| 词或词组 | 中文 | 英文解释中文解释 |
|---|---|---|
| Wind velocity (Unit m/s) | 风速（单位：m/s） |
1. In the Earth’s atmosphere, a vector quantity that quantifies both the magnitude of the wind speed and its direction at a given altitude and location, conveniently represented in the hodograph plane. For convenience, the unit kph is often used. It could in principle also include information about large- and small-scale unsteadiness. Spatial variation in wind velocity, either with altitude or in a horizontal plane, is termed wind shear. 2. The airspeed in the working section of a wind tunnel. 1.在地球大气层中，一种矢量量，用于量化给定高度和位置处的风速大小及其方向，方便地用速度计平面表示。为方便起见，通常使用单位kph。原则上，它还可以包括关于大尺度和小尺度不稳定性的信息。风速随高度或水平面的空间变化称为风切变。2.风洞工作段的空速。 |
| Preheating | 预热 |
Heating before some further thermal or mechanical treatment. For tool steel, heating to an intermediate temperature immediately before final austenitizing. For some nonferrous alloys, heating to a high temperature for a long time, to homogenize the structure before working. In welding and related processes, heating to an intermediate temperature for a short time immediately before welding, brazing, soldering, cutting, or thermal spraying. 在进一步热处理或机械处理之前加热。对于工具钢，在最终奥氏体化之前立即加热至中间温度。对于一些非铁合金，在工作前长时间加热到高温，以使结构均匀化。在焊接和相关工艺中，在焊接、钎焊、钎焊、切割或热喷涂之前，立即加热到中间温度。 |
| Radiosity (J) (Unit W/m²) | 辐射度（J）（单位W/m²） |
The total radiation leaving a given surface per unit area, including emitted, reflected, and transmitted radiation. 每单位面积离开给定表面的总辐射，包括发射、反射和透射辐射。 |
| Breaking load (Unit N) | 断裂负荷（单位N） |
The load applied at some point to a component or structure which leads to fracture. The breaking stress (breaking strength) is the average stress at which a member breaks, given by the breaking load divided by the area over which it acts. 在某个点施加到导致断裂的部件或结构的载荷。断裂应力（断裂强度）是构件断裂时的平均应力，由断裂载荷除以其作用的面积给出。 |
| Bulk density (Unit kg/m³) | 容重（单位kg/m³） |
The average density of a mass of granular or powdered material at ambient conditions. 在环境条件下大量粒状或粉状材料的平均密度。 |
| Band clutch | 带式离合器 |
A friction clutch in which drive is achieved by a band contracting on to the rim of the clutch. 一种摩擦离合器，其驱动是通过一条带在离合器边缘上收缩来实现的。 |
| Effective discharge area (Unit m²) | 有效排放面积（单位m²） |
A nominal area for flow through a pressure relief valve used to determine the valve’s flow capacity given the pressure difference across it, the fluid density and correction factors to allow for compressibility, the back pressure and the coefficient of discharge. 流经泄压阀的标称面积，用于确定阀门的流量，给定压力差、流体密度和允许可压缩性的校正因子、背压和排放系数。 |
| Tab washer (lock washer) | 止动垫圈（锁紧垫圈） |
A washer with one or more protruding tabs which can be bent in such a way that a nut or bolt head is prevented from becoming loose. 一种垫圈，具有一个或多个突出凸耳，可弯曲以防止螺母或螺栓头松动。 |
| Ferritic decarburization | 铁素体脱碳 |
Decarburization with sufficient loss of carbon to cause a lighter shade of tempered martensite and a significantly lower hardness than that of the adjacent base metal, with the presence of ferrite grains or grain boundary network under metallographic examination. 脱碳，碳损失充分，导致回火马氏体颜色较浅，硬度明显低于相邻母材，金相检查时存在铁素体晶粒或晶界网络。 |
| Quench cracking | 淬火开裂 |
Fracture of a metal during quenching from elevated temperature. Most frequently observed in hardened carbon steel, alloy steel, or tool steel parts of high hardness and low toughness. Cracks often emanate from fillets, holes, corners, or other stress raisers and result from high stresses due to the volume changes accompanying transformation to martensite. 高温淬火时金属断裂。在高硬度和低韧性的硬化碳钢、合金钢或工具钢零件中最常见。裂纹通常来自圆角、孔、角部或其他应力集中区，并由伴随马氏体转变的体积变化引起的高应力引起。 |
| Rpm (N) | 转速（N） |
An abbreviation for revolutions per minute. It is a widely used non-SI unit for rotational speed. The corresponding angular velocity ω in rad/s is given by πN/30. Rps (revolutions per second) is also used, the angular velocity then being 2πN. 每分钟转数的缩写。它是一种广泛使用的转速非SI单位。相应的角速度ω，单位为rad/s，由πN/30给出。还使用Rps（每秒转数），此时角速度为2πN。 |
| Nominal stress | 名义应力 |
The stress at a point calculated on the net cross section by simple elasticity theory without taking into account the effect on the stress produced by stress raisers such as holes, grooves, fillets, etc. 通过简单弹性理论在净截面上计算的点处的应力，不考虑孔、槽、圆角等应力提升器产生的应力影响。 |
| Finished hexagon bolts | 精制六角螺栓 |
A washer faced or chamfered bearing surface with a close body tolerance. 头下有垫圈面或倒角，尺寸公差小 |
| Physical crack size (ap) | 物理裂纹尺寸（ap） |
The distance from a reference plane to the observed crack front. This distance may represent an average of several measurements along the crack front. The reference plane depends on the specimen form, and it is normally taken to be either the boundary or a plane containing either the load line or the centerline of a specimen or plate. 从基准面到观察到的裂纹前沿的距离。该距离可以表示沿裂纹前沿的若干测量的平均值。基准面取决于试样形状，通常视为边界或包含试样或板的载重线或中心线的平面。 |
| Washer | 垫圈 |
An annular disc of metal, rubber, plastic, ceramic, etc., placed between two surfaces in contact either to spread the load (for example, between a surface and a tightened nut or a bolt head), to provide a seal, or to separate or align components. 由金属、橡胶、塑料、陶瓷等制成的环形圆盘，放置在两个接触面之间，以分散载荷（例如，在一个表面和拧紧的螺母或螺栓头之间），提供密封，或分离或对齐部件。 |
| Combustible | 易燃 |
(inflammable) A term for substances that can be ignited and burned. （易燃）可点燃和燃烧的物质的术语。 |
| Hot strength (Unit Pa) | 热强度（单位Pa） |
The yield stress (or sometimes fracture stress) of a material at temperatures above about half its melting point in kelvins. 材料在高于其熔点一半（以开尔文为单位）的温度下的屈服应力（有时为断裂应力）。 |
| Vibration isolation | 隔振 |
The prevention of transmission of vibration from one component of a system to another part of the same system, such as a building or other structure. Isolation may be achieved using dampers (vibration damping) or by active feedback-control methods. Mechanical vibration is often attenuated by means of components immersed in oil such as in dashpots (viscous damping). Vibration suppression can be achieved (a) using dampers and absorbers tuned to a particular frequency to suppress vibratory forces in structures and other systems (passive suppression) or (b) by the measurement of vibration at key locations in a structure and the application of cancellation forces (active suppression). 防止振动从系统的一个部件传递到同一系统的另一部分，如建筑物或其他结构。可以使用阻尼器（减振）或主动反馈控制方法实现隔离。机械振动通常通过浸入油中的部件来衰减，例如缓冲罐（粘性阻尼）。可以通过（a）使用调谐到特定频率的阻尼器和吸收器来抑制结构和其他系统中的振动力（被动抑制），或（b）通过测量结构中关键位置的振动并施加抵消力（主动抑制），实现振动抑制。 |
| Offset yield strength | 条件屈服强度 |
The stress at which the strain exceeds by a specified amount (the offset) an extension of the initial proportional portion of the stress-strain curve. Expressed in force per unit area. 应变超过应力-应变曲线初始比例部分延伸规定量（偏移）的应力。以每单位面积的力表示。 |
| Shrink fit | 过盈配合 |
A tight interference fit between two components resulting from heating an outer part and/or cooling an inner part to allow easy assembly. The outer component contracts on cooling, while the inner part expands on warming to ambient temperature, thus gripping the two parts together. 由于加热外部部件和/或冷却内部部件而导致的两个部件之间的紧密过盈配合，以便于组装。外部部件在冷却时收缩，而内部部件在加热到环境温度时膨胀，从而将两个部件夹在一起。 |
| 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）。 |
| 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。 |
| Verified loading range | 验证加载范围 |
For testing machines, the range of indicated loads for which the testing machine gives results within the permissible variation specified. 对于试验机，试验机在规定允许偏差范围内给出结果的指示载荷范围。 |
| Octane number | 辛烷值 |
(octane rating) A measure of the anti-knock properties of a fuel taken as the percentage by volume of iso-octane in the fuel. （辛烷值）以燃料中异辛烷的体积百分比表示的燃料抗爆性能的量度。 |
| Electrolyte | 电解质 |
The liquid with which the Electrodes of a battery or Corrosion cell are wetted. 润湿电池或腐蚀电池电极的液体。 |
| 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。 |
| 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。 |
| Delamination | 分层 |
A mode of failure of composite materials, including radial-ply tyres, in which the layers separate due to repeated cyclic loading, impact, or weak bonding. 复合材料的一种失效模式，包括子午线轮胎，其中层由于重复的循环载荷、冲击或弱粘合而分离。 |
| Volume flow rate | 体积流率 |
(volumetric flow rate, , ) (Unit m³/s) The volume of a material, usually a fluid or powder, that flows across a surface or through a pipe or other duct per unit time. （体积流量）（单位m³/s）单位时间内流经表面或管道或其他管道的材料体积，通常为流体或粉末。 |
| 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。 |
| 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。 |
| 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。 |
| Volume (Unit m³) | 体积（单位m³） |
The amount of space occupied by a specified mass of substance or by an object. 一定质量的物质或物体占据的空间量。 |
| Vacuum carburizing | 真空渗碳 |
A high-temperature gas carburizing process using furnace pressures between 7 and 55 kPa during the carburizing portion of the cycle. 在循环的渗碳部分期间使用7至55kPa之间的炉压的高温气体渗碳工艺。 |
| Ball screw and nut | 滚珠丝杠和螺母 |
A nut and bolt assembly having semi-circular helical grooves, as opposed to threads, in which run ball bearings. On rotation of the nut, the balls move along the helix and carry the axial load. Balls reaching the end of the groove are recirculated back to the beginning. Such devices have low friction and very little backlash, and are used in some steering mechanisms. 一种螺母和螺栓组件，具有半圆形螺旋槽，与螺纹相反，在其中运行滚珠轴承。在螺母旋转时，滚珠沿螺旋线移动并承受轴向载荷。到达凹槽末端的滚珠被循环回起点。这种装置具有低摩擦和非常小的背隙，并且用于一些转向机构。 |
| 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。 |
| 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。 |
| Ductile fracture | 韧性断裂 |
Fracture characterized by tearing of metal accompanied by appreciable gross plastic deformation and expenditure of considerable energy. A fracture of a component or structure which is preceded by extensive ductile deformation so that the broken pieces cannot be re-fitted to regain the original size and shape of the component or structure. 以金属撕裂为特征的断裂，伴随着明显的总塑性变形和相当大的能量消耗。一种部件或结构的断裂，在断裂前会发生大范围的延性变形，从而使断裂的碎片无法重新装配以恢复部件或结构原来的尺寸和形状。 |
| Lead angle | 导角 |
The angle of the helix of a screw thread or worm thread. It is the measure of the inclination of a screw thread from a plane perpendicular to the axis of the screw. 螺纹或蜗杆螺纹的螺旋角。它是螺纹从垂直于螺钉轴线的平面的倾斜度的量度。 |
| Zero-gravity | 零重力 |
The situation in which there is no force of gravity (i.e. weightlessness). 没有重力的情况（即失重）。 |
| Elastic deformation | 弹性变形 |
A change in dimensions directly proportional to and in phase with an increase or decrease in applied force. 尺寸的变化与施加的力的增加或减少成正比并同相。 |
| Zone melting (zone refining) | 区域熔炼（区域精炼） |
A process of purification of materials in which a narrow molten zone is moved along the length of the material, resulting in impurities being segregated at one end. 一种净化材料的过程，其中一个狭窄的熔融区沿材料长度移动，导致杂质在一端分离。 |
| Profilometer | 轮廓仪 |
An instrument used to quantify the roughness of a surface. For a contact profilometer, a diamond stylus sweeps across the surface along a series of parallel lines. Noncontact profilometers use optical techniques to map the surface irregularities. 用于量化表面粗糙度的仪器。对于接触式轮廓仪，钻石触针沿一系列平行线扫过表面。非接触式轮廓仪使用光学技术绘制表面不规则。 |
| 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。 |
| 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。 |
| Anti-freeze | 防冻液 |
A substance such as ethylene glycol added to the cooling system of a watercooled engine to lower the freezing point of the cooling water and also inhibit the formation of rust and other deposits. 一种物质，如乙二醇，添加到水冷发动机的冷却系统中，以降低冷却水的冰点，并抑制生锈和其他沉积物的形成。 |
| Ductility | 延展性 |
The ability of a material to deform plastically before fracturing. Measured by elongation or reduction in area in a tensile test, by height of cupping in a cupping test, or by the radius or angle of bend in a bend test. 材料在断裂前发生塑性变形的能力。通过拉伸试验中的伸长率或面积减少量、杯突试验中的杯突高度或弯曲试验中的弯曲半径或角度来测量。 |
| 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。 |
| Drift pin | 冲头 |
A round tapered steel pin used to align rivet holes so that the rivet will pass through the holes easily. 用于对齐铆钉孔的圆形锥形钢销，以便铆钉轻松穿过孔。 |
| Wave spring | 波形弹簧 |
A type of compression spring, similar to a coil spring, but made of strip shaped into waves around the circumference. 一种压缩弹簧，类似于螺旋弹簧，但由沿圆周成波浪形的条状物制成。 |
| Viscoelasticity | 粘弹性 |
A property involving a combination of elastic and viscous behavior. A material having this property is considered to combine the features of a perfectly elastic solid and a perfect fluid. A phenomenon of time-dependent, in addition to elastic, deformation (or recovery) in response to load. 结合弹性和粘性的特性。具有这种性质的材料被认为是完美弹性固体和完美流体的结合体。除了弹性变形（或恢复）外，还随时间变化的一种现象。 |
| Austenitic stainless steels | 奥氏体不锈钢 |
Austenitic stainless steels are non-magnetic. They contain significant additions of chromium (16–30%), but have the austenite (FCC) crystal structure, stabilized by the addition of nickel in the composition range 6–20%. Carbon content ranges from about 0.03 to 0.15%. The ‘18–8’ stainless steels containing approximately 18% chromium and 8% nickel are typical of the class. Austenitic stainless steels have high strength and corrosion resistance even at elevated temperatures, good ductility, good low-temperature properties, and good weldability. Used for aircraft and transport equipment, cutlery, chemical and food-processing equipment, surgical instruments, and cryogenic vessels. 奥氏体不锈钢是非磁性的。它们含有显着添加的铬（16–30%），但具有奥氏体（FCC）晶体结构，通过在6–20%的成分范围内添加镍来稳定。碳含量范围约为0.03至0.15%。含有大约18%铬和8%镍的“18-8”不锈钢是该级别的典型不锈钢。奥氏体不锈钢即使在高温下也具有高强度和耐腐蚀性，良好的延展性，良好的低温性能和良好的焊接性。用于飞机和运输设备、餐具、化学和食品加工设备、手术器械和低温容器。 |
| Planar anisotropy | 平面异向性 |
A variation in physical and/or mechanical properties with respect to direction within the plane of material in sheet form. 在片状材料平面内，物理和/或机械性能相对于方向的变化。 |
| Rated flow (Unit m³/s or kg/s) | 额定流量（单位：m³/s或kg/s） |
In a hydraulic system or machine, the volume or mass flow rate a manufacturer specifies for a component as the maximum desirable for it to function as designed. 在液压系统或机器中，制造商为部件指定的体积或质量流量是其按设计运行所需的最大值。 |
| Tare weight (Unit N) | 皮重（单位N） |
The weight of an empty container. 空容器的重量。 |
| Volumetric efficiency | 容积效率 |
For a piston engine, the ratio of the volume of the induced charge per induction stroke, determined at a reference pressure and temperature, to the swept volume. 对于活塞式发动机，在参考压力和温度下确定的每个进气冲程的进气体积与扫掠体积之比。 |
| Permanent set | 永久变形 |
The deformation or strain remaining in a previously stressed body after release of load. 释放荷载后，先前受力物体中剩余的变形或应变。 |
| Starting valve (regulator) | 起动阀（调节器） |
A valve which admits steam from the boiler to the cylinder(s) of a steam engine. 将蒸汽从锅炉送入蒸汽机汽缸的阀门。 |
| Dynamic recovery | 动态恢复 |
A process occurring in hot working of metals in which a fine subgrain structure forms within the elongated grains due to annihilation of dislocations due to easy cross slip and climb. It results in a lowering of the flow stress. Dynamic recovery, as opposed to dynamic recrystallization that occurs in hot working, occurs in metals of high stacking fault energy such as aluminum, αiron, and most bcc metals. 金属热加工中发生的一种过程，由于易于交叉滑动和攀爬，位错湮灭，细长晶粒内形成细亚晶粒结构。这导致流动应力降低。与热加工中发生的动态再结晶相反，动态回复发生在高层错能金属中，如铝、α铁和大多数bcc金属。 |
| Alloying element | 合金元素 |
Component added deliberately with the aim of improving the properties of an alloy. Alloying elements can affect the existence range of equilibrium phases present in an unalloyed material, or lead to the occurrence of new phases, or both. In addition, alloying elements strongly affect the kinetics of phase transformations and thus the microstructure formation in alloyed materials. 为改善合金性能而有意添加的成分。合金元素可以影响非合金材料中存在的平衡相的存在范围，或导致新相的出现，或两者兼而有之。此外，合金元素强烈影响相变动力学，从而影响合金材料的微观结构形成。 |
| Hypoeutectoid alloy | 亚共析合金 |
In an alloy system exhibiting a eutectoid, any alloy whose composition has an excess of base metal compared with the eutectoid composition, and whose equilibrium microstructure contains some eutectoid structure. 在呈现共析的合金系统中，与共析成分相比，其成分具有过量母材的任何合金，并且其平衡微观结构包含一些共析结构。 |
| Turning angle (θ) | 转向角（θ） |
The change in direction experienced by a gas flow passing through an oblique shock wave or Prandtl–Meyer expansion fan. 气流通过斜激波或Prandtl–Meyer膨胀风机时所经历的方向变化。 |
| Hardness test | 硬度测试 |
1. Any of various tests in which different hard indenters are forced into the surface of a solid under different loads to give permanent impressions, the pressure to cause which being called the hardness. The Brinell test employs a spherical indenter; the Vickers test a square-based pyramid. The relation between indentation hardness H and uniaxial yield stress Y is approximately H = (2.5 ~ 3.0)Y. Originally hardnesses were given in kg/mm² but now are often given in Pa. 2. The tests for scratch and file hardness relate either to one material being able to mark another (Mohs hardness scale for minerals), or to the size of groove produced by a rigid indenter slid under load across a surface. 3. Rebound hardness concerns the height of rebound of a dropped indenter, or an indenter at the end of a pivoted arm, having struck a surface. 1.任何一种试验，其中不同的硬压头在不同载荷下压入固体表面，以产生永久压痕，所产生的压力称为硬度。布氏试验采用球形压头；维氏硬度测试是一个方形金字塔。压痕硬度H与单轴屈服应力Y之间的关系约为H=（2.5~3.0）Y。最初硬度以kg/mm²为单位，但现在通常在Pa.2中给出。划痕和锉刀硬度测试要么与一种材料能够标记另一种材料（矿物的莫氏硬度标度）有关，要么与刚性压头在表面上滑动产生的凹槽大小有关。3.回弹硬度涉及掉落压头或旋转臂端部压头撞击表面后的回弹高度。 |
| Erosion | 侵蚀 |
Progressive loss of original material from a solid surface due to mechanical interaction between that surface and a fluid, a multicomponent fluid, or impinging liquid or solid particles. 由于固体表面与流体、多组分流体或撞击液体或固体颗粒之间的机械相互作用，原始材料从固体表面逐渐损失。 |
| 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。 |
| 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）。 |
| Thread run-out | 螺纹耗尽 |
That portion of the threads which are not cut or rolled full depth, but which provide the transition between full-depth threads and the body or head. Officially called thread washout or vanish, although the term run-out is more popular. (Run-out is officially reserved for rotational eccentricity, as defined by total indicator readings or the like.) 未全深度切割或轧制的螺纹部分，但提供全深度螺纹与主体或头部之间的过渡。官方称之为螺纹冲蚀或消失，但术语“耗尽”更为流行。（跳动是官方为旋转偏心度保留的，由总指示器读数等定义。） |
| Snap temper | 快速回火 |
A precautionary interim stress-relieving treatment applied to high-hardenability steels immediately after quenching to prevent cracking because of delay in tempering them at the prescribed higher temperature. 在淬火后立即对高淬透性钢进行预防性临时应力消除处理，以防止因在规定的更高温度下回火延迟而开裂。 |
| Vickers hardness test | 维氏硬度测试 |
An indentation hardness test employing a 136° diamond pyramid indenter (Vickers) and variable loads, enabling the use of one hardness scale for all ranges of hardness—from very soft lead to tungsten carbide. Also know as diamond pyramid hardness test. 采用136°金刚石棱锥压头（维氏硬度计）和可变载荷的压痕硬度测试，能够对从极软铅到碳化钨的所有硬度范围使用一个硬度标度。也称为钻石金字塔硬度测试。 |
| Rupture stress | 断裂应力 |
The stress at failure. Also known as breaking stress. 失效时的应力。也称为破裂应力。 |
| System engineering | 系统工程 |
A methodology which integrates all disciplines and specialty groups into a team effort, forming a structured development process that proceeds from concept to production to operation. 一种将所有学科和专业组整合到团队工作中的方法，形成从概念到生产再到运营的结构化开发过程。 |
| Taper | 变尖 |
A gradual, often linear, reduction in cross section or shape. A shaft or hole that gets gradually smaller toward one end. 横截面或形状的逐渐减小，通常是线性的。一端逐渐变小的轴或孔。 |
| Avogadro constant | 阿伏伽德罗常数 |
(Avogadro number, NA) A fundamental physical constant with the fixed numerical value 6.022 140 76 × 1023 mol−1. The mole contains exactly this number of elementary entities. A minor adjustment to the value of the Avogadro constant was made effective on 20 May 2019. （阿伏伽德罗数，NA）一个固定数值为6.02214076×1023mol的基本物理常数−摩尔正好包含这个数量的基本实体。对阿伏伽德罗常数值的微小调整于2019年5月20日生效。 |
| Crest clearance (Unit m) | 顶隙（单位米） |
For screw threads and gearing, the radial clearance between the crest of a thread (or gear) and the root of the engaging thread (or gear). 对于螺纹和齿轮，螺纹（或齿轮）的顶部与啮合螺纹（或齿轮）的根部之间的径向间隙。 |
| Grain refiner | 晶粒细化机 |
A material added to a molten metal to induce a finer-than-normal grain size in the final structure. 添加到熔融金属中以在最终结构中产生比正常晶粒尺寸更细的材料。 |
| Absolute viscosity | 绝对粘度 |
A measure of the internal shear properties of fluids, expressed as the tangential force per unit area at either of two horizontal planes separated by one unit thickness of a given fluid, one of the planes being fixed and the other moving with unit velocity. 流体内部剪切特性的量度，表示为两个水平面中的任何一个上的单位面积切向力，两个水平面被给定流体的一个单位厚度隔开，其中一个平面固定，另一个以单位速度移动。 |
| Nanomaterial | 纳米材料 |
A material defined by the European Commission as ‘A natural, incidental or manufactured material containing particles, in an unbound state or as an aggregate or as an agglomerate and where, for 50% or more of the particles in the number size distribution, one or more external dimensions is in the size range 1–100 nm. In specific cases and where warranted by concerns for the environment, health, safety or competitiveness the number size distribution threshold of 50% may be replaced by a threshold between 1 and 50%.’ 由欧盟委员会定义为“含有颗粒的天然、偶然或人造材料，处于未结合状态或聚集体或凝聚体，其中，对于数量-尺寸分布中的50%或更多颗粒，一个或多个外部尺寸在1-100nm的尺寸范围内”。在特定情况下，如果考虑到环境、健康、安全或竞争力，50%的数量大小分布阈值可以由1%到50%之间的阈值代替。 |
| Grain | 晶粒 |
1. An individual crystal in a polycrystalline solid. Most engineering materials such as metals and ceramics are used in polycrystalline form. 2. (gr) A non-SI unit of mass. The conversion to SI is 1 gr = 6.479 891 × 10−5 kg. 1.多晶固体中的单个晶体。大多数工程材料，如金属和陶瓷，都以多晶形式使用。2.（gr）非国际单位制的质量单位。转换为SI为1gr=6.479891×10-5kg。 |
| Impact strength 1. (Unit Pa) | 冲击强度1.（单位Pa） |
The stress to cause failure (by yielding or fracture) under conditions of high strain rate. 2. (Unit J) A term sometimes used to describe the energy required to fracture a specimen in a Charpy or Izod impact test even though the unit is not that of strength. 在高应变率条件下导致失效（通过屈服或断裂）的应力。2.（单位J）有时用于描述在夏比或悬臂梁式冲击试验中使样品断裂所需的能量，即使单位不是强度单位。 |
| Stress cracking | 应力开裂 |
A family of failure modes, each of which involves high stress and chemical action. The family includes Hydrogen embrittlement, Stress corrosion cracking, stress embrittlement, and hydrogen-assisted stress corrosion. 一系列失效模式，每种模式都涉及高应力和化学作用。该系列包括氢脆、应力腐蚀开裂、应力脆化和氢辅助应力腐蚀。 |
| Fatigue strength | 疲劳强度 |
The stress to which a metal can be subjected for a specified number of cyclic changes of stress. The maximum stress that can be sustained for a specified number of cycles without failure. The value of the maximum stress and the stress ratio also should be stated. 金属在指定数量的应力循环变化下可以承受的应力。可以在指定的循环次数内持续而不失效的最大应力。还应说明最大应力值和应力比。 |
| Relative density | 相对密度 |
(specific gravity) The ratio of the density of a substance to that of a reference substance, such as water for liquids and solids, and dry air for gases. （比重）物质密度与参考物质密度之比，如液体和固体为水，气体为干燥空气。 |
| Fracture mechanisms | 断裂机制 |
The microstructural mechanisms that cause fracture, such as void initiation, growth and coalescence, cleavage. 导致断裂的微观结构机制，如空隙的萌生、生长和聚结、解理。 |
| Annealing twin | 退火孪晶 |
A twin form in a crystal during recrystallization. 重结晶过程中晶体中的孪晶形式。 |
| Flame annealing | 火焰退火 |
Annealing in which the heat is applied directly by a flame. 通过火焰直接加热的退火。 |
| External load | 外部负载 |
Forces exerted on fastener and=or joint members by such external factors as weight, wind, inertia, vibration, temperature expansion, pressure, etc. Does not equal the Working load in the fastener. 由重量、风、惯性、振动、温度膨胀、压力等外部因素施加在紧固件和/或接头构件上的力。不等于紧固件中的工作负载。 |
| Shank | 螺杆 |
Portion of a bolt which lies under the head. 1. The stem of a tool, such as a broach, drill bit, reamer, or tap, which fits into a holder such as a chuck. 2. The stem of a rivet or the unthreaded part of a screw or bolt. 3. The shaft of a tool connecting the tip and the handle. 螺栓头部下方的部分。1.一种工具的柄部，如拉刀、钻头、铰刀或丝锥，可装入夹具（如卡盘）中。铆钉的杆或螺钉或螺栓的无螺纹部分。3.连接尖端和手柄的工具的轴。 |
| 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。 |
| Cotter pin | 开口销 |
(cotter) 1. A tapered wedge or pin passing through a tapered slot or hole in one member and bearing against a second member to fix it in location. 2. A split cotter is commonly called a split pin. A pin with two legs. With legs together, the pin is placed through the hole in a clevis pin. The legs are then opened outward to prevent the cotter pin from backing out of the hole. The cotter pin, in turn, prevents the load-bearing clevis pin from backing out of its retaining hole. （开口）1.锥形楔子或销钉穿过一个构件中的锥形槽或孔，并支撑在第二个构件上以将其固定到位。2.开口开口通常称为开口销。相当于有两条腿的别针，将支腿放在一起，销钉穿过U形夹销上的孔。然后将支腿向外打开以防止开口销从孔中退出。开口销反过来防止承重U形夹销从其固定孔中退出。 |
| Joint space | 关节空间 |
The description of the position and orientation of a robot in terms of the rotational angles and translational positions of the joints. Kinematic analysis, normally using homogeneous transforms, allows conversion between this description and the end‐effector position and orientation in x,y,z space. 根据关节的旋转角度和平移位置描述机器人的位置和方向。通常使用齐次变换的运动学分析允许在该描述与x、y、z空间中的末端执行器位置和方向之间进行转换。 |
| Mohs scale | 莫氏硬度 |
A scale of scratch hardness originally developed for minerals. 最初为矿物开发的划痕硬度标尺。 |
| Push rod | 推杆 |
A rod which opens and closes a valve via a valve rocker in an overhead-valve piston engine. The rod is actuated by a camshaft located in the crankcase. 在顶置气门活塞发动机中，通过气门摇臂打开和关闭气门的杆。连杆由曲轴箱中的凸轮轴驱动。 |
| Grip length | 夹紧长度 |
Combined thickness of all the things clamped together by the bolt and nut, including washers, gaskets, and joint members. 由螺栓和螺母夹紧在一起的所有部件的总厚度，包括垫圈、垫圈和接头构件。 |
| Quench annealing | 淬火退火 |
Annealing an austenitic ferrous alloy by solution heat treatment followed by rapid quenching. 通过固溶热处理然后快速淬火对奥氏体铁合金进行退火。 |
| Barcol hardness test | 巴氏硬度测试 |
An indentation test, similar to the Shore hardness test but using a pointed indentor with a flat tip, used to determine the hardness of such materials as rigid plastics and composites. 一种压痕测试，类似于肖氏硬度测试，但使用带有扁平尖端的尖头压头，用于确定硬质塑料和复合材料等材料的硬度。 |
| Displacement | 移位 |
The distance that a chosen measurement point on a cracked specimen displaces normal to the crack plane as the crack grows. 随着裂纹扩展，裂纹试样上选定的测量点垂直于裂纹平面位移的距离。 |
| 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。 |
| Lock-nut pipe thread | 锁紧螺母管螺纹 |
The lock-nut pipe thread is a straight thread of the largest diameter which can be cut on a pipe. Its form is identical with that of the American or Briggs standard taper pipe thread. In general, “Go” gages only are required. These consist of a straight-threaded plug representing the minimum female lock-nut thread, and a straight-threaded ring representing the maximum male lock-nut thread. This thread is used only to hold parts together, or to retain a collar on the pipe. It is never used where a tight threaded joint is required. 锁紧螺母管螺纹是最大直径的直螺纹，可在管道上切割。其形式与美国或布里格斯标准锥管螺纹相同。一般情况下，只需要通规。它们由一个表示最小内螺纹锁紧螺母螺纹的直螺纹塞和一个表示最大外螺纹锁紧螺帽螺纹的直形螺纹环组成。该螺纹仅用于将零件固定在一起，或用于将轴环固定在管道上。切勿使用于需要紧密螺纹接头的情况下。 |
| Strain rate | 应变率 |
The time rate of straining for the usual tensile test. Strain as measured directly on the specimen gage length is used for determining strain rate. Because strain is dimensionless, the units of strain rate are reciprocal time. 通常拉伸试验的应变时间速率。直接在试样标距上测量的应变用于确定应变率。因为应变是无因次的，所以应变率的单位是倒数时间。 |
| Dynamic mechanical measurement | 动态机械测量 |
A technique in which either the modulus and/or damping of a substance under oscillatory load or displacement is measured as a function of temperature, frequency, or time, or a combination thereof. 一种技术，其中在振荡载荷或位移下测量物质的模量和/或阻尼作为温度、频率或时间或其组合的函数。 |
| Alternative energy | 可替代能源 |
(alternate energy) Energy sources that are renewable and do not have the undesired consequences of fossil fuels and nuclear energy. （替代能源）可再生能源，不会产生化石燃料和核能的不良后果。 |
| Jack | 杰克装置 |
A lifting device that exerts large forces over small displacements, achieved by mechanical gearing or hydraulics. 通过机械传动或液压装置在小位移上施加大力的提升装置。 |
| Work ratio | 工作比 |
The ratio of the net work out to the actual work out for a thermodynamic cycle. 热力学循环的净功与实际功之比。 |
| Coarsening | 粗粒化 |
An increase in the grain size, usually, but not necessarily, by grain growth. 晶粒尺寸的增加，通常但不一定是晶粒变大。 |
| Flat head | 平头 |
Flat top surface and a conical bearing surface. 平顶表面和锥形轴承表面。 |
| Inch-pound force/inch² | 英寸磅力/英寸² |
A non-SI unit for the specific work of fracture (fracture toughness). The conversion to SI is 1 in.lbf/in² = 1.751 268 × 102 J/m². 用于特定断裂功（断裂韧性）的非国际单位制单位。到SI的转换为1英寸。lbf/in²=1.751268×102J/m²。 |
| Torque meter | 扭矩计 |
An instrument for measuring torque using spring-loaded, piezoelectric, or strain-gauged devices. 使用弹簧加载、压电或应变测量装置测量扭矩的仪器。 |
| 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。 |
| Durometer hardness | 硬度计硬度 |
Measure of the indentation hardness of plastics. It is the extent to which a spring-loaded steel indenter protrudes beyond the pressure foot into the material. 塑料压痕硬度的测量。它是弹簧加载的钢压头超出压力脚伸入材料的程度。 |
| 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。 |
| Unison ring | 协调环 |
In a turbomachine with adjustable guide or stator vanes, the ring to which a set of vanes is linked such that when the ring is rotated, all vane angles are adjusted. 在具有可调导向叶片或定子叶片的涡轮机中，一组叶片连接到的环，当环旋转时，所有叶片角度都可调整。 |
| Threshold stress for stress-corrosion cracking (σth) | 应力腐蚀开裂阈值应力（σth） |
An experimentally determined critical gross-section stress below which stress-corrosion cracking will not occur under specified test conditions. 实验确定的临界总截面应力，低于该应力，在规定的试验条件下不会发生应力腐蚀开裂。 |
| Strain hardening | 应变硬化 |
An increase in hardness and strengthcaused by plastic deformation at temperatures below the recrystallization range. Also known as work hardening. (workhardening) The increase in stress above the initial yield stress required to deform a metal to greater strains in the plastic range at temperatures below the recrystallization range (cold working). Unloading after some strain or work input gives a harder and stronger material. 在低于再结晶范围的温度下，塑性变形导致硬度和强度的增加。也称为加工硬化。（加工硬化）在低于再结晶范围（冷加工）的温度下，使金属在塑性范围内变形至更大应变所需的高于初始屈服应力的应力增加。在一定的应变或功输入后卸载，会得到更硬、更强的材料。 |
| Spring temper | 弹簧回火 |
A temper of nonferrous alloys and some ferrous alloys characterized by tensile strength and hardness about two-thirds of the way from full hard to extra spring temper. 非铁合金和一些铁合金的一种回火，其特点是抗拉强度和硬度约为全硬回火到超弹性回火的三分之二。 |
| Specific heat capacity | 比热容 |
The heat necessary to raise the temperature of 1 kg of a substance by 1 K. It is measured in J/(kg K). 将1千克物质的温度升高1K所需的热量。单位为J/（kg K）。 |
| Belt drive | 带传动 |
Transmission of motion from one shaft to another by means of a continuous plain, or toothed, flexible band (belt) passing over pulleys. In contrast to chain drives, belt drives tend to be employed in low-torque applications. Reduction in transmissible power may occur due to stretch of a plain transmission belt which results in slack in the drive (belt creep) or slip of a belt on a driving or driven pulley (belt slip). 通过穿过滑轮的连续平带或带齿柔性带（带）将运动从一根轴传递到另一根轴。与链条传动相比，皮带传动往往用于低扭矩应用。由于普通传动带的拉伸可能会导致传动松弛（皮带蠕变）或主动或从动皮带轮上的皮带打滑（皮带打滑），从而导致传动功率降低。 |
| Swift cup test | 斯威夫特杯测试 |
A simulative cupping test in which circular blanks of various diameters are clamped in a die ring and deep drawn into cups by a flat-bottomed cylindrical punch. 一种模拟拔杯试验，将不同直径的圆形坯料夹紧在模环中，并用平底圆柱冲头将其深拉入杯中。 |
| 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。 |
| 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。 |
| Tightness | 紧密度 |
A measure of the mass leak rate from a gasketed joint. 垫圈接头质量泄漏率的测量值。 |
| Stress raisers | 局部应力集中 |
Changes in contour or discontinuities in structure that cause local increases in stress. 导致局部应力增加的轮廓变化或结构不连续性变化。 |
| Scale height (Unit m) | 刻度高度（单位：m） |
The altitude H at which the atmospheric pressure has decreased to a certain fraction of its value at sea level B. It depends on the model adopted for the atmosphere: for an isothermal atmosphere, the pressure decreases exponentially with altitude. If H is taken as the altitude at which the pressure has fallen to B/e, then H = RT/g where R is the gas constant for air, T is the absolute temperature T, and g is the acceleration due to gravity. 大气压力降低到其在海平面B处数值的某一部分的高度H。它取决于大气采用的模型：对于等温大气，压力随高度呈指数下降。如果取H作为压力下降到B/e的高度，则H=RT/g，其中R是空气的气体常数，T是绝对温度T，g是重力引起的加速度。 |
| 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。 |
| Ablation cooling | 烧蚀冷却 |
The cooling of a surface exposed to very high external gas temperature which causes the surface material to sublime, melt or decompose. The chemical process absorbs heat while the mass flow of material away from the surface blocks the heat flux from the hot gas. 冷却暴露于非常高的外部气体温度的表面，导致表面材料升华、熔化或分解。化学过程吸收热量，而远离表面的物质的质量流阻挡了来自热气体的热通量。 |
| Electrode | 电极 |
The two metallic bodies in a battery or Corrosion cell which give up electrons (the Anode) or which attract them (the Cathode). 电池或腐蚀电池中释放电子（阳极）或吸引电子（阴极）的两个金属体。 |
| Longitudinal direction | 纵向 |
The principal direction of flow in a worked metal. See also normal direction and transverse direction. 加工金属中的主要流动方向。另请参见法向和横向。 |
| Lathe | 车床 |
A machine tool in which work, gripped in the headstock, is rotated against the cutting tool to produce turned, bored, faced, or threaded components. 一种机床，其中夹持在主轴箱中的工件靠着切削工具旋转，以生产车削、钻孔、端面或螺纹部件。 |
| 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。 |
| Stead’s brittleness | 斯特德脆性 |
A condition of brittleness that causes transcrystalline fracture in the coarse grain structure that results from prolonged annealing of thin sheets of low-carbon steel previously rolled at a temperature below about 705 °C (1300 °F). The fracture usually occurs at about 45° to the direction of rolling. 一种脆性状态，导致粗晶结构中发生穿晶断裂，这是由于之前在低于约705°C（1300°F）的温度下轧制的低碳钢薄板经过长时间退火造成的。断裂通常发生在与轧制方向约45°处。 |
| Proof strength (Unit Pa) | 验证强度（单位Pa） |
(proof stress, Rp, Rp,) The yield strength (offset yield strength) at some fixed value of the permanent strain given by the intersection of a line offset from, but parallel to, the elastic loading line and the engineering stress-engineering strain curve. The offset is arbitrary but is usually 0.1, 0.2, or 0.5% permanent strain (the proof strain). Used for materials which do not exhibit a sharply defined yield point. The notation Rp0.2 or Rp0.2 is employed for the 0.2% proof stress. （验证应力，Rp）在永久应变的某个固定值下的屈服强度（偏移屈服强度），由偏离但平行于弹性加载线的线与工程应力-工程应变曲线的交点给出。偏移是任意的，但通常为0.1、0.2或0.5%的永久应变（验证应变）。用于没有明确定义屈服点的材料。对于0.2%的验证应力，采用符号Rp0.2。 |
| Hot isostatic pressing | 热等静压 |
Sintering of powdered materials at high temperature and high hydrostatic pressure in order to minimize porosity. 在高温和高静水压力下烧结粉末材料，以尽量减少孔隙率。 |
| Dowel | 销钉 |
A headless cylindrical pin that fits into corresponding holes in mating components, thus ensuring relative location. A round metal or wooden pin. A pin, usually of circular shape like a cylinder, used to pin or fasten something in position temporarily or permanently. 一种圆头金属或木制圆柱销，可插入配合组件的相应孔中，从而确保相对位置，用于暂时或永久地将某物固定或固定到位。 |
| Fillet radius | 圆角半径 |
Concave junction at two intersecting surfaces of a fastener. Often used to describe the junction between the head and the shank of a threaded fastener (under head fillet). 在紧固件的两个相交表面处的凹形接合处。通常用于描述螺纹紧固件的头部和柄部之间的连接处（头部圆角下方）。 |
| Celsius | 摄氏度 |
The temperature scale based on the freezing point of water (0ºC) and the boiling point of water (100ºC). The interval between these points is divided into 100 degrees. The scale was devised by Anders Celsius. 基于水的冰点（0ºC）和水的沸点（100ºC）的温标。这些点之间的间隔被划分为100度。这个比例是由安德斯·摄氏设计的。 |
| Crack length (depth) (a) | 裂纹长度（深度）（a） |
In fatigue and stress corrosion cracking, the physical crack size used to determine the crack growth rate and the stress-intensity factor. For the compact-type specimen, crack length is measured from the line connecting the bearing points of load application. For the center-cracked-tension specimen, crack length is measured from the perpendicular bisector of the central crack. 在疲劳和应力腐蚀裂纹中，用于确定裂纹扩展速率和应力强度因子的物理裂纹尺寸。对于紧凑型试样，裂纹长度从连接载荷施加点的线开始测量。对于中心裂纹拉伸试样，从中心裂纹的垂直平分线测量裂纹长度。 |
| Stress distribution | 应力分布 |
The manner in which tensile, compressive, and shear stresses are distributed within a loaded body, indicated by loci of constant stress. 拉应力、压应力和剪应力在受载物体内的分布方式，由恒定应力轨迹表示。 |
| Absolute zero | 绝对零度 |
Temperature of -273.16″C or 459.69″F or OK at which molecular motion vanishes and a body has no heat energy. 温度为-273.16″C或459.69″F，此时分子运动消失且物体没有热能。 |
| Ion nitriding | 离子氮化 |
A method of surface hardening in which nitrogen ions are diffused into a workpiece in a vacuum through the use of high-voltage electrical energy. Synonymous with plasma nitriding or glowdischarge nitriding. 一种表面硬化方法，其中氮离子通过使用高压电能在真空中扩散到工件中。与等离子体氮化或辉光放电氮化同义。 |
| 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。 |
| Crystalline defects | 结晶缺陷 |
The deviations from a perfect three-dimensional atomic packing that are responsible for much of the structure-sensitive properties of the materials. Crystal defects can be point defects (dislocations) or surface defects (vacancies), line defects (dislocations), or surface defects (grain boundaries). 与完美的三维原子堆积的偏差是造成材料的大部分结构敏感特性的原因。晶体缺陷可以是点缺陷（位错）或表面缺陷（空位）、线缺陷（位错）或表面缺陷（晶界）。 |
| Deflection temperature under load (DTUL) | 负载变形温度（DTUL） |
The temperature at which a simple cantilever beam deflects a given amount under load. Formerly called heat distortion temperature. 简单悬臂梁在负载下偏转给定量的温度。以前称为热变形温度。 |
| Strain-age embrittlement | 应变时效脆化 |
A loss in ductility accompanied by an increase in hardness and strength that occurs when low-carbon steel (especially rimmed or capped steel) is aged following plastic deformation. The degree of embrittlement is a function of aging time and temperature, occurring in a matter of minutes at about 200°C (400 °F), but requiring a few hours to a year at room temperature. 塑性变形后低碳钢（尤其是边缘钢或封顶钢）时效时发生的延展性损失，伴随着硬度和强度的增加。脆化程度是老化时间和温度的函数，在大约200°C（400°F）的温度下，在几分钟内发生，但在室温下需要几小时到一年。 |
| Screw displacement | 螺杆位移 |
A rotation of a rigid body about an axis accompanied by a translation of the body along the same axis. 刚体绕轴旋转，同时刚体沿同一轴平移。 |
| 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。 |
| Condensation shock | 冷凝冲击 |
For supersonic flow of a moist gas through a divergent nozzle, condensation occurs in the form of spontaneous nucleation at some point downstream of that at which the temperature falls to the saturation temperature. The condensation process proceeds rapidly, and results in a fairly thick discontinuity termed a condensation shock. 对于通过发散喷嘴的湿气体超音速流动，在温度降至饱和温度的点下游的某个点处，冷凝以自发成核的形式发生。凝结过程进行得很快，导致相当厚的不连续性，称为凝结激波。 |
| Spalling | 剥落 |
The separation of macroscopic particles from a surface in the form of flakes or chips. 以薄片或碎片形式从表面分离宏观颗粒。 |
| Turbine blades (turbine buckets) | 涡轮叶片 |
1. The aerofoil-shaped vanes that form the rotor and stator of a gas, steam or hydraulic turbine. 2. The cup-shaped vanes of a Pelton wheel. 1.形成燃气、蒸汽或水力涡轮机的转子和定子的翼型叶片。2.冲击轮的杯形叶片。 |
| Torque monitor | 扭矩监测器 |
A torque tool control system which monitors the amount of torque being developed by the tool during use, but does not control the tool or the torque produced. 一种扭矩工具控制系统，监控工具在使用过程中产生的扭矩量，但不控制工具或产生的扭矩。 |
| Edge distance | 边距 |
The distance from the edge of a bearing specimen to the center of the hole in the direction of applied force. 在作用力方向上，从轴承试样的边缘到孔中心的距离。 |
| Blue brittleness | 蓝色脆性 |
Anomalous loss of ductility when quenched steels are tempered in the range 250–350°C (temperatures that produce blue tints on the surface of components). Brittleness exhibited by some steels after being heated to some temperature within the range of about 205 to 370 °C (400 to 700 °F), particularly if the steel is worked at the elevated temperature. Killed steels are virtually free of this kind of brittleness. 当淬火钢在250–350°C范围内回火（在部件表面产生蓝色色调的温度）时，延展性异常损失。某些钢在加热到约205至370°C（400至700°F）范围内的某个温度后表现出脆性，特别是在高温下加工钢时。镇静钢几乎没有这种脆性。 |
| Absorption dynamometer | 吸收式测功机 |
A dynamometer in which input work or power is dissipated by mechanical friction, electrical resistance, hydraulic resistance, etc. 通过机械摩擦、电阻、液压阻力等耗散输入功或功率的测功机。 |
| Centripetal | 向心力 |
Acting or moving in a direction towards the axis of rotation. 在朝向旋转轴的方向上起作用或移动。 |
| Minor diameter | 螺纹小径 |
On a straight thread, the diameter of the imaginary cylinder which just touches the root of an external thread or the crest of an internal thread. 在直螺纹上，仅接触外螺纹根部或内螺纹顶部的假想圆柱体的直径。 |
| 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。 |
| Tensile stress (Unit Pa) | 拉应力（单位Pa） |
A stress that causes two parts of an elastic body, on either side of a typical stress plane, to pull apart. A stress that tends to stretch a component, or local region of a component, when under load. In simple tension it results from the applied axial load, but tensile stresses occur in bending, torsion and other forms of loading. 一种应力，使弹性体的两个部分在典型应力平面的任一侧分离。在负载下，倾向于拉伸部件或部件局部区域的应力。在简单拉伸中，它由施加的轴向载荷产生，但拉伸应力发生在弯曲、扭转和其他形式的载荷中。 |
| Resistance factor | 阻力系数 |
Probabilistic factor representing the uncertainties in the designer’s estimate of the strength of a shear joint. Used in Load and resistance factor design. 概率系数，表示设计人员对剪切接头强度估计的不确定性。用于载荷和阻力系数设计。 |
| Atomic volume | 原子体积 |
Volume of unit cell per atom. 每个原子的晶胞体积。 |
| 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。 |
| Maximum stress-intensity factor (Kmax) | 最大应力强度因子（Kmax） |
The maximum value of the stress-intensity factorin a fatigue cycle. 疲劳循环中应力强度因子的最大值。 |
| Torque multiplier | 扭矩放大器 |
A gearbox used to multiply the torque produced by a small hand wrench (usually a Torque wrench). The output of the multiplier drives the nut or bolt with a torque that is higher, and a speed that is lower, than input torque and speed. There is no torque gage or readout on the multiplier. 一种齿轮箱，用于增加小手动扳手（通常是扭矩扳手）产生的扭矩。倍增器的输出以比输入扭矩和速度更高的扭矩和更低的速度驱动螺母或螺栓。倍增器上没有扭矩计或读数。 |
| Forced-air quench | 强制空气淬火 |
A quench utilizing blasts of compressed air against relatively small parts such as a gear. 利用压缩空气冲击相对较小的零件（例如齿轮）进行的淬火。 |
| Mohs hardness test | 莫氏硬度测试 |
A scratch hardness test for determining comparative hardness using 10 standard minerals—from talc (the softest) to diamond (the hardest). 刮擦硬度测试，用于使用从滑石（最软）到钻石（最硬）的10种标准矿物测定比较硬度。 |
| 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。 |
| Proof stress | 弹性极限应力 |
(1) The stress that will cause a specified small permanent set in a material. (2) A specified stress to be applied to a member or structure to indicate its ability to withstand service loads. （1）在材料中引起规定的小永久变形的应力。（2）施加在构件或结构上的规定应力，以表明其承受工作荷载的能力。 |
| Bearing strain | 轴承应变 |
The ratio of the deformation of the bearing hole, in the direction of the applied force, to the pin diameter in a bearing test. 轴承孔在作用力方向上的变形与轴承测试中销直径的比值。 |
| Design stress (Unit Pa) | 设计应力（单位Pa） |
The greatest allowable stress in a component or structure that will not result in failure under normal operating conditions. 在正常操作条件下不会导致失效的部件或结构中的最大许用应力。 |
| Track rod | 横拉杆 |
A bar connecting the ends of the steering arms in an automotive vehicle. 连接汽车转向臂端部的杆。 |
| Bolt stress (Unit Pa) | 螺栓应力（单位Pa） |
The axial tensile stress induced in a bolt by tightening. 通过拧紧在螺栓中产生的轴向拉应力。 |
| 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。 |
| Venturi | 文丘里管 |
A convergent–divergent flow nozzle, usually circular in cross section, with a relatively short convergent section (the confuser) upstream of a throat followed by a gradually diverging section (the diffuser). Such nozzles usually have flanges at either end for installation in a pipeline. Applications include flow meters and ejectors. When a fluid flows through a convergent duct at subsonic speed, there is an increase in velocity accompanied by a decrease in pressure (Venturi effect). 收敛-发散流喷嘴，横截面通常为圆形，喉部上游具有相对较短的收敛段（扰流器），然后是逐渐发散段（扩散器）。这种喷嘴通常在两端都有法兰，以便安装在管道中。应用包括流量计和喷射器。当流体以亚音速流过收敛管道时，速度增加，压力降低（文丘里效应）。 |
| Waist | 腰部 |
The joint in a robot corresponding to the human waist, i.e. providing rotation about a vertical axis. In an articulated robot, the first joint mounted at the base frame. 机器人中的关节对应于人的腰部，即提供绕垂直轴的旋转。在关节式机器人中，第一个关节安装在基架上。 |
| 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。 |
| Screw machine | 螺丝机 |
A machine tool for high-volume manufacture of small turned components from rod or bar. 一种用棒或棒大批量制造小零件的机床。 |
| Power | 力能 |
The rate of doing work or of producing or consuming energy. The unit of power is the watt, W, where 1 W = 1 N m/s. 做功或产生或消耗能量的速度。功率单位为瓦特，W，其中1W=1N m/s。 |
| 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。 |
| Working section | 工作区 |
That part of a wind tunnel in which models are placed for testing, or where detailed measurements are performed. 风洞中放置模型进行测试或进行详细测量的部分。 |
| Ferralium | 铁素体钢 |
Ferralium is a type of Super Duplex Stainless Steel which is optimised for use within fasteners. 一种超级双相不锈钢，经过优化用于紧固件。 |
| Waviness | 波纹度 |
Waviness is periodic deviations from geometric surface, often sinusoidal in form and often determined by low-level oscillations of the machine-tool-workpiece system during machining. Typically, wavelengths range from 1 to 10 mm (0.04 to 0.4 in.) and wave heights from a few to several hundred micrometers. 波纹度是与几何表面的周期性偏差，其形式通常是正弦的，通常由机床-工件系统在加工过程中的低水平振荡决定。通常，波长范围为1至10毫米（0.04至0.4英寸），波高范围为几微米至几百微米。 |
| Crack | 裂缝 |
A thin fissure-like defect in a component or structure across which material continuity is lost and which reduces the strength of the body. 部件或结构中的细裂缝状缺陷，材料连续性丧失并降低了身体的强度。 |
| Pre-stress | 预应力 |
To induce stresses into a component or structure before it is subjected to operating loads. 在部件或结构承受操作载荷之前，将应力引入部件或结构。 |
| Rosette | 玫瑰形的结 |
Strain gages arranged to indicate, at a single position, strain in three different directions. 应变计布置成在单个位置指示三个不同方向的应变。 |
| Clamping force | 夹紧力 |
The equal and opposite forces which exist at the interface between two joint members. The clamping force is created by tightening the bolts, but is not always equal to the combined tension in the bolts. Hole interference problems, for example, can create a difference between clamping force and bolt loads. 存在于两个连接构件之间的界面处的相等和相反的力。夹紧力是通过拧紧螺栓产生的，但并不总是等于螺栓中的组合张力。例如，孔干涉问题可能会在夹紧力和螺栓载荷之间产生差异。 |
| Galilean transformation | 伽利略变换 |
In steady fluid flow, the addition or subtraction of a constant velocity to the entire flowfield, e.g. so that flow can be considered relative to a moving object or flow feature, such as a shock wave. 在稳定的流体流动中，对整个流场增加或减少恒定速度，例如，可以考虑相对于移动物体或流动特征（例如冲击波）流动。 |
| Torque reaction (Unit N.m) | 扭矩反作用力（单位：N.m） |
The torque needed to counteract an applied torque. For example, in a helicopter with a single main rotor, the tendency of the fuselage to rotate in the opposite direction to the rotor. 抵消施加扭矩所需的扭矩。例如，在具有单个主旋翼的直升机中，机身沿与旋翼相反的方向旋转的趋势。 |
| 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。 |
| Die | 模具 |
1. A tool having an appropriately-shaped hole through which material may be extruded or drawn. 2. A tool employed in forging. 3. A block having the male or female shape employed in stamping operations. 4. A thick circular disc, driven by a die wrench, with internally-threaded cutting edges for producing a screw thread. A die wrench (die stock) holds a screw-cutting die and has two projecting arms for applying the torque necessary to cut the thread. A die having a hexagonal or square shape (die nut), driven by a spanner, is used in confined spaces where a die wrench cannot be rotated through a full circle. 1.一种具有适当形状的孔的工具，通过该孔可以挤压或拉伸材料。2.一种用于锻造的工具。3.一种用于冲压操作的具有阳或阴形状的块体。4.一种由模具扳手驱动的厚圆盘，具有用于产生螺纹的内螺纹切削刃。冲模扳手（冲模）装有一个螺旋切割模，并有两个突出臂，用于施加切割螺纹所需的扭矩。由扳手驱动的六边形或方形模具（模具螺母）用于模具扳手无法旋转一整圈的受限空间。 |
| Mean diameter (Unit m) | 平均直径（单位米） |
The average of the inside and outside diameters for a helical spring or hollow circular cylinder or sphere 螺旋弹簧或空心圆柱体或球体的内径和外径的平均值 |
| Bypass ratio | 旁路比 |
In a turbofan engine, the ratio of the mass flow rate of the bypass stream to the mass flow rate through the core of the engine. 在涡扇发动机中，旁通流的质量流量与通过发动机核心的质量流量之比。 |
| Gear wheel | 齿轮 |
Any form of toothed wheel, particularly those having conjugate teeth employed in the transmission of motion and power. 任何形式的齿轮，特别是用于传递运动和动力的共轭齿的齿轮。 |
| 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。 |
| Tension | 拉伸 |
The force or load that produces elongation. 1. The condition in a bar, belt, cable, spring, string, wire, etc. that is being pulled from either end. 2. (tensile force) (unit N) The force associated with tension as in (1). It is measured by a tension meter. 伸长力产生伸长的力或载荷。1.从两端拉出的杆、带、电缆、弹簧、线、线等的状态。2.（张力）（单位N）与张力相关的力。 |
| Batch furnace | 间歇式炉 |
A furnace used to heat treat a single load at a time. Batch-type furnaces are necessary for large parts such as heavy forgings and are preferred for complex alloy grades requiring long cycles. 用于一次热处理单个负载的炉子。对于重型锻件等大型零件，间歇式炉是必需的，对于需要长周期的复杂合金牌号来说是首选。 |
| Vent | 发泄 |
A small valve that allows the release of pressurized fluid from a pipe, pressure vessel, etc., often to the atmosphere. 一种小阀门，允许将加压流体从管道、压力容器等中释放到大气中。 |
| 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。 |
| Flame hardening | 火焰硬化 |
A process for hardening the surfaces of hardenable ferrous alloys in which an intense flame is used to heat the surface layers above the upper transformation temperature, whereupon the workpiece is immediately quenched. 一种用于硬化可硬化铁合金表面的工艺，其中使用强烈的火焰将表面层加热到转变温度上限以上，然后立即对工件进行淬火。 |
| Dynamics | 动力学 |
The branch of mechanics that deals with objects in motion. Its two main branches are kinematics, which studies motion without regards to its cause, and kinetics, which also takes into account forces that cause motion. 力学中研究运动物体的分支。它的两个主要分支是运动学和动力学，前者研究运动而不考虑其原因，后者也考虑引起运动的力。 |
| Prying | 撬动 |
The magnification of an External load by a pseudolever action when that load is an Eccentric tensile load. 当外部荷载为偏心拉伸荷载时，通过伪杠杆作用放大外部荷载。 |
| Anode | 阳极 |
That electrode in a battery or corrosion cell which produces electrons. It is the electrode which is destroyed (corrodes). 电池或腐蚀电池中产生电子的电极。被破坏（腐蚀）的是电极。 |
| Case hardening | 表面硬化 |
A generic term covering several processes applicable to steel that change the chemical composition of the surface layer by absorption of carbon, nitrogen, or a mixture of the two and, by diffusion, create a concentration gradient. The processes commonly used are carburizing and quench hardening; cyaniding; nitriding; and carbonitriding. The use of the applicable specific process name is preferred. 一个通用术语，涵盖适用于钢的几种工艺，这些工艺通过吸收碳、氮或二者的混合物改变表层的化学成分，并通过扩散形成浓度梯度。常用的工艺有渗碳和淬火硬化，氰化，氮化以及碳氮共渗。优选使用适用的特定工艺名称。 |
| Newton’s law of gravitation | 牛顿万有引力定律 |
(Newton’s law of universal gravitation) Any two bodies exert a gravitational force of attraction F on each other directed along the line joining their centres of mass, in magnitude proportional to the product of their masses and inversely proportional to the square of the distance r between them. （牛顿万有引力定律）任何两个物体沿其质心连接线相互施加引力F，其大小与其质量乘积成正比，与它们之间距离r的平方成反比。 |
| Dead load (Unit N) | 静载（单位N） |
A load on a component or structure that is steady with time, e.g. the self-weight of a bridge. 部件或结构上随时间稳定的载荷，例如桥梁的自重。 |
| Densimeter | 密度计 |
An instrument used to determine the density or relative density of a solid or liquid. 用于测定固体或液体的密度或相对密度的仪器。 |
| Shear strain | 剪切应变 |
The tangent of the angular change, as a response to force, between two lines originally perpendicular to each other through a point in a body. Also known as shearing strain. 角变化的切线，作为对力的响应，在两条原本通过物体中的一个点相互垂直的线之间。也称为剪切应变。 |
| Creep | 蠕变 |
The slow, plastic deformation of a body under heavy loads. Time-dependent plasticity. Time-dependent and permanent deformation of material under constant load or stress. The strain increases with time at a rate that increases with increasing temperature. Creep can lead to large strain and eventual failure, and so limit the lifetime of components subjected to load at high temperature. Creep in metals becomes significant at homologous temperatures in excess of about 0.4, e.g. 1200°C for tungsten, 504°C for titanium, 450°C for iron, and 100°C for aluminium. 物体在重载荷下缓慢的塑性变形，随时间变化的可塑性，材料在恒定载荷或应力下随时间变化的永久变形。应变随时间以随温度升高而增加的速率增加。蠕变可能导致大应变和最终失效，从而限制部件在高温下承受载荷的寿命。当同源温度超过约0.4℃时，金属蠕变变得显著，例如钨为1200℃，钛为504℃，铁为450℃，铝为100℃。 |
| Dynamic coupling | 动态耦合 |
In vibrations, the existence of inertial terms depending on mass in the governing equations, so that there is only a force if there is a corresponding acceleration. 在振动中，惯性项的存在取决于控制方程中的质量，因此只有当有相应的加速度时才有力。 |
| Non-ferrous metal | 有色金属 |
Strictly, all metals and alloys that do not contain iron, but usually taken to mean aluminium- and copper-based alloys. 严格来说，所有不含铁的金属和合金，但通常指铝基和铜基合金。 |
| 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。 |
| Nipple | 喷嘴 |
A device containing a non-return valve screwed into a lubrication point through which grease may be introduced, for example into a bearing. 一种包含止回阀的装置，该止回阀拧入润滑点，通过该润滑点可以将润滑脂引入，例如轴承中。 |
| Salt-velocity meter | 盐速计 |
A volume flow meter based on detecting the transit time for a small quantity of salt or radioactive isotope in a flow by measuring electrical conductivity or radiation level. 一种体积流量计，通过测量电导率或辐射水平来检测流量中少量盐或放射性同位素的渡越时间。 |
| 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。 |
| Transfer ratio | 传输比 |
(transfer constant) A complex variable representing the ratio between the output of a transducer and the input causing that output. （传递常数）一个复变量，表示传感器输出与产生该输出的输入之间的比率。 |
| Structure | 结构体 |
An assembly, usually load bearing, of connected (pinned, riveted, screwed, bolted, welded, etc.) components, such as bars, tubes, beams, and plates. 由连接（销接、铆接、螺纹连接、螺栓连接、焊接等）部件组成的组件，通常为承重组件，如杆、管、梁和板。 |
| Hoseclip | 软管夹 |
(hose clamp) A circular metal band, one end of which has a screw mechanism through which passes the other end such that the screw engages with indentations in the band, allowing the clip to be tightened or loosened. Used to hold a hose on to a pipe such as a water outlet. （软管夹）一种圆形金属带，其一端有一个螺钉组织，另一端穿过该螺钉组织，使螺钉与带子上的凹口啮合，从而可以拧紧或松开夹子。用于将软管固定在管道上，例如出水口。 |
| Strength (Unit Pa) | 强度（单位Pa） |
The maximum stress, in tension, compression, shear, or combinations thereof, that may be monotonically applied to a material, component, or structure before failure (defined as fracture, yielding, buckling, etc. as appropriate). 在破坏前（视情况定义为断裂、屈服、屈曲等），材料、部件或结构在拉伸、压缩、剪切或其组合中可能单调施加的最大应力。 |
| Hot shortness | 热脆性 |
The reduction of ductility in steels at high temperatures caused by melting of sulfides that wet grain boundaries and spread along them. 高温下钢的延展性降低，这是由于硫化物的熔化润湿晶界并沿晶界扩散而引起的。 |
| Dislocation density | 位错密度 |
The total length of dislocation lines per unit volume, or the number of dislocation lines that cut through a unit cross-sectional area. 每单位体积的位错线的总长度，或穿过单位横截面积的位错线的数量。 |
| Scatter | 分散 |
Data points or calculations are said to be scattered when they are not all the same. A ‘‘lot of scatter in preload’’ means wide variation in the preloads found in individual bolts. 当数据点或计算不尽相同时，它们被称为分散的。“预载的大量分散”意味着单个螺栓中的预载差异很大。 |
| Yielding | 屈服 |
Evidence of plastic deformation in structural materials. Also known as plastic flow or creep. 结构材料塑性变形的证据。也称为塑性流动或蠕变。 |
| Maximum continuous load | 最大连续负载 |
(maximum continuous rating) (Unit kg/s) The maximum rate of steam output that a boiler can supply for a specified period, usually 24 hours. （最大连续额定功率）（单位为kg/s）锅炉在规定时间内（通常为24小时）可供应的最大蒸汽输出率。 |
| Atomizing humidifier | 雾化加湿器 |
A humidifier that functions by spraying fine droplets of water into an airstream. 一种加湿器，通过将细小的水滴喷射到气流中来发挥作用。 |
| Hot dipping | 热浸 |
(hot-dip galvanizing) A process of coating an iron, steel, or aluminium object with a thin layer of zinc by passing it through a bath of molten zinc at a temperature of about 460°C. （热浸镀锌）通过使铁、钢或铝物体通过温度约为460°C的熔融锌浴，在铁、钢或铝物体上镀上一层薄薄的锌层的工艺。 |
| Elastic interactions | 弹性相互作用 |
When a bolt is tightened it partially compresses the joint members ‘‘in its own neighborhood.’’ When nearby bolts are tightened later, they further compress the joint in this region. This allows the first bolt to relax a little (lose a little preload). Tightening bolts on the opposite side of the joint, however, might increase preload in some of the earlier bolts tightened on the near side. These shifts and changes in the elastic energy stored in individual bolts, during assembly, are called elastic interactions. 当螺栓拧紧时，它会“在其自身附近”部分压缩接头构件稍后拧紧附近的螺栓时，进一步压缩该区域的接头。这允许第一个螺栓稍微松弛（失去一点预载）。但拧紧接头另一侧的螺栓可能会增加早期在近侧拧紧的一些螺栓的预载。在装配过程中，储存在单个螺栓中的弹性能量的这些位移和变化称为弹性相互作用。 |
| Slip joint | 滑动接头 |
A mechanical connection which allows limited endwise relative movement of two components such as pipes, rods, and ducts. 一种机械连接，允许两个部件（如管道、杆和管道）进行有限的轴向相对运动。 |
| Combined dimensioning | 组合尺寸标注 |
The use of chain dimensioning and parallel dimensioning on the same engineering drawing. 在同一工程图上使用链式尺寸标注和平行标注。 |
| Notch brittleness | 缺口脆性 |
Susceptibility of a material to brittle fractureat points of stress concentration. For example, in a notch tensile test, the material is said to be notch brittle if the notch strengthis less than the tensile strength of an unnotched specimen. Otherwise, it is said to be notch ductile. 材料在应力集中点易发生脆性断裂。例如，在缺口拉伸试验中，如果缺口强度小于无缺口试样的抗拉强度，则称材料为缺口脆性材料。否则，称其为缺口韧性。 |
| Torricellean barometer | 托里塞莱气压计 |
A vertical glass tube with its upper end sealed and the lower end submerged in a pool of mercury. The space above the mercury is under vacuum. The height to which the mercury rises up the tube is a measure of the barometric pressure. 一种垂直的玻璃管，上端密封，下端浸入汞池中。水银上方的空间处于真空状态。水银在管道中上升的高度是大气压力的量度。 |
| Condenser | 冷凝器 |
A heat exchanger in which a substance is changed from its vapour phase to its liquid phase by reducing its temperature to below the saturation temperature. 一种热交换器，通过将物质的温度降低到饱和温度以下，将其从气相变为液相。 |
| Coherent precipitate | 相干沉淀 |
A crystalline precipitate that forms from solid solution with an orientation that maintains continuity between the crystal lattice of the precipitate and the lattice of the matrix, usually accompanied by some strain in both lattices. Because the lattices fit at the interface between precipitate and matrix, there is no discernible phase boundary. 由固溶体形成的结晶沉淀物，其取向保持沉淀物晶格和基体晶格之间的连续性，通常伴随着两个晶格中的一些应变。由于晶格适合于沉淀和基体之间的界面，因此不存在可识别的相边界。 |
| Fatigue crack growth rate (da/dN) | 疲劳裂纹扩展率（da/dN） |
The rate of crack extension caused by constant-amplitude fatigue loading, expressed in terms of crack extension per cycle of load application. 恒幅疲劳荷载引起的裂纹扩展速率，以每次荷载施加循环的裂纹扩展表示。 |
| Neutralization number | 中和值 |
An ASTM number given to quenching oils that reflects the oil’s tendency towards oxidation and sludging. 淬火油的ASTM编号，反映了油的氧化和成泥趋势。 |
| 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。 |
| Union (union joint) | 活接头 |
A threaded pipe fitting that allows two pipes to be connected anddetached without the need for either to be rotated, and without damaging the pipe ends. 一种螺纹管件，允许连接和拆卸两个管道，而无需旋转任何一个管道，且不会损坏管道端部。 |
| 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。 |
| Combined stresses | 复合应力 |
The stress state at a point in a component subjected to combination of axial, bending, torsional loadings etc., acting along all reference axes. 沿所有参考轴作用的受轴向、弯曲、扭转载荷等组合作用的部件中某点的应力状态。 |
| Pascal’s law | 帕斯卡定律 |
When there is a change in pressure at any point in a confined fluid at rest, there is an equal change at every other point in the fluid volume. 当处于静止状态的受限流体中任何一点的压力发生变化时，流体体积中的每一点的变化都相等。 |
| 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。 |
| Thermal electromotive force | 热电动势 |
The electromotive force generated in a circuit containing two dissimilar metals when one junction is at a temperature different from that of the other. 当一个结处于不同于另一个结的温度时，在含有两种不同金属的电路中产生的电动势。 |
| Shoulder bolt | 轴肩螺栓 |
A bolt for which the unthreaded cylindrical section between the thread and the head is of larger diameter than the threaded section, precisely machined to length and diameter and hardened 一种螺栓，其螺纹和头部之间的无螺纹圆柱段的直径大于螺纹段的直径，精确加工至长度和直径并硬化 |
| 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。 |
| Shoulder screw | 轴肩螺钉 |
A screw having two or more diameters or shoulders and commonly used for supporting levers and other machine parts that have to operate freely. 一种具有两个或两个以上直径或轴肩的螺钉，通常用于支撑杠杆和其他必须自由操作的机器部件。 |
| Achme thread | Achme螺纹 |
A screw thread having an included angle of 29° and largely used for feed screws on machine tools. 一种夹角为29°的螺纹，主要用于机床上的进给丝杠。 |
| Shear strain rate(Unit 1/s) | 剪切应变率（单位1/s） |
In the deformation of solids, the rate at which shear strain is applied in a test or changes with time in a loaded component or structure. 在固体变形中，在试验中施加剪切应变的速率，或在加载部件或结构中随时间变化的速率。 |
| 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。 |
| Mohr–Coulomb yield criterion | Mohr–Coulomb屈服准则 |
A pressure-dependent yield criterion, according to which yielding occurs when the stress at a point in a material falls on the envelope created by the Mohr’s stress circles at yielding for various tests such as tension, shear, and compression that have different components of hydrostatic stress. 一种与压力相关的屈服准则，根据该准则，当材料中某一点的应力落在屈服时的莫尔应力圆所形成的包络线上时，即发生屈服，用于各种试验，如具有不同静水应力分量的拉伸、剪切和压缩。 |
| Precipitation heat treatment | 沉淀热处理 |
Artificial aging in which a constituent precipitates from a supersaturated solid solution. 成分从过饱和固溶体沉淀的人工时效。 |
| Gasket factors | 垫片系数 |
Experimentally derived ‘‘constants’’ used to define the behavior of a gasket or the assembly and in-service conditions required for acceptable behavior. 实验得出的“常数”用于定义垫圈的行为或可接受行为所需的组件和使用条件。 |
| Noble metals | 贵金属 |
Metallic elements from periods (rows) 5 and 6 of the periodic table, namely ruthenium, rhodium, palladium, silver, osmium, iridium, platinum, and gold. They resist corrosion and oxidation and are used for electrical contacts, thin-film circuits, and electroplating. Gold, silver, and platinum used for jewellery are also known as precious metals. They have face-centred cubic crystal structure and good ductility. 周期表第5和第6周期（行）中的金属元素，即钌、铑、钯、银、锇、铱、铂和金。它们抗腐蚀和氧化，用于电触点、薄膜电路和电镀。用于珠宝的金、银和铂也被称为贵金属。它们具有面心立方晶体结构和良好的延展性。 |
| Ductile cast iron | 球墨铸铁 |
A cast iron that has been treated while molten with an element such as magnesium or cerium to induce the formation of free graphite as nodules or spherulites, which imparts a measurable degree of ductility to the cast metal. Also known as nodular cast iron, spherulitic graphite cast iron and SG iron. 一种铸铁，在熔融时用镁或铈等元素进行处理，以诱导游离石墨形成为球粒或球晶，从而赋予铸造金属可测量的延展性。又称球墨铸铁、球晶石墨铸铁和SG铸铁。 |
| Heat tinting | 热着色 |
Coloration of a metal surface through oxidation by heating to reveal details of the microstructure. 通过加热氧化使金属表面着色，以揭示微观结构的细节。 |
| Reduction in area (RA) | 缩小面积（RA） |
The difference between the original cross-sectional area of a tensile specimen and the smallest area at or after fracture as specified for the material undergoing testing. Also known as reduction of area. 拉伸试样的原始横截面积与试验材料断裂时或断裂后的最小面积之间的差值，也称为减少面积。 |
| Orange peel | 橘皮 |
A surface roughening in the form of a pebble-grained pattern where a metal of unusually coarse grain is stressed beyond its elastic limit. Also known as pebbles and alligator skin. 一种以卵石颗粒图案形式出现的粗糙化表面，其中晶粒异常粗的金属受到的应力超过其弹性极限。也称为卵石和鳄鱼皮。 |
| Dilatometer | 膨胀计 |
An instrument for measuring length or volume changes in a solid during heating and subsequent cooling or isothermal holding. · An instrument for measuring the linear expansion or contraction in a metal resulting from changes in such factors as temperature and allotropy. 一种在加热和随后的冷却或等温保持过程中测量固体长度或体积变化，测量金属因温度和同素异形体等因素的变化而引起的线性膨胀或收缩的仪器。 |
| Compounding | 复合串联 |
In a steam engine (compound steam engine) or impulse turbine, the progressive reduction in pressure (expansion) across two or more stages in series. 在蒸汽机（复合蒸汽机）或脉冲涡轮机中，通过串联的两个或多个级逐渐降低压力（膨胀）。 |
| Socket head | 凹头 |
Screw head having a hexagonal or other form of recessed socket in the head so that the screw can be turned with a wrench or key, as a hexagon key. 螺钉头上有六角或其他形式的凹座，可以用扳手或钥匙（如六角钥匙）转动螺钉。 |
| Regenerative pump | 涡流泵 |
(regenerative turbine pump, peripheral pump) A pump with a double-sided impeller having a large number of radial blades. The pressure of the pumped liquid increases progressively over several revolutions of the impeller. It is particularly suited to producing large heads at small flow rates without cavitation. （再生涡轮泵，外围泵）具有具有大量径向叶片的双面叶轮的泵。泵送液体的压力在叶轮的几圈内逐渐增加。它特别适合于在小流速下产生大水头且不产生气穴。 |
| Size dimension (Unit m) | 尺寸范围（单位：米） |
The specified value of a diameter, length, width, etc. of a feature required to specify the finished form of a component or assembly. 指定部件或组件的成品形状所需的特征的直径、长度、宽度等的指定值。 |
| Absolute pressure | 绝对压力 |
1. The pressure measured relative to zero pressure (vacuum). 2. Gage pressure plus barometric pressure in the same units. 1.相对于零压力（真空）测量的压力。2.表压加上大气压力的单位相同。 |
| Vacuum pump | 真空泵 |
A pump for exhausting air and non-condensable gases from a vessel to be maintained at sub-atmospheric pressure. The pirani and thermal-conductivity gauges are vacuum gauges used to measure the absolute pressure within a vacuum system (vacuum level), usually expressed in torr or Pa. 用于从容器中排出空气和不凝性气体以保持在亚大气压的泵。皮拉尼和热导率计是用于测量真空系统内绝对压力（真空水平）的真空计，通常用托或帕表示。 |
| Wear rate | 磨损率 |
The rate of material removal or dimensional change due to wear per unit of exposure parameter—for example, quantity of material removed(mass, volume, thickness) in unit distance of sliding or unit time. 由于单位暴露参数的磨损而导致的材料去除率或尺寸变化，例如，单位滑动距离或单位时间内去除的材料数量（质量、体积、厚度）。 |
| Wrist pin | 腕销 |
A stud projecting from a crank as an attachment for a connecting rod. wrought alloys Metal alloys that are initially cast and then shaped into final form by processes such as extrusion, forging, or rolling. 从曲柄上伸出的一个螺柱，作为连接杆的附件。锻造合金最初铸造，然后通过挤压、锻造或轧制等工艺成形为最终形状的金属合金。 |
| Box annealing | 箱式退火 |
Annealing a metal or alloy in a sealed container under conditions that minimize oxidation. In box annealing a ferrous alloy, the charge is usually heated slowly to a temperature below the transformation range, but sometimes above or within it, and is then cooled slowly; this process is also called close annealing or pot annealing. 在使氧化最小化的条件下，在密封容器中对金属或合金进行退火。在对铁合金进行箱式退火时，通常将装料缓慢加热至低于转变范围的温度，但有时会高于或低于转变范围，然后缓慢冷却；这个过程也称为紧密退火或罐式退火。 |
| Transverse direction | 横向 |
Literally, the “across” direction, usually signifying a direction or plane perpendicular to the direction of working. In rolled plate or sheet, the direction across the width is often called long transverse, and the direction through the thickness, short transverse. 从字面上看，“横穿”方向，通常表示与工作方向垂直的方向或平面。在轧制钢板或薄板中，横跨宽度的方向通常称为长横向，穿过厚度的方向称为短横向。 |
| Typical basis | 典型基础 |
The typical property value is an average value. No statistical assurance is associated with this basis. 典型的属性值是平均值。没有与此基础相关的统计保证。 |
| Air classifier | 空气分级机 |
(air elutriator) A device in which an airstream, which may be swirling, sorts particles by a combination of size, shape, and mass. （空气淘析器）一种装置，在该装置中，气流（可能是漩涡）根据大小、形状和质量的组合对颗粒进行分类。 |
| Artificial aging | 人工时效 |
Aging above room temperature. 在室温以上的时效。 |
| Transmission | 传输 |
The system that transmits power and torque from a power source; for example a shaft, belts and pulleys, or a gear train. In the case of a motor vehicle, it includes the gearbox, clutch, propeller shaft, differential and final drive shafts. 从动力源传输功率和扭矩的系统；例如轴、皮带和滑轮或齿轮系。对于机动车辆，包括变速箱、离合器、传动轴、差速器和终传动轴。 |
| Median fatigue life | 中位疲劳寿命 |
The middle value when all of the observed fatigue life values of the individual specimens in a group tested under identical conditions are arranged in order of magnitude. When an even number of specimens are tested, the average of the two middlemost values is used. Use of the sample median rather than the arithmetic mean (that is, the average) is usually preferred. 当在相同条件下测试的一组中单个试样的所有观察疲劳寿命值按数量级排列时的中间值。当测试偶数个试样时，使用两个中间值的平均值。通常优选使用样本中值而不是算术平均值（即平均值）。 |
| Hydraulics | 液压系统 |
The study of water flow in open channels (including canals, rivers, etc.), water-supply, drainage, and irrigation systems. 研究明渠（包括运河、河流等）、供水、排水和灌溉系统中的水流。 |
| Shell hardening | 壳型硬化 |
A surface-hardening process in which a suitable steel workpiece, when heated through and quench hardened, develops a martensitic layer or shell that closely follows the contour of the piece and surrounds a core of essentially pearlitic transformation product. This result is accomplished by a proper balance among section size, steel hardenability, and severity of quench. 一种表面硬化工艺，在该工艺中，合适的钢工件在加热和淬火硬化后，会形成一层马氏体层或壳，该层或壳紧随工件的轮廓，并包围一个基本上为珠光体相变产物的核心。这一结果通过截面尺寸、钢淬透性和淬火强度之间的适当平衡来实现。 |
| Available resource | 可用资源 |
(total resource) (Unit J) The total annual energy theoretically available from a renewable-energy source, such as ocean waves, the wind, or the total incident solar energy. （总资源）（单位J）理论上可从可再生能源（例如海浪、风或总入射太阳能）获得的年度总能量。 |
| Screw | 螺钉 |
Threaded fastener designed to be used in a tapped or untapped (e.g., wood screw) hole, but not with a nut. A fastener with a screw thread cut or rolled into its cylindrical or conical shank, intended either to cut its own thread (as in a wood screw) or engage in a threaded hole. A self-tapping screw (sheet-metal screw, tapping screw) has a sufficiently hard thread that it cuts an internal thread in thin sheet or a component made of soft material when driven into a hole in the sheet or component. The screw head is the part of a screw used to apply torque to the screw. Common screw-head designs are circular in cross section with a diametral slot or cross, or hexagonal and recessed with a cross or hexagon. A screw thread is one or more continuous helical grooves of uniform section along either the exterior surface (male thread) or the interior surface (female thread) of a cylindrical or conical body. The three-dimensional shape that results when the thread cross section is rotated and axially advanced along an axis is called a helicoid, the angle that the thread makes when projected on to the axis being called the angle of inclination. Threads are employed in fasteners such as bolts, nuts, and screws; location and measuring instruments; in power drives; in some electrical fittings (Edison thread); and on the ends of crankshafts to suppress oil leakage (thrower thread). Parallel threads are formed on cylinders; tapered threads on cones, typically with a taper rate of 1:16. A screw with a righthanded thread appears to move away from the observer when turned clockwise. All standard screws, bolts and nuts have right-hand threads, but left-handed threads are sometimes employed. The axial distance between corresponding points on adjacent threads is called the screw pitch or screw rate and, for a single continuous helical groove (a single-start thread), is the same as the change in axial distance (the lead) between a nut and the head of a bolt during one revolution, the number of thread forms per mm then being the reciprocal of the pitch. For the same screw diameter, coarse threads have fewer threads per mm than fine threads. A multiple-start screw thread (usually coarse, see later) consists of two or more identical threads running simultaneously along its axis so as to provide greater bearing area and greater velocity ratio. The starts are separated by 180° (double start), 120° (triple start), 90° (quadruple start) etc., depending upon the number of threads. Thus, in double-start threads, the lead is twice the pitch; and so on. The axial distance between corresponding points on two adjacent threads in a multiple start thread is called the divided pitch. The position on a screw thread where there is equal distance between the flanks on the solid part of the thread and in the space between the threads is the pitch point, the associated diameter of which is termed the pitch diameter. The basic nomenclature for threads, some of which is common with that for toothed gearing, is shown in the diagrams. A helix formed or cut on a cylindrical surface which may advance along the axis to the right or left. The helix may be single or multiple. 一种螺纹紧固件，设计用于攻丝或未攻丝（如木螺钉）孔，但不与螺母配合使用。其螺纹被切割或卷成圆柱形或锥形柄，用于切割自身螺纹（如木螺钉）或嵌入螺纹孔。自攻螺钉（钣金螺钉、自攻螺钉）具有足够硬的螺纹，当打入薄板或部件中的孔时，它会在薄板或软材料部件中切割内螺纹。螺钉头是螺钉的一部分，用于向螺钉施加扭矩。常见的螺钉头设计为横截面为圆形，带有直径槽或十字，或为六边形，并带有十字或六边形凹槽。螺纹是沿圆柱形或锥形体的外表面（外螺纹）或内表面（内螺纹）具有均匀截面的一个或多个连续螺旋槽。当螺纹横截面旋转并沿轴轴向前进时产生的三维形状称为螺旋面，螺纹投影到轴上时形成的角度称为倾角。螺纹用于紧固件，如螺栓、螺母和螺钉；定位和测量仪器；在动力驱动中；在一些电气配件中（爱迪生螺纹）；并安装在曲轴端部，以抑制漏油（抛掷器螺纹）。在圆柱体上形成平行螺纹；圆锥上的锥形螺纹，通常具有1:16的锥形率。当顺时针旋转时，具有右手螺纹的螺钉似乎会远离观察者。所有标准螺钉、螺栓和螺母都有右手螺纹，但有时使用左手螺纹。相邻螺纹上对应点之间的轴向距离称为螺距或螺纹率，对于单个连续螺旋槽（单个起始螺纹），与螺母和螺栓头之间的轴向间距（导程）在一周内的变化相同，每mm的螺纹形式数为螺距的倒数。对于相同的螺钉直径，粗螺纹的每毫米螺纹数少于细螺纹。多头螺纹（通常为粗螺纹，见下文）由两个或多个沿其轴线同时延伸的相同螺纹组成，以提供更大的承载面积和更大的速比。根据螺纹的数量，起点之间的间隔为180°（双起点）、120°（三起点）、90°（四起点）等。因此，在双起始螺纹中，导程是螺距的两倍；多起点螺纹中两个相邻螺纹上对应点之间的轴向距离称为分割螺距。螺纹上的位置，即螺纹实体部分的侧面和螺纹之间的空间之间的距离相等，即节点，其相关直径称为节径。图中显示了螺纹的基本术语，其中一些与齿轮传动的基本术语相同。在圆柱面上形成或切割的螺旋线，可沿轴线向右或向左前进。螺旋可以是单个或多个。 |
| U-bolt | U型螺栓 |
A rod threaded at both ends and bent into a U-shape. It is used for clamping. An externally threaded fastener bent in the shape of the letter U and with both ends threaded. 两端有螺纹并弯曲成U形的杆。用于夹紧。一种外螺纹紧固件，弯曲成字母U的形状，两端带有螺纹。 |
| Centre line | 中心线 |
1. In an engineering drawing, a line of symmetry. 2. An imaginary line along a pipe, duct, or shaft that defines an axis of symmetry. 3. An imaginary straight line parallel to the intended direction of a surface located such that the areas above and below the line and the real wavy (rough) surface cancel out. 1.在工程图中，对称线。2.沿着管道、管道或竖井定义对称轴的假想线。3.一条平行于表面预期方向的假想直线，该直线上方和下方的区域与真实的波状（粗糙）表面相抵消。 |
| Angle of attack (α) | 攻角（α） |
(Unit °) The angle between a reference line on a lifting body and the vector direction of the relative velocity between the body and the fluid through which it is moving. In the case of an aerofoil, turbine, or compressor blade, the usual reference line is the chord line. （单位°）升力体上的参考线与升力体与其运动通过的流体之间的相对速度的矢量方向之间的角度。在机翼、涡轮或压缩机叶片的情况下，通常的参考线是弦线。 |
| Plowing | 犁 |
In tribology, the formation of grooves by plastic deformation of the softer of two surfaces in relative motion. 在摩擦学中，通过相对运动的两个表面中较软的表面的塑性变形形成凹槽。 |
| Tempered martensite embrittlement | 回火马氏体脆化 |
Embrittlement of ultrahigh-strength steels caused by tempering in the temperature range of 205 to 400 °C (400 to 750 °F); also called 350 °C or 500 °F embrittlement. Tempered martensite embrittlement is thought to result from the combined effects of cementite precipitation on prioraustenite grain boundaries or interlath boundaries and the segregation of impurities at prioraustenite grain boundaries. 超高强度钢在205至400°C（400至750°F）温度范围内回火引起的脆化；也称为350°C或500°F脆化。回火马氏体脆化被认为是由于渗碳体沉淀在原奥氏体晶界或层间晶界上以及杂质在原奥氏体晶粒边界处偏析的综合影响。 |
| 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。 |
| 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。 |
| Elongation | 伸张率 |
A term used in mechanical testing to describe the amount of extension of a test piece when stressed. 机械测试中使用的术语，用于描述试样在受力时的延伸量。 |
| Load factor (F) | 负载系数（F） |
The ratio between an increase in bolt tension and the external load which has caused the increase. Factors reflecting the probability of an increase in load in a shear joint. Used in load and resistant factor design. 螺栓张力增加与导致增加的外部载荷之间的比率。反映剪切接缝中荷载增加概率的系数。用于载荷和阻力系数设计。 |
| Nanoparticles | 纳米颗粒 |
Particles with dimensions of order 1 nm which have either been introduced into microstructures for reinforcement or are present as impurities. 尺寸为1nm级的颗粒，其已被引入微结构中用于增强或作为杂质存在。 |
| Coefficient of thermal expansion | 热膨胀系数 |
(1) Change in unit of length (or volume) accompanying a unit change of temperature, at a specified temperature. (2) The linear or volume expansion of a given material per degree rise of temperature, expressed at an arbitrary base temperature or as a more complicated equation applicable to a wide range. （1） 单位长度（或体积）随温度单位变化的变化。（2） 给定材料每上升一度的线性或体积膨胀，在任意基础温度下表示，或作为适用于宽范围的更复杂方程表示。 |
| Temper color | 回火颜色 |
A thin, tightly adhering oxide skin that forms when steel is tempered at a low temperature, or for a short time, in air or a mildly oxidizing atmosphere. The color, which ranges from straw to blue depending on the thickness of the oxide skin, varies with both tempering time and temperature. 一种薄的、紧密粘附的氧化皮，当钢在低温或短时间内在空气或轻度氧化气氛中回火时形成。颜色范围从稻草色到蓝色，取决于氧化皮的厚度，随回火时间和温度而变化。 |
| Water hammer | 水锤 |
The reflected pressure surge that occurs in a liquid flowing through a pipe, usually as a consequence of sudden closure of a valve. The surge may cause the pipe to vibrate and a hammering noise to be heard. Key factors affecting the surge amplitude are the compressibility of the liquid (especially if it contains undissolved gas) and the elasticity of the pipe wall. 在流经管道的液体中发生的反射压力波动，通常是阀门突然关闭的结果。浪涌可能导致管道振动，并听到锤击噪音。影响喘振幅度的关键因素是液体的可压缩性（特别是当其含有未溶解气体时）和管壁的弹性。 |
| Cavitation-resistance inducer | 抗气蚀诱导剂 |
An axial-flow pump used upstream of a main pump in order to prevent cavitation in the latter by increasing the inlet head. 在主泵上游使用的轴流泵，通过增加进口压头防止主泵出现气穴。 |
| 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。 |
| Design pressure (Unit Pa) | 设计压力（单位Pa） |
The greatest pressure that a closed container is expected to experience under normal operating conditions. 密闭容器在正常操作条件下预期承受的最大压力。 |
| Checks | 检查 |
Numerous, very fine cracks in a coating or at the surface of a metal part. Checks may appear during processing or during service and are most often associated with thermal treatment or thermal cycling. 涂层中或金属零件表面的许多非常细微的裂纹。在加工或服务期间可能会出现检查，并且通常与热处理或热循环有关。 |
| 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。 |
| Oxygen probe | 定氧测头 |
An atmosphere-monitoring device that electronically measures the difference between the partial pressure of oxygen in a furnace or furnace supply atmosphere and the external air. 一种大气监测装置，以电子方式测量熔炉或熔炉供应大气中的氧分压与外部空气之间的差值。 |
| 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。 |
| 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。 |
| Modulus of elasticity (E) | 弹性模量（E） |
The measure of rigidity or stiffness of a metal; the ratio of stress, below the proportional limit, to the corresponding strain. In terms of the stress-strain diagram, the modulus of elasticity is the slope of the stress-strain curve in the range of linear proportionality of stress to strain. 金属的刚度或刚度的量度；低于比例极限的应力与相应应变之比。根据应力应变图，弹性模量是应力应变曲线在应力应变线性比例范围内的斜率。 |
| Laser hardening | 激光硬化 |
A surface-hardening process which uses a laser to quickly heat a surface. Heat conduction into the interior of the part will quickly cool the surface, leaving a shallow martensitic layer. Hardening of steel by a moving CO2 or Nd:YAG laser beam focussed down to a few mm in diameter. A point in the surface of an object is rapidly heated into the austenite range and then rapidly cooled to form tempered martensite. 一种使用激光快速加热表面的表面硬化工艺。进入零件内部的热传导将快速冷却表面，留下浅马氏体层。通过移动CO2或Nd:YAG激光束使钢硬化，激光束聚焦至直径几毫米。物体表面的一点迅速加热到奥氏体范围，然后迅速冷却，形成回火马氏体。 |
| Yield strength | 屈服强度 |
That stress level which will create a permanent deformation of 0.2% or 0.5% or some other small, preselected, amount in a body. Approximately equal to the elastic and proportional limits of the material; a little higher than the proof strength of a bolt. The stress at which a material exhibits a specified deviation from proportionality of stress and strain. An offset of 0.2% is used for many metals. 该应力水平将在物体中产生0.2%或0.5%的永久变形，或其他一些小的、预先选定的量。近似等于材料的弹性和比例极限；略高于螺栓的强度。材料表现出与应力和应变比例的特定偏差的应力。许多金属使用0.2%的偏移量。 |
| ABS polymer | ABS聚合物 |
A class of thermoplastic co-polymer consisting of the three monomers acrylonitrile, butadiene and styrene that has improved properties (particularly toughness) over the individual constituents. 一类由丙烯腈、丁二烯和苯乙烯三种单体组成的热塑性共聚物，其性能（特别是韧性）优于单个成分。 |
| Weight (W) (Unit N) | 重量（W）（单位：N） |
The force of attraction on a body due to gravity. A body’s weight is the product of its mass and the gravitational field strength at that point. Mass remains constant, but weight depends on the object’s position on the Earth’s surface, decreasing with increasing altitude. If g is the acceleration due to gravity, the weight of a mass m is given by W = mg. On Earth, the acceleration due to gravity is approximately 9.81 m/s², so that the weight of a 1 kg mass is 9.81 N. More generally, the weight is the force exerted on the mass of a body when in the gravitational field of another body. 重力由于重力作用在物体上的吸引力。物体的重量是其质量和该点引力场强度的乘积。质量保持不变，但重量取决于物体在地球表面的位置，随着海拔的升高而减小。如果g是重力引起的加速度，则质量m的重量由W=mg给出。在地球上，重力引起的加速度约为9.81m/s²，因此1千克质量的重量为9.81N。更一般地说，重量是在另一个物体的重力场中施加在物体质量上的力。 |
| Edge distance ratio | 边距比 |
The ratio of the edge distance to the pin diameter in a bearing test. 轴承测试中边缘距离与销直径的比值。 |
| 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。 |
| Compressible flow | 可压缩流动 |
A gas flow in which the Mach number M is sufficiently high for the gas density to change significantly. For air, this is when M > 0.3. 马赫数M高到足以使气体密度发生显着变化的气流。对于空气，这是当M>0.3时。 |
| Acoustic pyrometer | 声学高温计 |
A non-intrusive pyrometer based on the principle that the sound speed in a gas is proportional to the square root of its absolute temperature. 一种非侵入式高温计，其原理是气体中的声速与其绝对温度的平方根成正比。 |
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