
| Crank pin | 曲柄销 |
It is a short shaft parallel to the axis of the crankshaft but radially offset from it, to which is attached the big end of a connecting rod in a bearing. Sometimes the crank pin is supported at one end only (a wrist pin) but in built-up or one-piece forged crankshafts, the crank pin is supported by thick plates (crank arms, crank webs) at either end. 它是一个短轴，平行于曲轴的轴线，但径向偏移，轴承中连杆的大端连接到该短轴上。有时曲柄销仅在一端支撑（腕销），在组合式或整体锻造曲轴中，曲柄销在两端由厚板（曲柄臂、曲柄腹板）支撑。 |
| U-bend | U形管 |
U-bend A 180° bend in a pipe. 180°弯曲的管道。 |
| Venturi | 文丘里管 |
A convergent–divergent flow nozzle, usually circular in cross section, with a relatively short convergent section (the confuser) upstream of a throat followed by a gradually diverging section (the diffuser). Such nozzles usually have flanges at either end for installation in a pipeline. Applications include flow meters and ejectors. When a fluid flows through a convergent duct at subsonic speed, there is an increase in velocity accompanied by a decrease in pressure (Venturi effect). 收敛-发散流喷嘴，横截面通常为圆形，喉部上游具有相对较短的收敛段（扰流器），然后是逐渐发散段（扩散器）。这种喷嘴通常在两端都有法兰，以便安装在管道中。应用包括流量计和喷射器。当流体以亚音速流过收敛管道时，速度增加，压力降低（文丘里效应）。 |
| 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。 |
| Carbonitriding | 碳氮共渗 |
A case hardening process in which a suitable ferrous material is heated above the lower transformation temperature in a gaseous atmosphere of such composition as to cause simultaneous absorption of carbon and nitrogen by the surface and, by diffusion, create a concentration gradient. The process is completed by cooling at a rate that produces the desired properties in the workpiece. 一种表面硬化工艺，在该工艺中，将合适的含铁材料在气体气氛中加热到较低的转变温度以上，使其表面同时吸收碳和氮，并通过扩散形成浓度梯度。该工艺通过以在工件中产生所需性能的速率冷却来完成。 |
| Remaining stress | 残留应力 |
The stress remaining at a given time during a stress-relaxation test. See also stress relaxation. 在应力松弛试验期间在给定时间内剩余的应力。参见压力松弛。 |
| Brittle lacquer coating | 脆性漆涂层 |
A lacquer that, when painted on to an unloaded body, reveals the direction of maximum tension stresses from the pattern of cracking produced in the lacquer when the body is loaded. 一种漆，当涂在未加载的车身上时，从车身加载时在漆中产生的裂纹图案中显示出最大拉应力的方向。 |
| Supercooling | 过冷 |
Cooling below the temperature at which an equilibrium phase transformation can take place, without actually obtaining the transformation. 在没有实际获得相变的情况下，冷却到可以发生平衡相变的温度以下。 |
| Shear | 扭剪 |
The type of force that causes or tends to cause two contiguous parts of the same body to slide relative to each other in a direction parallel to their plane of contact. 导致或倾向于导致同一物体的两个相邻部分在平行于其接触面的方向上相对滑动的力的类型。 |
| Fit | 装配 |
The general term used to signify the range of tightness which may result from the application of a specific combination of allowances and tolerances in the design of mating parts. 通用术语，用于表示配合零件设计中公差和公差的特定组合可能导致的紧密性范围。 |
| Creep limit (Unit Pa) | 蠕变极限（单位Pa） |
The maximum allowable stress under the action of which creep deformation of a material does not exceed a specified limit. 材料在其作用下的蠕变变形不超过规定限度的最大许用应力。 |
| Water column | 水柱 |
Water in a tube, which may be vertical or inclined. If the tube is open to the atmosphere, the vertical height h from a datum level to the water surface is a measure of the water static pressure p at the datum level given by p − B = ρgh where B is the barometric pressure, ρ denotes the water density, and g is the acceleration due to gravity. 管道中的水，可以是垂直的或倾斜的。如果管道向大气开放，则从基准面到水面的垂直高度h是基准面处水静压p的量度，由p给出−B=ρgh，其中B是大气压力，ρ表示水密度，g是重力引起的加速度。 |
| 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。 |
| Outside diameter (Unit m) | 外径（单位：m） |
(external diameter, OD) The diameter of a circular cylindrical tube or a sphere measured between opposite points on the external surface. （外径，OD）在外表面上的相对点之间测量的圆柱管或球体的直径。 |
| 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。 |
| Shear strain | 剪切应变 |
The tangent of the angular change, as a response to force, between two lines originally perpendicular to each other through a point in a body. Also known as shearing strain. 角变化的切线，作为对力的响应，在两条原本通过物体中的一个点相互垂直的线之间。也称为剪切应变。 |
| 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。 |
| Toggle (toggle clamp) | 拨动（拨动夹） |
A device consisting of two pinned levers that are almost in line between two end points in the same plane. Bringing the levers into line generates large forces between the ends. Used to obtain a large mechanical advantage or as a locking mechanism. 由两个销杆组成的装置，在同一平面的两个端点之间几乎成一条直线。将杠杆对齐会在端部之间产生较大的力。用于获得较大的机械优势或用作锁定机构。 |
| Pressure ratio | 压力比 |
One pressure divided by another which may be a reference pressure. In many flow and thermodynamic processes, the pressure ratio is more important than the absolute pressure levels. For example, in compressible gas flow the Mach number is determined by the ratio of the stagnation pressure to the static pressure. 一个压力除以另一个压力，该压力可以是参考压力。在许多流动和热力学过程中，压力比比绝对压力水平更重要。例如，在可压缩气流中，马赫数由停滞压力与静压之比决定。 |
| Screw area (Unit m²) | 螺丝面积（单位m²） |
The area of a circle described by the tips of a propeller. 螺旋桨尖端所描述的圆的面积。 |
| Abradant | 研磨剂 |
The differently sized grits of hard materials such as emery employed for grinding, polishing, etc. The abrasive grade is determined by the grit size (grit number) originally related to the hole sizes in wire sieves. 用于研磨、抛光等的硬质材料（例如金刚砂）的不同尺寸粒度。磨料等级由最初与金属丝筛孔尺寸相关的粒度（粒度数）决定。 |
| Clearance fit | 间隙配合 |
A range of clearances ranging from close sliding to loose running, i.e. a fit in which the limits for the mating parts always permit assembly. 从紧密滑动到松动运行的一系列间隙，即配合零件的限制始终允许组装的配合。 |
| 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。 |
| 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。 |
| 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。 |
| Heat balance (heat budget) | 热平衡（热预算） |
An energy balance involving only heat transfer across the system boundary and the stored energy. 仅涉及跨系统边界的热传递和存储能量的能量平衡。 |
| Total elongation | 总伸长率 |
A total amount of permanent extension of a test piece broken in a tensile test. 拉伸试验中断裂试样的永久延伸总量。 |
| Thumb screw | 蝶形螺钉 |
A type of screw having a winged or knurled head for turning by hand when a quick and light clamping effect is desired. 一种螺钉，具有翼形或滚花头，当需要快速、轻夹紧效果时，可手动转动。 |
| 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。 |
| 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。 |
| Hot strength (Unit Pa) | 热强度（单位Pa） |
The yield stress (or sometimes fracture stress) of a material at temperatures above about half its melting point in kelvins. 材料在高于其熔点一半（以开尔文为单位）的温度下的屈服应力（有时为断裂应力）。 |
| 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。 |
| Newton’s law of viscosity | 牛顿内摩擦定律 |
The shear stress between two parallel layers of fluid is proportional to the velocity of one relative to that of the other, and inversely proportional to the distance between them. The constant of proportionality is the dynamic viscosity μ. For a Newtonian fluid μ is independent of pressure gradient, shear stress, and strain, but may change with temperature and pressure. 两个平行流体层之间的剪切应力与其中一层相对于另一层的速度成正比，与它们之间的距离成反比。比例常数是动态粘度μ。对于牛顿流体，μ与压力梯度、剪切应力和应变无关，但可能随温度和压力而变化。 |
| Coarse threads | 粗螺纹 |
Threads with relatively large separation between corresponding points on the threads. 螺纹上相应点之间的间距相对较大的螺纹。 |
| Wrinkling | 起皱 |
A wavy condition obtained in deep drawing of sheet metal, in the area of the metal between the edge of the flange and the draw radius. Wrinkling may also occur in other forming operations when unbalanced compressive forces are set up. 在金属板深冲过程中，在法兰边缘和拉深半径之间的金属区域内获得的波浪状状态。当设置不平衡压缩力时，在其他成形操作中也可能发生起皱。 |
| 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。 |
| Stress corrosion | 应力腐蚀 |
(stress-corrosion cracking) Corrosion failure accelerated by local stresses (particularly tensile) which enhance cracking in both monotonic and fatigue loading. （应力腐蚀开裂）局部应力（特别是拉伸应力）加速的腐蚀失效，该局部应力在单调载荷和疲劳载荷下都会增强开裂。 |
| 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。 |
| Bright annealing | 光亮退火 |
Annealing in a protective medium to prevent discoloration of the bright surface. 在保护介质中退火以防止光亮表面变色。 |
| Ultimate strength | 极限应力 |
The maximum tensile strength a bolt or material can support prior to rupture. Always found in the plastic region of the stress–strain or force–elongation curve, and so is not a design strength. Also called Tensile strength and ultimate tensile strength. The maximum stress (tensile, compressive, or shear) a material can sustain without fracture, determined by dividing maximum load by the original cross-sectional area of the specimen. Also known as nominal strength or maximum strength. 螺栓或材料在断裂前可支撑的最大抗拉强度。总是出现在应力-应变或力-伸长率曲线的塑性区域，因此不是设计强度。也称为抗拉强度和极限抗拉强度。材料在不断裂的情况下能够承受的最大应力（拉伸、压缩或剪切），通过将最大载荷除以试样的原始横截面积来确定。也称为标称强度或最大强度。 |
| Abrasivity | 磨蚀性 |
The extent to which a surface, particle, or collection of particles will tend to cause abrasive wear when forced against a solid surface under relative motion and under prescribed conditions. 在相对运动和规定条件下，一个表面、颗粒或颗粒集合在被迫抵靠固体表面时趋向于引起磨粒磨损的程度。 |
| Amontons friction | 阿蒙顿摩擦 |
(Coulomb friction) Friction between surfaces where the ratio of the frictional force F to the normal force N is constant and independent of the area in contact. （库仑摩擦）摩擦力F与法向力N之比恒定且与接触面积无关的表面之间的摩擦。 |
| Major diameter | 螺纹大径 |
On a straight thread, the diameter of the imaginary cylinder that just touches the crest of an external thread or the root of an internal thread. 在直螺纹上，仅接触外螺纹顶部或内螺纹根部的假想圆柱体的直径。 |
| Toothed belt | 齿带 |
A flat belt, typically of a reinforced-rubber material, with transverse teeth that engage with teeth on a wheel or pulley. 一种扁平皮带，通常由增强橡胶材料制成，带有横向齿，与车轮或皮带轮上的齿啮合。 |
| 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。 |
| Die casting | 压铸 |
A process in which molten metal, particularly alloys of aluminium, magnesium, copper, and zinc, is forced under pressure (10 to 200 MPa) into a reusable hardened-steel mould machined into a die. 在压力（10至200MPa）下将熔融金属（特别是铝、镁、铜和锌的合金）强制进入加工成模具的可重复使用的硬化钢模具中的过程。 |
| Grain-boundary liquation | 晶界液化 |
An advanced stage of overheating in which material in the region of austenitic grain boundaries melts. 奥氏体晶界区域的材料熔化的过热阶段。 |
| Hypoeutectic alloy | 亚共晶合金 |
In an alloy system exhibiting a eutectic, any alloy whose composition has an excess of base metal compared with the eutectic composition, and whose equilibrium microstructure contains some eutectic structure. 在呈现共晶的合金系统中，其成分比共晶成分多的任何合金，其平衡微观结构包含一些共晶结构。 |
| 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。 |
| V-block | V型块 |
A block having a 90° V-shaped recess; used in a workshop to hold round workpieces. 具有90°V形凹槽的块体；在车间里用来装圆形工件。 |
| Wheel | 轮 |
A solid disc, or a circular ring with spokes radiating from a central hub, either attached to an axle around which it revolves or which revolves with a rotating axle. 一个实心圆盘，或一个带有辐条的圆环，辐条从一个中心毂放射出来，或附在一个绕其旋转的轴上，或与一个旋转轴一起旋转。 |
| Subcritical annealing | 不完全退火 |
A process anneal performed on ferrous alloys at a temperature below Ac1. 在低于Ac1的温度下对铁合金进行的工艺退火。 |
| Generator | 发电机 |
1. A machine for converting mechanical energy to electrical energy. 2. (generatrix) A point, line, or surface regarded as moving and so forming a line, a surface, or a volume, respectively. 1.将机械能转化为电能的机器。2.（母线）被认为是运动的点、线或面，因此分别形成一条线、一个面或一个体积。 |
| 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。 |
| 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。 |
| Reverse engineering | 逆向工程 |
The disassembly of a machine, mechanism, system or device, measurement of its component parts, and identification of the materials used so that if required, a functioning replica can be produced. 拆卸机器、机构、系统或装置，测量其组成部分，并识别所用材料，以便在需要时可以生产出功能正常的复制品。 |
| 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。 |
| 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。 |
| 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。 |
| Positive-displacement machine | 正排量机 |
A machine that incorporates pistons, valves, etc. to ensure positive admission and delivery of a working fluid and prevent undesired reversal of flow. This class of machine incorporates all reciprocating compressors and expanders and some types of rotary compressor, the Roots blower, agear pump, a lobe pump, and a vane pump. 包含活塞、阀门等的机器，以确保工作流体的正向进入和输送，并防止不期望的反向流动。这类机器包括所有往复式压缩机和膨胀机以及一些类型的旋转压缩机、罗茨鼓风机、抽水机、凸轮泵和叶片泵。 |
| Machine screw | 机械螺丝 |
A countersunk, slotted screw with machined threads such as are found on bolts. A relatively small screw, usually less than 20 mm in diameter, with the thread running along the whole length up to the head, intended to be screwed into threaded holes. If inserted through plain holes in assembled parts and held together by a nut, an undesirable contact surface of threads bearing against the surface of a hole results. 带有机加工螺纹的沉头开槽螺钉，如螺栓上的螺纹。一种相对较小的螺钉，直径通常小于20毫米，螺纹沿整个长度一直延伸到头部，用于拧入螺纹孔中。如果通过装配零件上的平孔插入并用螺母固定在一起，则会导致螺纹与孔表面接触不良。 |
| Mechanical units | 机械单位 |
The units of physical quantities, the dimensions of which includemass, length, and time. 物理量的单位，其量纲包括质量、长度和时间。 |
| Ion carburizing | 离子渗碳 |
A method of surface hardening in which carbon ions are diffused into a workpiece in a vacuum through the use of high-voltage electrical energy. Synonymous with plasma carburizing or glowdischarge carburizing. 一种表面硬化方法，利用高压电能将碳离子在真空中扩散到工件中。与等离子渗碳或辉光放电渗碳同义。 |
| 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。 |
| Acceleration due to gravity | 重力加速度 |
(acceleration of free fall, gravitational acceleration, g) (Unit m/s²) The acceleration of a freely-falling body in a vacuum, with a mean value at sea level of approximately 9.81 m/s². （自由落体加速度，重力加速度，g）（单位m/s²）自由落体在真空中的加速度，在海平面处的平均值约为9.81m/s²。 |
| Oxidized surface (on steel) | 氧化表面（在钢上） |
Surface having a thin, tightly adhering, oxidized skin (from straw to blue in color), extending in from the edge of a coil or sheet. Sometimes called annealing border. 表面具有薄的、紧密粘附的氧化皮（从稻草色到蓝色），从线圈或薄片的边缘延伸。有时称为退火边界。 |
| 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。 |
| Decompression chamber | 减压舱 |
A chamber in which ambient-air pressure can be increased to levels found in deep-sea diving. It is used to gradually acclimatize divers back to normal conditions and avoid ‘the bends’. 环境气压可以提高到深海潜水水平的腔室。它用于逐渐使潜水员适应正常条件，避免“弯曲”。 |
| Nominal stress | 名义应力 |
The stress at a point calculated on the net cross section by simple elasticity theory without taking into account the effect on the stress produced by stress raisers such as holes, grooves, fillets, etc. 通过简单弹性理论在净截面上计算的点处的应力，不考虑孔、槽、圆角等应力提升器产生的应力影响。 |
| Cooling curve | 冷却曲线 |
A curve showing the relation between time and temperature during the cooling of a material. 显示材料冷却过程中时间和温度之间关系的曲线。 |
| Dynamic mechanical measurement | 动态机械测量 |
A technique in which either the modulus and/or damping of a substance under oscillatory load or displacement is measured as a function of temperature, frequency, or time, or a combination thereof. 一种技术，其中在振荡载荷或位移下测量物质的模量和/或阻尼作为温度、频率或时间或其组合的函数。 |
| Cheese head | 圆柱头 |
A cylindrical head on a screw or bolt. For driving, it may be slotted, or hexagonally recessed. 螺钉或螺栓上的圆柱头。为了驱动，它可以是开槽的，也可以是六角形的。 |
| Pressure loss (Unit Pa) | 压力损失（单位Pa） |
The loss in stagnation pressure in internal flow due to wall friction and minor losses in fittings. 壁面摩擦引起的内部流动停滞压力损失和配件的微小损失。 |
| Gear motor | 齿轮马达 |
Essentially a gear pump run in reverse, in which high-pressure fluid supplied to one side of the casing causes the gears to rotate. 本质上是一个齿轮泵反向运行，其中供应到外壳一侧的高压流体导致齿轮旋转。 |
| AISC | AISC |
The American Institute of Steel Construction. 美国钢结构学会。 |
| Screw machine | 螺丝机 |
A machine tool for high-volume manufacture of small turned components from rod or bar. 一种用棒或棒大批量制造小零件的机床。 |
| 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。 |
| Lead screw | 丝杠 |
The master screw running along the length of the bed of a lathe from which all screws threads on that machine are cut. Master screw used for cutting a screw thread in a lathe. 沿车床床身长度方向运行的主螺钉，该机床上的所有螺钉和螺纹都从主螺钉上切割下来。用于在车床上切削螺纹的主螺钉。 |
| Heat-capacity ratio (c*) | 热容量比（c*） |
A non-dimensional parameter that arises in the analysis of heat exchangers, defined as the ratio cMIN/cMAX where cMIN is the heat-capacity rate c for the fluid with the smaller value of c and cMAX the value for the fluid with the larger value of c. Different flow rates and specific-heat values give rise to different values for c. 热交换器分析中出现的无量纲参数，定义为比率cMIN/cMAX其中cMIN是流体的热容率c，c值较小，cMAX是流体的值具有较大的c值。不同的流速和比热值产生不同的c值。 |
| 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。 |
| Bend test | 弯曲试验 |
A test for determining the relative ductility of metal that is to be formed (usually sheet, strip, plate, or wire) or for determining soundness and toughness of metal (after welding, for example). The specimen is usually repeatedly bent over a specified diameter through a specified angle and then unbent for a specified number of cycles. There are four general types of bend tests, named according to the manner in which the forces are applied to the specimen to make the bend: free bend, guided bend, semiguided bend, and wrap-around bend. 确定待成形金属（通常为薄板、带材、板材或线材）的相对延展性或确定金属的坚固性和韧性（例如，焊接后）的试验。试样通常在规定的直径上重复弯曲一个规定的角度，然后在规定的循环次数内弯曲。弯曲试验有四种一般类型，根据施加在试样上的力进行弯曲的方式命名：自由弯曲、引导弯曲、半引导弯曲和环绕弯曲。 |
| Torque reaction (Unit N.m) | 扭矩反作用力（单位：N.m） |
The torque needed to counteract an applied torque. For example, in a helicopter with a single main rotor, the tendency of the fuselage to rotate in the opposite direction to the rotor. 抵消施加扭矩所需的扭矩。例如，在具有单个主旋翼的直升机中，机身沿与旋翼相反的方向旋转的趋势。 |
| 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。 |
| 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。 |
| 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。 |
| 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。 |
| Vertical engine | 立式发动机 |
A piston engine having the cylinders above the crankshaft. 气缸位于曲轴上方的活塞发动机。 |
| 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。 |
| Grain | 晶粒 |
1. An individual crystal in a polycrystalline solid. Most engineering materials such as metals and ceramics are used in polycrystalline form. 2. (gr) A non-SI unit of mass. The conversion to SI is 1 gr = 6.479 891 × 10−5 kg. 1.多晶固体中的单个晶体。大多数工程材料，如金属和陶瓷，都以多晶形式使用。2.（gr）非国际单位制的质量单位。转换为SI为1gr=6.479891×10-5kg。 |
| Fillister head | 槽头 |
Similar to a pan head but with a smaller head diameter and a taller head, with higher vertical sides. 类似于盘头，但头部直径较小，头部较高，垂直边较高。 |
| 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。 |
| Tolerances | 公差 |
A fractional allowance for variation from the specifications. In mass production, using automatic machines, parts are intended to be completely or partially interchangeable, and in batch production parts should ideally fit without the need for selection. In practice it is impossible for mass-produced parts to have exactly the same size, owing to tool wear, variations in raw materials, thermal effects, etc. In consequence, variations from exactness, termed tolerances, are assigned to what is permissible on the basic size. 与规范不同的部分公差。在大规模生产中，使用自动机器时，零件应完全或部分可互换，在批量生产中，零件应理想匹配，无需选择。在实践中，由于刀具磨损、原材料变化、热效应等原因，批量生产的零件不可能具有完全相同的尺寸。因此，将精度偏差（称为公差）指定给基本尺寸上允许的尺寸。 |
| 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。 |
| Design heating load (Unit kW) | 设计热负荷（单位kW） |
The heating requirements based on a specified number of heating degree days, or required to maintain a building or other enclosed space at a specified temperature for a given outside temperature. 基于指定的采暖度日数的加热要求，或在给定的外部温度下将建筑物或其他封闭空间保持在指定温度下所需的加热要求。 |
| Bolt | 螺栓 |
(machine bolt) A fastener in the form of an externally-threaded cylinder with a head on one end that is inserted through holes in assembled parts that are then held together by a nut tightened on to the thread. A bolt has an unthreaded region below the head so that when located in a hole, transverse loads are borne by two plain cylindrical surfaces in contact. In contrast, use of a machine screw, that has threads all along its length, results in threads bearing against the plain surface of a hole. Officially, a threaded fastener designed to be used with a nut. （机械螺栓）外螺纹圆柱状紧固件：一端有头的紧固件，通过装配零件上的孔插入，然后通过拧紧到螺纹上的螺母固定在一起。螺栓头部下方有一个无螺纹区域，因此当位于孔中时，横向载荷由两个接触的平面圆柱面承担。相反，使用沿其长度具有螺纹的机器螺钉，会导致螺纹支撑在孔的平面上。正式情况下，螺纹紧固件设计用于与螺母一起使用。 |
| Atomic volume | 原子体积 |
Volume of unit cell per atom. 每个原子的晶胞体积。 |
| Air-cooled condenser | 风冷冷凝器 |
A heat exchanger, in which the cooling medium is air, used to condense the exhaust steam from a steam turbine, the condensate being returned to the boiler. 一种热交换器，其中冷却介质为空气，用于冷凝蒸汽轮机排出的蒸汽，冷凝水返回锅炉。 |
| Engineering stress (s) | 工程应力 |
A term sometimes used for conventional stress in order to differentiate it from true stress. In tension testing, it is calculated by dividing the breaking load applied to the specimen by the original crosssectional area of the specimen. 一个术语，有时用于常规应力，以区别于真实应力。在拉伸试验中，通过将施加在试样上的断裂载荷除以试样的原始横截面积来计算。 |
| Total heat (Unit kJ) | 总热量（单位kJ） |
An alternative term for enthalpy. It is inappropriate as it suggests that it includes kinetic energy in the same way as total enthalpy, but it does not. Also, heat and enthalpy are quite different quantities, as their definitions show. 焓的另一个术语。这是不恰当的，因为它表明，它包括动能的方式与总焓相同，但它实际上并不是的。此外，热和焓是完全不同的量，正如它们的定义所示。 |
| Torque wrench | 扭矩扳手 |
A manual wrench which incorporates a gage or measuring apparatus of some sort to measure and display the amount of torque being delivered to the nut or bolt. All wrenches produce torque. Only a torque wrench tells how much torque. A socket wrench or ring spanner that can be set to allow a specific torque to be applied to a nut or bolt head. 一种手动扳手，包括某种量规或测量装置，用于测量和显示传递至螺母或螺栓的扭矩量。所有扳手都产生扭矩。只有扭矩扳手才能显示扭矩大小。一种套筒扳手或梅花扳手，可设置为允许对螺母或螺栓头施加特定扭矩。 |
| 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。 |
| 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。 |
| 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。 |
| Cavitation | 空蚀空化 |
The formation of vapour- or gas-filled cavities in a liquid due to reduction of the local pressure, often due to acceleration of the fluid, such as in flow through a convergent nozzle. If there is no dissolved gas in the liquid, vaporous cavitation occurs when the pressure falls below the saturated vapour pressure. If the bubbles are formed due to high temperature, the process is termed boiling. If there is dissolved gas, gaseous cavitation occurs due to pressure reduction, temperature increase, or diffusion (degassing). At the tips of marine propellers and in hydraulic machinery, the collapse of cavitation bubbles can cause noise and vibration and lead to surface damage in the form of pitting. 由于局部压力降低而在液体中形成充满蒸汽或气体的空腔，通常原因是流体的加速，例如收敛喷嘴的流动。如果液体中没有溶解气体，当压力降至饱和蒸汽压力以下时，会发生蒸汽空化。如果气泡是由于高温形成的，则该过程称为沸腾。如果存在溶解气体，则由于压力降低、温度升高或扩散（脱气），会发生气穴。在船用螺旋桨尖端和液压机械中，空化气泡的破裂可能会引起噪音和振动，并导致以点蚀形式出现的表面损坏。 |
| Resistance thermometer | 电阻温度计 |
A thermometer in which the sensing element is basically a metal wire, usually of platinum, for which the variation of resistance with temperature is known accurately. A resistance pyrometer is a resistance thermometer intended for use up to about 1 000°C. 一种温度计，其中传感元件基本上是一根金属线，通常是铂，可以准确地知道电阻随温度的变化。电阻高温计是一种电阻温度计，用于高达约1000°C的温度。 |
| 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。 |
| Freezing range | 冻融范围 |
That temperature range between liquidus and solidus temperatures in which molten and solid constituents coexist. 熔融和固体成分共存的液相线和固相线温度之间的温度范围。 |
| Helical spring | 螺旋弹簧 |
A spring manufactured by forming elastic wire into a helix which may be cylindrical, conical, barrel-shaped, or hourglass in overall form. Closed-coiled springs are used in tension; open-coiled in both tension and compression. 一种弹簧，通过将弹性线材制成螺旋形而制成，螺旋形的整体形状可以是圆柱形、圆锥形、桶形或沙漏形。拉力采用闭合盘簧；在拉伸和压缩中都开卷。 |
| Fatigue notch factor (Kf) | 疲劳缺口系数（Kf） |
The ratio of the fatigue strength of an unnotched specimen to the fatigue strength of a notched specimen of the same material and condition; both strengths are determined at the same number of stress cycles. 无缺口试样的疲劳强度与相同材料和条件的有缺口试样的疲劳强度之比；两种强度都是在相同数量的应力循环下确定的。 |
| 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。 |
| Sample median | 样本中间值 |
The middle value when all observed values in a sample are arranged in order of magnitude. If an even number of samples are tested, the average of the two middlemost values is used. It is a point estimate of the population median, or 50% point. 当样本中的所有观测值按数量级排列时的中间值。如果测试的样本数为偶数，则使用两个中间值的平均值。这是人口中位数的一个点估计值，或50%的点。 |
| Residual preload | 残余预载荷 |
The tension which remains in an unloaded bolted joint after Relaxation. 松弛后未加载螺栓连接中保持的张力。 |
| Dynamic load (Unit N) | 动态负载（单位N） |
1. Loading of a component or structure by a moving object whose point of application changes with time, e.g. the live load of a train passing over a bridge. 2. A load applied to a particular part of a component or structure in a short time interval. 1. 应用点随时间变化的移动物体对部件或结构的加载，例如通过桥梁的火车的活荷载。2. 在短时间内施加到部件或结构的特定部分的载荷。 |
| 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。 |
| Infinite life diagram | 无限疲劳寿命图 |
A simple plot experimentally derived fatigue-life data, showing the conditions required for infinite life. 一个简单的曲线图，实验得出的疲劳寿命数据，显示了无限寿命所需的条件。 |
| 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。 |
| Terminal temperature difference (Unit K) | 终端温差（单位K） |
The temperature difference between the two fluid streams at either inlet or outlet of a heat exchanger. 热交换器入口或出口处两种流体流之间的温差。 |
| Scleroscope hardness test | 反跃式硬度试验 |
A dynamic indentation-hardness test using a calibrated instrument that drops a diamond-tipped hammer from a fixed height onto the surface of the material being tested. The height of rebound of the hammer is a measure of the hardness of the material. Also known as Shore hardness test. 使用校准仪器的动态压痕硬度测试，该仪器将金刚石锤从固定高度落在被测材料表面上。锤的回弹高度是材料硬度的一种度量。也称为肖氏硬度测试。 |
| Dimension line | 尺寸线 |
A line on an engineering drawing with a numeral above it that shows the length of a feature, usually in millimetres. 工程图上的一条线，上面有一个数字，表示特征的长度，通常以毫米为单位。 |
| 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。 |
| 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。 |
| 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。 |
| 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。 |
| Offset modulus | 补偿模量 |
The ratio of the offset yield stress to the extension at the offset point (plastics). 偏移屈服应力与偏移点（塑料）处延伸的比率。 |
| 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。 |
| 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）。 |
| Fatigue test | 疲劳测试 |
A method for determining the range of alternating (fluctuating)stresses a material can withstand without failing. 一种确定材料可以承受而不会失效的交变（波动）应力范围的方法。 |
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