| 词或词组 | 中文 | 英文解释中文解释 |
|---|---|---|
| Clevis | U形夹 |
A U-shaped hook with holes at the ends through which a retaining bolt or pin (clevis pin) passes. 一种U形钩，末端有孔，固定螺栓或销（U形销）穿过这些孔。 |
| 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。 |
| Compressometer | 压力计 |
Instrument for measuring change in length over a given gage length caused by application or removal of a force. Commonly used in compression testing of metal specimens. 用于测量在给定标距上由施加或移除力引起的长度变化的仪器。常用于金属试样的压缩试验。 |
| Altitude chamber | 高空舱 |
(hypobaric chamber) A chamber in which conditions at different altitudes are simulated by a combination of appropriate pressures, temperatures and relative humidity. （低压舱）通过适当的压力、温度和相对湿度的组合来模拟不同高度条件的舱室。 |
| Wind energy (Unit kJ) | 风能（单位kJ） |
The kinetic energy associated with wind that can be converted by a wind energy conversion system (WECS) into electrical or mechanical power by a rotor, such as a multi-bladed propeller, exposed to the wind. If the air density is ρ and the wind speed is V, then the kinetic energy flux is ρV3/2. The actual wind power that can be extracted by a wind turbine intercepting a cross section of wind A is CPρAV3/2 where CP is an empirical efficiency factor termed the power coefficient. The wind-energy distribution is a histogram of the calculated wind power that can be generated annually from the windspeed frequency distribution at a given location. A windmill generates mechanical power whereas a wind turbine (wind generator) generates electrical power. The largest wind turbine, manufactured by MHI Vestas, has a power rating of 9.5 MW, a rotor diameter of 164 m, and a hub height of 105 m (the highest wind turbines have heights in the region of 190 m). A wind farm is an array of wind turbines, typically ten to several hundred, at a single location, either onshore or offshore. Energy derived from wind is a major contributor to sustainable energy generation. The largest operational offshore wind farm, located in the Irish Sea, has 87 turbines and a total generating capacity of 659 MW. The largest onshore wind farm is in Kern County, California with some 586 turbines and a total capacity of 1 550 MW. 风能转换系统（WECS）可通过暴露于风中的转子（如多叶片螺旋桨）将与风相关的动能转换为电能或机械能。如果空气密度为ρ，风速为V，则动能通量为ρV3/2。可由截获风a横截面的风力涡轮机提取的实际风功率为CPρAV3/2，其中CP是称为功率系数的经验效率因子。风能分布是根据给定位置处的风速频率分布每年可产生的计算风力的直方图。风车产生机械功率，而风力涡轮机（风力发电机）产生电功率。MHI Vestas制造的最大风力涡轮机的额定功率为9.5MW，转子直径为164m，轮毂高度为105m（最高风力涡轮机的高度为190m）。风电场是一系列风力涡轮机，通常为十到几百台，位于单一位置，无论是陆上还是海上。风能是可持续能源发电的主要贡献者。最大的海上风电场位于爱尔兰海，拥有87台涡轮机，总发电容量为659MW。最大的陆上风电场位于加利福尼亚州克恩县，拥有约586台涡轮机，总容量为1550兆瓦。 |
| Stroke | 一击 |
1. (stroke length) (Unit m) The linear distance between top dead centre and bottom dead centre of a piston in a reciprocating engine or mechanism. 2. The movement of a piston or plunger in a reciprocating machine to execute a particular function; for example, the exhaust stroke of an engine in which the exhaust gases are expelled from a cylinder. 1.（冲程长度）（单位：m）往复式发动机或机构中活塞上止点和下止点之间的线性距离。2.活塞或柱塞在往复式机器中执行特定功能的运动；例如发动机的排气冲程，其中排气从气缸中排出。 |
| 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。 |
| Pressure tap | 测压口 |
A small hole in the wall of a pipe or pressure vessel to which is attached a tube, the other end of which is connected to one side of a pressure transducer. 管子或压力容器壁上的小孔，与管子相连，管子的另一端与压力传感器的一侧相连。 |
| Half nut | 半螺母 |
A mechanism attached to the apron of a lathe and operated by a lever. The lever opens and closes a nut that has been split lengthwise so that the two halves of the nut can be closed upon the lead screw when threads are being cut. Also called Split Nut. 固定在车床裙板上并由杠杆操作的机械装置，杠杆打开和关闭纵向分开的螺母，以便在切割螺纹时，螺母的两半可以在丝杠上闭合。也称为剖分螺母。 |
| 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。 |
| Dead space | 死区 |
(dead volume) (Unit m³) That volume of a gas-filled thermometer in which the gas is not at the same temperature as that being measured. （死容）（单位m³）充气温度计的体积，其中气体的温度与被测温度不同。 |
| Joint diagrams | 接合处关系图 |
Mathematical diagrams which illustrate the forces on and deflections of fasteners and joint members. 说明紧固件和连接件上的力和变形的数学图。 |
| 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。 |
| Plane stress | 平面应力 |
The stress condition in linear-elastic fracture mechanics in which the stress in the thickness direction is zero; most nearly achieved in loading very thin sheet along a direction parallel to the surface of the sheet. Under plane-stress conditions, the plane of fracture instability is inclined 45° to the axis of the principal tensile stress. 线弹性断裂力学中厚度方向上的应力为零的应力条件；在沿着平行于薄片表面的方向加载非常薄的薄片时最接近。在平面应力条件下，断裂失稳平面与主拉应力轴倾斜45°。 |
| Stress factor | 应力因子 |
A calibration constant used in ultrasonic measurement of bolt stress or strain. It is the ratio between the change in ultrasonic transit time caused by the change in length of the fastener, under load, to the total change in transit time. 用于螺栓应力或应变超声波测量的校准常数。它是由紧固件长度变化引起的超声波传输时间变化与总传输时间变化之间的比率。 |
| Acoustic separation | 声学分离 |
(Unit m) The separation of particles in a fluid using standing acoustic waves, typically ultrasound, to drive them to nodal points (acoustic particle concentration). （单位m）使用驻声波（通常是超声波）将流体中的粒子分离，以将它们驱动到节点（声学粒子浓度）。 |
| Free carbon | 游离碳 |
The part of the total carbon in steel or cast iron that is present in elemental form as graphite or temper carbon. Contrast with combined carbon. 钢或铸铁中总碳中以石墨或回火碳等元素形式存在的部分。与结合碳形成对比。 |
| Condensate strainer | 冷凝水过滤器 |
A filter in a steam plant used to remove particulate matter from condensate before it is added to feedwater. 蒸汽设备中的过滤器，用于在将冷凝水添加到给水中之前去除冷凝水中的颗粒物。 |
| Total carbon | 总碳 |
The sum of the free and combined carbon (including carbon in solution) in a ferrous alloy. 铁合金中游离碳和结合碳（包括溶液中的碳）的总和。 |
| Charles law/Charles' law | 查尔斯定律 |
(Gay–Lussac law) The volume of a fixed mass of gas at constant pressure is proportional to its absolute temperature. The volume of a gas at constant pressure is directly proportional to its absolute temperature. （盖-吕萨克定律）在恒定压力下，固定质量气体的体积与其绝对温度成正比。恒压下气体的体积与其绝对温度成正比。 |
| Manometer | 压力计 |
An instrument used in the measurement of a pressure difference in a fluid (manometry). 用于测量流体压力差（测压）的仪器。 |
| Testing machine | 试验机 |
A machine used to apply either a steady or oscillatory or impact load to a testpiece. The load may be tensile, compressive, shear, bending, or torsional. 用于向试件施加稳定或振荡或冲击载荷的机器。载荷可以是拉伸的、压缩的、剪切的、弯曲的或扭转的。 |
| Relaxed stress | 松弛应力 |
The initial stress minus the remaining stress at a given time during a stress-relaxation test. 在应力松弛试验期间，初始应力减去给定时间的剩余应力。 |
| High-tensile bolt | 高强度螺栓 |
(high-tension bolt) A bolt manufactured from an alloy steel that has a high tensile strength of about 1 GPa. （高压螺栓）由合金钢制成的螺栓，具有约1GPa的高抗拉强度。 |
| Nanotechnology | 纳米技术 |
The science and engineering of materials that have been structured on length scales of 1–100 nm, resulting in modified physical properties owing to changes in the ratio of surface area to volume (atoms on surfaces having different symmetry from those in the bulk) and because many of the fundamental physical processes that underpin the properties of materials have a characteristic length scale of a few nm, so that alteration of microstructure at the nm level alters the bulk properties. 材料科学与工程，其结构长度为1-100nm，由于表面积与体积之比的变化（表面上的原子与体中的原子具有不同的对称性），并且支撑材料性质的许多基本物理过程具有几纳米的特征长度尺度，因此改变纳米级微观结构会改变体性质。 |
| 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。 |
| Impact energy (Unit J) | 冲击能量（单位J） |
The amount of energy required to fracture a material, usually measured by means of an Izod test or Charpy test.The type of specimen and test conditions affect the values and therefore should be specified. 1. The sum of the kinetic energies of all the bodies involved at the instant of collision of two or more moving bodies. 2. The energy required to fracture a specimen in a Charpy or Izod impact test. 使材料断裂所需的能量，通常通过悬臂梁式试验或夏比试验测量。试样类型和试验条件会影响数值，因此应加以说明。1.两个或多个运动物体碰撞瞬间所有物体的动能之和。2.夏比或悬臂冲击试验中断裂试样所需的能量。 |
| Torsion test | 扭力测试 |
A test designed to provide data for the calculation of the shear modulus, modulus of rupture in torsion, and yield strength in shear. 为计算剪切模量、扭转断裂模量和剪切屈服强度而设计的试验。 |
| Diesel engine | 柴油发动机 |
(compression–ignition engine) A piston engine operating on the Diesel cycle in which the air is compressed to a temperature above the autoignition temperature of the fuel and combustion is initiated as the fuel is injected into the hot air. Diesel engines operate at higher compression ratios (typically in the range 12 to 24) than petrol engines. Although named after Rudolf Diesel, the inventor, Diesel engine is often spelled with a lower case d, contrary to normal practice. （压燃式发动机）在柴油循环中运行的活塞式发动机，在该循环中，空气被压缩至高于燃料自燃温度的温度，当燃料喷射到热空气中时，燃烧开始。柴油发动机在比汽油发动机更高的压缩比下运行（通常在12到24的范围内）。虽然以发明人鲁道夫·迪塞尔命名，但迪塞尔发动机通常拼写为小写d，这与正常做法相反。 |
| Ferrite | 铁素体 |
A solid solution of one or more elements in body-centered cubic iron. Unless otherwise designated (for instance, as chromium ferrite), the solute is generally assumed to be carbon. On some equilibrium diagrams, there are two ferrite regions separated by an austenite area. The lower area is alpha ferrite; the upper, delta ferrite. If there is no designation, alpha ferrite is assumed. 一种或多种元素在体心立方铁中的固溶体。除非另有说明（例如，铁酸铬），否则通常假定溶质为碳。在一些平衡图上，有两个铁素体区域被一个奥氏体区域隔开。下部区域为α铁素体；上部，δ铁氧体。如果没有指定，则假定为 α 铁氧体。 |
| Submerged-electrode furnace | 浸入式电极炉 |
A furnace used for liquid carburizing of parts by heating molten salt baths with the use of electrodes submerged in the ceramic lining. 一种通过使用浸入陶瓷衬里中的电极加热熔融盐浴对零件进行液体渗碳的炉。 |
| Generator | 发电机 |
1. A machine for converting mechanical energy to electrical energy. 2. (generatrix) A point, line, or surface regarded as moving and so forming a line, a surface, or a volume, respectively. 1.将机械能转化为电能的机器。2.（母线）被认为是运动的点、线或面，因此分别形成一条线、一个面或一个体积。 |
| Cheese head | 圆柱头 |
A cylindrical head on a screw or bolt. For driving, it may be slotted, or hexagonally recessed. 螺钉或螺栓上的圆柱头。为了驱动，它可以是开槽的，也可以是六角形的。 |
| Inspection gauge | 检验规 |
Any of various gauges used in manufacturing and quality control to check dimensions, finish, etc. 任何用于制造和质量控制的各种量规，以检查尺寸、光洁度等。 |
| Coalescence | 聚结 |
Growth of grains at the expense of the remainder by absorption or the growth of a phase or particle at the expense of the remainder by absorption or reprecipitation. 通过吸收以牺牲剩余为代价的晶粒的生长或以通过吸收或再沉淀为代价的以剩余为代价的相或颗粒的生长。 |
| 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。 |
| Concentration ratio | 浓度比 |
For a concentrating solar collector, the ratio of the projected area of the concentrator facing the solar beam to the actual area of the receiver. 对于聚光太阳能集热器，集中器面向太阳光束的投影面积与接收器的实际面积之比。 |
| 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。 |
| Screw area (Unit m²) | 螺丝面积（单位m²） |
The area of a circle described by the tips of a propeller. 螺旋桨尖端所描述的圆的面积。 |
| Preload adjustments | 预载调整 |
Preloads may be applied directly by axial loading or indirectly by turning of the nut or bolt. When preload is applied by turning of nuts or bolts, a torsion load component is added to the desired axial bolt load. 预载荷可通过轴向载荷直接施加，或通过转动螺母或螺栓间接施加。当通过转动螺母或螺栓施加预载荷时，扭转载荷分量被添加到所需的轴向螺栓载荷中。 |
| Centre of pressure | 压力中心 |
1. The location, on an aerofoil or other body that develops lift, of the resultant lift force. 2. The location, on a surface submerged in a liquid, of the resultant force due to the pressure acting on the surface. Because hydrostatic pressure increases with depth, the centre of pressure is generally below the centroid of the surface. 1.在产生升力的机翼或其他物体上，合成升力的位置。2.在浸没在液体中的表面上，由于作用在表面上的压力而产生的合力的位置。由于静水压力随深度增加，压力中心通常低于表面质心。 |
| 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）。 |
| Car furnace | 车炉 |
A batch-type furnace using a car on rails to enter and leave the furnace area. Car furnaces are used for lower stress relieving ranges. 一种间歇式炉，使用轨道上的小车进出炉区。汽车炉用于较低的应力消除范围。 |
| 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。 |
| 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。 |
| Deposit gauge | 沉积量计 |
(deposition gauge) An instrument employed in air pollution studies for measuring the amount of pollutant deposited on a given area in a given time under given conditions. （沉降计）在空气污染研究中使用的仪器，用于测量在给定条件下在给定时间内沉积在给定区域上的污染物量。 |
| Nut | 螺母 |
A metal fastener of square, hexagon or other shape, having an internal thread which screws onto a bolt, stud or arbor. An internally-threaded fastener used with externally-threaded bolts. Usually hexagonal in shape but there is a multitude of other geometries, such as square, for special purposes and different gripping tools. 一种方形、六角形或其他形状的金属紧固件，具有内螺纹，可拧在螺栓、螺柱或心轴上。与外螺纹螺栓一起使用的内螺纹紧固件。通常为六边形，但也有许多其他几何形状，如方形，用于特殊用途和不同的夹持工具。 |
| Modulus of rupture | 断裂模量 |
Nominal stress at fracture in a bend test or torsion test. In bending, modulus of rupture is the bending moment at fracture divided by the section modulus. In torsion, modulus of rupture is the torque at fracture divided by the polar section modulus. 弯曲试验或扭转试验中的标称断裂应力。在弯曲中，断裂模量是断裂时的弯矩除以截面模量。在扭转中，断裂模量是断裂时的扭矩除以极截面模量。 |
| Thread form | 螺纹形式 |
The cross-sectional shape of the threads, defining thread angle, root, and crest profiles, etc. Thread length Length of that portion of the fastener which contains threads cut or rolled to full depth. 螺纹的横截面形状，定义螺纹角度、齿根和齿冠轮廓等。螺纹长度：紧固件中包含全深度切割或轧制螺纹的部分的长度。 |
| Inch (in) | 英寸（in） |
A non-SI unit of length now defined as 25.4 mm. The conversion to SI is 1 in = 2.54 × 10−2 m. 现在定义为25.4毫米的非SI长度单位。转换为SI为1in=2.54×10-2m。 |
| Bioengineering | 生物工程 |
(biological engineering) The application of engineering principles to biology, medicine, agriculture, etc. （生物工程）工程原理在生物学、医学、农业等方面的应用。 |
| Tribology | 摩擦学 |
The science and technology concerned with interacting surfaces in relative motion. 与相对运动中相互作用的表面有关的科学和技术。 |
| Fog quenching | 雾淬 |
Quenching in a fine vapor or mist. 在细蒸汽或薄雾中淬火。 |
| Rivet | 铆钉 |
A short rod with a head on one end that is inserted through aligned holes in plates to be joined, after which a second head is made on the protruding shank by hammering or forming. The most common head shapes are flat, domed, and inverse conical. In an array, the rivet pitch is the distance between the centres of adjacent rivets. Failure may occur by different mechanisms or modes. A one piece fastener consisting of a head and a body and used for fastening two or more pieces together by passing the body through a hole in each piece and then forming a second head on the body end. It cannot be removed except by taking off the head. 一种一端有头的短杆，插入待连接板上对齐的孔中，然后通过锤击或成型在突出的杆身上制作第二个头。最常见的头部形状是扁平、圆顶和倒锥形。在阵列中，铆钉间距是相邻铆钉中心之间的距离。故障可能由不同的机制或模式发生。一种一体式紧固件，由头部和主体组成，用于将两个或多个部件紧固在一起，方法是将主体穿过每个部件上的孔，然后在主体端部形成第二个头部。除非取下头部，否则无法移除。 |
| Percent error | 误差百分比 |
For testing machines, the ratio, expressed as a percentage, of the error to the correct value of the applied load. 对于试验机，以百分比表示的误差与所施加载荷的正确值之比。 |
| Creep–time relations | 蠕变时间关系 |
Algebraic or numerical relations between creep strain and time at constant stress. 恒定应力下蠕变应变与时间之间的代数或数值关系。 |
| Hot-wire analyzer | 热电阻丝型分析仪 |
An electrical atmosphere analysis device that is based on the fact that the electrical resistivity of steel is a linear function of carbon content over a range from 0.05% C to saturation. The device measures the carbon potential of furnace atmospheres (typically). This term is not to be confused with the hot-wire test which measures heat extraction rates. 一种基于以下事实的电气氛分析设备：钢的电阻率是从0.05%C到饱和范围内的碳含量的线性函数。该设备测量炉内气氛的碳势（通常）。不要将此术语与测量热提取率的热线测试相混淆。 |
| Hot stamping | 热冲压 |
Hot forging of brass and bronze alloys. 黄铜和青铜合金的热锻。 |
| Stress cycle | 应力循环 |
The smallest segment of the stress-time function that is repeated periodically. 周期性重复的应力时间函数的最小段。 |
| 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。 |
| Constant-mesh gearbox | 恒啮合齿轮箱 |
A gearbox in which the pairs of gears giving different speed ratios are constantly in mesh, different ratios being obtained by connecting or disconnecting the relevant gear to the driving shaft. 一种齿轮箱，其中提供不同速比的齿轮对始终啮合，通过将相关齿轮连接或断开驱动轴获得不同的速比。 |
| Working pressure (Unit Pa) | 工作压力（单位Pa） |
The pressure at which a pressure vessel, such as a boiler, is designed to operate under normal conditions. 压力容器（如锅炉）设计用于在正常条件下运行的压力。 |
| 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。 |
| Stress–strain curve | 应力-应变曲线 |
(stress–strain diagram) A plot of stress vs strain for a solid material obtained from a test in which a specimen is loaded in tension, compression, shear, or combinations thereof. Diagrams of true stress vs true strain deviate from those of nominal stress vs nominal strain only at large strains where appreciable changes in cross section of testpieces occur. （应力-应变图）从试验中获得的固体材料的应力与应变图，其中试样在拉伸、压缩、剪切或其组合中加载。只有在试件横截面发生明显变化的大应变下，真实应力与真实应变图与标称应力与标称应变图不同。 |
| Maximum stress (Smax) | 最大应力（Smax） |
The stress having the highest algebraic value in the stress cycle, tensile stress being considered positive and compressive stress negative. The nominal stress is used most commonly. 在应力循环中具有最高代数值的应力，拉应力被认为是正的，压应力被认为是负的。名义应力是最常用的。 |
| Compressed liquid | 压缩液体 |
A liquid subjected to a pressure greater than the saturation pressure corresponding to its temperature. 承受大于与其温度对应的饱和压力的压力的液体。 |
| T-bolt | T型螺栓 |
A threaded bolt having a square or rectangular end which fits into the T slot of a machine table for clamping workpieces. 一种带有方形或矩形端头的螺栓，可嵌入机床工作台的T形槽中，用于夹紧工件。 |
| Notch ductility | 缺口延展性 |
The percentage reduction in area after complete separation of the metal in a tensile test of a notched specimen. 在缺口试样的拉伸试验中，金属完全分离后的面积减少百分比。 |
| Knot (kn) | 节（kn） |
A non-SI unit defined as one nautical mile per hour. The conversion to SI is 1 kn = 5.144 444 444×10−1 m/s. 非国际单位制单位，定义为每小时一海里。转换为SI为1kN=5.144444×10−1米/秒。 |
| Carbonization | 碳化 |
Conversion of an organic substance into elemental carbon. 将有机物质转化为元素碳。 |
| 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。 |
| Hydrogen embrittlement | 氢脆 |
A condition of low toughness, low ductility or cracking in metals resulting from the absorption of hydrogen. A common and troublesome form of Stress cracking. Several theories have been proposed to explain hydrogen embrittlement, but, at present, the exact mechanism is still unknown. What is known, however, is the fact that if hydrogen is trapped in a bolt by poor electroplating practices, it can encourage stress cracking. Bolts can fail, suddenly and unexpectedly, under normal loads. Premature crack growth over time under tensile stress leading to unexpected failure in certain metals, caused by small amounts of hydrogen in the microstructure. Hydrogen may enter steels during melting or heat treating, or during processes such as electroplating. 因吸收氢而导致金属韧性低、延展性低或开裂的情况，是一种常见且麻烦的应力开裂形式。在拉伸应力下，裂纹随时间过早扩展，导致某些金属发生意外失效，这是由微观结构中的少量氢引起的。在熔化或热处理过程中，或在电镀等过程中，氢可能进入钢中。已经提出了几种理论来解释氢脆，但目前，确切的机理仍然未知。已知的事实是，如果氢因电镀不当而被困在螺栓中，则会导致应力开裂。在正常载荷下，螺栓可能突然意外失效。 |
| Fin | 翼 |
A thin projecting rib. 一根细长的凸肋。 |
| Steady pin | 定位销 |
A dowel, key, or pin that prevents a pulley from turning on its shaft. 防止滑轮在其轴上转动的销钉、键或销。 |
| 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。 |
| Semi-rotary pump | 半回转泵 |
A form of self-priming pump, often hand-operated, suitable for pumping water and light oils such as diesel oil and petrol. As shown in the diagram, liquid is sucked into one side of the pump through flap valves and simultaneously ejected from the other side on one stroke. The sequence is reversed on each successive stroke. 一种自吸泵，通常是手动的，适用于泵送水和轻油，如柴油和汽油。液体通过翻板阀吸入泵的一侧，同时在一个冲程中从另一侧排出。在每个连续冲程上，顺序颠倒。 |
| 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 jack | 螺旋千斤顶 |
A lifting device (jack) consisting of a nut and square-threaded shaft at the top of which is a load-bearing pad. Rotation of the nut raises or lowers the pad. 一种起重装置（千斤顶），由螺母和方形螺纹轴组成，其顶部为承重垫。螺母的旋转可升高或降低衬垫。 |
| Atomic volume | 原子体积 |
Volume of unit cell per atom. 每个原子的晶胞体积。 |
| True strain | 真应变 |
(1) The ratio of the change in dimension, resulting from a given load increment, to the magnitude of the dimension immediately prior to applying the load increment. (2) In a body subjected to axial force, the natural logarithm of the ratio of the gage length at the moment of observation to the original gage length. Also known as natural strain. Compare with engineering strain. （1）给定载荷增量导致的尺寸变化与施加载荷增量之前尺寸大小的比率。（2）在承受轴向力的物体中，观察时刻标距与原始标距之比的自然对数。也称为自然应变。与工程应变相比。 |
| Air-cooled engine | 风冷发动机 |
An internal-combustion engine directly cooled by airflow, rather than by water flowing through the engine block being cooled by a radiator. 一种由气流直接冷却的内燃机，而不是通过流经发动机缸体的水被散热器冷却。 |
| Vehicle | 车辆 |
A means of conveyance for transporting goods and people, generally with wheels powered by a petrol, diesel, or steam engine, or by an electric motor, or by a hybrid combination of an electric motor and a diesel or petrol engine. 一种运输货物和人员的交通工具，通常由汽油机、柴油机或蒸汽机、电动机或电动机与柴油机或汽油机的混合动力驱动。 |
| Quarter hard | （1/4H）低硬（回火） |
A temper of nonferrous alloys and some ferrous alloys characterized by tensile strength aboutmidway between that of dead soft and half hard tempers. 非铁合金和某些铁合金的一种回火，其特点是抗拉强度介于软态和半硬态之间。 |
| Specific weight (γ) (Unit N/m³) | 比重（γ）（单位：N/m³） |
The weight per unit volume of a substance: if W is the weight of a volume of the substance, ρ is its density, and g is the acceleration due to gravity, γ = W/ = ρg. 物质单位体积的重量：W是物质体积的重量，ρ是其密度，g是重力引起的加速度，γ=W/=ρg。 |
| Atomization | 雾化 |
The production of a spray of fine droplets from a liquid, such as diesel oil or petrol, by injection through a nozzle (an atomizer). 通过喷嘴（雾化器）喷射从液体（例如柴油或汽油）中产生细小液滴喷雾。 |
| Bar | 巴（气压单位） |
A widely used (non-SI) unit of pressure approximately equal to normal atmospheric pressure at sea level. The conversion to SI is 1 bar = 105 Pa. Unit of pressure – the pressure created by a column of€mercury 75.006 cm high at 0ºC, or about 33.45 feet of water at 4ºC. It is equal to 105 pascal. Standard atmospheric pressure (at sea level) is 1.01325 bar, or 1013.25 mb. 一种广泛使用的（非SI）压力单位，大约等于海平面上的正常大气压。转换为SI为1bar=105Pa。压力单位——0ºC时75.006厘米高的水银柱或4ºC时约33.45英尺水柱产生的压力。它等于105帕斯卡。标准大气压（海平面）为1.01325bar或1013.25mb。 |
| Air-cooled condenser | 风冷冷凝器 |
A heat exchanger, in which the cooling medium is air, used to condense the exhaust steam from a steam turbine, the condensate being returned to the boiler. 一种热交换器，其中冷却介质为空气，用于冷凝蒸汽轮机排出的蒸汽，冷凝水返回锅炉。 |
| Core | 核心 |
In a ferrous alloy prepared for case hardening, that portion of the alloy that is not part of the case . Typically considered to be the portion that (a) appears light on an etched cross section, (b) has an essentially unaltered chemical composition, or (c) has a hardness, after hardening, less than a specified value. 在为表面硬化而制备的铁合金中，合金中不属于表面的那部分。通常被认为是（a）在蚀刻横截面上看起来很轻，（b）化学成分基本不变，或（c）硬化后硬度低于规定值的那部分。 |
| Permissible variation | 允许偏差 |
For testing machines, the maximum allowable error in the value of the quantity indicated. It is convenient to express permissible variation in terms of the percent error. 对于试验机，所示数量值的最大允许误差。用误差百分比表示允许偏差是很方便的。 |
| 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。 |
| Thermal insulation (insulation) | 隔热（绝缘） |
A material that may be a low-conductivity solid, or a porous solid or fabric in which there are voids containing air or another gas, resulting in overall low thermal conductivity. When applied to the surface of a hot or cold object, surface heat transfer is generally reduced. 一种材料，可以是低导电性固体，或多孔固体或织物，其中存在含有空气或其他气体的空隙，从而导致整体低导热性。当应用于热或冷物体的表面时，表面传热通常减少。 |
| Blank nitriding | 空白渗氮 |
Simulating the nitriding operation without introducing nitrogen. This is usually accomplished by using an inert material in place of the nitriding agent or by applying a suitable protective coating to the ferrous alloy. 在不引入氮气的情况下模拟氮化操作。这通常通过使用惰性材料代替氮化剂或通过在铁合金上施加合适的保护涂层来实现。 |
| Slip band | 滑带 |
A group of parallel slip lines so closely spaced as to appear as a single line when observed under an optical microscope. 一组平行滑移线，间距如此之近，以至于在光学显微镜下观察时显示为一条直线。 |
| Process annealing | 中间退火 |
An imprecise term denoting various treatments used to improve workability. For the term to be meaningful, the condition of the material and the time-temperature cycle used must be stated. 一个不精确的术语，表示用于改善可加工性的各种处理方法。为了使术语有意义，必须说明材料的条件和使用的时间-温度循环。 |
| Ferritic stainless steels | 铁素体不锈钢 |
Ferritic stainless steels have the ferrite (BCC) crystal structure and contain 10–28% chromium and typically 0.1–0.35% carbon (all in wt%). They are magnetic and can be hardened by cold working. They have good to moderate mechanical properties, good oxidation and corrosion resistance at elevated temperatures, and susceptibility to embrittlement at temperatures between 400 and 540°C. Used for turbine parts, hightemperature valves, automotive exhaust components, and nuclear reactor core components. 铁素体不锈钢具有铁素体（BCC）晶体结构，含有10-28%的铬，通常含有0.1-0.35%的碳（均为重量%）。它们具有磁性，可通过冷加工硬化。它们具有良好至中等的机械性能，在高温下具有良好的抗氧化性和耐腐蚀性，在400至540°C的温度下易脆化。用于涡轮零件、高温阀、汽车排气部件和核反应堆堆芯部件。 |
| Flexural strength | 抗弯强度 |
The maximum stress in the outer fiber at the moment of crack or break. 断裂或断裂时刻外层纤维的最大应力。 |
| Starting taper | 起始锥度 |
The taper on the end of a reamer or tap which aids in starting the cut. 铰刀或丝锥端部的锥度，有助于开始切割。 |
| 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。 |
| Inclusions | 夹杂物 |
Small pieces of nonmetallic impurities trapped within the base metal of. 存在于金属基体中的小块非金属杂质。 |
| 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。 |
| Pressure recovery (Unit Pa) | 压力恢复（单位Pa） |
The progressive increase in static pressure for unseparated flow through a diverging nozzle or diffuser. 通过发散喷嘴或扩散器的未分离流的静压逐渐增加。 |
| Liquid nitriding | 液体氮化 |
A method of surface hardening in which molten nitrogen-bearing, fused-salt baths containing both cyanides and cyanates are exposed to parts at subcritical temperatures. 一种表面硬化方法，其中含有氰化物和氰酸盐的熔融含氮熔盐浴在亚临界温度下暴露于零件。 |
| Radiator | 散热器 |
A heat exchanger used to transfer thermal energy from one fluid to another for heating or cooling purposes. Despite the name, the principal mode of heat transfer is convection rather than radiation. In motor vehicles, water circulated through the engine block is cooled as it flows through the tubes of an air-cooled heat exchanger. In domestic radiators, hot water from a boiler is circulated through a heat exchanger with a large surface area which transfers heat to the surrounding air. 一种热交换器，用于将热能从一种流体传递到另一种流体，用于加热或冷却。尽管有这个名字，但热传递的主要方式是对流而不是辐射。在机动车辆中，通过发动机缸体循环的水在流经风冷热交换器的管道时被冷却。在家用散热器中，来自锅炉的热水通过具有大表面积的热交换器循环，该热交换器将热量传递给周围的空气。 |
| Seal | 密封件 |
A component which controls or prevents leakage of fluids into or out of parts of a machine. 控制或防止流体流入或流出机器部件的部件。 |
| Cold extrusion | 冷挤压 |
In simplest terms, cold extrusion can be defined as the forcing of unheated metal to flow through a shape-forming die. It is a method of shaping metal by plastically deforming it under compression at room temperature while the metal is within a die cavity formed by the tools. The metal issues from the die in at least one direction with the desired cross-sectional contour, as permitted by the orifice created by the tools. Cold extrusion is always performed at a temperature well below the recrystallization temperature of the metal (about 1100 to 1300 degrees F. for steel) so that work-hardening always occurs. In hot extrusion, recrystallization eliminates the effects of work-hardening, unless rapid cooling of the extrusion prevents recrystallization from being completed. 用简单的术语来说，冷挤压可以定义为迫使未加热的金属流过成形模具。这是一种通过在室温下压缩使金属塑性变形来成形金属的方法，同时金属处于由工具形成的模腔中。金属至少在一个方向上从模具中流出，并具有所需的横截面轮廓，这是由工具产生的孔口所允许的。冷挤压总是在远低于金属再结晶温度的温度下进行（钢约1100至1300华氏度），因此总是发生加工硬化。在热挤压中，再结晶消除了加工硬化的影响，除非挤压的快速冷却阻止再结晶完成。 |
| 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。 |
| Thermal energy (heat energy) (Unit J) | 热能（单位：J） |
The sensible and latent forms of internal energy. 内能的感知和潜在形式。 |
| Atom | 原子 |
The smallest unit of matter that has the properties of a chemical element. The simplest description of an atom (Bohr model) is of a compact nucleus surrounded by one or more orbiting electrons. 具有化学元素性质的最小物质单位。原子的最简单描述（玻尔模型）是由一个或多个轨道电子包围的致密原子核。 |
| 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。 |
| Imperial system | 英制单位体系 |
The units of measurement developed in the UK. Formerly known as the fps system, which is an abbreviation for the ‘foot-pound-second system of units. 英国开发的计量单位。以前称为fps系统，是“英尺-磅-秒（foot-pound-second）单位制”的缩写。 |
| Fretting fatigue | 微动疲劳 |
Fatigue fracture that initiate at a surface area where fretting has occurred. The progressive damage to a solid surface that arises from fretting. 在发生微动的表面区域开始的疲劳断裂。由微动引起的对固体表面的渐进性损坏。 |
| Computer-aided manufacturing | 计算机辅助制造 |
(CAM, computer-integrated manufacturing, CIM) The use of computers in all branches of manufacturing, not only to control machines and robots for manufacturing and assembly, but also for process planning, and monitoring progress of materials and components during production, etc. （CAM，计算机集成制造，CIM）在制造的所有分支中使用计算机，不仅可以控制制造和组装的机器和机器人，还可以进行工艺规划，以及在生产过程中监控材料和组件的进度等。 |
| Induction tempering | 感应回火 |
Tempering of steel using low-frequency electrical induction heating. 钢的回火采用低频电感应加热。 |
| Compression ratio | 压缩率 |
The volume of a combustion chamber with the piston at the top of its stroke as a proportion of the total volume of the cylinder with the piston at the bottom of its stroke. For a piston engine, if the swept volume is SW and the clearance volume is CL, the compression ratio is given by ( SW + CL)/CL, i.e. it is a volume ratio rather than a pressure ratio. 活塞位于其冲程顶部的燃烧室的容积与活塞位于其冲程底部的气缸总体积的比例。对于活塞发动机，如果扫气量为SW，间隙容积为CL，则压缩比由(SW+CL)/CL给出，即它是体积比而不是压力比。 |
| Pressure chamber | 压力室 |
A chamber in which components or devices can be subjected to high or low fluid (liquid or gas) pressure. 部件或装置可承受高或低流体（液体或气体）压力的腔室。 |
| 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。 |
| 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。 |
| Air pump | 气泵 |
A machine for providing a flow of air or for increasing or decreasing the mass and pressure of air in a closed container. The term pump is more usual when the working fluid is a liquid, while compressor is more usual for gases. 一种用于提供空气流动或用于增加或减少密闭容器中空气质量和压力的机器。当工作流体是液体时，术语泵更常用，而气体更常用压缩机。 |
| Three-quarters hard | 四分之三硬度 |
A temper of nonferrous alloys and some ferrous alloys characterized by tensile strength and hardness about midway between those of half hard and full hard tempers. 一种非铁合金和一些铁合金的回火，其特征是抗拉强度和硬度介于半硬回火和全硬回火之间。 |
| Izod test | 悬臂梁试验 |
A type of impact test in which a V-notched specimen, mounted vertically, is subjected to a sudden blow delivered by the weight at the end of a pendulum arm. The energy required to break off the free end is a measure of the impact strength or toughness of the material. 一种冲击试验，其中垂直安装的V形切口试样受到摆臂末端重量的突然冲击。断开自由端所需的能量是材料冲击强度或韧性的量度。 |
| Contact strength (Unit N) | 接触强度（单位N） |
The maximum allowable load between contacting bodies converted into a stress. 换算成应力的接触体之间的最大允许载荷。 |
| Wind tunnel | 风洞 |
A duct in which a controlled flow of air is used for testing and research. Types include blow down, closed circuit, open return, and open section. Closed-circuit tunnels may be pressurized or evacuated. The working section is usually situated immediately downstream of the flow-conditioning elements, which may include a plenum chamber, honeycomb, screens, turbulence grids, and a contraction. Immediately downstream there is usually a diffuser. For basic research the usual requirement is for uniform steady flow in the working section with low swirl and turbulence intensity. For some applications the flow may be density stratified, sheared, unsteady, or of high turbulence intensity. 用于测试和研究的可控气流管道。类型包括排污、闭路、开路回路和开路段。闭路隧道可加压或排空。工作段通常位于流量调节元件的下游，可包括增压室、蜂窝、滤网、湍流格栅和收缩管。紧靠下游通常有一个扩散器。对于基础研究，通常的要求是在低涡流和湍流强度的工作段中实现均匀稳定流动。对于某些应用，流动可能是密度分层、剪切、不稳定或高湍流强度。 |
| 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。 |
| 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。 |
| Pitch-circle diameter (Unit m) | 节圆直径（单位：m） |
The diameter of the circle (the pitch circle) centred on a component’s axis, around which holes or bolts are equally spaced. 以部件轴为中心的圆（节圆）的直径，孔或螺栓围绕其等距分布。 |
| Induction heating | 感应加热 |
Heating by combined electrical resistance and hysteresis losses induced by subjecting a metal to the varying magnetic field surrounding a coil carrying alternating current. 通过将金属置于承载交流电的线圈周围的变化磁场中而引起的电阻和磁滞损耗的组合加热。 |
| Vapour–pressure curve | 蒸汽压力曲线 |
For a pure substance, the curve of saturation pressure plotted vs saturation temperature. 对于纯物质，绘制了饱和压力与饱和温度的曲线。 |
| Clearance hole | 间隙孔 |
A hole of specified size such that a bolt, stud, etc. of the same nominal size will always pass through. 指定尺寸的孔，使相同标称尺寸的螺栓、螺柱等可以通过。 |
| Damage tolerance | 损伤容限 |
(defect tolerance) A design philosophy that takes into account initial imperfections, crack-growth rates and conditions at final fracture, and uses fracture mechanics to demonstrate that cracks should not grow to their critical length within the design life (or at least should be capable of ready detection). （缺陷公差）考虑初始缺陷、裂纹扩展速率和最终断裂条件的设计理念，并使用断裂力学证明裂纹不应在设计寿命内增长到其临界长度（或至少应能够随时检测）。 |
| Shock load | 冲击载荷 |
The sudden application of an external force that results in a very rapid build-up of stress. 突然施加外力，导致应力迅速增加。 |
| Machine | 机器 |
A mechanism that transmits power in the performance of a useful task. More than one machine in one place, either connected or performing separate functions, is termed machinery. 在执行有用任务时传递能量的机制。一个地方有一台以上的连接或执行单独的功能，称为机器。 |
| Set pressure (Unit Pa) | 设定压力（单位Pa） |
The pressure at which a relief valve or safety valve is set to open, corresponding to the relevant code or standard which applies to the pressure vessel being protected. 安全阀或安全阀开启时的压力，对应于适用于受保护压力容器的相关规范或标准。 |
| 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。 |
| Kiln | 窑 |
An industrial oven for burning, baking, or drying. 用于燃烧、烘烤或干燥的工业烤箱。 |
| Fatigue | 疲劳 |
The phenomenon leading to fracture under repeated or fluctuating stresses having a maximum value less than the ultimate tensile strength of the material. Fatigue failure generally occurs at loads that, applied statically, would produce little perceptible effect. Fatigue fractures are progressive, beginning as minute cracks that grow under the action of the fluctuating stress. A term referring, in components and structures subjected to either random or cyclic periodically-varying loads, to a progressive reduction in strength leading to failure at stresses lower than those that cause failure under monotonic loading. Variable loads arise from outof-balance machinery and other vibration sources, wind gusts, etc., and a large proportion of service failures is caused by fatigue. Fatigue results from the initiation and slow propagation of cracks. In manufactured components, crack initiation usually occurs at a point of stress concentration. After a period, often of millions of stress cycles, the crack reaches a critical length at which the next peak load causes sudden brittle or ductile fracture. Fracture surfaces resulting from fatigue display characteristic striations or progression marks emanating from the crack initiation site during the slow crack growth period, with a different surface appearance for the final fracture. 在最大值小于材料极限抗拉强度的重复或波动应力下导致断裂的现象。疲劳失效通常发生在静态施加的载荷下，不会产生明显影响。疲劳断裂是渐进性的，从在波动应力作用下生长的微小裂纹开始。在承受随机或周期性变化载荷的部件和结构中，指强度逐渐降低，导致在低于单调载荷下导致失效的应力下发生失效的术语。可变负载由失衡的机械和其他振动源、阵风等引起，大部分故障是由疲劳引起的。疲劳是裂纹萌生和缓慢扩展的结果。在制造部件中，裂纹萌生通常发生在应力集中点。在一段时间（通常是数百万次应力循环）后，裂纹达到临界长度，此时下一个峰值载荷会导致突然脆性或韧性断裂。疲劳产生的断裂表面在缓慢裂纹扩展期间显示出从裂纹萌生部位发出的特征条纹或进展标记，最终断裂的表面外观不同。 |
| Turbocharging | 涡轮增压 |
A method of supercharging in which the hot exhaust gas from a piston engine is used to drive a turbine which powers the supercharging compressor. A turbocharger is the turbine/compressor combination. The compressor is usually of radial outflow design while radial, axial, and mixed-flow turbines are all in use. The wastegate is a valve that reduces the flow of exhaust gas into the turbine to limit the boost produced or overspeeding. Not shown in the diagram are bearings, oil passages, etc. 一种增压方法，其中活塞发动机的热废气用于驱动涡轮，涡轮为增压压缩机提供动力。涡轮增压器是涡轮/压缩机组合。压缩机通常为径向流出设计，而径向、轴向和混流式涡轮机都在使用。废气旁通阀是一种减少进入涡轮的废气流量以限制产生的增压或超速的阀。 |
| Combined carbon | 复合碳 |
The part of the total carbon in steel or cast iron that is present as other than free carbon. 钢或铸铁中总碳中除游离碳外的部分。 |
| Bolt 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。 |
| Heat-treatable alloy | 可热处理合金 |
An alloy that can be hardened by heat treatment. 一种可以通过热处理硬化的合金。 |
| Cold treatment | 冷处理 |
Treatment carried out after quenching to transform retained austenite into martensite, involving cooling and holding at a temperature below ambient. 淬火后进行的处理，以将残余奥氏体转变为马氏体，包括冷却和保持在低于环境温度的温度。 |
| Vapour static pressure | 蒸汽静压 |
(Unit Pa or bar) A pressure analogous to hydrostatic pressure, where the fluid is a vapour such as steam. A term used in geothermal applications. （单位Pa或bar）类似于静水压力的压力，其中流体是蒸汽，如蒸汽。地热应用中使用的术语。 |
| 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。 |
| Dew point | 压力露点 |
The temperature and pressure at which a gas begins to condense to a liquid. 气体开始凝结成液体的温度和压力。 |
| Tensile strength (Unit Pa) | 抗拉强度（单位Pa） |
In tension testing, the ratio of maximum load to original cross-sectional area. Also known as ultimate strength. The resistance that a material offers to tensile stress. It is defined as the smallest tensile stress required to break the body. (ultimate strength, ultimate tensile strength, UTS, Rm, Rm) The nominal or engineering stress given by the maximum load in a tension test divided by the original cross-sectional area of the specimen. The maximum load could be the fracture load for a brittle material, but for a ductile material it is usually taken as the load at which necking begins, beyond which the load falls. 在拉伸试验中，最大载荷与原始横截面积之比。也称为极限强度。材料对拉伸应力的抵抗力。它被定义为破坏主体所需的最小拉伸应力。（极限强度、极限抗拉强度、UTS、Rm、Rm）拉伸试验中最大载荷除以试样原始横截面积得出的标称或工程应力。对于脆性材料，最大载荷可以是断裂载荷，但对于韧性材料，最大荷载通常被视为颈缩开始时的载荷，超过该载荷时，载荷下降。 |
| Face | 表平面 |
To machine a flat surface perpendicular to the axis at rotation on a lathe. 在车床上加工一个垂直于旋转轴的平面。 |
| Carburizing | 渗碳 |
Absorption and diffusion of carbon into solid ferrous alloys by heating, to a temperature usually above Ac3, in contact with a suitable carbonaceous material. A form of case hardening that produces a carbon gradient extending inward from the surface, enabling the surface layer to be hardened either by quenching directly from the carburizing temperature or by cooling to room temperature, then reaustenitizing and quenching. 通过与合适的含碳材料接触加热至通常高于Ac3的温度，将碳吸收和扩散到固体铁合金中。一种表面硬化形式，产生从表面向内延伸的碳梯度，通过直接从渗碳温度淬火或冷却至室温，然后重新奥氏体化和淬火，使表层硬化。 |
| Shore hardness | 肖氏硬度 |
A measure of the hardness of materials such as elastomers, plastics, and rubbers determined using a Shore durometer which measures the penetration depth of a hardened steel rod (the indenter) 1.1–1.4 mm in diameter into the test material for a given force applied rapidly with a calibrated spring. There are two main indenter designs: type A (for softer materials) for which the end of the rod is a truncated 35° cone tapering to a diameter of 0.79 mm, and type D (harder materials) for which the end is a 30° cone with a 0.1 mm radius tip. The spring force is 8.05 N for type A and 44.45 N for type D. The hardness value is related to the penetration depth (limited to a maximum of 2.5 mm) such that for zero penetration the hardness is 100 and for maximum penetration the hardness is zero. The relevant standards are ISO 48-1, 48-4, and 48-7. Shore hardness values of selected materials are as follows: ABS 100, cellulose acetate 50–95, high-density polyethylene 60–70, low density polyethylene 40–50, polymethylmethacrylate 90–99, PTFE 50–65, and plasticized PVC 15–70. 使用肖氏硬度计测量弹性体、塑料和橡胶等材料的硬度，肖氏硬度仪测量直径为1.1–1.4mm的硬化钢棒（压头）在用校准弹簧快速施加的给定力下渗入试验材料的深度。有两种主要的压头设计：A型（适用于较软的材料），其杆端为截头35°锥形，逐渐变细至直径0.79 mm；D型（较硬的材料），端部为30°锥形，尖端半径为0.1mm。A型的弹簧力为8.05N，D型为44.45N。硬度值与渗透深度相关（最大限制为2.5mm），因此，对于零渗透，硬度为100，对于最大渗透，硬度是零。相关标准为ISO 48-1、48-4和48-7。所选材料的肖氏硬度值如下：ABS100、醋酸纤维素50-95、高密度聚乙烯60-70、低密度聚乙烯40-50、聚甲基丙烯酸甲酯90-99、PTFE50-65和塑化PVC15-70。 |
| Graphitic carbon | 石墨碳 |
Free carbon in steel or cast iron. 钢或铸铁中的游离碳。 |
| Secondary stresses (Unit Pa) | 二次应力（单位Pa） |
Stresses different from those induced by the major loading but nevertheless resulting from the major loads; for example, the hoop stresses that occur around the circumference of barrelled compression testpieces and forgings. 与主要荷载引起的应力不同，但主要荷载产生的应力；例如，桶装压缩试件和锻件周围产生的环向应力。 |
| 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。 |
| Fatigue notch factor (Kf) | 疲劳缺口系数（Kf） |
The ratio of the fatigue strength of an unnotched specimen to the fatigue strength of a notched specimen of the same material and condition; both strengths are determined at the same number of stress cycles. 无缺口试样的疲劳强度与相同材料和条件的有缺口试样的疲劳强度之比；两种强度都是在相同数量的应力循环下确定的。 |
| Atmospheric pressure | 气压 |
The downward force exerted by the atmosphere because of its weight, (gravitational attraction to the Earth), measured by barometers, and usually expressed in units of millibars. Standard atmospheric pressure at sea level is 1013.25 mb.expressed in units of millibars. Standard atmospheric pressure at sea level is 1013.25 mb. 大气由于其重量（对地球的引力）而施加的向下的力，用气压计测量，通常以毫巴为单位表示。海平面的标准大气压为1013.25mb。以毫巴为单位表示。海平面的标准大气压为1013.25mb。 |
| Honing | 珩磨 |
Honing is a controlled, low-speed sizing and surface-finishing process in which stock is removed by the shearing action to the bonded abrasive grains of a honing stone, or stick. Finish polishing of surfaces and cutting edges in which very fine abrasive powders, such as rouge, are employed. Honing is usually applied to cylindrical surfaces and lapping to flat, but the usage is not consistent. 珩磨是一种受控的低速尺寸和表面精加工工艺，其中通过对珩磨石或棒的粘结磨粒的剪切作用去除原料。表面和切削刃的精抛光，其中使用了非常细的研磨粉，例如胭脂。珩磨通常用于圆柱面，研磨至平面，但用法并不一致。 |
| Air-hardening steel | 空气硬化钢 |
A steel containing sufficient carbon and other alloying elements to harden fully during cooling in air or other gaseous mediums from a temperature above its transformation range. The terms should be restricted to steels that are capable of being hardened by cooling in air in fairly large sections, about 2 in. (50 mm) or more in diameter. Same as self-hardening steel. 一种钢，含有足够的碳和其他合金元素，可以在空气或其他气体介质中从高于其转变范围的温度冷却过程中完全硬化。这些术语应仅限于能够通过在相当大的截面（直径约2英寸（50毫米）或更大）中通过空气冷却而硬化的钢。与自硬钢相同。 |
| Sampling | 抽样 |
The process of measuring a series of values of a time-varying quantity. 测量一系列时变量值的过程。 |
| R-curve/Resistance curve | 阻力曲线 |
In linear-elastic fracture mechanics, a plot of crack-extension resistance as a function of stable crack extension, which is either the difference between the physical crack size, or the effective crack size, and the original crack size. R-curves normally depend on specimen thickness and, for some materials, on temperature and strain rate. An increase in fracture toughness with crack propagation shown by rising plots of toughness vs growing crack length. 在线弹性断裂力学中，作为稳定裂纹扩展函数的裂纹扩展阻力图，即物理裂纹尺寸或有效裂纹尺寸与原始裂纹尺寸之间的差值。R曲线通常取决于试样厚度，对于某些材料，还取决于温度和应变率。是随着裂纹扩展，断裂韧性增加，表现为韧性与扩展裂纹长度的上升曲线。 |
| 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。 |
| Safe working load (Unit N) | 安全工作负荷（单位：N） |
The steady or unsteady load against which a component or structure is designed for normal operation. It is lower than that which would cause failure by buckling, fracture, or yielding, so as to accommodate uncertainty, possible fault or accident conditions. 部件或结构设计用于正常运行的稳定或不稳定荷载。该值低于因屈曲、断裂或屈服而导致失效的值，以适应不确定性、可能的故障或事故条件。 |
| Stretch ratio (extension ratio, λ) | 拉伸比（拉伸比，λ） |
A measure, used for highly-extensible materials such as rubber, of the extensional or normal strain of a component subjected to tension and defined as the ratio of the final length l, for a given load, to the initial or gauge length l0, where the coordinate axes are those of principal strain. It is related to the engineering strain e by λ = 1 + e. 用于高度可延展材料（如橡胶）的一种测量方法，用于测量受拉构件的拉伸或法向应变，定义为给定载荷下的最终长度l与初始或标距长度l0之比，其中坐标轴为主应变轴。它与工程应变e的关系为λ=1+e。 |
| Low-E coating | 低辐射涂层 |
(low-emittance coating) A thin metallic or metal-oxide coating on a glass sheet to absorb and reflect infrared radiation. The coating is applied either by a pyrolytic chemical vapour-deposition process (hard coat), or by sputtering (soft coat). （低辐射涂层）玻璃板上的薄金属或金属氧化物涂层，用于吸收和反射红外辐射。通过热解化学气相沉积工艺（硬涂层）或溅射（软涂层）施加涂层。 |
| Scratch hardness test | 划痕硬度测试 |
A form of hardness test in which a sharp-pointed stylus or corner of a mineral specimen is traversed along a surface so as to determine the resistance of that surface to cutting or abrasion. 硬度测试的一种形式，用尖头笔或矿物样品的一角沿一个表面移动，以确定该表面的抗切割或耐磨性。 |
| Millimetre of mercury | 毫米汞柱 |
A non-SI unit of pressure equal to the pressure exerted by a vertical column of mercury 1 mm high. Approximately equal to 133.3 Pa or 1 torr. 一种非SI压力单位，等于1毫米高的垂直水银柱施加的压力。大约等于133.3Pa或1托。 |
| 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。 |
| Diaphragm compressor | 隔膜式压缩机 |
A machine in which compression is achieved by the reciprocating motion of a flexible membrane of metal, plastic, or elastomeric material. This arrangement is ideally suited to pumping high-purity, toxic, or explosive gases. A similar machine incorporating check valves is a self-priming positive-displacement pump (diaphragm pump, membrane pump). 通过金属、塑料或弹性材料的柔性薄膜的往复运动实现压缩的机器。这种布置非常适合泵送高纯度、有毒或爆炸性气体。装有止回阀的类似机器是自吸容积泵（隔膜泵、隔膜泵）。 |
| Crystalline fracture | 结晶断裂 |
A pattern of brightly reflecting crystal facets on the fracture surface of a polycrystalline metal, resulting from cleavage fracture of many individual crystals. 多晶金属断裂面上明亮反射的晶面图案，由许多单个晶体的解理断裂产生。 |
| End-quench hardenability test | 端淬淬透性试验 |
A laboratory procedure for determining the hardenability of a steel or other ferrous alloy. Hardenability is determined by heating a standard specimen above the upper critical temperature, placing the hot specimen in a fixture so that a stream of cold water impinges on one end, and, after cooling to room temperature is completed, measuring the hardness near the surface of the specimen at regularly spaced intervals along its length. The data are normally plotted as hardness versus distance from the quenched end. 测定钢或其他铁合金淬透性的实验室程序。淬透性是通过将标准试样加热到高于上临界温度，将热试样放置在夹具中，使冷水流冲击一端，并在冷却至室温后，沿试样长度以规则间隔测量试样表面附近的硬度来确定的。数据通常绘制为硬度与距淬火端距离的关系。 |
| Dead centre | 止点 |
The point at which, in a crank mechanism, the piston connecting rod and crank are all in line so that there can be no driving moment. 在曲柄机构中，活塞连杆和曲柄都在一条线上，因此不会有驱动力矩。 |
| Mechanical properties of solid materials | 固体材料的力学性能 |
The strength and stiffness properties of solid materials such as fracture toughness, the moduli of elasticity, percent elongation, 固体材料的强度和刚度特性，例如断裂韧性、弹性模量、伸长率、 |
| Total head (hT) (Unit m) | 总水头（hT）（单位：m） |
Total pressure pT expressed in terms of the vertical height of a column of liquid, typically water or mercury, i.e. hT = pT/ρg where g is the acceleration due to gravity and ρ is the liquid density. 总压力pT以液体柱（通常为水或汞）的垂直高度表示，即hT=pT/ρg，其中g为重力加速度，ρ为液体密度。 |
| Extra hard | 额外硬化 |
A temper of nonferrous alloys and some ferrous alloys characterized by tensile strength and hardness about one-third of the way from full hard to extra spring temper. 有色合金和一些铁合金的回火，其特征是抗拉强度和硬度大约是从完全硬回火到额外弹簧回火的三分之一。 |
| Positive-displacement flow meter | 容积式流量计 |
An instrument of high accuracy that determines volumetric flow rate by dividing the flowing fluid into successive fixed volumes, and measuring their times of passage through the meter. 一种高精度仪器，通过将流动的流体分成连续的固定体积并测量其通过流量计的时间来确定体积流量。 |
| Infinite life diagram | 无限疲劳寿命图 |
A simple plot experimentally derived fatigue-life data, showing the conditions required for infinite life. 一个简单的曲线图，实验得出的疲劳寿命数据，显示了无限寿命所需的条件。 |
| Absorptance | 吸收率 |
(absorptivity, absorption coefficient, α) The fraction of radiant flux incident on a surface that is absorbed by the surface. The term also applies to absorption of radiation by a volume of fluid. For a semi-transparent surface, α + ρ + τ = 1, where ρ is the reflectance and τ is the transmittance. （吸收率，吸收系数，α）入射到表面的辐射通量被表面吸收的部分。该术语也适用于一定体积的流体对辐射的吸收。对于半透明表面，α+ρ+τ=1，其中ρ是反射率，τ是透射率。 |
| Newton (N) | 牛顿（N） |
The basic unit of force in the SI system, defined as the force that results in an acceleration of 1 m/s² when acting on a 1 kg mass. SI国际单位制中力的基本单位，定义为作用于1kg质量时产生1m/s²加速度的力。 |
| 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）。 |
| Available draught (Unit Pa) | 可用通风量（单位Pa） |
The reduced pressure of combustion gases in a furnace or boiler, either forced or due to the buoyancy of hot gases, which is used to draw in combustion air and remove products of combustion. 炉子或锅炉中燃烧气体的压力降低，无论是强制还是由于热气体的浮力，用于吸入燃烧空气并去除燃烧产物。 |
| Design code | 设计规范 |
(design standard) A standard or specification for any aspect of engineering design, issued by national organizations such as ANSI, ASME, BSI, DIN, and ISO. （设计标准）工程设计任何方面的标准或规范，由ANSI、ASME、BSI、DIN和ISO等国家组织发布。 |
| Austenite finish temperature (Af) | 奥氏体完成温度（Af） |
Temperature at which the transformation of martensite into austenite completes upon heating. The same designation is also applied to nonferrous alloys in which martensite transforms into some parent phase. 加热时马氏体转变为奥氏体的温度。相同的名称也适用于马氏体转变为某些母相的有色合金。 |
| Turning | 车削 |
Turning is a machining process for generating external surfaces of revolution by the action of a cutting tool on a rotating workpiece, usually in a lathe. The rotation of a workpiece held against a cutting tool in a lathe to produce components with a circular cross section. 车削是一种机械加工过程，通常在车床上，通过刀具对旋转工件的作用产生旋转外表面。在车床中，工件靠着刀具旋转，以生产具有圆形横截面的部件。 |
| Bucket | 吊桶 |
1. A cup-shaped vane with a central dividing ridge attached to the periphery of the runner of an impulse water turbine such as a Pelton turbine. 2. A rotor blade in a compressor or turbine. 1.一种杯形叶片，所述杯形叶片具有附接到冲击式水轮机（例如冲击式水轮机台）的转轮的外围的中央分隔脊。2.压缩机或涡轮机中的转子叶片。 |
| 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。 |
| Shear | 扭剪 |
The type of force that causes or tends to cause two contiguous parts of the same body to slide relative to each other in a direction parallel to their plane of contact. 导致或倾向于导致同一物体的两个相邻部分在平行于其接触面的方向上相对滑动的力的类型。 |
| Surface hardening | 表面硬化 |
A generic term covering several processes applicable to a suitable ferrous alloy that produces, by quench hardening only, a surface layer that is harder or more wear resistant than the core. There is no significant alteration of the chemical composition of the surface layer. The processes commonly used are carbonitriding, carburizing, induction hardening, flame hardening, nitriding, and nitrocarburizing. Use of the applicable specific process name is preferred. 一个通用术语，涵盖适用于仅通过淬火硬化产生比型芯更硬或更耐磨的表面层的合适铁合金的几种工艺。表面层的化学成分没有显著改变。常用的工艺有碳氮共渗、渗碳、感应淬火、火焰淬火、氮化和氮碳共渗。最好使用适用的特定工艺名称。 |
| Socket wrench | 套筒扳手 |
A form of spanner with an internally ridged steel socket to fit a nut or the head of a bolt or screw. 扳手的一种形式，带有内脊钢套筒，用于安装螺母或螺栓或螺钉的头部。 |
| 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。 |
| Corrosion | 腐蚀 |
The deterioration of an exposed metal surface due to electrochemical oxidation with its surroundings. In the oxidation reaction, metal atoms give up electrons which are transferred to form another chemical species by a reduction reaction, usually with hydrogen and/or oxygen. A common example is the formation of the iron oxide rust Fe(OH)3 on iron or steel in moist air or water. Rust breaks away easily, exposing fresh iron to the atmosphere, whereas the corrosion product of some metals forms an adherent layer that prevents further oxidation reaction at fresh metal, an effect known as passivation. Examples include aluminium oxide on aluminium, chromium oxide on chromium, chromium oxide on alloys containing chromium such as stainless steels, and the patina formed on copper and zinc. Corrosion protection takes many forms. Good design to avoid crevices and stress is important. In some situations, substances known as inhibitors may be added to the environment to decrease its corrosiveness. The electrochemical nature of corrosion results in some metals having a greater tendency for oxidation than others. Zinc has a stronger tendency than iron and this is made use of in galvanizing. This is one example of cathodic protection, in which one metal is connected electrically to a more reactive metal, called a sacrificial anode, that oxidizes by giving up electrons and so protects the first metal. Coatings may be used to resist corrosion. Paints, plating, and diffusion coatings are the most common and the electrochemical process of anodizing is used to deliberately form a passive layer of oxide on aluminium alloys. Material selection plays a major role. For example, stainless steels with their high chromium content are widely used in corrosive environments. 暴露的金属表面由于与周围环境的电化学氧化而劣化。在氧化反应中，金属原子放弃电子，这些电子通过还原反应（通常与氢和/或氧）转移形成另一种化学物质。一个常见的例子是在潮湿的空气或水中在铁或钢上形成氧化铁锈Fe(OH)3。铁锈很容易脱落，将新鲜铁暴露在大气中，而一些金属的腐蚀产物形成一层粘附层，防止新鲜金属发生进一步的氧化反应，这种效果称为钝化。实例包括铝上的氧化铝、铬上的氧化铬、含铬合金上的氧化铬如不锈钢，以及铜和锌上形成的铜绿。腐蚀防护有多种形式。避免裂缝和应力的良好设计非常重要。在某些情况下，可以向环境中添加称为抑制剂的物质，以降低其腐蚀性。腐蚀的电化学性质导致一些金属比其他金属具有更大的氧化倾向。锌比铁具有更强的倾向性，这可用于镀锌。这是阴极保护的一个例子，其中一种金属与活性更强的金属（称为牺牲阳极）电连接，牺牲阳极通过释放电子进行氧化，从而保护第一种金属。涂层可用于抗腐蚀。油漆、电镀和扩散涂层是最常见的，阳极氧化的电化学过程用于有意在铝合金上形成一层钝化氧化物。材料选择起着重要作用。例如，铬含量高的不锈钢广泛用于腐蚀性环境。 |
| 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。 |
| Standard fit | 标准匹配 |
The fit of a component machined or otherwise manufactured to standardized clearances and tolerances. 根据标准间隙和公差加工或以其他方式制造的部件的配合。 |
| Scleroscope hardness test | 反跃式硬度试验 |
A dynamic indentation-hardness test using a calibrated instrument that drops a diamond-tipped hammer from a fixed height onto the surface of the material being tested. The height of rebound of the hammer is a measure of the hardness of the material. Also known as Shore hardness test. 使用校准仪器的动态压痕硬度测试，该仪器将金刚石锤从固定高度落在被测材料表面上。锤的回弹高度是材料硬度的一种度量。也称为肖氏硬度测试。 |
| Flame straightening | 火焰矫直 |
Correcting distortion in metal structures by localized heating with a gas flame. 通过使用气体火焰进行局部加热来纠正金属结构的变形。 |
| Stress difference (Unit Pa) | 应力差（单位Pa） |
The algebraic difference between the largest and least principal stresses in a loaded body, equal to twice the greatest shear stress in the system. For σ1 > σ2 > σ3, it is given by (σ1 − σ3). 载荷体中最大和最小主应力之间的代数差，等于系统中最大剪应力的两倍。由（σ1− σ3).，可得σ1＞σ2＞σ3。 |
| Conditioning heat treatment | 调质热处理 |
A preliminary heat treatment used to prepare a material for desired reaction to a subsequent heat treatment. For the term to be meaningful, the exact heat treatment must be specified. 用于制备材料的初步热处理，以便对随后的热处理进行所需的反应。为了使该术语有意义，必须指定确切的热处理。 |
| Eutectoid | 共析 |
(1) An isothermal reversible reaction in which a solid solution is converted into two or more intimately mixed solids on cooling, the number of solids formed being the same as the number of components in the system. (2) An alloy having the composition indicated by the eutectoid point on an equilibrium diagram. (3) An alloy structure of intermixed solid constituents formed by a eutectoid reaction. （1）一种等温可逆反应，其中固溶体在冷却时转化为两种或两种以上紧密混合的固体，形成的固体数量与系统中组分的数量相同。（2）具有平衡图上共析点所示成分的合金。（3）由共析反应形成的混合固体成分的合金结构。 |
| Surface roughness (roughness) | 表面粗糙度 |
The small-scale, irregular peaks and troughs in a solid surface which are quantified using a surface analyser. Roughness may be a consequence of wear and corrosion, or of the manufacturing process. It leads to increased friction in solid– solid contact or fluid flow over a surface. Errors of form and waviness are excluded, but surface texture includes roughness and waviness. Surface topography incorporates the small-scale, three-dimensional geometry of a surface including surface roughness, machined, and etched features, typically at sub-mm scales. 固体表面中的小尺度不规则峰谷，使用表面分析仪进行量化。粗糙度可能是磨损和腐蚀或制造过程的结果。它会导致表面上的固-固接触或流体流动中的摩擦增加。不包括形状和波纹度误差，但表面纹理包括粗糙度和波纹度。表面形貌包括表面的小尺度三维几何结构，包括表面粗糙度、机加工和蚀刻特征，通常为亚毫米尺度。 |
| 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。 |
| 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。 |
| 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。 |
| 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。 |
| Gravity | 重力 |
The attractive force by which bodies are drawn towards the centre of Earth or other celestial object. Its intensity is measured by the acceleration produced. The gravitational force of attraction at the surface of a planet or other celestial body. The Earth’s gravity produces an acceleration of around 9.8m/s² for any unsupported body. 物体被拉向地球中心或其他天体的吸引力，行星或其他天体表面的引力。它的强度是通过产生的加速度来衡量的，对于任何无支撑的物体，地球的重力都会产生大约9.8m/s²的加速度。 |
| 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。 |
| Relaxation rate | 松弛率 |
The absolute value of the slope of a stress-relaxation curve at a given time. 给定时间应力松弛曲线斜率的绝对值。 |
| Vapour-pressure thermometer | 蒸汽压力温度计 |
(vapour-filled thermometer) A type of fluidexpansion thermometer in which the working fluid is a volatile liquid. （蒸汽填充温度计）一种流体膨胀温度计，其中工作流体为挥发性液体。 |
| 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。 |
| Caterpillar | 毛虫式履带 |
(crawler vehicle) A vehicle that ‘lays its own road’ by running on endless belts, driven by toothed wheels, on each side. Used on soft ground where spreading of the load reduces contact stress. （履带式车辆）通过在每一侧由齿轮驱动的环形皮带运行来“铺设自己的道路”的车辆。用于负载分散可减少接触应力的松软地面。 |
| True stress (σ) (Unit Pa) | 真应力（σ）（单位Pa） |
The value obtained by dividing the load applied to a member at a given instant by the cross-sectional area over which it acts. Compare with engineering stress. The applied load on a test specimen divided by the current cross-section area over which it acts. σ = s expε where s is the engineering stress given by the applied load divided by the original cross-section area over which it acts, and ε is the true strain. 通过将给定时刻施加在构件上的荷载除以其作用的横截面积而获得的值。与工程应力相比。施加在试样上的荷载除以其作用的当前横截面积。σ=s expε，其中s是由施加荷载除以其作用的原始横截面面积得出的工程应力，ε是真实应变。 |
| Angle of torsion | 扭转角 |
(angle of twist) (Unit ° or rad) The angle relative to a chosen section, normal to the axis of twist, through which another part of a component rotates when subjected to a torque. （扭转角）（单位°或弧度）相对于选定截面的角度，垂直于扭转轴，部件的另一部分在受到扭矩时通过该角度旋转。 |
| Tension testing | 张力测试 |
A method of determining the behavior of materials subjected to uniaxial loading, which tends to stretch the metal. A longitudinal specimen of known length and diameter is gripped at both ends and stretched at a slow, controlled rate until rupture occurs. Also known as tensile testing. 一种确定材料在单轴载荷下的行为的方法，这种载荷倾向于拉伸金属。将已知长度和直径的纵向试样夹持在两端，并以缓慢、受控的速率拉伸，直到发生断裂。也称为拉伸测试。 |
| Slot | 狭槽 |
A groove machined into a component, e.g. to allow for thermal expansion, or in which the tongue or tip of another component can fit or slide. 在部件上加工的凹槽，例如，允许热膨胀，或另一部件的榫舌或尖端可在其中安装或滑动。 |
| Eutectic melting | 共晶熔化 |
Melting of localized microscopic areas whose composition corresponds to that of the eutectic in the system. 局部微观区域的熔化，其成分对应于系统中的共晶成分。 |
| Abrasive wear | 磨料磨损 |
The removal or displacement of material from a surface when hard particles slide or roll across the surface under pressure. The particles may be loose or may be part of another surface in contact with the surface being worn. Contrast with adhesive wear. 当硬质颗粒在压力下在表面上滑动或滚动时，材料从表面上的去除或位移。颗粒可能是松散的或可能是与被磨损表面接触的另一个表面的一部分。与粘着磨损形成对比。 |
| Torsion-bar suspension | 扭杆悬架 |
A type of motor-vehicle suspension in which one end of a torsion bar is rigidly fixed to the chassis while the other carries a lever to which are attached the components that carry a wheel. In a torsion-beam suspension, a beam connects the wheels on either side of the vehicle. 一种汽车悬架，其中扭力杆的一端刚性固定在底盘上，而另一端带有一个杠杆，杠杆上连接着承载车轮的部件。在扭转梁悬架中，梁连接车辆两侧的车轮。 |
| Tow | 拖拉 |
1. To cause a vehicle to move by pulling with a rope, chain, bar, etc. 2. A bundle of fibres employed in reinforcement. 1.用绳子、链条、钢筋等拉动车辆移动。2.用于加固的纤维束。 |
| Square thread | 方螺纹 |
A form of screw thread in which the cross–section of the thread forms a square, making the width of the thread equal to the space between the threads. 螺纹的一种形式，螺纹的横截面形成正方形，使螺纹的宽度等于螺纹之间的间距。 |
| Minimum stress (Smin) | 最小应力（Smin） |
In fatigue, the stress having the lowest algebraic value in the cycle, tensile stress being considered positive and compressive stress negative. 在疲劳中，循环中代数值最低的应力，拉应力被视为正应力，压应力为负应力。 |
| Double-shear test | 双剪试验 |
A shear test having two stationary, shear blades and one moving one and that uses solid round bars as test specimens. 一种剪切试验，具有两个固定的剪切刀片和一个移动的刀片，并使用实心圆棒作为试样。 |
| Gearbox | 变速箱 |
A mechanism consisting of meshing gears which transmit power and torque to an output shaft from an input shaft directly connected to an engine. The mechanism is normally contained within a casing filled with lubricating oil. The diagram shows a simple four-speed sliding-mesh gearbox in which gears with different numbers of teeth are slid along parallel splined shafts within the gearbox to mesh with each other and change the ratio of output to input speed (gear ratio). 一种由啮合齿轮组成的机构，将动力和扭矩从直接连接到发动机的输入轴传递到输出轴。该机构通常包含在充满润滑油的外壳内。示例一个简单的四速滑动啮合齿轮箱，其中具有不同齿数的齿轮沿着齿轮箱内的平行花键轴滑动，以相互啮合并改变输出与输入速度的比率（齿轮比）。 |
| 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。 |
| 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。 |
| 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。 |
| 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。 |
| Tera (T) | 特拉（T） |
An SI unit prefix indicating a multiplier of 1012; thus terawatt (TW) is a unit of power equal to one trillion watts. 指示乘数1012的SI单位前缀；因此，太瓦（TW）是等于1万亿瓦的功率单位。 |
| Beta annealing | β退火 |
Producing a beta phase by heating certain titanium alloys in the temperature range of which this phase forms followed by cooling at an appropriate rate to prevent its decomposition. 通过在形成β相的温度范围内加热某些钛合金，然后以适当的速率冷却以防止其分解，从而产生β相。 |
| Left hand screw | 左螺旋 |
One that screws into the mating part or advances when turned to the left or counter clockwise. 旋入配合部分或向左或逆时针旋转时前进的螺钉。 |
| Scale effect | 规模效应 |
The change in behaviour with size of a material, component, or structure. For example, cube-square scaling where one element changes with volume and another with area, as in the range of a projectile or ship, droplet formation, and fracture mechanics. 性能随材料、部件或结构尺寸的变化。例如，立方体平方比例，其中一个元素随体积变化，另一个元素因面积变化，如在射弹或飞船的射程、液滴形成和断裂力学中。 |
| 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。 |
| Biaxial stress | 双轴应力 |
Generalized loading of a body in a single plane with no loading normal to it. 物体在一个平面内的广义载荷，没有垂直于它的载荷。 |
| 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。 |
| Thermoelectric junction | 热电结 |
A welded, soldered, or twisted connection between the ends of two wires of dissimilar metals, as in a thermocouple. 两根不同金属线的末端之间的焊接、锡焊或绞合连接，如热电偶。 |
| Torque control | 扭矩控制 |
A system of optimizing rotor speed for a variable-speed wind turbine by controlling the torque demands of the generator. 通过控制发电机的扭矩需求来优化变速风力涡轮机的转子速度的系统。 |
| Sizing | 颗粒化 |
1. A finishing operation to ensure the specified dimensions and tolerances for a component are met. 2. (size classification) Separating an aggregate of mixed particles into groups according to size using a series of screens. 1.精加工操作，以确保满足部件的规定尺寸和公差。2.（粒度分类）使用一系列筛网根据粒度将混合颗粒的聚集体分成组。 |
| Coaxial | 同轴 |
A term for components having a common axis such as concentric shafts. 具有共同轴线的部件的术语，例如同心轴。 |
| 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。 |
| 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。 |
| Stiffness | 刚度 |
(1) The ability of a metal or shape to resist elastic deflection.(2) The rate of stress increase with respect to the rate of increase in strain induced in the metal or shape; the greater the stress required to produce a given strain, the stiffer the material is said to be. （1）金属或形状抵抗弹性变形的能力。（2）所述应力增加速率相对于在所述金属或形状中诱导的应变增加速率；产生给定应变所需的应力越大，材料就越硬。 |
| Vice | 老虎钳 |
A workshop tool used to hold a workpiece and consisting of two jaws, one fixed and the other moved by turning a screw. 一种用于夹持工件的车间工具，由两个钳口组成，一个固定，另一个通过转动螺钉移动。 |
| Full-size fastener | 全尺寸紧固件 |
Finished fastener with a shank diameter of ds ≈ d or ds > d, or screw threaded to the head, or fully threaded stud. 柄径为ds≈d或ds>d的紧固件，或螺纹连接到头部，或全螺纹螺柱。 |
| Flattening test | 压扁试验 |
This term as applied to tubing refers to a method of testing a section of tubing by flattening it until the inside walls are parallel and separated by a given distanceusually equal to three times the wall thickness for seamless tubes and five times the wall thickness for lap-welded tubes. Boiler tubes subjected to this test should show no cracks or flaws. The flattening test applied to rivets, consists in flattening a rivet head while hot to a diameter equal to 21⁄2 times the diameter of the shank or body of the rivet. Good rivet steel must not crack at the edges of the flattened head. 该术语适用于管材，是指通过压扁管材直至内壁平行并隔开给定距离（通常等于无缝钢管壁厚的三倍，搭接焊管壁厚的五倍）来测试管材截面的方法。进行该试验的锅炉管应无裂纹或缺陷。适用于铆钉的压扁试验包括在热态下压扁铆钉头，使其直径等于铆钉柄或铆钉体直径的21⁄2倍。良好的铆钉钢不得在扁平头部边缘开裂。 |
| Turbine | 涡轮 |
A turbomachine in which a rotor (turbine wheel) or impeller is caused to rotate and convert flow energy into shaft power or thrust. 转子（涡轮）或叶轮旋转并将流动能量转换为轴功率或推力的涡轮机。 |
| 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。 |
| Absolute value error | 绝对值误差 |
The magnitude of the error dlsregarding the algebraic sign, or, for a vectorial error, disregarding its function. 关于代数符号的误差幅度，或者，对于矢量误差，不考虑其函数。 |
| Pitch | 沥青节距 |
The nominal distance between two adjacent thread roots or crests. In screw threads, the distance from a point on one thread to a corresponding point on the next thread measured parallel to the axis. In the case of spur gears, indicates the size of the gear teeth and is correctly called diametral pitch. 两个相邻螺纹根部或顶部之间的标称距离。在螺纹中，从一根螺纹上的一点到下一根螺纹对应点的距离，平行于轴线测量。对于正齿轮，表示齿轮齿的尺寸，正确地称为径向节距。 |
| 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。 |
| Rolled thread | 滚制螺纹 |
A thread formed by plastically deforming the surface of the blank rather than by cutting operations. Increases fatigue life and thread strength, but is not possible (or perhaps economical) on larger sizes. 通过塑性变形坯料表面而不是通过切割操作形成的螺纹。增加疲劳寿命和螺纹强度，但不太可能（或者说是经济上不太可能）用于较大的尺寸。 |
| Water quenching | 水淬 |
A quench in which water is the quenching medium. The major disadvantage of water quenching is its poor efficiency at the beginning or hot stage of the quenching process. 以水为淬火介质的淬火。水淬的主要缺点是在淬火过程的开始或热阶段效率低。 |
| 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。 |
| ASME | ASME |
The American Society of Mechanical Engineers. 美国机械工程师学会。 |
| Caustic cracking | 苛性开裂 |
A form of stress-corrosion cracking most frequently encountered in carbon steels or iron-chromiumnickel alloys that are exposed to concentrated hydroxide solutions at temperatures of 200 to 250 °C (400 to 480 °F). Also known as caustic embrittlement. 在200至250°C（400至480°F）的温度下暴露于浓氢氧化物溶液中的碳钢或铁铬镍合金中最常遇到的一种应力腐蚀开裂形式。也称为碱脆。 |
| Stretch-bending test | 拉伸弯曲试验 |
A simulative test for sheet metal formability in which a strip of sheet metal is clamped at its ends in lock beads and deformed in the center by a punch. Test conditions are chosen so that fracture occurs in the region of punch contact. 金属板成形性的模拟试验，其中金属板条在其端部夹紧在锁珠中，并通过冲头在中心变形。选择试验条件，以便在冲头接触区域发生断裂。 |
| Actual value | 实际价值 |
The output of a plant that is being controlled, i.e. the controlled variable. Not directly accessible by the control system, as it can only be measured by a sensor which may distort the measurement. 受控设备的输出，即受控变量。控制系统不能直接访问，因为它只能由可能会扭曲测量结果的传感器测量。 |
| AISC | AISC |
The American Institute of Steel Construction. 美国钢结构学会。 |
| 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。 |
| Two-stroke engine | 二冲程发动机 |
(two-cycle engine) A petrol or diesel engine in which an air/fuel charge is introduced through an induction port, compressed and burned, expanded and then exhausted through an exhaust port. The two ports in the cylinder wall are opened and closed by the piston. There are two strokes in each revolution of the crankshaft. In total-loss lubrication petrol engines, the lubricating oil is mixed with the fuel. （双循环发动机）一种汽油或柴油发动机，其中空气/燃料通过进气口引入，压缩和燃烧，膨胀，然后通过排气口排出。气缸壁上的两个口由活塞打开和关闭。曲轴每转一圈有两个冲程。在全失润滑汽油发动机中，润滑油与燃油混合。 |
| 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。 |
| International Practical Temperature Scale (IPTS) | 国际实用温标（IPTS） |
A close approximation to the thermodynamic temperature scale based upon the triple points of hydrogen (13.8 K), neon (24.6 K), oxygen (54.4 K), argon (83.8 K), mercury (234.3 K), and water (273.2 K); the melting point of gallium (302.9 K); and the freezing points of indium (429.7 K), tin (505.1 K), zinc (692.7 K), aluminium (933.5 K), silver (1 234.9 K), gold (1 337.3 K), and copper (1 基于氢（13.8K）、氖（24.6K）、氧（54.4K）、氩（83.8K），汞（234.3K）和水（273.2K）的三相点的热力学温度标度的近似值；镓的熔点（302.9K）；铟（429.7K）、锡（505.1K）、锌（692.7K），铝（933.5K）、银（1234.9K）、金（1337.3K）和铜等。 |
| Selective heating | 局部加热 |
Intentionally heating only certain portions of a workpiece. 有意仅加热工件的某些部分。 |
| Single-shear test | 单剪试验 |
(1) A shear test similar to the double-shear test used for round-bar specimens, but that uses only one stationary shear blade. (2) A shear test that uses a sheet or thin-plate specimen. （1）一种剪切试验，类似于用于圆棒试样的双剪切试验，但仅使用一个固定剪切刀片。（2）使用薄板或薄板试样的剪切试验。 |
| Continuous precipitation | 连续沉淀 |
Precipitation from a supersaturated solid solution in which the precipitate particles grow by longrange diffusion without recrystallization of the matrix. Continuous precipitates grow from nuclei distributed more or less uniformly throughout the matrix. They usually are randomly oriented, but may form a Widmanstätten structure. 来自过饱和固溶体的沉淀，其中沉淀颗粒通过长程扩散生长而无需基质再结晶。连续析出物从在整个基体中或多或少均匀分布的核生长而来。它们通常是随机取向的，但可能形成魏氏结构。 |
| Structural frame | 结构框架 |
The underlying load-bearing framework of beams, columns, bracing, etc., of steel, concrete, brick, stone, timber etc., required to support the static and dynamic forces a building or component is subjected to, including its weight and that of its contents. 由钢、混凝土、砖、石、木材等制成的梁、柱、支撑等构成的底层承重框架，用于支撑建筑物或构件承受的静态和动态力，包括其重量及其内含物的重量。 |
| Grain coarsening | 晶粒粗化 |
A heat treatment that produces excessively large austenitic grains. 产生过大奥氏体晶粒的热处理。 |
| 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。 |
| 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。 |
| Fine pitch | 细牙螺纹 |
Fine pitch threads are often used within the automotive industry. They are more easily tapped into harder materials and have less tendency to loosen. 细螺距螺纹通常用于汽车行业。它们更容易被敲入较硬的材料中，并且不太容易松动。 |
| Absorption hygrometer | 吸收式湿度计 |
An instrument that determines the content of water vapour in the atmosphere by it being absorbed into a hygroscopic medium. 通过吸收到吸湿介质中来确定大气中水蒸气含量的仪器。 |
| Burning | 燃烧化 |
(1) Permanently damaging a metal or alloy by heating to cause either incipient melting or intergranular oxidation. See overheating, grain-boundary liquation. (2) In grinding, getting the work hot enough to cause discoloration or to change the microstructure by tempering or hardening. （1）通过加热导致初期熔化或晶间氧化而永久损坏金属或合金。参见过热、晶界液化。（2）在磨削过程中，使工件热到足以引起变色或通过回火或硬化改变微观结构。 |
| Breaking load | 断裂载荷 |
The maximum load (or force) applied to a test specimen or structural member loaded to rupture. 施加到加载到破裂的试样或结构构件上的最大载荷（或力）。 |
| Diffusion coating | 扩散涂层 |
Coating on metal for corrosion- and/or oxidation-resistance. Coatings are produced by heating a metal in contact with an alloy in powder, liquid, or gaseous form at elevated temperature such that atoms of the coating diffuse into the substrate. Examples include chromium, aluminium, or silicon on substrates such as nickel-based superalloys, steels, and refractory metals. 金属上的防腐和/或抗氧化涂层。涂层是通过在高温下加热与粉末、液体或气体形式的合金接触的金属，从而使涂层的原子扩散到基体中而产生的。实例包括基底上的铬、铝或硅，如镍基高温合金、钢和耐火金属。 |
| 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。 |
| Force ratio | 力比 |
The factor by which a simple machine multiplies an applied force. It is the ratio of the load (output force) to the effort (input force). 简单机器乘以所施加的力的因子。它是负载（输出力）与作用力（输入力）的比值。 |
| Allowable stress | 许用应力 |
The maximum stress a designer can assume that the parts will stand. It is always less than the minimum strength of the material. For example, the ASME Boiler and Pressure Vessel Code typically specifies an allowable stress that is one-quarter of the service temperature yield strength of the material. This introduces a four-to-one safety factor into the design process and is intended to compensate for uncertainties in estimates of strength, service loads, etc. 设计师可以假设零件能够承受的最大应力。它总是小于材料的最小强度。例如，ASME锅炉和压力容器规范通常指定允许应力为材料使用温度屈服强度的四分之一。这在设计过程中引入了四比一的安全系数，旨在补偿强度、服务载荷等估计的不确定性。 |
| Toughness (Unit J/m²) | 韧性（单位：J/m²） |
The ability of a metal to absorb energy and deform plastically before fracturing. 1. The ability of a material to resist crack initiation and propagation. 2. The ability of a material to absorb strain energy without fracturing. 金属在破裂前吸收能量和塑性变形的能力。1.材料抵抗裂纹萌生和扩展的能力。2.材料在不发生断裂的情况下吸收应变能的能力。 |
| Case | 包盖 |
That portion of a ferrous alloy, extending inward from the surface, whose composition has been altered so that it can be case hardened. Typically considered to be the portion of the alloy (a) whose composition has been measurably altered from the original composition, (b) that appears dark on an etched cross section, or (c) that has a hardness, after hardening, equal to or greater than a specified value. Contrast with core. 铁合金的一部分，从表面向内延伸，其成分已经改变，可以进行表面硬化。通常被认为是合金的一部分，（a）其成分与原始成分发生了可测量的变化，（b）在蚀刻横截面上呈黑色，或（c）硬化后硬度等于或大于规定值。与核心形成对比。 |
| Alloy steels | 合金钢 |
Steels that contain alloying elements such as chromium, nickel, molybdenum, manganese, silicon, tungsten, and vanadium. These are added to improve properties such as the hardenability, toughness, strength, wear resistance, and corrosion resistance compared with those of plain-carbon steel. Low-alloy steels have a total alloy content (including carbon) of less than about 8%. They are hardenable and have strength up to 30% higher than plain-carbon steels. High-alloy steels contain considerably more alloy content and are developed for specific properties such as superior corrosion and chemical resistance. 含有铬、镍、钼、锰、硅、钨和钒等合金元素的钢。添加这些是为了提高与普通碳钢相比的淬透性、韧性、强度、耐磨性和耐腐蚀性等性能。低合金钢的总合金含量（包括碳）小于约8%。它们是可硬化的，强度比普通碳钢高出30%。高合金钢含有相当多的合金含量，并针对特定性能而开发，例如卓越的耐腐蚀性和耐化学性。 |
| Strain-hardening exponent (n value) | 应变硬化指数（n值） |
The value n in the relationship σ = Kεn, where σ is the true stress, ε is the true strain, and K, the strength coefficient, is equal to the true stress at a true strain of 1.0. The strain hardening exponent is equal to the slope of the true stress/true strain curve up to maximum load, when plotted on log-log coordinates. The n-value relates to the ability of a sheet of material to be stretched in metalworking operations. The higher the n-value, the better the formability(stretchability). Also known as the strain-hardening coefficient. 关系式σ=Kεn中的值n，其中σ是真应力，ε是真应变，K是强度系数，等于真应变为1.0时的真应力。在对数坐标上绘制时，应变硬化指数等于真应力/真应变曲线的斜率，直到最大载荷。n值与一片材料在金属加工操作中拉伸的能力有关。n值越高，成形性（拉伸性）越好。也称为应变硬化系数。 |
| 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。 |
| Bolt | 螺栓 |
(machine bolt) A fastener in the form of an externally-threaded cylinder with a head on one end that is inserted through holes in assembled parts that are then held together by a nut tightened on to the thread. A bolt has an unthreaded region below the head so that when located in a hole, transverse loads are borne by two plain cylindrical surfaces in contact. In contrast, use of a machine screw, that has threads all along its length, results in threads bearing against the plain surface of a hole. Officially, a threaded fastener designed to be used with a nut. （机械螺栓）外螺纹圆柱状紧固件：一端有头的紧固件，通过装配零件上的孔插入，然后通过拧紧到螺纹上的螺母固定在一起。螺栓头部下方有一个无螺纹区域，因此当位于孔中时，横向载荷由两个接触的平面圆柱面承担。相反，使用沿其长度具有螺纹的机器螺钉，会导致螺纹支撑在孔的平面上。正式情况下，螺纹紧固件设计用于与螺母一起使用。 |
| Radial marks | 径向标记 |
Lines on a fracture surface that radiate from the fracture origin and are visible to the unaided eye or at low magnification. Radial lines result from the intersection and connection of brittle fractures propagating at different levels. Also known as shear ledges. 断裂表面上的线，从断裂起点辐射，肉眼可见或在低放大率下可见。径向线是在不同层面上传播的脆性断裂相交和连接的结果。也称为剪切壁架。 |
| Mechatronics | 机电一体化 |
The integration of mechanical engineering, electrical engineering, electronic engineering, and software engineering. 机械工程、电气工程、电子工程和软件工程的集成。 |
| Combustion efficiency | 燃烧效率 |
(source efficiency, ηCOMB) A performance measure for combustion equipment defined by ηCOMB = amount of heat released during combustion/(calorific value of the fuel burned). （源效率，ηCOMB）燃烧设备的性能度量，定义为ηCOMB=燃烧过程中释放的热量/（燃烧燃料的热值）。 |
| Punch | 冲床 |
1. A hand tool with a sharp point, used to mark the position of a hole centre in a workpiece prior to drilling. 2. A flat-ended tool with sharp edges, used to shear out a hole in a plate that is supported underneath on a die having a slightly larger same-shaped orifice. 1.一种带有尖头的手动工具，用于在钻孔前标记工件中孔中心的位置。2.一种具有锐边的平头工具，用于剪切板上的孔，该板支撑在具有稍大相同形状孔口的模具下方。 |
| Degradation failure | 退化失效 |
Failure of a system, component, or structure owing to material degradation. 由于材料退化导致的系统、组件或结构失效。 |
| Frequency | 频率 |
(temporal frequency, f) (Unit Hz) The number of cycles per second in an oscillation or the repetition rate for a cyclic process. （时间频率，f）（单位Hz）振荡中每秒的周期数或循环过程的重复率。 |
| Chilled castings | 冷铸件 |
Iron castings cooled at a rate that results in white iron (slow enough to avoid the formation of martensite, yet fast enough to prevent any silicon present from causing decomposition of cementite into iron and graphite). 铸铁件以产生白口铁的速度冷却（足够慢以避免形成马氏体，但足够快以防止任何存在的硅导致渗碳体分解成铁和石墨）。 |
| Essential conditions | 必要条件 |
Each type of failure to which bolted joints are subject is set up by three or four conditions. The conditions vary, depending on the mode of failure, but never number more than four. Eliminating any one of the essential conditions for a particular type of failure can prevent that type of failure. 螺栓连接所遭受的每种类型的故障都由三个或四个条件确定。根据故障模式的不同，情况会有所不同，但数量不得超过四个。消除特定类型故障的任何一个基本条件都可以防止该类型故障。 |
| Pressure control valve | 压力控制阀 |
A valve used to set the pressure level in a pressure vessel or piping system. 用于设置压力容器或管道系统中压力水平的阀门。 |
| Endurance | 耐力 |
The capacity of a material to withstand repeated application of stress. 材料承受反复施加应力的能力。 |
| Horizontal batch furnace | 卧式间歇炉 |
A versatile batch-type furnace that can give light or deep case depths, and because the parts are not exposed to air, horizontal batch furnaces can give surfaces almost entirely free of oxides. 一种多功能间歇式炉，可以提供浅或深的外壳深度，并且由于零件不暴露在空气中，卧式间歇式炉可以使表面几乎完全没有氧化物。 |
| 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。 |
| Pascal (Pa) | 帕斯卡（Pa） |
The SI unit of pressure, 1 Pa = 1 N/m². 压力的国际单位制，1Pa=1N/m²。 |
| Fatigue wear | 疲劳磨损 |
Wear of a solid surface caused by fracture arising from material fatigue. 由材料疲劳引起的断裂引起的固体表面磨损。 |
| Computed path control | 计算路径控制 |
In CNC or robotics, the use of a control program to determine the required path for the tool or end effector. This required path forms the set points for the motor controllers moving the machine tool or robot. 在CNC或机器人技术中，使用控制程序来确定工具或末端执行器所需的路径。这条所需的路径形成了用于移动机床或机器人的电机控制器的设定点。 |
| Swept volume (Unit m³) | 扫描体（单位m³) |
In the cylinder of a piston engine or other device, the volume between top and bottom dead centre positions of a piston; equal to πR2S where R is the piston radius and S is the stroke. 在活塞发动机或其他装置的气缸中，活塞上止点和下止点位置之间的体积；等于πR2S，其中R是活塞半径，S是冲程。 |
| Shoulder | 轴肩 |
The portion of a shaft, stepped component, or flanged component, where a change in diameter or other dimension occurs. Even for a nominal step change, in practice there will be a radius where shoulder and shaft meet in order to avoid too severe a stress concentration. 轴、阶梯部件或法兰部件的直径或其他尺寸发生变化的部分。即使是名义阶跃变化，在实践中，肩部和轴相交处也会有一个半径，以避免出现过严重的应力集中。 |
| Transgranular fracture | 穿晶断裂 |
Fracture in crystalline materials where the path of cracking is predominantly across grains. 晶体材料中的断裂，其中裂纹路径主要跨越晶粒。 |
| 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。 |
| Shear strength | 抗剪强度 |
The maximum shear stress that a material is capable of sustaining. Shear strength is calculated from the maximum load during a shear or torsion test and is based on the original dimensions of the cross section of the specimen. 材料能够承受的最大剪切应力。抗剪强度根据剪切或扭转试验期间的最大载荷计算，并基于试样横截面的原始尺寸。 |
| Stator | 定子 |
A ring of non-rotating blades or nozzles in a compressor, turbine, or other turbomachine, which directs fluid flow into an adjacent rotor. 涡轮压缩机、涡轮或其他涡轮机械中的一圈不旋转的叶片或喷嘴，将流体引导到相邻的转子中。 |
| Final annealing | 最终退火 |
An imprecise term used to denote the last anneal given to a nonferrous alloy prior to shipment. 一个不精确的术语，用于表示有色金属合金在装运前的最后一次退火。 |
| Rotary pump | 旋转泵 |
A positive-displacement pump that pumps a liquid by rotation of internal components, such as a gear pump, lobe pump (similar to a Roots blower), or progressivecavity pump. 通过内部部件的旋转来泵送液体的容积泵，如齿轮泵、凸轮泵（类似于罗茨鼓风机）或螺杆泵。 |
| Universal joint (Hooke’s joint) | 万向节（胡克接头） |
A double-pivoted connection that allows power and torque to be transmitted between two shafts at an angle to each other. For constant driving angular velocity of the input yoke, the angular velocity of the output yoke fluctuates by amounts depending on the angle of intersection of the shafts. Speeds of the driving and driven shafts may be made identical (giving a constant-velocity joint) when an intermediate shaft, at each end of which there is a universal joint, is interposed. The driving and driven shafts must be equally inclined to the intermediate shaft, the two forks of which must lie in the same plane. 一种双枢轴连接，允许动力和扭矩以一定角度在两个轴之间传递。对于输入磁轭的恒定驱动角速度，输出磁轭的角速度根据轴的相交角度波动。当插入中间轴时，驱动轴和从动轴的速度可以相同（提供恒定速度接头），中间轴的两端都有万向节。主动轴和从动轴必须与中间轴倾斜相等，中间轴的两个叉必须位于同一平面内。 |
| Intermediate annealing | 中间退火 |
Annealing wrought metals at one or more stages during manufacture and before final treatment. 在制造过程中和最终处理之前的一个或多个阶段对锻造金属进行退火。 |
| Radial wave equation | 径向波动方程 |
A differential equation describing the transmission of a wave in a system with radial symmetry. 描述波在径向对称系统中传输的微分方程。 |
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