| 词或词组 | 中文 | 英文解释中文解释 |
|---|---|---|
| Acid rain | 酸雨 |
Any form of precipitation, including rain, snow, sleet, fog, dew, and particulates, which contains higher than normal levels of sulfuric and nitric acids. These acids result from natural and man-made emissions of sulfur dioxide and oxides of nitrogen, respectively. Acid soot consists of unburned carbon particles, typically larger than 10 μm, in the atmosphere contaminated with sulfuric acid. The particles result from poor combustion of fossil fuels. 任何形式的降水，包括雨、雪、雨夹雪、雾、露水和颗粒物，其中含有高于正常水平的硫酸和硝酸。这些酸分别来自二氧化硫和氮氧化物的自然排放和人为排放。酸烟灰由未燃烧的碳颗粒组成，通常大于10微米，在被硫酸污染的大气中。这些颗粒是化石燃料燃烧不良造成的。 |
| Plane strain | 平面应变 |
The stress condition in linear-elastic fracture mechanics in which there is zero strain in a direction normal to both the axis of applied tensile stress and the direction of crack growth (i.e., parallel to the crack front); most nearly achieved in loading thick plates along a direction parallel to the plate surface. Under plane-strain conditions, the plane of fracture instability is normal to the axis of the principal tensile stress. 线弹性断裂力学中的应力条件，其中在垂直于施加拉应力轴和裂纹扩展方向（即平行于裂纹前沿）的方向上存在零应变；最接近于沿平行于板表面的方向加载厚板。在平面应变条件下，断裂失稳平面垂直于主拉应力轴。 |
| Net weight (Unit N) | 净重（单位：N） |
The difference between the gross weight of any container including its contents and the tare weight of the empty container. 任何容器（包括其内容物）的毛重与空容器皮重之间的差值。 |
| Machine tool | 机床工具 |
A powered machine, such as a borer, grinder, lathe, milling machine or planer, used for cutting and shaping metal, plastics, composites, etc. (machining). A machining centre is a CNC machine tool working about several axes, having a stock of tools and automatic tool changing ability, which is capable of diverse machining operations under automated control. 一种动力机器，如钻孔机、磨床、车床、铣床或刨床，用于切割和成形金属、塑料、复合材料等（机加工）。加工中心是围绕多个轴工作的CNC机床，具有刀具库存和自动换刀能力，能够在自动化控制下进行各种加工操作。 |
| Preload | 预载 |
The tension created in a threaded fastener when the nut is first tightened. Often used interchangeably, but incorrectly, with Working load or bolt force or bolt tension 第一次拧紧螺母时螺纹紧固件中产生的张力。经常与工作载荷或螺栓力或螺栓张力互换使用但容易使用不当。 |
| Flange bolt | 法兰螺栓 |
A bolt with a built in washer-like flange just below the head. 在头部下方带有内置垫圈状法兰的螺栓。 |
| 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。 |
| Crosshead | 十字头 |
1. A reciprocating member, sliding between guides, to which the piston rod is firmly attached on one side and to which the connecting rod is pinned on the other for the conversion of reciprocating into rotary motion. 2. The moveable beam in early designs of mechanical testing machines. 3. A screwhead having slots in a + shape that takes a mating screwdriver. 1.一种往复式构件，在导轨之间滑动，活塞杆一侧固定在其上，连杆另一侧固定在该构件上，用于将往复式运动转换为旋转运动。2.机械试验机早期设计中的活动梁。3.一种螺钉头，其具有采用配合螺丝刀的+形槽。 |
| Equation, long form | 方程，长格式 |
An equation which relates the torque applied to a bolt to the preload created in it, and involves fastener geometry and the coefficient of friction between mating surfaces. A theoretical equation based on rigid body mechanics and the assumption that the geometry of the fastener is perfectly described by blueprint dimensions. 将施加在螺栓上的扭矩与螺栓中产生的预载荷联系起来的方程，该方程涉及紧固件几何形状和配合面之间的摩擦系数。基于刚体力学和紧固件几何结构由蓝图尺寸完美描述的假设的理论方程。 |
| Stator | 定子 |
A ring of non-rotating blades or nozzles in a compressor, turbine, or other turbomachine, which directs fluid flow into an adjacent rotor. 涡轮压缩机、涡轮或其他涡轮机械中的一圈不旋转的叶片或喷嘴，将流体引导到相邻的转子中。 |
| Semiguided bend | 半导弯曲 |
The bend obtained by applying a force directly to the specimen in the portion that is to be bent. The specimen is either held at one end and forced around a pin or rounded edge, or is supported near the ends and bent by a force applied on the side of the specimen opposite the supports and midway between them. In some instances, the bend is started in this manner and finished in the manner of a free bend. 通过将力直接施加于待弯曲部分中的试样而获得的弯曲。将试样固定在一端，并围绕销或圆边施力，或者在靠近端部的位置支撑试样，并通过施加在试样与支撑件相对的一侧以及两者中间的力进行弯曲。在某些情况下，折弯以此方式开始，然后以自由折弯的方式结束。 |
| Cleavage | 分裂 |
The tendency of a material to cleave or split along definite crystallographic planes. 材料沿特定晶面劈裂或分裂的趋势。 |
| Hypereutectoid alloy | 过共析合金 |
In an alloy system exhibiting a eutectoid, any alloy whose composition has an excess of alloying element compared with the eutectoid composition, and whose equilibrium microstructure contains some eutectoid structure. 在呈现共晶的合金系统中，合金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。 |
| Time quenching | 时间淬火 |
A term used to describe a quench in which the cooling rate of the part being quenched must be changed abruptly at some time during the cooling cycle. 用于描述淬火的术语，其中被淬火零件的冷却速率必须在冷却循环的某个时间突然改变。 |
| Compressive stress (Unit Pa) | 压缩应力（单位Pa） |
The compressive load per unit area at a point in a component. 部件中某点的每单位面积的压缩载荷。 |
| Dead space | 死区 |
(dead volume) (Unit m³) That volume of a gas-filled thermometer in which the gas is not at the same temperature as that being measured. （死容）（单位m³）充气温度计的体积，其中气体的温度与被测温度不同。 |
| Relaxation curve | 松弛曲线 |
A plot of either the remaining, or relaxed, stress as a function of time. 剩余压力或松弛压力随时间变化的曲线图。 |
| Crack-growth rate | 裂纹增长速度 |
Rate of propagation of a crack through a material due to statically or dynamically applied load. 由于静态或动态施加的载荷，裂纹在材料中的扩展速率。 |
| Stress-strain diagram | 应力-应变图 |
A graph in which corresponding values of stress and strain are plotted against each other. Values of stress are usually plotted vertically(ordinates or y-axis) and values of strain horizontally (abscissas or xaxis). Also known as deformation curve and stress-strain curve. 对应的应力和应变值相对绘制的图表。应力值通常垂直绘制（纵坐标或y轴），应变值水平绘制（横坐标或X轴）。也称为变形曲线和应力-应变曲线。 |
| Salt bath heat treatment | 盐浴热处理 |
Heat treatment carried out in a bath of molten salt. 在熔融盐浴中进行的热处理。 |
| 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。 |
| Minimum load (Pmin) | 最小负载（Pmin） |
In fatigue, the least algebraic value of applied load in a cycle. 在疲劳中，循环中施加载荷的最小代数值。 |
| Grinding stress (Unit Pa) | 磨削应力（单位Pa） |
The residual stresses left in the surface of a component after grinding, owing to non-uniform cooling from the high surface temperatures produced. 由于产生的高表面温度造成的不均匀冷却，磨削后留在部件表面的残余应力。 |
| Stress equalizing | 应力均衡 |
A low-temperature heat treatment used to balance stresses in cold-worked material without an appreciable decrease in the mechanical strength produced by cold working. 一种低温热处理，用于平衡冷加工材料中的应力，而不会明显降低冷加工产生的机械强度。 |
| Microindentation hardness test | 显微压痕硬度测试 |
Hardness test using a calibrated machine to force a diamond indenter of specific geometry, under a test load of 1 to 1000 gramforce, into the surface of the test material and to measure the diagonal or diagonals of the indentation optically. 使用校准机器进行硬度试验，以在1至1000克力的试验载荷下，将特定几何形状的金刚石压头压入试验材料表面，并光学测量压痕的对角线。 |
| Latent heat | 潜热 |
Thermal energy absorbed or released when a substance undergoes a phase change. 物质发生相变时吸收或释放的热能。 |
| Variance | 方差 |
A measure of the squared dispersion of observed values or measurements expressed as a function of the sum of the squared deviations from the population mean or sample average. 观测值或测量值的平方离散度的度量，表示为总体平均值或样本平均值的平方偏差之和的函数。 |
| Vector | 矢量 |
Any physical quantity, such as velocity, acceleration, force, or momentum, that is specified in terms of both its magnitude and its direction. The convention of printing vector quantities in boldface was introduced by the physicist Josiah Willard Gibbs. 任何物理量，如速度、加速度、力或动量，以其大小和方向来表示。用黑体印刷矢量量的惯例是由物理学家约西亚·威拉德·吉布斯提出的。 |
| Millimetre of water | 毫米水柱 |
A non-SI unit of pressure equal to the pressure exerted by a vertical column of water 1 mm high. Approximately equal to 9.81 Pa. 一种非SI压力单位，等于1毫米高的垂直水柱施加的压力。大约等于9.81Pa。 |
| 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。 |
| Uniform elongation | 均匀伸长 |
The elongation at maximum load and immediately preceding the onset of necking in a tension test. 在拉伸试验中，在最大载荷下和颈缩开始之前的伸长率。 |
| Pitting | 点蚀 |
In tribology, a type of wear characterized by the presence of small, sharp surface cavities formed by processes such as fatigue, local adhesion, wear, corrosion, or cavitation. 在摩擦学中的一种磨损，其特征是存在由疲劳、局部粘附、磨损、腐蚀或空穴等过程形成的小而尖锐的表面空穴。 |
| Clearance angle | 后角 |
(relief angle) (Unit °) The angle between the underneath or flank of a cutting tool and the machined surface. （后角）（单位°）切削刀具的底部或侧面与加工表面之间的角度。 |
| Homogeneous carburizing | 均匀渗碳 |
Use of a carburizing process to convert a low-carbon ferrous alloy to one of uniform and higher carbon content throughout the section. 使用渗碳工艺将低碳铁合金转化为整个截面中碳含量均匀且较高的合金。 |
| Maximum allowable working pressure (Unit Pa) | 最大允许工作压力（单位Pa） |
The pressure on which the design of a pressure system is based and the highest pressure at which relief valves should be set. The lowest-rated component in the system typically has a design safety factor of 4. 压力系统设计所依据的压力和应设置安全阀的最高压力。系统中最低额定部件的设计安全系数通常为4。 |
| Turbine flow meter | 涡轮流量计 |
(axial flow meter, propeller meter) An in-line flow meter in which the rotation speed N of a propeller or rotor is a measure of the mass flowrate ṁ. Calibration is always necessary but with appropriate design ṁ is closely proportional to N over a wide range. （轴向流量计、螺旋桨流量计）一种串联流量计，其中螺旋桨或转子的转速N是质量流量的测量值ṁ. 校准总是必要的，但需要适当的设计ṁ在很宽的范围内与N成正比。 |
| Biaxial stress | 双轴应力 |
Generalized loading of a body in a single plane with no loading normal to it. 物体在一个平面内的广义载荷，没有垂直于它的载荷。 |
| Brittle | 脆性材料 |
A brittle material is one that breaks, often suddenly, with no permanent deformation. Examples of brittle materials are some cast irons, glass, concrete, and some plastics. A bolt is said to be brittle if it will break when stretched only a small amount past its yield point. 脆性材料通常会突然断裂，不会产生永久变形。脆性材料的例子有一些铸铁、玻璃、混凝土和一些塑料。如果螺栓在拉伸时仅超过其屈服点一小部分就会断裂，则称其为脆性螺栓。 |
| Following flank | 跟随侧翼 |
The flank of a thread opposite to the leading flank. 与前牙面相对的螺纹牙面。 |
| Rivet | 铆钉 |
A short rod with a head on one end that is inserted through aligned holes in plates to be joined, after which a second head is made on the protruding shank by hammering or forming. The most common head shapes are flat, domed, and inverse conical. In an array, the rivet pitch is the distance between the centres of adjacent rivets. Failure may occur by different mechanisms or modes. A one piece fastener consisting of a head and a body and used for fastening two or more pieces together by passing the body through a hole in each piece and then forming a second head on the body end. It cannot be removed except by taking off the head. 一种一端有头的短杆，插入待连接板上对齐的孔中，然后通过锤击或成型在突出的杆身上制作第二个头。最常见的头部形状是扁平、圆顶和倒锥形。在阵列中，铆钉间距是相邻铆钉中心之间的距离。故障可能由不同的机制或模式发生。一种一体式紧固件，由头部和主体组成，用于将两个或多个部件紧固在一起，方法是将主体穿过每个部件上的孔，然后在主体端部形成第二个头部。除非取下头部，否则无法移除。 |
| Bánki turbine | 班基涡轮机 |
A cross-flow, impulse-type water turbine for very low heads in which a jet of water in the form of a flat sheet passes transversely through the turbine, so going through the runner twice. The thin runner blades which run horizontally across the turbine parallel to the axis of rotation are profiled in cross section. 一种用于非常低水头的横流脉冲式水轮机，其中平板形式的水射流横向穿过涡轮机，因此穿过转轮两次。平行于旋转轴水平穿过涡轮机的薄转轮叶片在横截面上具有轮廓。 |
| Transition temperature (Unit K) | 转变温度（单位K） |
(1) An arbitrarily defined temperature that lies within the temperature range in which metal fracture characteristics (as usually determined by tests of notched specimens) change rapidly, such as from primarily fibrous (shear)to primarily crystalline (cleavage) fracture. (2) Sometimes used to denote an arbitrarily defined temperature within a range in which the ductility changes rapidly with temperature. (transition point) 1. The temperature at which the mechanism of fracture in metal alloys having a face-centred cubic crystal structure changes from ductile void growth to brittle cleavage. 2. The temperature at which a material changes from one crystal state to another. （1） 任意定义的温度，位于金属断裂特性（通常通过缺口试样的试验确定）快速变化的温度范围内，如从主要纤维（剪切）断裂到主要结晶（解理）断裂。（2） 有时用于表示延性随温度快速变化的范围内的任意定义的温度。（转变点）1.具有面心立方晶体结构的金属合金的断裂机制从韧性孔洞生长转变为脆性解理的温度。2.材料从一种晶体状态转变为另一种晶体的温度。 |
| Fretting corrosion | 微动腐蚀 |
(1) The accelerated deterioration at the interface between contacting surfaces as the result of corrosion and slight oscillatory movement between the two surfaces. (2) A form of fretting in which chemical reaction predominates. Fretting corrosion is often characterized by the removal of particles and subsequent formation of oxides, which are often abrasive and so increase the wear. Fretting corrosion can involve other chemical reaction products, which may not be abrasive. （1）由于两个表面之间的腐蚀和轻微振荡运动，接触表面之间的界面加速劣化。（2）一种以化学反应为主的微动磨损形式。微动腐蚀通常以颗粒的去除和随后形成的氧化物为特征，这些氧化物通常具有研磨性，因此会增加磨损。微动腐蚀可能涉及其他化学反应产物，这些化学反应产物可能不是磨料。 |
| mechanical engineering | 机械工业 |
That branch of engineering concerned with energy conversion, stress analysis, vibration, dynamics, and kinematics, especially applied to design (machine design, mechanical-engineering design). 与能量转换、应力分析、振动、动力学和运动学有关的工程分支，尤其适用于设计（机器设计、机械工程设计）。 |
| Austenitic grain size | 奥氏体晶粒尺寸 |
The size attained by the grains of steel when heated to the austenitic region; may be revealed by appropriate etching of cross sections after cooling to room temperature. 当加热到奥氏体区域时钢晶粒达到的尺寸；冷却至室温后，可通过适当蚀刻横截面来显示。 |
| Half hard | 半硬化回火 |
A temper of nonferrous alloys and some ferrous alloys characterized by tensile strength about mid-way between that of dead soft and full hard tempers. 非铁合金和某些铁合金的一种回火，其特点是抗拉强度介于完全软回火和完全硬回火之间。 |
| Carbon potential | 碳势 |
A measure of the ability of an environment containing active carbon to alter or maintain, under prescribed conditions, the carbon level of the steel. Note: In any particular environment, the carbon level attained will depend on such factors as temperature, time, and steel composition. 衡量含有活性碳的环境在规定条件下改变或保持钢的碳含量的能力。注意：在任何特定环境中，所达到的碳含量将取决于温度、时间和钢成分等因素。 |
| Ventilation | 通风系统 |
A system for circulating fresh air in a room, building, passenger vehicle, orother enclosed space. 在房间、建筑物、乘用车或其他封闭空间中循环新鲜空气的系统。 |
| X-ray thickness gauge | X射线厚度计 |
A device comprising an X-ray source and a detector used to determine the thickness of material in sheet or plate form, including metals, paper, plastics, rubber, and ceramics. 一种由X射线源和探测器组成的装置，用于测定片状或平板状材料的厚度，包括金属、纸张、塑料、橡胶和陶瓷。 |
| Design load (Unit N) | 设计荷载（单位N） |
The greatest load that a component or structure is expected to experience under normal operating conditions. 部件或结构在正常运行条件下预期承受的最大负载。 |
| Sampling frequency (Unit Hz) | 采样频率（单位Hz） |
(sampling rate) The number of measurement samples per unit time taken from a continuous analogue signal to produce a discrete signal. It is the inverse of the time between successive measurements (sampling interval, sampling period, or sampling time). （采样率）从连续模拟信号中提取以产生离散信号的每单位时间的测量样本数。它是连续测量之间时间的倒数（采样间隔、采样周期或采样时间）。 |
| Press quenching | 压淬 |
A quench in which hot dies are pressed and aligned with a part before the quenching process begins. Then the part is placed in contact with a quenching medium in a controlled manner. This process avoids part distortion. 一种淬火方法，在淬火过程开始之前，热模具被压制并与零件对齐。然后将零件以受控方式放置在与淬火介质接触的位置。该过程避免了零件变形。 |
| Die threading | 模具螺纹 |
Die threading is a machining process for cutting external threads in cylindrical or tapered surfaces by the use of solid or self-opening dies. Die threading is a slower method of producing external threads than thread rolling, but it is faster than single-point threading in a lathe. 模具螺纹加工是一种通过使用实心或自开模具在圆柱形或锥形表面上切削外螺纹的加工工艺。模具螺纹加工是一种比滚丝加工更慢的外螺纹加工方法，但它比车床中的单点螺纹加工要快。 |
| Altitude | 高度 |
(Unit m) Vertical height measured relative to a specified datum such as sea level. （单位m）相对于特定基准（例如海平面）测量的垂直高度。 |
| Thermodynamics laws | 热力学定律 |
The zeroth, first, second, and third laws of thermodynamics. 热力学第零、第一、第二和第三定律。 |
| 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。 |
| Spanner (wrench) | 扳手 |
A tool for applying torque to tighten or loosen a nut, bolt, or screw. Grip is applied by a serrated ring or an open U-shape at the end of the tool. On imperial-size spanners, the BSW and BSF marking refers to the diameter of the screw thread; similarly for BA spanners. Spanners for unified and metric threads are marked with the distance across the flats (‘A/F’) of the nut or head of the bolt. 拧紧或松开螺母、螺栓或螺丝的工具。通过工具端部的锯齿环或开口U形应用夹持。在英制扳手上，BSW和BSF标记是指螺纹的直径；类似于BA扳手。用于统一螺纹和公制螺纹的扳手在螺母或螺栓头的平面（'A/F'）上标记距离。 |
| Diaphragm meter | 隔膜计 |
A dry flow meter in which there are two or more interconnected chambers, each having a diaphragm in the wall. The chambers empty and fill alternately and the flow rate of gas is determined from the movement of diaphragms. Diaphragm meters are commonly used to monitor domestic and commercial gas supply. 一种干式流量计，其中有两个或多个相互连接的腔室，每个腔室的壁上都有一个隔膜。腔室交替排空和填充，气体流速由隔膜的移动确定。隔膜流量计通常用于监测家用和商用燃气供应。 |
| Gear pump | 齿轮泵 |
A positive-displacement pump in which fluid is pumped by meshing gears, one driven and the other an idler gear, on parallel axes within a closed casing. 一种容积式泵，其中流体由啮合齿轮泵送，在封闭外壳内的平行轴上一个驱动，另一个为空套齿轮。 |
| Radial load (Unit N) | 径向负荷（单位：N） |
1. Centrifugal loading induced in a rotating body. 2. (through-wallthickness load) The radial component of loading arising from internal or external pressurization of a closed vessel. There will also be axial and hoop loading. 1.旋转体中产生的离心载荷。2.（贯穿壁厚载荷）由封闭容器的内部或外部加压产生的载荷的径向分量。还存在轴向和环向载荷。 |
| Extra hard | 额外硬化 |
A temper of nonferrous alloys and some ferrous alloys characterized by tensile strength and hardness about one-third of the way from full hard to extra spring temper. 有色合金和一些铁合金的回火，其特征是抗拉强度和硬度大约是从完全硬回火到额外弹簧回火的三分之一。 |
| Turbine pump (turbopump) | 涡轮泵 |
An axial or centrifugal pump driven by a turbine. Typically used to supply fuel to the combustion chamber of a rocket engine such as on the space shuttle. 由涡轮驱动的轴向或离心泵。通常用于向火箭发动机（如航天飞机）的燃烧室供应燃料。 |
| Liquation temperature | 液化温度 |
The lowest temperature at which partial melting can occur in an alloy that exhibits the greatest possible degree of segregation. 偏析程度最高的合金发生部分熔融的最低温度。 |
| Retaining clip | 固定夹 |
(R-clip, hair cotter pin) A wire clip roughly with the shape of the letter R. The straight part of the clip passes through a hole drilled into a shaft or rod such that a wheel is held in position on the shaft, or the shaft is prevented from moving axially. （R形夹，开口销）大致与字母R形状相同的线夹。线夹的直线部分穿过钻在轴或杆上的孔，从而将车轮固定在轴上，或防止轴轴向移动。 |
| Crack-extension resistance (KR) | 抗裂扩展性（KR） |
A measure of the resistance of a material to crack extension, expressed in terms of the stress-intensity factor, the crack-extension force, or values of Jderived using the J-integral concept. 材料对裂纹扩展的抵抗力的量度，以应力强度因子、裂纹扩展力或使用J积分概念导出的J值表示。 |
| 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。 |
| 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。 |
| Cold treatment | 冷处理 |
Treatment carried out after quenching to transform retained austenite into martensite, involving cooling and holding at a temperature below ambient. 淬火后进行的处理，以将残余奥氏体转变为马氏体，包括冷却和保持在低于环境温度的温度。 |
| Knoop hardness test | 努氏硬度试验 |
An indentation-hardness test using calibrated machines to force a rhombic-based pyramidal diamond indenter having specified edge angles, under specified conditions, into the surface of the material under test and to measure the long diagonal after removal of the load. An indentation hardness test in which the indenter is an elongated diamond pyramid that gives an impression in the form of a parallelogram, in which the longer diagonal is about seven times the shorter. Used for studies of anisotropy in solid materials. 使用校准机器进行的一种压痕硬度试验，在规定条件下，将具有规定边缘角的菱形棱锥金刚石压头压入受试材料表面，并在移除荷载后测量长对角线。其中压头是一个细长的菱形棱锥，以平行四边形的形式给出压痕，其中较长的对角线约为较短的七倍。用于研究固体材料的各向异性。 |
| Centrifugal compressor | 离心式压缩机 |
A compressor in which kinetic energy is added to a fluid by radial acceleration in an impeller and then converted into a pressure increase by flow though a diffuser. 一种压缩机，其中动能通过叶轮中的径向加速度添加到流体中，然后通过扩散器的流动转换为压力增加。 |
| 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。 |
| Creep rupture strength (Unit Pa) | 蠕变断裂强度（单位Pa） |
The fracture stress at the end of a creep test in metals and polymers, often plotted against time to give a stress-rupture curve. 金属和聚合物蠕变试验结束时的断裂应力，通常与时间作图以给出应力-断裂曲线。 |
| Residual stress (Unit Pa) | 残余应力（单位Pa） |
Stresses that remain within a body as the result of thermal or mechanical treatment or both. (internal stress) An internal-stress system found in components that have experienced elastic unloading from non-uniform plastic-strain fields during manufacture. 由于热处理或机械处理或两者兼而有之而留在物体内的应力。（内应力）在制造期间从非均匀塑性应变场经历弹性卸载的部件中发现的内应力系统。 |
| Material velocity | 材料速度 |
The velocity of sound in a body (e.g., a bolt). A term used in the ultrasonic measurement of bolt stress or strain. 声音在物体（例如螺栓）中的速度。用于螺栓应力或应变的超声波测量的术语。 |
| Fitted bolt | 装配螺栓 |
A bolt with a plain unthreaded portion immediately beneath the head. 一种螺栓，其头部正下方有一个普通的无螺纹部分。 |
| Gamma iron | 加马铁 |
The face-centered cubic form of pure iron, stable from 910 to 1400 °C (1670 to 2550 °F). 纯铁的面心立方形式，在910至1400°C（1670 2550°F）温度范围内稳定。 |
| 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。 |
| Springback | 回弹 |
The extent to which metal tends to return to its original shape or contour after undergoing a forming operation. 金属在经历成形操作后趋于恢复其原始形状或轮廓的程度。 |
| Ductile | 延展性材料 |
(ductile material) Describes a material that can be deformed permanently to large strains without fracture. If a bolt can be stretched well past its yield point before breaking, it is said to be ductile. （延展性材料）描述一种可以永久变形到大应变而不断裂的材料。如果螺栓在断裂前可以很好地拉伸超过其屈服点，则称其具有延展性。 |
| Absorber | 吸收器 |
1. An auxiliary vibratory system that favourably modifies the vibration characteristics of a main system. 2. Part of an absorption refrigeration system in which the refrigerant is absorbed by a transport medium. 3. The absorber plate is the receiver of a concentrating solar collector where the radiation is absorbed. 1.一种辅助振动系统，可有利地改变主系统的振动特性。2.吸收式制冷系统的一部分，其中制冷剂被传输介质吸收。3.吸收板是吸收辐射的聚光太阳能集热器的接收器。 |
| Pin expansion test | 插头膨胀试验 |
A test for determining the ability of a tube to be expanded or for revealing the presence of cracks or other longitudinal weaknesses in it, made by forcing a tapered pin into the open end of the tube, similar to flare test. 通过将锥形销压入管道开口端来确定管道膨胀能力或揭示其存在裂纹或其他纵向缺陷的试验，类似于扩口试验。 |
| Anisotropy | 各向异性 |
The characteristic of exhibiting different values of a property in different directions with respect to a fixed reference system in the material. 相对于材料中的固定参考系统，在不同方向上表现出不同属性值的特性。 |
| Translational joint | 平移铰 |
A robot joint where the controlled variable is straight line movement. 控制变量为直线运动的机器人关节。 |
| Monotron hardness test | 摩诺硬度试验 |
An obsolete method of determining indentation hardnessby measuring the load required to force a spherical penetrator into a metal to a specified depth. 一种已被淘汰的方法，通过测量将球形侵彻体压入金属至规定深度所需的载荷来确定压痕硬度。 |
| Anelastic | 无弹性 |
Literally ‘not elastic’, but in practice used for materials that display timedependent recovery on unloading. 字面意思是“没有弹性”，但实际上用于在卸载时显示随时间恢复的材料。 |
| Corrosive wear | 腐蚀磨损 |
Wear in which chemical or electrochemical reaction with the environment is significant. 与环境发生显着化学或电化学反应的磨损。 |
| 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。 |
| Population | 集合 |
The hypothetical collection of all possible test specimens that could be prepared in the specified way from the material under consideration. Also known as universe. 从所考虑的材料中以规定方式制备的所有可能试样的假设集合。也称为体系。 |
| 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。 |
| Fretting fatigue | 微动疲劳 |
Fatigue fracture that initiate at a surface area where fretting has occurred. The progressive damage to a solid surface that arises from fretting. 在发生微动的表面区域开始的疲劳断裂。由微动引起的对固体表面的渐进性损坏。 |
| Elastic recovery | 弹性恢复 |
Amount the dimension of a stressed elastic material returns to its original (unstressed) dimension on release of an applied load. In hardness testing, the shortening of the original dimensions of the indentation upon release of the applied load. 在释放施加的载荷时，受应力弹性材料的尺寸恢复到其原始（无应力）尺寸的量。在硬度测试中，当释放所施加的载荷时，压痕的原始尺寸缩短。 |
| Trepanning | 开孔 |
Trepanning is a machining process for producing a circular hole or groove in solid stock, or for producing a disk, cylinder, or tube from solid stock, by the action of a tool containing one or more cutters (usually single-point) revolving around a center. 开孔是一种机械加工工艺，通过包含一个或多个围绕中心旋转的刀具（通常为单点）的作用，在实心坯料中制造圆孔或凹槽，或从实心坯料生产圆盘、圆柱体或管。 |
| Dynamic modulus | 动态模量 |
The ratio of stress to strain under cyclic conditions (calculated from data obtained from either free or forced vibration tests, in shear, compression, or tension). 循环条件下的应力与应变之比（根据在剪切、压缩或拉伸中的自由或强制振动测试中获得的数据计算得出）。 |
| 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。 |
| Cup washer | 杯形垫圈 |
A dished leather or neoprene washer fitted to the rod end in some piston-style pumps. 在某些活塞式泵中，安装在杆端的碟形皮革或氯丁橡胶垫圈。 |
| Base metal hardness | 母材硬度 |
Hardness closest to the surface (when traversing from core to outside diameter) just before an increase or decrease occurs, denoting, respectively, carburization or decarburization. 在发生增加或减少之前最接近表面的硬度（从芯部到外径时），分别表示渗碳或脱碳。 |
| Stress factor | 应力因子 |
A calibration constant used in ultrasonic measurement of bolt stress or strain. It is the ratio between the change in ultrasonic transit time caused by the change in length of the fastener, under load, to the total change in transit time. 用于螺栓应力或应变超声波测量的校准常数。它是由紧固件长度变化引起的超声波传输时间变化与总传输时间变化之间的比率。 |
| Oldham coupling | 十字联轴节 |
(double-slider coupling) A device for connecting a pair of misaligned parallel shafts, on the end of each of which are flanges having diametral tenons (tongues) that engage with matching slots spaced at 90° in an intermediate disc. As the coupling rotates, the disc compensates for shaft offset by sliding along each tenon in turn. Low-friction surfaces are requisite and the disc is often made of a polymer. An alternative arrangement has the slots in the flanges and the tenons on the disc. （双滑块联轴器）一种连接一对未对准平行轴的装置，在每个平行轴的端部有法兰，法兰具有直径榫（舌），与中间盘中间隔90°的匹配槽接合。当联轴器旋转时，圆盘通过依次沿每个榫头滑动来补偿轴偏移。低摩擦表面是必需的，阀盘通常由聚合物制成。另一种布置方式是法兰上的槽和阀盘上的榫头。 |
| True strain | 真应变 |
(1) The ratio of the change in dimension, resulting from a given load increment, to the magnitude of the dimension immediately prior to applying the load increment. (2) In a body subjected to axial force, the natural logarithm of the ratio of the gage length at the moment of observation to the original gage length. Also known as natural strain. Compare with engineering strain. （1）给定载荷增量导致的尺寸变化与施加载荷增量之前尺寸大小的比率。（2）在承受轴向力的物体中，观察时刻标距与原始标距之比的自然对数。也称为自然应变。与工程应变相比。 |
| Fin neck carriage bolt | 翼颈圆头方颈螺栓 |
A plain, circular, oval head bolt with two oppositely located fins to prevent rotation. 一种普通的圆形椭圆头螺栓，有两个相对的翼片以防止旋转。 |
| Waste-heat recovery | 废热回收 |
The recovery of thermal energy from flue and exhaust gases, or from liquids heated in industrial processes. Recovery devices include pre-heaters, recuperators, regenerators, and waste-heat boilers. 从烟道和废气中或从工业过程中加热的液体中回收热能。回收装置包括预热器、回热器、再生器和余热锅炉。 |
| Connecting rod | 连杆 |
(con rod) A link that transmits power from one system to another, often changing linear to rotary motion, as in the rod connecting the piston to the crankshaft in a reciprocating compressor or pump or to the crankshaft in an internal-combustion engine, as in the diagram. The big end (bottom end) is the larger end that connects to the bearing on one of the crankpins of the crankshaft. The little end (small end) is joined by a gudgeon pin to the piston. （连杆）将动力从一个系统传递到另一个系统的连杆，通常由线性运动变为旋转运动，如图所示，连杆将活塞连接到往复式压缩机或泵的曲轴或内燃机的曲轴上。大端（底端）是连接到曲轴一个曲柄销上轴承的大端。小端（小端）通过活塞销连接到活塞上。 |
| 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。 |
| Screw thread | 螺纹 |
A ridge of uniform section or shape in the form of a helix on the external or internal surface of a cylinder, or in the form of a conical spiral on the external or internal surface of a cone. 在圆柱体的外表面或内表面上呈螺旋形或在圆锥体的外表面和内表面上以锥形螺旋形的均匀截面或形状的脊。 |
| 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。 |
| Thread insert | 螺纹嵌件 |
(threaded bushing) Either a thin cylinder with an internal thread (and sometimes also an external thread) or a helical coil of wire, pressed or screwed into a hole to accept a bolt or screw. Used in material too soft or a component too thin to be threaded, to change one form of thread to another or to repair a damaged thread. （螺纹衬套）一种带有内螺纹（有时也有外螺纹）的薄圆柱体或螺旋形线圈，压入或拧入孔中以接受螺栓或螺钉。用于材料太软或部件太薄而无法螺纹连接，用于将一种形式的螺纹更换为另一种形式或修复损坏的螺纹。 |
| Coextrusion | 复合挤压 |
The simultaneous extrusion through the same die of two or more materials in combination. 通过同一模具同时挤出两种或多种材料的组合。 |
| Anneal to temper | 退火回火 |
A final partial anneal that softens a cold worked nonferrous alloy to a specified level of hardness or tensile strength. 将冷加工的有色金属合金软化到规定的硬度或抗拉强度水平的最终局部退火。 |
| 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。 |
| Materials science | 材料科学 |
The study of the properties, behaviour, and application of solid substances such as metals, ceramics, glasses, polymers, composites, biomaterials, and semiconductors, at all scales from the atomic to the macroscopic. The topic has its origins in metallurgy. 研究金属、陶瓷、玻璃、聚合物、复合材料、生物材料和半导体等固体物质的特性、行为和应用，涵盖从原子到宏观的所有范围。起源于冶金学。 |
| Torque converter | 变矩器 |
A turbomachine used for torque amplification consisting of an impeller, a turbine, and a reaction member. Applications include motor-vehicle transmissions. 用于扭矩放大的涡轮机，由叶轮、涡轮机和反作用构件组成。应用包括机动车变速器。 |
| Thermoelectric material | 热电材料 |
A material in which any of the thermoelectric phenomena, such as the Peltier, Seebeck, and Thomson effects, are especially strong. 一种热电现象特别强烈的材料，如珀尔帖效应、塞贝克效应和汤姆森效应。 |
| Applied thermodynamics | 应用热力学 |
(engineering thermodynamics, thermodynamics) The science of the relationship between heat, work and the properties of systems and the ways in which heat energy from fuels can be converted into mechanical work. It involves the study of all aspects of energy use and energy transformation, including power generation, refrigeration, the relevant properties of the substances involved and the relationships between them. The principle of conservation of energy is a fundamental law of nature. （工程热力学、热力学）热、功和系统特性之间关系的科学，以及燃料中的热能可以转化为机械功的方式。它涉及能源使用和能源转换的各个方面的研究，包括发电、制冷、所涉及物质的相关特性以及它们之间的关系。能量守恒定律是自然的基本规律。 |
| Seal | 密封件 |
A component which controls or prevents leakage of fluids into or out of parts of a machine. 控制或防止流体流入或流出机器部件的部件。 |
| 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。 |
| Hydrogen embrittlement | 氢脆 |
A condition of low toughness, low ductility or cracking in metals resulting from the absorption of hydrogen. A common and troublesome form of Stress cracking. Several theories have been proposed to explain hydrogen embrittlement, but, at present, the exact mechanism is still unknown. What is known, however, is the fact that if hydrogen is trapped in a bolt by poor electroplating practices, it can encourage stress cracking. Bolts can fail, suddenly and unexpectedly, under normal loads. Premature crack growth over time under tensile stress leading to unexpected failure in certain metals, caused by small amounts of hydrogen in the microstructure. Hydrogen may enter steels during melting or heat treating, or during processes such as electroplating. 因吸收氢而导致金属韧性低、延展性低或开裂的情况，是一种常见且麻烦的应力开裂形式。在拉伸应力下，裂纹随时间过早扩展，导致某些金属发生意外失效，这是由微观结构中的少量氢引起的。在熔化或热处理过程中，或在电镀等过程中，氢可能进入钢中。已经提出了几种理论来解释氢脆，但目前，确切的机理仍然未知。已知的事实是，如果氢因电镀不当而被困在螺栓中，则会导致应力开裂。在正常载荷下，螺栓可能突然意外失效。 |
| 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。 |
| Graphitic carbon | 石墨碳 |
Free carbon in steel or cast iron. 钢或铸铁中的游离碳。 |
| 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。 |
| Cap | 帽 |
A cover, often in the form of a short cylinder, one end of which is closed. Typically used to close an orifice or pipe end, on to which it can be pushed, welded, screwed, or attached with fasteners. 一种盖子，通常为短圆柱体，一端封闭。通常用于封闭孔口或管端，可将其推入、焊接、拧紧或用紧固件连接到其上。 |
| Radius of bend | 弯曲半径 |
The radius of the cylindrical surface of the pin or mandrel that comes in contact with the inside surface of the bend during bending. For free or semiguided bends to 180° in which a shim or block is used, the radius of bend is one-half the thickness of the shim or block. 在弯曲过程中与弯曲内表面接触的销或心轴的圆柱面半径。对于使用垫片或垫块的180°自由弯曲或半导向弯曲，弯曲半径为垫片或垫板厚度的一半。 |
| Dimensioning | 尺寸标注 |
The specification on an engineering drawing of the size (e.g. length, radius, angle, or spacing) and the relative location (e.g. angular position) of each feature of a component. The numerical values often include the tolerances. There should be no more dimensions than are necessary to manufacture the component. 工程图纸上对部件每个特征的尺寸（例如长度、半径、角度或间距）和相对位置（例如角位置）的规范。数值通常包括公差。尺寸不应超过制造组件所需的尺寸。 |
| 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。 |
| Hardness | 硬度 |
A measure of the resistance of a material to surface indentation or abrasion; may be thought of as a function of the stress required to produce some specified type of surface deformation. There is no absolute scale for hardness; therefore, to express hardness quantitatively, each type of test has its own scale of arbitrarily defined hardness. Indentation hardness can be measured by Brinell hardness test, Rockwell hardness test, Vickers hardness test, Knoop hardness test, and the Scleroscope hardness test. The ability of a ductile material to resist permanent deformation. It is a measure of plastic flow properties determined principally by indentation testing, but scratch hardness and rebound hardness are also employed. hardness scales The different measures of hardness given by different tests, such as indentation pressure in the Brinell and in the Vickers hardness tests, and the different Rockwell hardness numbers. 测量材料对表面压痕或磨损的阻力；可以认为是产生某些特定类型的表面变形所需的应力的函数。硬度没有绝对刻度，因此为了定量表示硬度，每种类型的试验都有自己的任意定义硬度等级。压痕硬度可通过布氏硬度试验、洛氏硬度试验，维氏硬度试验和努氏硬度试验以及硬化镜硬度试验进行测量。延展性材料具有抵抗永久变形的能力，它是主要通过压痕测试确定的塑性流动性能的量度，也使用划痕硬度和回弹硬度。硬度标度不同试验给出的不同硬度测量值，如布氏硬度试验和维氏硬度试验中的压痕压力，以及不同的洛氏硬度值。 |
| 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。 |
| Vapour–pressure curve | 蒸汽压力曲线 |
For a pure substance, the curve of saturation pressure plotted vs saturation temperature. 对于纯物质，绘制了饱和压力与饱和温度的曲线。 |
| 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。 |
| Safety valve (safety-relief valve) | 安全阀（安全泄压阀） |
A mechanical valve, fitted by law to all pressure vessels (e.g. steam boilers), which opens to prevent the internal pressure exceeding the maximum design value for that vessel. The valve closes again once the pressure reduces to a safe level. 根据法律安装在所有压力容器（如蒸汽锅炉）上的机械阀，其打开以防止内部压力超过该容器的最大设计值。一旦压力降至安全水平，阀门将再次关闭。 |
| Shear strength | 抗剪强度 |
The maximum shear stress that a material is capable of sustaining. Shear strength is calculated from the maximum load during a shear or torsion test and is based on the original dimensions of the cross section of the specimen. 材料能够承受的最大剪切应力。抗剪强度根据剪切或扭转试验期间的最大载荷计算，并基于试样横截面的原始尺寸。 |
| Condensate strainer | 冷凝水过滤器 |
A filter in a steam plant used to remove particulate matter from condensate before it is added to feedwater. 蒸汽设备中的过滤器，用于在将冷凝水添加到给水中之前去除冷凝水中的颗粒物。 |
| 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。 |
| Coefficient of discharge (CD) | 流量系数（CD） |
For flow through a nozzle or orifice plate, the ratio of the actual mass flow rate to the theoretical mass flow rate calculated assuming the flow to be isentropic. The coefficient of velocity (velocity coefficient) is the corresponding ratio of the actual average velocity to the theoretical value. For incompressible flow, the theoretical flow rate and velocity can be calculated using Bernoulli’s equation. 对于通过喷嘴或孔板的流量，实际质量流量与假设流量为等熵计算的理论质量流量之比。速度系数（速度系数）是实际平均速度与理论值的对应比。对于不可压缩流，可以使用伯努利方程计算理论流量和速度。 |
| Steady loads | 稳定负载 |
Loads that do not change in intensity or that change so slowly they may be regarded as steady. 强度不变或变化缓慢的荷载可视为稳定荷载。 |
| 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。 |
| Absolute manometer | 绝对压力计 |
A manometer that measures absolute pressure, i.e. pressure measured relative to a perfect vacuum. Absolute pressure cannot be negative. 测量绝对压力的压力计，即相对于完美真空测量的压力。绝对压力不能为负。 |
| Torque (T) (Unit N.m) | 扭矩（T）（单位：N.m） |
The twisting moment, product of force and wrench length, applied to a nut or bolt (for example). The twisting moment of a force or couple about an axis which results in torsion. 施加在螺母或螺栓（例如）上的扭矩，是力和扳手长度的乘积。力或力偶绕轴产生扭转的力矩。 |
| Fastener manufacturer | 紧固件制造商 |
An organization that fabricates raw steel into a fastener meeting specified standards. 将生钢加工成符合规定标准的紧固件的组织。 |
| Pressure difference (Unit Pa) | 压差（单位Pa） |
(pressure differential, Δp) The difference between two pressures, one of which may be a reference pressure such as barometric pressure. In many flow processes, the pressure difference is more important than the absolute pressure level. （压差，Δp）两个压力之间的差值，其中一个压力可以是参考压力，如大气压力。在许多流动过程中，压差比绝对压力水平更重要。 |
| Bioengineering | 生物工程 |
(biological engineering) The application of engineering principles to biology, medicine, agriculture, etc. （生物工程）工程原理在生物学、医学、农业等方面的应用。 |
| Malleable cast iron | 可锻铸铁 |
A cast iron made by prolonged annealing of white cast iron in which decarburization or graphitization, or both, take place to eliminate some or all of the cementite. The graphite is in the form of temper carbon. If decarburization is the predominant reaction, the product will exhibit a light fracture surface, hence, “whiteheart malleable;” otherwise, the fracture surface will be dark, hence, “blackheart malleable.” Ferritic malleable has a predominantly ferritic matrix; pearlitic malleable may contain pearlitic, spheroidite or tempered martensite depending on heat treatment and desired hardness. 白口铸铁一种通过长时间退火制成的铸铁，脱碳，石墨化，或两者都发生，以消除部分或全部渗碳体。石墨是回火碳的形式。如果脱碳是主要反应，产品将呈现出较轻的断裂表面，“白心可锻”。否则，断裂表面将变暗，“黑心可锻”。铁素体可锻性材料主要为铁素体基体；根据热处理和所需硬度，珠光体可锻材料可能包含珠光体、球状体或回火马氏体。 |
| Deposit gauge | 沉积量计 |
(deposition gauge) An instrument employed in air pollution studies for measuring the amount of pollutant deposited on a given area in a given time under given conditions. （沉降计）在空气污染研究中使用的仪器，用于测量在给定条件下在给定时间内沉积在给定区域上的污染物量。 |
| 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。 |
| Tracking problem | 跟踪问题 |
A control problem where the set point changes with time and thus the plant output must follow the changing set point. The opposite of a regulator problem. 一种控制问题，其中设定值随时间变化，因此设备输出必须遵循变化的设定值。与调节器问题相反。 |
| Ultrasonic method | 超声波法 |
Measuring elongation uses a sound pulse, generated at one end of a bolt, that travels the length of a bolt, bounces off the far end, and returns to the sound generator in a measured period of time. 测量伸长使用在螺栓一端产生的声音脉冲，该脉冲沿螺栓长度传播，从远端反弹，并在测量的时间段内返回到声音发生器。 |
| Ballonet | 气囊 |
An airbag used in a hybrid airship. Helium gas expels air from the ballonet during ascent. Fans draw air in during descent. 混合动力飞艇中使用的安全气囊。氦气在上升过程中将空气从气囊中排出。风扇在下降过程中吸入空气。 |
| Fastener identification marking | 紧固件识别标记 |
A stamp, paint, or other permanent identifier that may include manufacturer information and applicable grade markings for certification purposes. 印章、油漆或其他永久性标识符，其中可能包括制造商信息和用于认证的适用等级标记。 |
| Double aging | 双级时效 |
Employment of two different aging treatments to control the type of precipitate formed from a supersaturated matrix in order to obtain the desired properties. The first aging treatment, sometimes referred to as intermediate or stabilizing, is usually carried out at higher temperature than the second. 采用两种不同的时效处理来控制由过饱和基质形成的沉淀物类型，以获得所需的性能。第一次时效处理，有时称为中间处理或稳定处理，通常在比第二次更高的温度下进行。 |
| Effective length of a bolt | 螺栓的有效长度 |
The grip length plus some portion of the bolt (often one-half of the thickness of the nuts) which lies within the nut(s) plus some portion (often one-half the thickness) of the head. 握持长度加上位于螺母内的螺栓的某些部分（通常是螺母厚度的二分之一）加上头部的某些部分（通常是厚度的二分之一）。 |
| 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。 |
| 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。 |
| Steel-wire rope | 钢丝绳 |
A rope or cable made up of many steel strands wrapped helically about an axis, each strand being made of metal wires twisted together like a helix. 一种绳索或缆绳，由许多绕轴螺旋缠绕的钢绞线组成，每根钢绞线由金属丝缠绕在一起形成螺旋。 |
| Activation energy | 活化能 |
(Ea, U) (Unit kJ/mol) The minimum energy for a chemical reaction to occur or for processes such as diffusion to take place in crystals. （Ea, U）（单位kJ/mol）发生化学反应或在晶体中发生扩散等过程的最小能量。 |
| 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。 |
| Air conditioning | 空调 |
The process of controlling the temperature and humidity in rooms, buildings, aircraft, passenger vehicles, etc. More generally it includes control of dust, levels of radiant heat, etc. 控制房间、建筑物、飞机、客运车辆等的温度和湿度的过程。更一般地说，它包括控制灰尘、辐射热水平等。 |
| Autonomous energy system | 自主能源系统 |
(stand-alone energy system) A sole source of electricity, usually small-scale, for applications remote from a grid, especially with energy storage in the system. Hydroelectric, photovoltaic, wind-power and other renewable systems are well suited to stand-alone applications. （独立能源系统）一种唯一的电力来源，通常是小规模的，用于远离电网的应用，尤其是系统中的能量存储。水电、光伏、风力和其他可再生能源系统非常适合独立应用。 |
| Lobe | 凸轮 |
The projecting part such as rotor lobe or the cam lobe. 转子凸角或凸轮凸角等突出部分。 |
| Pressure surface | 压力面 |
The high-pressure surface of an aerofoil, turbine, or compressor blade. In normal aircraft applications, this is the lower surface of a wing. For applications, such as to high-performance motor vehicles, where the aerofoil is inverted to generate downforce, it is the upper surface. 机翼、涡轮或压缩机叶片的高压表面。在正常的飞机应用中，这是机翼的下表面。对于高性能机动车辆等应用，机翼翻转以产生下压力，它是上表面。 |
| Threading machine | 螺纹机 |
A machine used to cut an external thread on a rod, tube, bolt blank, etc. or an internal thread in a hole, tube, nut blank, etc. 用于切割杆、管、螺栓毛坯等上的外螺纹或孔、管、螺母毛坯等中的内螺纹的机器。 |
| Tolerance limits | 公差极限 |
The extreme values (upper and lower) that define the range of permissible variation in size or other quality characteristic of a part. 定义零件尺寸或其他质量特性允许偏差范围的极值（上限和下限）。 |
| Standard fit | 标准匹配 |
The fit of a component machined or otherwise manufactured to standardized clearances and tolerances. 根据标准间隙和公差加工或以其他方式制造的部件的配合。 |
| Ausforming | 形变热处理 |
Thermomechanical treatment of steel in the metastable austenitic condition below the recrystallization temperature followed by quenching to obtain martensite and/or bainite. 在低于再结晶温度的亚稳态奥氏体条件下对钢进行热机械处理，然后淬火以获得马氏体和/或贝氏体。 |
| Notch depth | 缺口深度 |
The distance from the surface of a notched test specimen to the bottom of the notch. In a cylindrical test specimen, the percentage of the original cross-sectional area removed by machining an annular groove. 从缺口试样表面到缺口底部的距离。在圆柱形试样中，通过加工环形槽去除的原始横截面积的百分比。 |
| Minimum stress (Smin) | 最小应力（Smin） |
In fatigue, the stress having the lowest algebraic value in the cycle, tensile stress being considered positive and compressive stress negative. 在疲劳中，循环中代数值最低的应力，拉应力被视为正应力，压应力为负应力。 |
| Cast steel | 铸钢 |
Steel that is cast into shapes. It has superior properties to most cast irons, but is more expensive to produce. 铸成形状的钢。与大多数铸铁相比，它具有优越的性能，但生产成本更高。 |
| Full hard | 全硬化 |
A temper of nonferrous alloys and some ferrous alloys corresponding approximately to a coldworked state beyond which the material can no longer be formed by bending. In specifications, a full hard temper is commonly defined in terms of minimum hardness or minimum tensile strength (or, alternatively, a range of hardness or strength) corresponding to a specific percentage of cold reduction following a full anneal. For aluminum, a full hard temper is equivalent to a reduction of 75% from dead soft ; for austenitic stainless steels, a reduction of about 50 to 55%. 有色金属合金和一些铁合金的回火状态，大致对应于冷加工状态，超过该状态，材料就不能再通过弯曲形成。在规范中，完全硬质回火通常定义为与完全退火后的特定冷压下率百分比相对应的最小硬度或最小抗拉强度（或者，硬度或强度范围）。对于铝来说，完全硬回火相当于从极软状态减少75%；对于奥氏体不锈钢，减少约50%至55%。 |
| Thermochemical treatment | 热化学处理 |
Heat treatment carried out in a medium suitably chosen to produce a change in the chemical composition of the object by exchange with the medium. 在适当选择的介质中进行热处理，以通过与介质交换产生物体化学成分的变化。 |
| Endurance limit | 耐力极限 |
The maximum stress below which a material can presumably endure an infinite number of stress cycles. The value of the maximum stress and the stress ratio also should be stated. That completely reversing stress limit below which a bolt or joint member will have an essentially infinite life under cyclic fatigue loads. Note that the mean stress on the bolts here is zero. 材料可以承受无限次应力循环的最大应力。还应说明最大应力值和应力比。完全逆转的应力极限，低于该极限螺栓或接头构件在循环疲劳载荷下将具有基本上无限的寿命。请注意，此处螺栓上的平均应力为零。 |
| Boiler and Pressure Vessel Code | 锅炉和压力容器规范 |
A large and complex document, maintained and published by the American Society of Mechanical Engineers. The code 一份庞大而复杂的文件，由美国机械工程师协会出版和维护。 |
| Accelerated testing | 加速测试 |
A type of testing, for rates of wear, fatigue, corrosion etc., in which failure times are reduced by employing greater loads, more frequent power cycling, higher vibration levels, higher humidity, higher temperatures, greater potential differences etc. than would be encountered in normal operation. 一种测试类型，用于测试磨损率、疲劳率、腐蚀率等，通过采用比正常运行中更大的负载、更频繁的功率循环、更高的振动水平、更高湿度、更高温度、更大的电位差等，减少故障时间。 |
| Sample average | 样本平均值 |
The sum of all the observed values in a sample divided by the sample size. It is a point estimate of the population mean. Also known as arithmetic mean. 样本中所有观察值的总和除以样本大小。它是总体平均值的点估计。也称为算术平均值。 |
| Stress ratio (A or R) | 应力比（A或R） |
The algebraic ratio of two specified stress values in a stress cycle. Two commonly used stress ratios are the ratio of the alternating stress amplitude to the mean stress, A = Sa/Sm, and the ratio of the minimum stress to the maximum stress, R = Smin/Smax. 应力循环中两个指定应力值的代数比。两种常用的应力比是交变应力振幅与平均应力之比，A=Sa/Sm，以及最小应力与最大应力之比R=Smin/Smax。 |
| Thermodynamic properties | 热力学性质 |
Temperature, pressure, and the intensive properties that define the state of a working fluid: specific internal energy, specific enthalpy and specific entropy. 温度、压力和定义工作流体状态的密集属性：比内能、比焓和比熵。 |
| Pressure gauge | 压力表 |
An instrument used to measure absolute or gauge pressure. The sensing element may be a tube which deflects when pressurized, as in a Bourdon gauge, a bellows as in an aneroid barometer, a piezoelectric crystal, a piezoresistive element, etc. 测量绝对压力或表压的仪器。传感元件可以是加压时会偏转的管，如波登压力表、无液气压计中的波纹管、压电晶体、压阻元件等。 |
| Wrap-around bend | 环绕弯曲 |
The bend obtained when a specimen is wrapped in a closed helix around a cylindrical mandrel. This term is sometimes applied to a semiguided bend of 180° or less. 当试样缠绕在圆柱形心轴周围的闭合螺旋中时获得的弯曲。该术语有时适用于180°或更小的半导弯曲。 |
| Pneumatic control valve | 气动控制阀 |
(pneumatic valve) A valve in which the position of the valve stem, which varies the open area, is determined by the net force generated by compressed air acting on a diaphragm operating against the force of a compression spring. Depending upon the arrangement of the spring, in the event of air-supply failure, the valve may open or close. （气动阀）一种阀门，其中阀杆的位置随开口面积的变化而变化，由压缩空气作用在隔膜上产生的净力决定，隔膜克服压缩弹簧的力进行操作。根据弹簧的布置，在供气故障的情况下，阀门可以打开或关闭。 |
| Zirconia-toughened alumina composites | 氧化锆增韧氧化铝复合材料 |
(ZTA composites) Ceramic composites based on aluminium oxide to which zirconium oxide is added, resulting in improved fracture toughness. （ZTA复合材料）基于氧化铝的陶瓷复合材料，其中添加了氧化锆，从而提高了断裂韧性。 |
| Angle of friction | 摩擦角 |
(friction angle, β) (Unit °) For a body in contact with a plane surface, the angle between the normal to the surface and the resultant force between the body and the surface. If the friction force is F and normal force is N, β is given by F/N = μ = tan β where μ is the coefficient of friction. （摩擦角，β）（单位°）对于与平面接触的物体，表面法线与物体与表面之间的合力之间的夹角。如果摩擦力为F，法向力为N，则β由F/N=μ=tanβ给出，其中μ是摩擦系数。 |
| Scleroscope hardness number (HSc or HSd) | 硬化镜硬度值（HSc或HSd） |
A number related to the height of rebound of a diamond-tipped hammer dropped on the material being tested. It is measured on a scale determined by dividing into 100 units the average rebound of the hammer from a quenched(to maximum hardness) and untempered AISI W5 tool steel test block. 与落在被测材料上的菱形锤的回弹高度相关的数字。通过将锤子从淬火（达到最大硬度）和未淬火的AISI W5工具钢试块上的平均回弹分为100个单位来测量。 |
| 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。 |
| Magnetic materials | 磁性材料 |
Materials in which the magnetic moment of adjacent atoms can adopt either parallel or antiparallel alignment. Ferromagnetism occurs when the magnetic moments adopt parallel alignment. When adjacent magnetic moments cancel due to antiparallel alignment, the material exhibits antiferromagnetism and has no overall magnetic moment. Examples of the latter include ferrous oxide and manganese oxide. The phenomenon of ferrimagnetism occurs when adjacent magnetic moments adopt antiparallel alignment but have unequal magnitude. The region of ferromagnetic or ferrimagnetic material in which the magnetic moments are aligned is known as a magnetic domain and adjacent regions are separated by domain walls. Diamagnetic and paramagnetic materials exhibit weak forms of magnetism that results from independent (uncoupled) alignment of magnetic atomic dipoles induced by an applied magnetic field. Ferromagnetic and ferrimagnetic materials can acquire high degrees of magnetization in relatively weak magnetic fields. They have different hysteresis characteristics and are classified as either hard magnets or soft magnets. Hard magnets retain large magnetization in the absence of an applied magnetic field and are used as permanent magnets. Conventional materials include magnet steels alloyed with tungsten or cobalt. Rare-earth magnets made from alloys of rare-earth elements produce significantly stronger magnetic fields. The most common of these are samarium-cobalt and neodymiumiron-boron permanent magnets. Their strength allows them to be small and used in numerous applications, including cordless tools, disk drives, headphones, toys, and motors for automotive components such as wipers, fans, washers, and windows. Soft magnets may be magnetized and demagnetized relatively easily. When subjected to an alternating magnetic field the energy loss due to hysteresis is small. Common materials include iron-silicon alloys (known as electrical steels), nickel-iron alloys (permalloy), soft ferrites, and amorphous nanocrystalline alloys, the last of which can be produced in the form of tape by meltspinning. Soft magnets are used to enhance the magnetic flux produced by an electric current. 相邻原子的磁矩可以采用平行或反平行排列的材料。当磁矩采用平行排列时，会产生铁磁性。当相邻磁矩因反平行排列而抵消时，材料表现出反铁磁性，没有总磁矩。后者的实例包括氧化亚铁和氧化锰。当相邻磁矩采用反平行排列但大小不等时，就会出现铁磁现象。磁矩对齐的铁磁或铁磁材料区域称为磁畴，相邻区域由磁畴壁分隔。抗磁和顺磁材料表现出弱磁性形式，这是由外加磁场诱导的磁原子偶极子的独立（非耦合）排列引起的。铁磁性和铁磁性材料可以在相对弱的磁场中获得高磁化度。它们具有不同的磁滞特性，分为硬磁铁和软磁铁。硬磁铁在没有外加磁场的情况下保持较大的磁化强度，用作永磁体。常规材料包括与钨或钴合金化的磁钢。由稀土元素合金制成的稀土磁体产生明显更强的磁场。其中最常见的是钐钴和钕硼永磁体。它们的强度使其体积小，可用于多种应用，包括无绳工具、磁盘驱动器、耳机、玩具和汽车部件（如雨刷、风扇、洗衣机和车窗）的电机。软磁体可以相对容易地磁化和退磁。当受到交变磁场时，由于磁滞引起的能量损失很小。常见材料包括铁硅合金（称为电工钢）、镍铁合金（坡莫合金）、软铁氧体和非晶纳米晶合金，最后一种可以通过熔钉以胶带的形式生产。软磁铁用于增强电流产生的磁通量。 |
| 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。 |
| Uniform strain | 均匀应变 |
The strain occurring prior to the beginning of localization of strain (necking); the strain to maximum load in the tension test. 在应变局部化（颈缩）开始之前发生的应变；拉伸试验中最大载荷的应变。 |
| Total combustion air (Unit kg/s) | 总燃烧空气（单位：kg/s） |
1. The combination of the stoichiometric flow of air required for combustion together with any excess air. 2. The flow of fresh air into a boiler plus any flue gas recirculated. 1.燃烧所需的化学计量空气流与任何过量空气的组合。2.进入锅炉的新鲜空气流加上再循环的任何烟气。 |
| Bearing test | 轴承测试 |
A method of determining the response to stress (load) of metal products that are subjected to riveting, bolting, or a similar fastening procedure. The purpose of the test is to determine the bearing strength of the material and to measure the bearing stress versus the deformation of the hole created by a pin or rod of circular cross section that pierces the sheet perpendicular to the surface. 一种确定经受铆接、螺栓连接或类似紧固程序的金属产品对应力（载荷）的响应的方法。测试的目的是确定材料的承载强度，并测量承载应力与由垂直于表面刺穿板材的圆形横截面的销或杆产生的孔的变形。 |
| Gibbs–Dalton law | 吉布斯-道尔顿定律 |
An extension of Dalton’s law of additive pressures to include the statement that the internal energy, enthalpy, and entropy of a mixture of gases are equal to the sum of the internal energies, enthalpies, and entropies the individual constituents would have if each existed alone at the same temperature and volume. Gibbs rule is that part of the law pertaining to entropy. 道尔顿附加压力定律的扩展，包括以下陈述：气体混合物的内能、焓和熵等于各个成分单独存在时的内能、焓和熵之和。相同的温度和体积。吉布斯定律是与熵有关的定律的一部分。 |
| Forging cracks | 锻造裂纹 |
This may occur during fastener manufacturing at the cutting or forging operations and are located on the top of the head or on the raised periphery of indented head bolts. 这可能发生在紧固件制造过程中的切削或锻造操作中，并且位于头部的顶部或带锯齿的头部螺栓的凸起周边上。 |
| Impact extrusion | 冲击挤压 |
The extrusion of separate components of soft metals whose properties permit the action to be performed quickly. 挤压单独的软金属组件，其特性允许快速执行操作。 |
| Rotary blower | 旋转鼓风机 |
(rotary compressor) A positive-displacement gas compressor which may be of the blade type, helical-screw type, meshing-lobe type (the Roots blower), or sliding-vane type. （旋转式压缩机）一种容积式气体压缩机，可以是叶片式、螺旋式、啮合凸角式（罗茨鼓风机）或滑动叶片式。 |
| Thermomechanical working | 热机械加工 |
A general term covering a variety of processes combining controlled thermal and deformation treatments to obtain specific properties. Same as thermal-mechanical treatment. 一个通用术语，涵盖结合受控热处理和变形处理以获得特定性能的各种工艺。与热机械处理相同。 |
| Sampling | 抽样 |
The process of measuring a series of values of a time-varying quantity. 测量一系列时变量值的过程。 |
| Eccentric load | 偏心载荷 |
The external load on a fastener or groups of fasteners is said to be eccentric if the resultant of that load does not pass through the centroid of the group of fasteners (eccentric shear load ) or does not coincide with the bolt axis (eccentric tensile load ). 如果一个或多个紧固件上的外部载荷的合力未穿过紧固件组的质心（偏心剪切载荷）或与螺栓轴不重合（偏心拉伸载荷），则称该外部载荷为偏心。 |
| Fastener with waisted shank | 带腰柄的紧固件 |
Finished fastener with a shank diameter of ds < d2. 柄径ds |
| Corrosion failure | 腐蚀失效 |
1. The failure of a component or structure after corrosion has reduced the load-bearing area to an unsupportable level. 2. A situation in which a mechanism cannot function owing to corrosion products preventing free movement at joints. 1、部件或结构在腐蚀后失效，使承重面积减少到无法支撑的程度。2.由于腐蚀产物阻止关节处的自由运动，导致机构无法运行的情况。 |
| Toughening mechanisms | 增韧机理 |
Various methods of increasing the resistance to crack initiation and propagation in materials. They include transformation toughening, in which the microstructure around the crack tip alters so as to slow down or arrest cracks; deflexion of cracks; various ways of de-sharpening crack tips; fibre bridging of cracks; and fibre pull-out. 增加材料中裂纹萌生和扩展阻力的各种方法。它们包括相变增韧，其中裂纹尖端周围的微观结构发生变化，以减缓或阻止裂纹；裂纹偏转；消除裂纹尖端锐化的各种方法；纤维桥接裂纹；和纤维拉出。 |
| Valve | 阀门 |
Any of various manual or automatic devices that are able to initiate, regulate, or stop the flow of a fluid through a conduit or from a closed container. 任何一种手动或自动装置，能够启动、调节或停止通过导管或封闭容器的流体流动。 |
| Compressor | 压缩机 |
A turbomachine, of either axial or radial type, that increases the pressure of a gas or vapour. 一种增加气体或蒸汽压力的轴向或径向涡轮机。 |
| Fatigue life for p % survival | p%存活率的疲劳寿命 |
An estimate of the fatigue life that p% of the population would attain or exceed at a given stress level. The observed value of the median fatigue life estimates the fatigue life for 50% survival. Fatigue life for p% survival values, where p is any number, such as 95, 90, etc., may also be estimated from the individual fatigue life values. p%存活在给定应力水平下达到或超过的疲劳寿命估计值。中值疲劳寿命的观察值估计了50%存活率的疲劳寿命。p%存活值的疲劳寿命，其中p为任何数字，如95、90等，也可根据单个疲劳寿命值进行估算。 |
| Water-jet cutting | 水射流切割 |
Cutting of materials such as rock by means of a high-speed jet of water containing abrasive particles. 通过含有磨料颗粒的高速水射流切割岩石等材料。 |
| Clearance | 间距 |
(Unit m or μm) 1. The distance (if any) between mating components in an assembly. 2. The distance between two moving parts, or a moving part and stationary part, in a machine (e.g. the gap between a piston and a cylinder head). 3. With threads, the major clearance is the distance between the design form at the root of an internal thread and the crest of its mating external thread; the minor clearance is the corresponding dimension between the crest of an internal thread and the root of the external thread. （单位m或μm）1.装配体中配合组件之间的距离（如果有）。2.机器中两个运动部件之间的距离，或运动部件和静止部件之间的距离（例如活塞和气缸盖之间的间隙）。3.带螺纹时，主要间隙是内螺纹根部的设计形状与其配合的外螺纹牙顶之间的距离；小间隙是内螺纹牙顶和外螺纹牙根之间的对应尺寸。 |
| Blanking shear test | 落料剪力试验 |
A method used to determine the through-thickness shear strength of sheet material that involves blanking a disk out of flat strip using a simple punch-and-die method. Alson known as punching shear test. 一种用于确定板材全厚度剪切强度的方法，包括使用简单的冲模方法从扁平带材中冲裁出圆盘。也称为冲切试验。 |
| Tangent screw | 微动螺旋 |
A worm screw used to adjust measuring instruments such as sextants and vernier callipers. 用于调整六分仪和游标卡尺等测量仪器的蜗杆。 |
| Gauge | 测量 |
1. Any instrument for measuring or checking dimensions, including adjustable gauges such as a micrometer and non-adjustable gauges such as go/no-go limit gauges that indicate the maximum and minimum dimensions allowable in a component during manufacture. 2. A term often used to mean an instrument, e.g. pressure gauge. 3. The diameter of a wire or thickness of a sheet according to a standard. 4. The distance between the rails of a railway track. 1. 任何用于测量或检查尺寸的仪器，包括可调节量规（例如千分尺）和不可调节量规（例如指示制造过程中组件允许的最大和最小尺寸的通过/不通过限制量规）。2. 常用于表示仪器的术语，例如压力表。3.根据标准的线材直径或片材厚度。4.铁路轨道的钢轨之间的距离。 |
| Hydrogen damage | 氢损伤 |
A general term for the embrittlement, cracking, blistering, and hydride formation that can occur when hydrogen is present in some metals. 当氢存在于某些金属中时可能发生的脆化、开裂、起泡和氢化物形成的总称。 |
| Bolt gage | 螺栓量规 |
An ultrasonic instrument used to measure the stress or strain in bolts. 用于测量螺栓应力或应变的超声波仪器。 |
| Sigma-phase embrittlement | σ相脆化 |
Embrittlement of iron-chromium alloys (most notably austenitic stainless steels) caused by precipitation at grain boundaries of the hard, brittle intermetallic sigma phase during long periods of exposure to temperatures between approximately 565 and 980 °C (1050 and 1800 °F). Sigmaphase embrittlement results in severe loss in toughness and ductility and can make the embrittled material structure susceptible to intergranular corrosion. 铁铬合金（最显著的是奥氏体不锈钢）的脆化是由于在长时间暴露于约565至980°C（1050至1800°F）的温度下，硬脆金属间化合物σ相的晶界处沉淀造成的。σ相脆化导致韧性和延展性的严重损失，可使脆化的材料结构易于发生晶间腐蚀。 |
| Nominal diameter | 公称直径 |
The ‘‘catalog diameter’’ of a fastener. Usually roughly equal to the diameter of the body, or the outer diameter of the threads. 紧固件的“目录直径”。通常大致等于主体的直径或螺纹的外径。 |
| Plug gauge | 塞规 |
A steel gauge used to determine the dimension or dimensions of a hole. It may be straight or tapered, and is typically circular, but in principle can have any cross section. 用于确定孔的尺寸的钢制量规。它可以是直的或锥形的，通常是圆形的，原则上可以有任何横截面。 |
| Span (Unit m) | 跨度（单位：m） |
A dimension measured between the extremities of a body or structure, such as between the tips of a wing or the supports of a bridge. 在身体或结构的末端之间测量的尺寸，如机翼尖端或桥梁支架之间。 |
| Initial stress | 初始应力 |
The stress produced by strain in a specimen immediately on achieving the given constant-strain conditions in a stress-relaxation test before stress-relaxation occurs. Sometimes referred to as instantaneous stress. 在应力松弛发生之前，在应力松弛试验中达到给定的恒定应变条件时，试样立即应变所产生的应力。有时称为瞬时压力。 |
| Grain coarsening | 晶粒粗化 |
A heat treatment that produces excessively large austenitic grains. 产生过大奥氏体晶粒的热处理。 |
| Widmanstätten structure | 魏氏组织 |
A structure characterized by a geometrical pattern resulting from the formation of a new phase along certain crystallographic planes of the parent solid solution. The orientation of the lattice in the new phase is related crystallographically to the orientation of the lattice in the parent phase. The structure is readily produced in many alloys by appropriate heat treatment. 一种结构，其特征是沿母体固溶体的某些晶体学平面形成新相而形成的几何图案。新相中晶格的取向在晶体学上与母相中晶格的定向相关。通过适当的热处理，在许多合金中容易产生这种结构。 |
| Pitch angle (Unit °) | 俯仰角（单位°） |
For a bevel gear, the angle between the axis and the pitch-cone generator. 对于锥齿轮，轴与节锥生成器之间的角度。 |
| Grub screw | 平头螺丝 |
A short headless screw with a recess at one end to receive a screw driver or key. 一种短的无头螺钉，一端有一个凹槽，用于安装螺丝刀或钥匙。 |
| Transgranular fracture | 穿晶断裂 |
Fracture in crystalline materials where the path of cracking is predominantly across grains. 晶体材料中的断裂，其中裂纹路径主要跨越晶粒。 |
| Centrifugal clutch | 离心离合器 |
A clutch that engages and disengages at a defined speed of rotation of the driving shaft, as when expanding friction shoes act against the inside of a drum. 一种离合器，以驱动轴规定的旋转速度接合和分离，如当膨胀的摩擦片作用在滚筒内部时。 |
| Valve spring | 气门弹簧 |
The spring that restores a valve to its closed position after having been opened, and is also intended to prevent valve bounce. 在阀门打开后将其恢复到关闭位置的弹簧，也用于防止阀门反弹。 |
| 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。 |
| Starting torque (Unit N.m) | 起动扭矩（单位：N.m） |
The torque developed by a motor at zero rotational speed in order to initiate rotation of the applied load. 电机在零转速下产生的扭矩，以启动所施加负载的旋转。 |
| Dimensional stability | 尺寸稳定性 |
Ability of a plastic part to retain the precise shape in which it was molded, fabricated, or cast. 塑料零件保持其成型、制造或铸造时的精确形状的能力。 |
| Compressive stress | 压缩应力 |
A stress that causes an elastic body to deform (shorten) in the direction of the applied load. Contrast with tensile stress. 使弹性体沿施加载荷方向变形（缩短）的应力。与拉应力对比。 |
| Fin | 翼 |
A thin projecting rib. 一根细长的凸肋。 |
| PSI (pounds per square inch) | PSI（磅/平方英寸） |
Pressure measurement. Psia (pounds per square inch absolute) measures actual pressure with no allowance for atmospheric pressure. Psig (pounds per square inch gauge) measures pressure with the gauge set to zero (0) at atmospheric pressure (14.7 psia). In other words psig = psia – 14.7. 压力测量。Psia（绝对磅/平方英寸）测量实际压力，不考虑大气压力。Psig（磅/平方英寸表压）在大气压（14.7 psia）下，将表压设置为零（0）时测量压力。换句话说，psig=psia–14.7。 |
| Cohesive strength | 内聚强度 |
(Unit Pa) A theoretical fracture strength for solids based on interatomic forces, approximately equal to E/10 where E is Young’s modulus. （单位Pa）基于原子间力的固体理论断裂强度，大约等于E/10，其中E是杨氏模量。 |
| Mean value | 平均值 |
The average value of a number of data points. Computed by dividing the sum of all data by the number of data points. 多个数据点的平均值。通过将所有数据的总和除以数据点的数量来计算。 |
| Scratching | 刮擦 |
In tribology, the mechanical removal or displacement, or both, of material from a surface by the action of abrasive particles or protuberances sliding across the surfaces. 在摩擦学中，通过在表面上滑动的磨粒或突起的作用，材料从表面上的机械移除或移位，或两者兼而有之。 |
| Right hand thread | 右旋螺纹 |
A screw thread which advances into the mating part when turned clockwise or to the right. 顺时针或向右转动时进入配合部件的螺纹。 |
| Coefficient of restitution (e) | 回弹系数（e） |
The ratio of the relative velocity of two colliding bodies after collision to that before. In perfectly elastic collisions e = 1; when all the impact energy is dissipated, e = 0. 两个碰撞体在碰撞后与碰撞前的相对速度之比。在完全弹性碰撞中e=1；当所有的冲击能量都消散时，e=0。 |
| Grinding | 研磨 |
1. A process of high-speed multiple scratching of surfaces by a wheel formed from hard grits and a binder which are progressively exposed as the binder wears away. It is a process of micromachining employed particularly in accurate finishing operations on hard materials. 2. A form of comminution. 1.一种通过由硬砂砾和粘合剂形成的轮对表面进行高速多次刮擦的方法，所述硬砂砾和粘结剂随着粘合剂的磨损而逐渐暴露。这是一种微机械加工工艺，特别适用于硬材料的精确精加工操作。2.一种粉碎形式。 |
| Critical load (Unit N) | 临界负荷（单位N） |
1. The applied load that causes propagation of an existing crack of known length, and hence fracture of a component or structure. 2. The applied load that results in buckling of a column of given end fixity. 1.导致已知长度的现有裂纹扩展并因此导致部件或结构断裂的施加荷载。2.导致具有给定端部固定性的柱屈曲的施加荷载。 |
| 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。 |
| Microstrain | 微应变 |
The strain over a gage length comparable to interatomic distances. These are the strains being averaged by the macrostrain measurement. Microstrain is not measurable by currently existing techniques. Variance of the microstrain distribution can, however, be measured by x-ray diffraction. 与原子间距离相当的标距上的应变。这些是通过宏观应变测量得到的平均应变。现有技术无法测量微应变。然而微应变分布的变化可以通过x射线衍射来测量。 |
| 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）。 |
| 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”。 |
| Pressure regulator | 压力调节器 |
(pressure-regulating valve) A device installed in a pneumatic or gas system to maintain the downstream pressure at the required level. （压力调节阀）安装在气动或气体系统中以将下游压力保持在所需水平的装置。 |
| 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。 |
| Acicular ferrite | 针状铁素体 |
A highly substructured non-equiaxed ferrite that forms upon continuous cooling by a mixed diffusion and shear mode of transformation that begins at a temperature slightly higher than the temperature transformation range for upper bainite. It is distinguished from bainite in that it has a limited amount of carbon available; thus, there is only a small amount of carbide present. Ferrite crystallite growing, apparently, as in the course of bainitic transformation. It has a lath-like shape and an increased dislocation 一种高度亚结构的非等轴铁素体，在连续冷却时通过混合扩散和剪切相变模式形成，其开始温度略高于上贝氏体的温度转变范围。它与贝氏体的区别在于它的碳含量有限。因此，仅存在少量碳化物。显然，铁素体微晶在贝氏体转变过程中生长。它具有板条状的形状和增加的位错。 |
| Plastic deformation | 塑性变形 |
The permanent (inelastic) distortion of a material under applied stress that strains the material beyond its elastic limit. 材料在施加应力下的永久（非弹性）变形，使材料应变超过其弹性极限。 |
| Pressure snubber | 压力缓冲器 |
(pressure-pulse snubber) A device used for filtering, dampening, and the protection of transducers, pressure gauges, and switches, from pressure surges, pressure spikes, and water hammer. A typical design uses a fixed mesh or porous metal disc installed in an inline body. In a piston-type pressure-gauge snubber, a piston is forced against an orifice leading to the gauge. （压力脉冲缓冲器）一种用于过滤、阻尼和保护传感器、压力表和开关免受压力浪涌、压力尖峰和水锤影响的装置。典型的设计使用安装在内联阀体中的固定网格或多孔金属盘。在活塞式压力表缓冲器中，活塞被压靠在通向压力表的孔口上。 |
| 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。 |
| Total-loss lubrication | 全损耗润滑 |
A system in which the lubricating oil for an internal-combustion engine is burned together with the fuel. 内燃机润滑油与燃料一起燃烧的系统。 |
| Rotational joint (revolute joint) | 旋转关节 |
In robotics, a single degree-of-freedom joint where the controlled variable is the joint angle. 在机器人技术中，一种单自由度关节，其中受控变量为关节角度。 |
| Liquid carburizing | 液体渗碳 |
Surface hardening of steel by immersion into a molten bath consisting of cyanides and other salts. 通过浸入由氰化物和其他盐组成的熔池中对钢进行表面硬化。 |
| Adhesive wear | 粘着磨损 |
Wear that develops when two surfaces slide across one another under pressure. The removal or displacement of material from a surface by the welding together and subsequent shearing of minute areas of two surfaces that slide across each other under pressure. In advanced stages, may lead to galling. Contrast with abrasive wear. 当两个表面在压力下相互滑动时产生的磨损。通过焊接在一起并随后剪切在压力下相互滑动的两个表面的微小区域，从表面去除或置换材料。在晚期，可能会导致擦伤。与磨料磨损形成对比。 |
| Intergranular cracking | 沿晶断裂 |
Cracking or fracturing that occurs between the grains or crystals in a polycrystalline aggregate. Also called intercrystalline cracking. 多晶聚集体中的晶粒或晶体之间发生的开裂或断裂。也称为晶间断裂。 |
| Acceleration-error constant | 加速度误差常数 |
When the reference (demand) input to a control system is parabolic, the output signal will also be parabolic in steady state. The signal that is constant in this situation is the acceleration and thus for a parabolic input the steady-state error, referred to as the acceleration-error constant, is the error in the acceleration. 当控制系统的参考（需求）输入是抛物线时，输出信号在稳定状态下也将是抛物线。在这种情况下恒定的信号是加速度，因此对于抛物线输入，称为加速度误差常数的稳态误差是加速度中的误差。 |
| Steady pin | 定位销 |
A dowel, key, or pin that prevents a pulley from turning on its shaft. 防止滑轮在其轴上转动的销钉、键或销。 |
| Turbo generator | 涡轮发电机 |
(turboset) The combination of a steam or gas turbine and an electrical generator with a single shaft or connected coaxial shafts. （汽轮发电机组）蒸汽或燃气轮机与发电机的组合，具有单轴或连接的同轴。 |
| Screw compressor | 螺杆压缩机 |
A positive-displacement rotary compressor in which gas is progressively compressed by two intermeshing, counter-rotating, helical screws. 一种容积式旋转压缩机，其中气体由两个相互啮合、反向旋转的螺旋螺杆逐渐压缩。 |
| Critical cooling rate | 临界冷却速度 |
The rate of continuous cooling required to prevent undesirable transformation. For steel, it is the minimum rate at which austenite must be continuously cooled to suppress transformations above the Ms temperature. 防止不期望的转变所需的连续冷却速率。对于钢，它是奥氏体必须持续冷却以抑制Ms温度以上的转变的最小速率。 |
| Fastener quality | 紧固件质量 |
A fastener’s adherence to its specification for dimensional tolerances, mechanical properties, and other requirements stated under applicable standards. 紧固件对尺寸公差、机械性能和适用标准规定的其他要求的规范的遵守情况。 |
| Atomization | 雾化 |
The production of a spray of fine droplets from a liquid, such as diesel oil or petrol, by injection through a nozzle (an atomizer). 通过喷嘴（雾化器）喷射从液体（例如柴油或汽油）中产生细小液滴喷雾。 |
| Annealing | 退火 |
A generic term denoting a treatment, consisting of heating to and holding at a suitable temperature followed by cooling at a suitable rate, used primarily to soften metallic materials, but also to simultaneously produce desired changes in other properties or in microstructure. 一个通用术语，表示一种处理，包括加热并保持在合适的温度，然后以合适的速率冷却，主要用于软化金属材料，但也同时产生其他性能或微观结构的所需变化。 |
| Biodiesel | 生物柴油 |
A substitute for diesel fuel derived from the oily seeds of sunflowers, oilseed rape, soya beans, etc. 从向日葵、油菜、大豆等的油性种子中提取的柴油的替代品。 |
| Form of thread | 螺纹形式 |
The profile of a thread in an axial plane for a length of one pitch. 一个螺距长度的螺纹在轴向平面中的轮廓。 |
| Wallner lines | Wallner线 |
A distinct pattern of intersecting sets of parallel lines, usually producing a set of V-shaped lines, sometimes observed when viewing brittle fracture surfaces at high magnification in an electron microscope. Wallner lines are attributed to interaction between a shock wave and a brittle crack front propagating at high velocity. Sometimes Wallner lines are misinterpreted as fatigue striations. 一组相交的平行线的独特图案，通常产生一组V形线，有时在电子显微镜下高倍观察脆性断裂表面时观察到。Wallner线归因于高速传播的冲击波和脆性裂纹前沿之间的相互作用。有时Wallner线被误解为疲劳条纹。 |
| 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。 |
| 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。 |
| Cooling coil | 冷却盘管 |
A simple heat exchanger consisting of a coiled tube, typically of copper or stainless steel, through which is circulated a coolant such as a refrigerant, chilled water, or water mixed with ethylene glycol. Applications include air conditioning, process cooling, and refrigeration. 一种简单的热交换器，由通常由铜或不锈钢制成的盘管组成，冷却剂如制冷剂、冷冻水或与乙二醇混合的水通过盘管循环。应用包括空调、工艺冷却和制冷。 |
| 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。 |
| Meyer hardness (Unit Pa) | 迈耶硬度（单位Pa） |
A material hardness similar to the Brinell hardness but based upon the projected area of the impression rather than the surface area. 与布氏硬度相似的材料硬度，但基于印模的投影面积而不是表面面积。 |
| Thermodynamic process | 热力学过程 |
A change in equilibrium state undergone by a quantity of matter or a system. 一定量的物质或系统所经历的平衡状态的变化。 |
| Yield point (Unit Pa) | 屈服点（单位Pa） |
The first stress in a material, usually less than the maximum attainable stress, at which an increase in strain occurs without an increase in stress. Only certain metals—those which exhibit a localized, heterogeneous type of transition from elastic to plastic deformation—produce a yield point. If there is a decrease in stress after yielding, a distinction may be made between upper and lower yield points. The load at which a sudden drop in the flow curve occurs is called the upper yield point. The constant load shown on the flow curve is the lower yield point. (yield strength, yield stress, Rel, Rel) The stress at which the onset of permanent (plastic) deformation (yielding) occurs in a body under increasing loading. In some materials, a yield-point phenomenon occurs in which stress falls on initial yielding and plastic deformation continues without increase in stress as strain increases further. The yield criterion is the combination of normal and shear stresses which produces yielding under multiaxial loading. 材料中的第一应力，通常小于可达到的最大应力，在该应力下应变增加而应力不增加。只有某些金属——表现出从弹性变形到塑性变形的局部、非均匀类型的金属——才会产生屈服点。如果屈服后应力降低，可区分上屈服点和下屈服点。流量曲线突然下降时的荷载称为上屈服点。流量曲线上显示的恒定载荷为较低屈服点。（屈服强度，屈服应力，Rel）在不断增加的载荷下，物体发生永久（塑性）变形（屈服）时的应力。在某些材料中，会出现屈服点现象，即应力在初始屈服时下降，随着应变进一步增加，塑性变形继续，而应力没有增加。屈服准则是在多轴载荷下产生屈服的正应力和剪应力的组合。 |
| 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。 |
| Pressure rating (Unit Pa or bar) | 额定压力（单位Pa或bar） |
The internal pressure at which a pressure vessel, boiler, tank, piping, etc. is designed to operate safely. 压力容器、锅炉、储罐、管道等设计用于安全运行的内部压力。 |
| Condenser vacuum | 冷凝器真空 |
The sub-atmospheric pressure imposed on the condenser of a steam-power plant which leads to an appreciable increase in overall efficiency. 施加在蒸汽发电厂冷凝器上的低于大气压的压力导致整体效率显着提高。 |
| Fracture stress | 断裂应力 |
The true normal stress on the minimum cross-sectional area at the beginning of fracture. This term usually applies to tension tests of unnotched specimens. 断裂开始时最小横截面积上的真实正应力。该术语通常适用于无缺口试样的拉伸试验。 |
| Poisson’s ratio (ν) | 泊松比（ν） |
The absolute value of the ratio of transverse (lateral) strain to the corresponding axial strain resulting from uniformly distributed axial stress below the proportional limit of the material. 横向（侧向）应变与相应轴向应变之比的绝对值，该比值由低于材料比例极限的均匀分布的轴向应力产生。 |
| Toughness (Unit J/m²) | 韧性（单位：J/m²） |
The ability of a metal to absorb energy and deform plastically before fracturing. 1. The ability of a material to resist crack initiation and propagation. 2. The ability of a material to absorb strain energy without fracturing. 金属在破裂前吸收能量和塑性变形的能力。1.材料抵抗裂纹萌生和扩展的能力。2.材料在不发生断裂的情况下吸收应变能的能力。 |
| Flattening test | 压扁试验 |
This term as applied to tubing refers to a method of testing a section of tubing by flattening it until the inside walls are parallel and separated by a given distanceusually equal to three times the wall thickness for seamless tubes and five times the wall thickness for lap-welded tubes. Boiler tubes subjected to this test should show no cracks or flaws. The flattening test applied to rivets, consists in flattening a rivet head while hot to a diameter equal to 21⁄2 times the diameter of the shank or body of the rivet. Good rivet steel must not crack at the edges of the flattened head. 该术语适用于管材，是指通过压扁管材直至内壁平行并隔开给定距离（通常等于无缝钢管壁厚的三倍，搭接焊管壁厚的五倍）来测试管材截面的方法。进行该试验的锅炉管应无裂纹或缺陷。适用于铆钉的压扁试验包括在热态下压扁铆钉头，使其直径等于铆钉柄或铆钉体直径的21⁄2倍。良好的铆钉钢不得在扁平头部边缘开裂。 |
| Radial engine | 径向发动机 |
A piston engine in which the cylinders are arranged radially around the crankshaft, a design commonly used in early aircraft engines. 气缸沿径向围绕曲轴布置的活塞式发动机，这种设计通常用于早期飞机发动机。 |
| 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。 |
| 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。 |
| Principal stress (normal) | 主应力（正常） |
The maximum or minimum value of the normal stressat a point in a plane considered with respect to all possible orientations of the considered plane. On such principal planes the shear stress is zero. There are three principal stresses on three mutually perpendicular planes. The state of stress at a point may be: (1) uniaxial, a state of stress in which two of the three principal stresses are zero; (2) biaxial, a state of stress in which only one of the three principal stresses is zero; or (3) triaxial, a state of stress in which none of the principal stresses is zero. Multiaxial stress refers to either biaxial or triaxial stress. 相对于所考虑平面的所有可能方向，所考虑平面中某点处的法向应力的最大值或最小值。在这样的主平面上，剪切应力为零。在三个相互垂直的平面上有三个主应力。一点的应力状态可以是：（1）单轴，三个主应力中的两个为零的应力；（2）双轴，三个主应力中只有一个为零的应力状态；或（3）三轴，即主应力均不为零的应力状态。多轴应力是指双轴或三轴应力。 |
| Absolute humidity | 绝对湿度 |
The weight of water vapor in a gadwater vapor mixture per unit volume of space occupied, expressed, for example, in grains or pounds per cubic foot. 单位体积空间占用的水蒸气混合物中水蒸气的重量，例如，以谷物或磅/立方英尺表示。 |
| AISC | AISC |
The American Institute of Steel Construction. 美国钢结构学会。 |
| Stability | 稳定性 |
1. A term relating to whether a body, structure, system, or flow is in a state of stable, unstable, or neutral equilibrium. 2. In numerical analysis, whether numerical errors, such as roundoff or input-data errors, are damped, propagate, or cause divergence of the solution as the numerical method proceeds. 3. A control system is often described as stable when a step change in input results in a steady output without continuing oscillation. 1.与物体、结构、系统或流是否处于稳定、不稳定或中性平衡状态有关的术语。2.在数值分析中，随着数值方法的进行，数值误差（如舍入误差或输入数据误差）是否衰减、传播或导致解发散。3.当输入的阶跃变化导致稳定输出而无持续振荡时，控制系统通常被描述为稳定的。 |
| Extensometer | 引伸计 |
An instrument for measuring changes in length over a given gage length caused by application or removal of a force. Commonly used in tension testing of metal specimens. Any instrument which measures the change in length of a part as the part is loaded. 一种用于测量在给定标距上由施加或移除力引起的长度变化，在零件加载时测量零件长度变化的仪器。常用于金属试样的拉力试验。 |
| Stress area | 应力面积 |
The effective cross-sectional area of the threaded section of a fastener. Used to compute average stress levels in that section. Based on the mean of pitch and minor diameters. 紧固件螺纹部分的有效横截面积。用于计算该截面中的平均应力水平。基于节距和小直径的平均值。 |
| Crack arrest | 止裂 |
Crack propagation that stops of its own accord when the energy release rate of the loaded component or structure falls below a critical value. If predictable, it can be incorporated into structural-integrity assessments. 当加载部件或结构的能量释放率低于临界值时，裂纹自行停止扩展。如果可以预测，可以将其纳入结构完整性评估。 |
| Wedge | 楔子 |
A short triangular prism whose major surfaces subtend an acute angle, that can be driven between two objects or parts of an object to split, tighten, or secure them, or to widen an opening or raise a heavy object. The acute angle gives a high mechanical advantage. 一种短的三棱镜，其主面对着一个锐角，可在两个物体或物体的一部分之间驱动，以将它们分开、拧紧或固定，或加宽开口或举起重物。锐角具有很高的机械优势。 |
| Materials selection | 材料选择 |
The process of selecting the most suitable material for a particular application. In the case of solid materials, it involves assessment of candidate materials in terms of their physical properties (density, elastic moduli, fracture toughness, yield strength, hardness, fatigue resistance, coefficient of thermal expansion, thermal conductivity, resistance to thermal shock, creep resistance, corrosion resistance, radiation resistance, etc), and such factors as the function of the final product, its shape, method of manufacture, required tolerances, number to be made, ease of inspection and quality control, cost, and design methodology employed. 为特定应用选择最合适材料的过程。对于固体材料，它涉及根据其物理特性（密度、弹性模量、断裂韧性、屈服强度、硬度、抗疲劳性、热膨胀系数、导热系数、抗热冲击性、抗蠕变性、耐腐蚀性、抗辐射性等）评估候选材料，以及诸如最终产品的功能、其形状、制造方法、所需公差、制造数量、检查和质量控制的容易程度、成本和采用的设计方法等因素。 |
| Plug | 螺塞 |
1. An object, usually tapered, used to block a hole to prevent fluid from escaping or flowing. 2. The central moveable part of a valve. 3. In the flow of a yield-stress fluid through a pipe or duct, the central region is often assumed to take the form of a plug with uniform axial velocity. 4. In thermoforming, a shaping tool that forces a heated plastic sheet into a female mould. 1.一种物体，通常为锥形，用于堵塞孔以防止流体逸出或流动。2.阀门的中心可移动部分。3.在屈服应力流体通过管道或管道的流动中，中心区域通常假定为具有均匀轴向速度的塞子形式。4.在热成型技术中，一种成型工具，将加热的塑料板压入阴模中。 |
| 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。 |
| 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。 |
| Fahrenheit | 华氏度 |
The temperature scale based on the freezing point of water (32ºF) and the boiling point of water (212ºF). The interval between these points is divided into 180 equal parts. Although replaced by the Celsius scale, the Fahrenheit scale is still sometimes used for non-scientific measurements. 温标基于水的冰点（32ºF）和水的沸点（212ºF）。这些点之间的间隔被分成180等份。尽管被摄氏刻度所取代，华氏刻度有时仍用于非科学测量。 |
| Eyebolt (eyescrew) | 吊环螺栓（眼螺丝） |
A bolt threaded at one end and bent to a loop at the other end. A bolt or screw with a closed loop in place of a head. 一端有螺纹，另一端弯曲成环的螺栓。带有闭合环代替头部的螺栓或螺钉。 |
| Constant life diagram | 恒定寿命图 |
A plot of experimentally derived fatigue-life data; perhaps the most complex and complete of the popular charts used to represent such data. 实验得出的疲劳寿命数据图；可能是用于表示此类数据的最复杂和最完整的流行图表。 |
| Least count | 最小计数 |
The smallest value that can be read from an instrument having a graduated scale. Except on instruments provided with a vernier, the least count is that fraction of the smallest division which can be conveniently and reliably estimated; this fraction is ordinarily one-fifth or one-tenth, except where the graduations are very closely spaced. 可从具有刻度尺的仪器中读取的最小值。除配备游标的仪器外，最小计数是可以方便可靠地估计的最小除法的分数；这个分数通常是五分之一或十分之一，除非刻度间隔非常近。 |
| Relaxation rate | 松弛率 |
The absolute value of the slope of a stress-relaxation curve at a given time. 给定时间应力松弛曲线斜率的绝对值。 |
| Slot | 狭槽 |
A groove machined into a component, e.g. to allow for thermal expansion, or in which the tongue or tip of another component can fit or slide. 在部件上加工的凹槽，例如，允许热膨胀，或另一部件的榫舌或尖端可在其中安装或滑动。 |
| Differential heating | 差动加热 |
Heating that intentionally produces a temperature gradient within an object such that, after cooling, a desired stress distribution or variation in properties is present within the object. 加热有意在物体内产生温度梯度，从而在冷却后，在物体内出现所需的应力分布或特性变化。 |
| Continuous-type furnace | 连续式炉 |
A furnace used for heat treating materials that progress continuously through the furnace, entering one door and being discharged from another. See belt furnac, direct-fired tunnel-type furnac, rotary retort furnace, shaker-hearth furnace. 一种用于热处理材料的炉子，该炉子连续通过炉子，进入一个门并从另一个门排出。参见带式高炉、直燃隧道式高炉、旋转罐式炉、振动炉。 |
| Stress | 应力（单位Pa） |
The intensity of the internally distributed forces or components of forces that resist a change in the volume or shape of a material that is or has been subjected to external forces. Stress is expressed in force per unit area and is calculated on the basis of the original dimensions of the cross section of the specimen. Stress can be either direct (tension or compression)or shear. 1. Stress ‘at a point’ (i.e. over a volume of material that is very small compared with that of the component or structure) is the load per unit area for every face of an infinitesimal cube surrounding the point. 2. In fluid flow the stress tensor σij is the sum of an isotropic part −pδij, δij being the Kronecker delta, having the same form as the stress tensor for a fluid at rest, p being the static pressure, and the non-isotropic, deviatoric stress tensor dij which is due entirely to the fluid motion. 内部分布力或力分量的强度，这些力或力的分量抵抗正在或已经受到外力的材料的体积或形状的变化。应力以单位面积的力表示，并根据试样横截面的原始尺寸计算。应力可以是直接（拉伸或压缩）或剪切。1.“在一点”的应力（即在与组件或结构相比非常小的材料体积上）是围绕该点的无限小立方体的每个面的单位面积载荷。2. 在流体流动中，应力张量σij是各向同性部分-pδij的总和，δij是Kroneckerδ，具有与静止流体的应力张量相同的形式，p是静压，非各向同性, 偏应力张量 dij 完全由流体运动引起。 |
| Dynamic compressor | 动态压缩器 |
A machine, such as a centrifugal or axial compressor, that compresses a gas by rotational rather than reciprocating motion. 一种机器，例如离心式或轴流式压缩机，通过旋转而不是往复运动来压缩气体。 |
| Actuating system | 驱动系统 |
A system in which an electrical, pneumatic or hydraulic input supplied to an actuator produces force, torque, or displacement, usually in a controlled way. 一种系统，其中提供给执行器的电气、气动或液压输入通常以受控方式产生力、扭矩或位移。 |
| 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。 |
| 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。 |
| Hydrodynamics | 流体力学 |
A term sometimes used to mean fluid dynamics, even when the fluid is a gas or a liquid other than water. 有时用于表示流体动力学的术语，即使流体是气体或水以外的液体。 |
| Compression member | 压缩构件 |
A structural component, the major loading on which is compressive. 一种结构部件，其上的主要载荷是压缩的。 |
| Spray quenching | 喷雾淬火 |
A quenching process using spray nozzles to spray water or other liquids on a part. The quench rate is controlled by the velocity and volume of liquid per unit area per unit of time of impingement. 使用喷嘴将水或其他液体喷射到零件上的淬火过程。淬火速率由每单位撞击时间内每单位面积的液体速度和体积控制。 |
| Granular fracture | 粒状断裂 |
A type of irregular surface produced when metal is broken that is characterized by a rough, grainlike appearance, rather than a smooth or fibrous one. It can be subclassified as transgranular or intergranular. 金属破碎时产生的一种不规则表面，其特征是粗糙的颗粒状外观，而不是光滑或纤维状的外观。它可以细分为穿晶或晶间。 |
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