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Condenser vacuum 冷凝器真空 The sub-atmospheric pressure imposed on the condenser of a steam-power plant which leads to an appreciable increase in overall efficiency.
施加在蒸汽发电厂冷凝器上的低于大气压的压力导致整体效率显着提高。
Circlip 卡簧 (snap ring) An external or internal retaining ring that locates parts of circular cross section in an axial direction. It consists of an incomplete ring, with holes on either side of the gap, that may be expanded by a plier-like tool to pass into a groove in a shaft or contracted to pass into a groove in a bore.
(卡环)在轴向定位圆形横截面部分的外部或内部保持环。它由一个不完整的环组成,在间隙的任一侧都有孔,可以通过钳形工具将其扩展以进入轴中的凹槽或收缩以进入孔中的凹槽。
Refractory materials 耐火材料 Metals or ceramics that do not melt when exposed to temperature above about 1 500°C or deteriorate rapidly in a continuous temperature above about 550°C.
当暴露于高于约1500°C的温度时不熔化或在高于约550°C的连续温度下快速劣化的金属或陶瓷。
Centi (c) 厘(c) An SI unit prefix indicating a multiplier of 0.01; thus centimetre is a unit of length equal to one one-hundredth of a metre or 10 mm.
表示乘数0.01的SI单位前缀;因此厘米是长度单位,等于一米的百分之一或10毫米。
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、
Critical load (Unit N) 临界负荷(单位N) 1. The applied load that causes propagation of an existing crack of known length, and hence fracture of a component or structure. 2. The applied load that results in buckling of a column of given end fixity.
1.导致已知长度的现有裂纹扩展并因此导致部件或结构断裂的施加荷载。2.导致具有给定端部固定性的柱屈曲的施加荷载。
Bias pressure (Unit Pa) 偏压(单位Pa) In a fluidic device controlled by pressure difference, the magnitude of that difference.
在由压力差控制的流体装置中,该差值的大小。
Crack size (a) 裂纹尺寸(a) A lineal measure of a principal planar dimension of a crack. This measure is commonly used in the calculation of quantities descriptive of the stress and displacement fields. In practice, the value of crack size is obtained from procedures for measurement of physical crack size, original crack size, or effective crack size, as appropriate to the situation under consideration.
裂纹主平面尺寸的线性度量。这种测量通常用于计算描述应力场和位移场的量。在实践中,裂纹尺寸的值是通过测量物理裂纹尺寸、原始裂纹尺寸或有效裂纹尺寸的程序获得的,视情况而定。
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。
Observed value 观测值 The particular value of a characteristic determined as a result of a test or measurement.
作为测试或测量结果确定的特性的特定值。
Grain growth 晶粒生长 An increase in the average size of the grains in polycrystalline metal, usually as a result of heating at elevated temperature.
多晶金属中晶粒平均尺寸的增加,通常是高温加热的结果。
Transverse direction 横向 Literally, the “across” direction, usually signifying a direction or plane perpendicular to the direction of working. In rolled plate or sheet, the direction across the width is often called long transverse, and the direction through the thickness, short transverse.
从字面上看,“横穿”方向,通常表示与工作方向垂直的方向或平面。在轧制钢板或薄板中,横跨宽度的方向通常称为长横向,穿过厚度的方向称为短横向。
Martempering 淬火 (1) A hardening procedure in which an austenitized ferrous workpiece is quenched into an appropriate medium whose temperature is maintained substantially at the Ms of the workpiece, held in the medium until its temperature is uniform throughout–but not long enough to permit bainite to form–and then cooled in air. The treatment is frequently followed by tempering. (2) When the process is applied to carburized material, the controlling Ms temperature is that of the case. This variation of the process is frequently called marquenching.
(1)一种淬火工艺,将奥氏体化铁质工件淬火到适当的介质中,该介质的温度基本保持在工件的Ms,保持在该介质中直到其温度在整个过程中均匀,但不足以形成贝氏体,然后在空气中冷却。处理后经常进行回火。(2) 当该工艺应用于渗碳材料时,控制Ms温度与实际情况相同。这个过程的变化经常被称为淬火。
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。
Check valve 止回阀 (clack valve, non-return valve) A mechanical device that allows fluid flow in one direction only. The numerous designs include ball, diaphragm, disc, lift, split disc, and swing check valves.
(瓣阀、止回阀)一种仅允许流体单向流动的机械装置。众多设计包括球阀、隔膜阀、盘阀、升降阀、分体盘阀和旋启式止回阀。
Amontons friction 阿蒙顿摩擦 (Coulomb friction) Friction between surfaces where the ratio of the frictional force F to the normal force N is constant and independent of the area in contact.
(库仑摩擦)摩擦力F与法向力N之比恒定且与接触面积无关的表面之间的摩擦。
Magnetic test 磁性测试 Method used to test heat extraction rates of various quenchants. The test works by utilizing the change in magnetic properties of metals at their Curie point–the temperature above which metals lose their magnetism.
用于测试各种淬火剂的热提取率的方法。该测试通过利用金属在居里点(即金属失去磁性的温度)的磁性变化来进行。
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。
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。
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。
Water column 水柱 Water in a tube, which may be vertical or inclined. If the tube is open to the atmosphere, the vertical height h from a datum level to the water surface is a measure of the water static pressure p at the datum level given by p − B = ρgh where B is the barometric pressure, ρ denotes the water density, and g is the acceleration due to gravity.
管道中的水,可以是垂直的或倾斜的。如果管道向大气开放,则从基准面到水面的垂直高度h是基准面处水静压p的量度,由p给出−B=ρgh,其中B是大气压力,ρ表示水密度,g是重力引起的加速度。
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。
Compression 压缩 1. Loading, the principal effect of which is to squeeze and shorten a component or testpiece. 2. The reduction in volume and increase in density of a substance as a consequence of increased pressure.
1.加载,其主要作用是挤压和缩短部件或试件。2.压力增加导致物质体积减少和密度增加。
Grain-boundary liquation 晶界液化 An advanced stage of overheating in which material in the region of austenitic grain boundaries melts.
奥氏体晶界区域的材料熔化的过热阶段。
Dimensioning 尺寸标注 The specification on an engineering drawing of the size (e.g. length, radius, angle, or spacing) and the relative location (e.g. angular position) of each feature of a component. The numerical values often include the tolerances. There should be no more dimensions than are necessary to manufacture the component.
工程图纸上对部件每个特征的尺寸(例如长度、半径、角度或间距)和相对位置(例如角位置)的规范。数值通常包括公差。尺寸不应超过制造组件所需的尺寸。
Altitude 高度 (Unit m) Vertical height measured relative to a specified datum such as sea level.
(单位m)相对于特定基准(例如海平面)测量的垂直高度。
Critical compression ratio 临界压缩比 1. The compression ratio for incipient knock of hydrocarbon fuels as determined in a variable-compression single-cylinder piston engine. 2. The compression ratio at which an air–fuel mixture will spontaneously ignite due to the temperature increase produced.
1.在可变压缩单缸活塞发动机中确定的烃类燃料初期爆震的压缩比。2.空气-燃料混合物由于产生的温度升高而自燃的压缩比。
Solenoid 螺线管 A coil of electrically-conducting wire wrapped around a metal core, typically iron, to produce a magnetic field and hence a force on the core when an electric current passes through the coil. Solenoids are widely used to produce linear movement to actuate valves (solenoid valves) and other devices.
绕在金属芯(通常为铁)上的导线线圈,当电流通过线圈时产生磁场,从而在芯上产生力。电磁阀广泛用于产生线性运动以驱动阀(电磁阀)和其他装置。
Swift cup test 斯威夫特杯测试 A simulative cupping test in which circular blanks of various diameters are clamped in a die ring and deep drawn into cups by a flat-bottomed cylindrical punch.
一种模拟拔杯试验,将不同直径的圆形坯料夹紧在模环中,并用平底圆柱冲头将其深拉入杯中。
Mole number (N) 摩尔数(N) The number of moles in a given mass m of a substance, equal to m divided by the molar mass of the substance.
摩尔数物质给定质量m中的摩尔数,等于m除以物质的摩尔质量。
Decompression chamber 减压舱 A chamber in which ambient-air pressure can be increased to levels found in deep-sea diving. It is used to gradually acclimatize divers back to normal conditions and avoid ‘the bends’.
环境气压可以提高到深海潜水水平的腔室。它用于逐渐使潜水员适应正常条件,避免“弯曲”。
Twist 扭转 The helix produced in a cylindrical component, such as a shaft, wire, tensioned cable, or rope, when one end is rotated relative to the other. Measured either as the number of turns per unit length, or by the helix angle (twist angle).
当一端相对于另一端旋转时,在圆柱形部件(如轴、钢丝、张紧电缆或绳索)中产生的螺旋。以每单位长度的圈数或螺旋角(扭曲角)测量。
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。
Sound pressure (Unit μPa) 声压(单位:μPa) The instantaneous deviation of pressure from the ambient pressure caused by the passage of a sound wave, which can be measured by a microphone in air and a hydrophone in water.
声波传播引起的压力与环境压力的瞬时偏差,可通过空气中的麦克风和水中的水听器测量。
Vacuum relief valve 真空安全阀 A valve that admits gas to a system under vacuum, should the degree of vacuum become excessive.
如果真空度过高,允许气体在真空下进入系统的阀门。
Nominal size 公称尺寸 The intended size of a component. The actual size will depend on manufacturing tolerances.
组件的预期尺寸。实际尺寸取决于制造公差。
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。
Constant-force spring 恒力弹簧 A spring that has the same restoring force regardless of displacement. The most common type takes the form of a coiled strip that, owing to tight coiling during manufacture, is pre-stressed (a steel measuring tape is an example). The uncoiling force is approximately constant as the change of curvature of the strip is approximately constant. Not to be confused with a clockwork spring from which power can be obtained.
无论位移如何,具有相同恢复力的弹簧。最常见的类型是卷绕带,由于制造过程中的紧密卷绕,该卷绕带是预应力的(钢卷尺就是一个例子)。随着带材曲率的变化近似恒定,开卷力近似恒定。不要与可获得动力的发条弹簧混淆。
Heat balance (heat budget) 热平衡(热预算) An energy balance involving only heat transfer across the system boundary and the stored energy.
仅涉及跨系统边界的热传递和存储能量的能量平衡。
Accommodation 适应能力 The ability of a robot to respond to changes in the environment.
机器人对环境变化做出反应的能力。
Statistic 统计 A summary value calculated from the observed values in a sample.
根据样本中的观察值计算得出的汇总值。
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。
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。
Ideal gas laws 理想气体定律 The law relating pressure, temperature and volume of an ideal (perfect) gas pV = mRT, where R is the gas constant. The law implies that at constant temperature T, the product of pressure p and volume V is constant (Boyle’s law), and at constant pressure, the volume is proportional to the temperature (Charles’ law).
与理想(完美)气体的压力、温度和体积相关的定律pV=mRT,其中R是气体常数。该定律意味着在恒定温度T下,压力p和体积V的乘积是恒定的(波义耳定律),而在恒定压力下,体积与温度成正比(查尔斯定律)。
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。
High strength low alloy steels 高强度低合金钢 (HSLA steels) Steels with various micro-alloying elements such as copper, nickel, chromium, molybdenum, niobium, titanium, and vanadium in small quantities that give improved strength (as high as 900 MPa) and corrosion properties compared with plain carbon steels. Improvements are due to grain refinement and precipitation hardening, better control of the chemistry during steel making, and accurate rolling temperatures.
(HSLA钢)是含有各种微合金元素的钢,如少量的铜、镍、铬、钼、铌、钛和钒,与普通碳钢相比,具有更好的强度(高达900MPa)和腐蚀性能。这些改进归功于晶粒细化和沉淀硬化、炼钢过程中更好的化学控制以及精确的轧制温度。
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。
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。
Intercritical annealing 临界退火 Any annealing treatment that involves heating to, and holding at, a temperature between the upper and lower critical temperatures to obtain partial austenitization, followed by either slow cooling or holding at a temperature below the lower critical temperature.
任何退火处理,包括加热至并保持在上临界温度和下临界温度之间的温度,以获得部分奥氏体化,然后缓慢冷却或保持在低于下临界温度的温度。
Absolute temperature (Unit K) 绝对温度(单位K) A temperature T measured relative to absolute zero, 0 K or −273.15°C, the lowest temperature achievable at which molecular motion vanishes so that a body would have zero heat energy. The kelvin is equal in magnitude to the degree Celsius (°C). The kelvin temperature scale (kelvin absolute temperature scale) is an absolute or thermodynamic temperature scale derived from the Celsius scale: T(K) = T(°C) + 273.15. The Rankine absolute scale is derived from the Fahrenheit scale such that T(R) = T(°F) + 459.67, i.e. a scale relative to 0 R or −459.67°F where R is the Rankine degree symbol and °F is the Fahrenheit symbol.
相对于绝对零、0K或0K测量的温度T−273.15°C,分子运动消失的最低温度,因此物体的热能为零。开尔文的大小等于摄氏度(℃)。开尔文温度标度(开尔文绝对温度标度)是从摄氏标度得出的绝对或热力学温度标度:T(K)=T(°C)+273.15。兰金绝对标度是从华氏标度得出,使得T(R)=T(°F)+459.67,即相对于0R或0R的标度−459.67°F,其中R是朗肯度符号,°F是华氏度符号。
Maraging steels 马氏体时效钢 Very high-strength iron alloys named after ‘martensitic’ and ‘aging’. They contain nickel, chromium, cobalt, and molybdenum, and form martensite on air cooling with a strength of about 1 GPa. When reheated to about 500°C and aged for some hours, a room-temperature strength of some 2.4 GPa is reached.
以“马氏体”和“时效”命名的超高强度铁合金。它们含有镍、铬、钴和钼,在空气冷却下形成强度约为1GPa的马氏体。当再加热至约500°C并老化数小时时,室温强度达到约2.4GPa。
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。
PSI (pounds per square inch) PSI(磅/平方英寸) Pressure measurement. Psia (pounds per square inch absolute) measures actual pressure with no allowance for atmospheric pressure. Psig (pounds per square inch gauge) measures pressure with the gauge set to zero (0) at atmospheric pressure (14.7 psia). In other words psig = psia – 14.7.
压力测量。Psia(绝对磅/平方英寸)测量实际压力,不考虑大气压力。Psig(磅/平方英寸表压)在大气压(14.7 psia)下,将表压设置为零(0)时测量压力。换句话说,psig=psia–14.7。
Kilo (k) 千(k) An SI unit prefix indicating a multiplier of 103; thus kilometre (km) is a unit of length equal to one thousand metres.
表示乘法器103的SI单位前缀;1千米是长度单位,等于1000米。
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。
Combustion deposit 燃烧沉积物 Ash, carbon, and other incombustible solids, often due to impurities in the fuel, that build up on any surfaces exposed to products of combustion. They can lead to corrosion, reduced heat transfer and so higher flue-gas temperatures and reduced efficiency.
灰、碳和其他不燃固体,通常是由于燃料中的杂质,在暴露于燃烧产物的任何表面上堆积。它们会导致腐蚀、传热降低,从而导致烟气温度升高和效率降低。
Ackerman linkage 阿克曼装置 A steering linkage on a motor vehicle that approximately gives rolling without slipping of both wheels about the turning point. This is achieved by having the inner stub axle (on the inside of the turning curve) move through a greater angle than the outer stub axle.
机动车辆上的一种转向联动装置,在转向点附近两个车轮几乎不会打滑。这是通过使内短轴(在转弯曲线的内侧)比外短轴移动更大的角度来实现的。
Bánki turbine 班基涡轮机 A cross-flow, impulse-type water turbine for very low heads in which a jet of water in the form of a flat sheet passes transversely through the turbine, so going through the runner twice. The thin runner blades which run horizontally across the turbine parallel to the axis of rotation are profiled in cross section.
一种用于非常低水头的横流脉冲式水轮机,其中平板形式的水射流横向穿过涡轮机,因此穿过转轮两次。平行于旋转轴水平穿过涡轮机的薄转轮叶片在横截面上具有轮廓。
Remaining stress 残留应力 The stress remaining at a given time during a stress-relaxation test. See also stress relaxation.
在应力松弛试验期间在给定时间内剩余的应力。参见压力松弛。
Density 密度 The mass per unit volume of a solid material. (mass density, ρ) (Unit kg/m³) The mass per unit volume of a substance that satisfies the continuum assumption. The reciprocal of specific volume.
固体材料每单位体积的质量。(质量密度,ρ)(单位kg/m³)满足连续统假设的物质每单位体积的质量。和比容相关联。
Transverse strain 横向应变 Linear strain in a plane perpendicular to the loading axis of a specimen.
垂直于试样加载轴的平面内的线性应变。
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。
Mass flow rate (ṁ) (Unit kg/s) 质量流量(ṁ)(单位kg/s) The mass of a material, usually a fluid or powder, that flows across a surface or through a pipe or other duct per unit time. The corresponding mass flux (ṁ″), with unit kg/s.m², is the mass flow across a real surface or through a duct, divided by the surface or cross-sectional area A, i.e. ṁ″ = ṁ/A or ṁ″ = ρV where ρ is the material density and V is its velocity normal to the surface.
单位时间内流过表面或通过管道或其他管道的材料质量,通常是流体或粉末。相应的质量通量(ṁ″),单位为kg/s.m²,是通过真实表面或通过管道的质量流量除以表面或横截面积A,即ṁ″=ṁ/A或ṁ″=ρV,其中ρ是材料密度,V是其垂直于表面的速度。
Fastener standard 紧固件标准 A document which details the attributes of a finished fastener and includes such characteristics as geometry, material or chemistry, heat treatment, finish, testing lot size, and packaging.
详细说明紧固件属性的文件,包括几何形状、材料或化学、热处理、表面处理、测试批量和包装等特性。
Joule 焦耳 The SI unit of energy. One joule is the work done by a force of one newton acting over a distance of one metre. The symbol is J, where 1 J = 1 N m.
国际单位制能量单位。一焦耳是一牛顿的力在一米的距离上所做的功。符号为J,其中1j=1m。
Crest of screw thread 螺纹牙顶 The top surface joining the two sides of flanks of a thread.
连接螺纹牙侧两侧的顶面。
Freezing point 冰点 The temperature at which a substance changes phase (or state) from liquid to solid. The freezing point for most substances increases as pressure increases. The reverse process, from solid to liquid, is melting; melting point is the same as freezing point.
物质从液态变为固态的温度。大多数物质的冰点随着压力的增加而增加。从固体到液体的逆过程是熔化;熔点与凝固点相同。
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。
Absolute specific gravity 绝对比重 The ratio of the weight of any volume of a substance to the weight of an equal volume of a reference substance at the same temperature, often water at 4°C, both measured in a vacuum to avoid any effect of buoyancy.
在相同温度下,任何体积的物质的重量与等体积的参考物质的重量之比,通常是4°C的水,两者都是在真空中测量的,以避免任何浮力的影响。
Plug 螺塞 1. An object, usually tapered, used to block a hole to prevent fluid from escaping or flowing. 2. The central moveable part of a valve. 3. In the flow of a yield-stress fluid through a pipe or duct, the central region is often assumed to take the form of a plug with uniform axial velocity. 4. In thermoforming, a shaping tool that forces a heated plastic sheet into a female mould.
1.一种物体,通常为锥形,用于堵塞孔以防止流体逸出或流动。2.阀门的中心可移动部分。3.在屈服应力流体通过管道或管道的流动中,中心区域通常假定为具有均匀轴向速度的塞子形式。4.在热成型技术中,一种成型工具,将加热的塑料板压入阴模中。
Range of stress (Sr) 应力范围(Sr) The algebraic difference between the maximum and minimum stress in one cycle—that is, Sr = Smax – Smin
一个循环中最大和最小应力之间的代数差,即Sr=Smax–Smin
Brine quenching 盐水淬火 A quench in which brine (salt water-chlorides, carbonates, and cyanides) is the quenching medium. The salt addition improves the efficiency of water at the vapor phase or hot stage of the quenching process.
一种淬火,其中盐水(盐水-氯化物、碳酸盐和氰化物)是淬火介质。添加盐提高了水在淬火过程的气相或热阶段的效率。
Tightness 紧密度 A measure of the mass leak rate from a gasketed joint.
垫圈接头质量泄漏率的测量值。
Melting point (Unit K or °C) 熔点(单位K或°C) The temperature at which a solid material undergoes the phase change to a liquid at a specified pressure, usually 1 atm. Pure metals and eutectics have single-valued melting points, while alloys with other compositions melt over a range of temperature such that there is a well-defined start and end to the melting process, but there are states in between where solid and liquid are both present.
在特定压力下,固体材料发生相变为液体的温度,通常为1大气压。纯金属和共晶具有单值熔点,而具有其他成分的合金在一定温度范围内熔化,熔化过程有一个明确的起点和终点,但其间存在固态和液态并存的状态。
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。
Screw feeder 螺旋给料机 A mechanism for handling bulk materials in which a rotating helicoidal screw moves the material axially forward. Similar to a screw conveyor, but required to discharge material at a controlled rate very accurately. It operates with the screw completely full.
一种用于处理散装物料的机构,其中旋转的螺旋螺杆使物料轴向向前移动。类似于螺旋输送机,但需要以受控速率非常精确地排出物料。它在螺杆完全充满的情况下运行。
Embedment 嵌入 Localized plastic deformation in heavily loaded fasteners allows one part to sink into, or smooth the surface of, a softer or more heavily loaded second part. Nuts embed themselves in joint surfaces. Bolt threads embed themselves in nut threads, etc.
重载紧固件中的局部塑性变形允许一个零件陷入较软或更重载的第二零件中,或使其表面光滑。螺母嵌入接合面中。例如螺栓螺纹嵌入螺母螺纹等。
Minute (min) 分钟(min) A non-SI unit of time. The conversion to SI is 1 min = 60 s.
非SI时间单位。转换为1分钟=60秒。
Temper 回火 (1) In heat treatment, reheating hardened steel or hardened cast iron to some temperature below the eutectoid temperature for the purpose of decreasing hardness and increasing toughness. The process also is sometimes applied to normalized steel. (2) In tool steels, temper is sometimes used, but inadvisedly, to denote the carbon content. (3) In nonferrous alloys and in some ferrous alloys (steels that cannot be hardened by heat treatment), the hardness and strength produced by mechanical or thermal treatment, or both, and characterized by a certain structure, mechanical properties, or reduction in area during cold working.
(1)在热处理中,将硬化钢或硬化铸铁重新加热到共析温度以下的温度,以降低硬度和增加韧性。该工艺有时也适用于正火钢。(2)在工具钢中,有时使用回火来表示碳含量,但这是不恰当的。(3)在非铁合金和一些铁合金(不能通过热处理硬化的钢)中,通过机械或热处理或两者产生的硬度和强度,其特征是在冷加工过程中具有一定的结构、机械性能或面积减小。
Thread milling 螺纹铣削 Thread milling is a method of cutting screw threads with a milling cutter in a thread mill. Thread milling cutters are either single form or multiple form and are used in either conventional or planetary thread mills.
螺纹铣削是在螺纹铣刀中用铣刀切削螺纹的一种方法。螺纹铣刀为单形或多形,用于传统或行星式螺纹铣刀。
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。
Materials science 材料科学 The study of the properties, behaviour, and application of solid substances such as metals, ceramics, glasses, polymers, composites, biomaterials, and semiconductors, at all scales from the atomic to the macroscopic. The topic has its origins in metallurgy.
研究金属、陶瓷、玻璃、聚合物、复合材料、生物材料和半导体等固体物质的特性、行为和应用,涵盖从原子到宏观的所有范围。起源于冶金学。
Anelastic 无弹性 Literally ‘not elastic’, but in practice used for materials that display timedependent recovery on unloading.
字面意思是“没有弹性”,但实际上用于在卸载时显示随时间恢复的材料。
Balance piston 平衡活塞 (balance drum, dummy piston) A disc attached to the shaft of a turbine or compressor, to one side of which high or low pressure is applied to counteract the axial thrust produced by the pressure change across the machine. A form of thrust bearing.
(平衡鼓,假活塞)连接在涡轮机或压缩机轴上的圆盘,在其一侧施加高压或低压,以抵消机器压力变化产生的轴向推力。推力轴承的一种形式。
Centrifugal clutch 离心离合器 A clutch that engages and disengages at a defined speed of rotation of the driving shaft, as when expanding friction shoes act against the inside of a drum.
一种离合器,以驱动轴规定的旋转速度接合和分离,如当膨胀的摩擦片作用在滚筒内部时。
Sinter (sintering) 烧结 A solid-state diffusion densification process for the production of objects, particularly porous objects, from raw material in powder, granular, mesh, perforatedsheet, or fibre form by heating to a temperature below the melting point until the constituents bond together. It is used for ceramic materials and metals. Applications of sintered materials include filtration, separation, flow control, fluidization, and noise reduction. The bonding of adjacent surfaces in a mass of particles by molecular or atomic attraction on heating at high temperatures below the melting temperature of any constituent in the material. Sintering strengthens a powder mass and normally produces densification and, in powdered metals, recrystallization.
一种固态扩散致密化工艺,用于从粉末、粒状、网状、穿孔片或纤维形式的原材料中生产物体,尤其是多孔物体,方法是加热至低于熔点的温度,直到成分结合在一起。它用于陶瓷材料和金属。烧结材料的应用包括过滤、分离、流量控制、流化和降噪。在低于材料中任何成分熔化温度的高温下加热时,通过分子或原子引力将大量颗粒的相邻表面结合起来。烧结增强了粉末质量,通常会产生致密化,在粉末金属中还会产生再结晶。
Elastic limit 弹性极限 The maximum stress which a material is capable of sustaining without any permanent strain (deformation) remaining on complete release of the stress.
材料在完全释放应力时能够承受的最大应力,且不会留下任何永久应变(变形)。
Clearance fit 间隙配合 A range of clearances ranging from close sliding to loose running, i.e. a fit in which the limits for the mating parts always permit assembly.
从紧密滑动到松动运行的一系列间隙,即配合零件的限制始终允许组装的配合。
Torsion spring 扭簧 1. A spring in the form of a torsion bar. 2. A helical spring to which torque can be applied at the ends.
1.一种扭杆形式的弹簧。2.一种螺旋弹簧,其端部可施加扭矩。
ANSI ANSI The acronym for American National Standards Institute.
美国国家标准协会的缩写。
Counter sink 台面水槽 To cut or shape a depression in an object so that the head of a screw may set flush or below the surface.
在物体上切割或塑造一个凹陷,使螺钉的头部可以齐平或低于表面。
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。
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。
Brake fluid 制动液 The hydraulic fluid used to transmit force to the pistons in disc brakes or the wheel cylinders in drum brakes. Requirements include a high boiling point and low hygroscopy.
用于将力传递到盘式制动器中的活塞或鼓式制动器中的轮缸的液压油。要求包括高沸点和低吸湿性。
Turbomachine 涡轮机械 (rotodynamic machine) A machine in which there is a transfer of energy between a continuous stream of fluid and a component, called a rotor, rotating about a fixed axis. Fans and turbines (gas, hydraulic, steam, or wind) are turbomachines in which energy is transferred to the rotor, causing it to rotate. Pumps and compressors are turbomachines in which energy is transferred from the externally driven rotor to the fluid.
(旋转动力机器)在连续的流体流和绕固定轴旋转的部件(称为转子)之间进行能量传递的机器。风扇和涡轮机(燃气、液压、蒸汽或风力)是涡轮机械,其中能量传递到转子,使其旋转。泵和压缩机是涡轮机械,其中能量从外部驱动的转子传递到流体。
Crest clearance (Unit m) 顶隙(单位米) For screw threads and gearing, the radial clearance between the crest of a thread (or gear) and the root of the engaging thread (or gear).
对于螺纹和齿轮,螺纹(或齿轮)的顶部与啮合螺纹(或齿轮)的根部之间的径向间隙。
Torsion bar 扭杆 A metal bar designed to act as an elastic spring when torque is applied.
当施加扭矩时用作弹性弹簧的金属棒。
Metre (m) 米(m) The base unit of length in the SI system. It is equal to the distance travelled by light in vacuum in 1/299 792 458 seconds.
SI系统中长度的基本单位。它等于光在真空中在1/299792458秒内传播的距离。
Minimum stress-intensity factor (Kmin) 最小应力强度因子(Kmin) In fatigue, the minimum value of the stress-intensity factor in a cycle. This value corresponds to the minimum loadwhen the load ratio is 0 and is taken to be 0 when the load ratio is ≤0.
在疲劳中,一个循环中应力强度因子的最小值。该值对应于负载比为0时的最小负载,当负载比为≤0
Volume (Unit m³) 体积(单位m³) The amount of space occupied by a specified mass of substance or by an object.
一定质量的物质或物体占据的空间量。
Pulley 带轮 A free or driven wheel on a shaft with an appropriately shaped rim to carry a flat belt, vee belt, notched belt, rope, or chain. Used to transmit power or motion.
轴上的自由轮或从动轮,具有适当形状的轮缘,以承载平皮带、V形皮带、槽口皮带、绳索或链条。用于传递动力或运动。
Nautical mile (M) 海里(M) A special unit of distance employed for marine and aerial navigation. The conversion to SI is 1 M = 1 852 m.
用于海上和空中导航的特殊距离单位。SI的转换为1M=1852m。
Screw 螺钉 Threaded fastener designed to be used in a tapped or untapped (e.g., wood screw) hole, but not with a nut. A fastener with a screw thread cut or rolled into its cylindrical or conical shank, intended either to cut its own thread (as in a wood screw) or engage in a threaded hole. A self-tapping screw (sheet-metal screw, tapping screw) has a sufficiently hard thread that it cuts an internal thread in thin sheet or a component made of soft material when driven into a hole in the sheet or component. The screw head is the part of a screw used to apply torque to the screw. Common screw-head designs are circular in cross section with a diametral slot or cross, or hexagonal and recessed with a cross or hexagon. A screw thread is one or more continuous helical grooves of uniform section along either the exterior surface (male thread) or the interior surface (female thread) of a cylindrical or conical body. The three-dimensional shape that results when the thread cross section is rotated and axially advanced along an axis is called a helicoid, the angle that the thread makes when projected on to the axis being called the angle of inclination. Threads are employed in fasteners such as bolts, nuts, and screws; location and measuring instruments; in power drives; in some electrical fittings (Edison thread); and on the ends of crankshafts to suppress oil leakage (thrower thread). Parallel threads are formed on cylinders; tapered threads on cones, typically with a taper rate of 1:16. A screw with a righthanded thread appears to move away from the observer when turned clockwise. All standard screws, bolts and nuts have right-hand threads, but left-handed threads are sometimes employed. The axial distance between corresponding points on adjacent threads is called the screw pitch or screw rate and, for a single continuous helical groove (a single-start thread), is the same as the change in axial distance (the lead) between a nut and the head of a bolt during one revolution, the number of thread forms per mm then being the reciprocal of the pitch. For the same screw diameter, coarse threads have fewer threads per mm than fine threads. A multiple-start screw thread (usually coarse, see later) consists of two or more identical threads running simultaneously along its axis so as to provide greater bearing area and greater velocity ratio. The starts are separated by 180° (double start), 120° (triple start), 90° (quadruple start) etc., depending upon the number of threads. Thus, in double-start threads, the lead is twice the pitch; and so on. The axial distance between corresponding points on two adjacent threads in a multiple start thread is called the divided pitch. The position on a screw thread where there is equal distance between the flanks on the solid part of the thread and in the space between the threads is the pitch point, the associated diameter of which is termed the pitch diameter. The basic nomenclature for threads, some of which is common with that for toothed gearing, is shown in the diagrams. A helix formed or cut on a cylindrical surface which may advance along the axis to the right or left. The helix may be single or multiple.
一种螺纹紧固件,设计用于攻丝或未攻丝(如木螺钉)孔,但不与螺母配合使用。其螺纹被切割或卷成圆柱形或锥形柄,用于切割自身螺纹(如木螺钉)或嵌入螺纹孔。自攻螺钉(钣金螺钉、自攻螺钉)具有足够硬的螺纹,当打入薄板或部件中的孔时,它会在薄板或软材料部件中切割内螺纹。螺钉头是螺钉的一部分,用于向螺钉施加扭矩。常见的螺钉头设计为横截面为圆形,带有直径槽或十字,或为六边形,并带有十字或六边形凹槽。螺纹是沿圆柱形或锥形体的外表面(外螺纹)或内表面(内螺纹)具有均匀截面的一个或多个连续螺旋槽。当螺纹横截面旋转并沿轴轴向前进时产生的三维形状称为螺旋面,螺纹投影到轴上时形成的角度称为倾角。螺纹用于紧固件,如螺栓、螺母和螺钉;定位和测量仪器;在动力驱动中;在一些电气配件中(爱迪生螺纹);并安装在曲轴端部,以抑制漏油(抛掷器螺纹)。在圆柱体上形成平行螺纹;圆锥上的锥形螺纹,通常具有1:16的锥形率。当顺时针旋转时,具有右手螺纹的螺钉似乎会远离观察者。所有标准螺钉、螺栓和螺母都有右手螺纹,但有时使用左手螺纹。相邻螺纹上对应点之间的轴向距离称为螺距或螺纹率,对于单个连续螺旋槽(单个起始螺纹),与螺母和螺栓头之间的轴向间距(导程)在一周内的变化相同,每mm的螺纹形式数为螺距的倒数。对于相同的螺钉直径,粗螺纹的每毫米螺纹数少于细螺纹。多头螺纹(通常为粗螺纹,见下文)由两个或多个沿其轴线同时延伸的相同螺纹组成,以提供更大的承载面积和更大的速比。根据螺纹的数量,起点之间的间隔为180°(双起点)、120°(三起点)、90°(四起点)等。因此,在双起始螺纹中,导程是螺距的两倍;多起点螺纹中两个相邻螺纹上对应点之间的轴向距离称为分割螺距。螺纹上的位置,即螺纹实体部分的侧面和螺纹之间的空间之间的距离相等,即节点,其相关直径称为节径。图中显示了螺纹的基本术语,其中一些与齿轮传动的基本术语相同。在圆柱面上形成或切割的螺旋线,可沿轴线向右或向左前进。螺旋可以是单个或多个。
Coefficient of restitution (e) 回弹系数(e) The ratio of the relative velocity of two colliding bodies after collision to that before. In perfectly elastic collisions e = 1; when all the impact energy is dissipated, e = 0.
两个碰撞体在碰撞后与碰撞前的相对速度之比。在完全弹性碰撞中e=1;当所有的冲击能量都消散时,e=0。
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。
Precipitation heat treatment 沉淀热处理 Artificial aging in which a constituent precipitates from a supersaturated solid solution.
成分从过饱和固溶体沉淀的人工时效。
Wrist pin 腕销 A stud projecting from a crank as an attachment for a connecting rod. wrought alloys Metal alloys that are initially cast and then shaped into final form by processes such as extrusion, forging, or rolling.
从曲柄上伸出的一个螺柱,作为连接杆的附件。锻造合金最初铸造,然后通过挤压、锻造或轧制等工艺成形为最终形状的金属合金。
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)。
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。
Cone pulley 锥轮 A stepped pulley having several diameters which, when linked by a laterallymoveable transmission belt to a corresponding pulley, gives a series of speed ratios.
具有多种直径的阶梯式皮带轮,当通过可横向移动的传动带连接到相应的皮带轮时,会产生一系列速比。
Cycle annealing 循环退火 An annealing process employing a predetermined and closely controlled time-temperature cycle to produce specific properties or microstructures.
采用预定且严格控制的时间-温度循环来产生特定性能或微观结构的退火工艺。
Design load (Unit N) 设计荷载(单位N) The greatest load that a component or structure is expected to experience under normal operating conditions.
部件或结构在正常运行条件下预期承受的最大负载。
Crank pin 曲柄销 It is a short shaft parallel to the axis of the crankshaft but radially offset from it, to which is attached the big end of a connecting rod in a bearing. Sometimes the crank pin is supported at one end only (a wrist pin) but in built-up or one-piece forged crankshafts, the crank pin is supported by thick plates (crank arms, crank webs) at either end.
它是一个短轴,平行于曲轴的轴线,但径向偏移,轴承中连杆的大端连接到该短轴上。有时曲柄销仅在一端支撑(腕销),在组合式或整体锻造曲轴中,曲柄销在两端由厚板(曲柄臂、曲柄腹板)支撑。
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。
Pressure snubber 压力缓冲器 (pressure-pulse snubber) A device used for filtering, dampening, and the protection of transducers, pressure gauges, and switches, from pressure surges, pressure spikes, and water hammer. A typical design uses a fixed mesh or porous metal disc installed in an inline body. In a piston-type pressure-gauge snubber, a piston is forced against an orifice leading to the gauge.
(压力脉冲缓冲器)一种用于过滤、阻尼和保护传感器、压力表和开关免受压力浪涌、压力尖峰和水锤影响的装置。典型的设计使用安装在内联阀体中的固定网格或多孔金属盘。在活塞式压力表缓冲器中,活塞被压靠在通向压力表的孔口上。
Clutch 离合器 A device for connecting and disconnecting rotating shafts, for example between an engine and a gearbox.
一种用于连接和断开旋转轴的装置,例如在发动机和变速箱之间。
Repeatability 重复性 A term used to refer to the test-result variability associated with a limited set of specifically defined sources of variability within a single laboratory.
一个术语,用于指与单个实验室内一组有限的特定变异源相关的测试结果变异性。
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。
Rockwell superficial hardness test 洛氏表面硬度试验 Same as Rockwell hardness test, except that smaller minor and major loads are used.
与洛氏硬度测试相同,只是使用较小的次要载荷和主要载荷。
Working fluid 工作流体 In thermodynamics, the fluid contained within the boundary of a system that experiences changes in its properties during any fluid dynamic or thermodynamic process.
在热力学中,包含在系统边界内的流体,在任何流体动力学或热力学过程中其性质发生变化。
Available head (Unit m) 可用水头(单位米) In a hydroelectric power system, the difference between the vertical height of the water level in the supply reservoir above the turbine inlet less the head loss due to friction and fittings in the duct leading to the turbine.
在水力发电系统中,水轮机入口上方供水水库中水位垂直高度之间的差减去由于通向涡轮机的管道中的摩擦和配件造成的水头损失。
Nanoparticles 纳米颗粒 Particles with dimensions of order 1 nm which have either been introduced into microstructures for reinforcement or are present as impurities.
尺寸为1nm级的颗粒,其已被引入微结构中用于增强或作为杂质存在。
Thermoelastic effect 热弹性效应 The change in temperature of material under adiabatic elastic deformation, e.g. when loading is so rapid that the material is not in thermal equilibrium with its surroundings. For most materials, elastic tension lowers the temperature and compression raises it. The reverse occurs in elastomers such as rubber that exhibit entropic elasticity because stretching reduces the number of possible molecular configurations and so reduces the entropy. The thermoelastic effect gives rise to a stress–strain hysteresis loop in cyclic elastic loading and is one mechanism by which vibrational energy is dissipated internally in materials.
材料在绝热弹性变形下的温度变化,例如当加载速度如此之快,以至于材料与其周围环境不处于热平衡时。对于大多数材料,弹性张力降低温度,压缩提高温度。相反的情况发生在弹性体中,如橡胶,其表现出熵弹性,因为拉伸减少了可能的分子构型的数量,从而降低了熵。热弹性效应在循环弹性载荷中产生应力-应变迟滞回线,是振动能量在材料内部耗散的一种机制。
Thermoelectric converter 热电转换器 (thermoelectric generator) A device consisting of series-connected alternate n- and p-type semiconductor elements sandwiched between two ceramic plates. Due to the Seebeck effect, electrical power is generated when a temperature difference is maintained across the plates. Due to the Peltier effect, a thermoelectric converter can act as either a thermoelectric heater or a thermoelectric cooler (thermoelectric refrigerator) by passing an electrical current through it. The thermoelectric figure of merit (Z), with unit 1/K, is a dimensional parameter on which the efficiency of a thermoelectric device is primarily dependent, defined by Z = σα2/k where α is the Seebeck coefficient, σ is the electrical conductivity, and k is the thermal conductivity. The product of Z and a temperature is non-dimensional.
(热电发生器)由串联连接的交替的n型和p型半导体元件夹在两块陶瓷板之间组成的装置。由于塞贝克效应,当板之间保持温差时,就会产生电能。由于珀尔帖效应,热电转换器可以通过使电流通过而充当热电加热器或热电冷却器(热电制冷机)。热电优值(Z)和第一单元/K是一个尺寸参数,热电装置的效率主要取决于此,由Z=σα2/K定义,其中α是塞贝克系数,σ是电导率,K是热导率。Z和温度的乘积是无量纲的。
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。
Differential heating 差动加热 Heating that intentionally produces a temperature gradient within an object such that, after cooling, a desired stress distribution or variation in properties is present within the object.
加热有意在物体内产生温度梯度,从而在冷却后,在物体内出现所需的应力分布或特性变化。
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。
Extensometer 引伸计 An instrument for measuring changes in length over a given gage length caused by application or removal of a force. Commonly used in tension testing of metal specimens. Any instrument which measures the change in length of a part as the part is loaded.
一种用于测量在给定标距上由施加或移除力引起的长度变化,在零件加载时测量零件长度变化的仪器。常用于金属试样的拉力试验。
Reverse engineering 逆向工程 The disassembly of a machine, mechanism, system or device, measurement of its component parts, and identification of the materials used so that if required, a functioning replica can be produced.
拆卸机器、机构、系统或装置,测量其组成部分,并识别所用材料,以便在需要时可以生产出功能正常的复制品。
Galling 磨损 An extreme form of adhesive wear, in which large chunks of one part stick to the mating part (during sliding contact).
一种极端形式的粘着磨损,其中一个零件的大块粘在配合零件上(在滑动接触期间)。
Piston pump 活塞泵 A positive-displacement pump in the basic configuration of which a piston reciprocates in a cylinder. On the suction stroke, fluid is drawn into a chamber through the inlet valve, which is then open while the outlet valve is closed. On the delivery stroke the fluid is forced out of the chamber through the outlet valve, which then opens while the inlet valve is closed. Both axial and radial configurations are common.
活塞在气缸中往复运动的一种容积泵。在吸入冲程,流体通过入口阀吸入腔室,然后在出口阀关闭时打开。在输送冲程中,流体通过出口阀被迫流出腔室,然后出口阀打开,同时入口阀关闭。轴向和径向配置都很常见。
Speed of rotation (N) 转速(N) (Unit rps or rpm) For an object rotating about a fixed axis, the speed of rotation is the number of turns (revolutions) of the object per unit time. It is equal to the angular velocity Ω (or ω) (unit rad/s) divided by 2π.
(单位rps或rpm)对于绕固定轴旋转的物体,旋转速度是物体每单位时间的转数。它等于角速度Ω(或ω)(单位rad/s)除以2π。
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。
Waste-heat recovery 废热回收 The recovery of thermal energy from flue and exhaust gases, or from liquids heated in industrial processes. Recovery devices include pre-heaters, recuperators, regenerators, and waste-heat boilers.
从烟道和废气中或从工业过程中加热的液体中回收热能。回收装置包括预热器、回热器、再生器和余热锅炉。
Maximum load (Pmax) 最大负载(Pmax) (1) The load having the highest algebraic value in the load cycle. Tensile loads are considered positive and compressive loads negative. (2)Used to determine the strength of a structural member; the load that can be borne before failure is apparent.
(1)负载循环中具有最高代数值的负载。拉伸荷载视为正荷载,压缩荷载视为负荷载。(2)用于确定结构构件的强度;失效前可承受的载荷是明显的。
Plug gauge 塞规 A steel gauge used to determine the dimension or dimensions of a hole. It may be straight or tapered, and is typically circular, but in principle can have any cross section.
用于确定孔的尺寸的钢制量规。它可以是直的或锥形的,通常是圆形的,原则上可以有任何横截面。
Critical diameter 临界直径 (D) Diameter of the bar that can be fully hardened with 50% martensite at its center.
(D)中心有50%马氏体可完全硬化的棒材直径。
Form of thread 螺纹形式 The profile of a thread in an axial plane for a length of one pitch.
一个螺距长度的螺纹在轴向平面中的轮廓。
Columnar structure 柱状结构 A coarse structure of parallel elongated grains formed by unidirectional growth, most often observed in castings, but sometimes in structures resulting from diffusional growth accompanied by a solid-state transformation.
由单向生长形成的平行细长晶粒的粗略结构,最常见于铸件中,但有时也出现在伴随固态转变的扩散生长产生的结构中。
Oxidized surface (on steel) 氧化表面(在钢上) Surface having a thin, tightly adhering, oxidized skin (from straw to blue in color), extending in from the edge of a coil or sheet. Sometimes called annealing border.
表面具有薄的、紧密粘附的氧化皮(从稻草色到蓝色),从线圈或薄片的边缘延伸。有时称为退火边界。
Torsion 扭矩 A twisting deformation of a solid body about an axis in which lines that were initially parallel to the axis become helices. The twisting of an object about an axis due to an applied couple (torque).
一种固体绕轴的扭转变形,在该变形中,最初平行于轴的线变成螺旋线。由于施加的力偶(扭矩),物体绕轴扭曲。
Creep 蠕变 The slow, plastic deformation of a body under heavy loads. Time-dependent plasticity. Time-dependent and permanent deformation of material under constant load or stress. The strain increases with time at a rate that increases with increasing temperature. Creep can lead to large strain and eventual failure, and so limit the lifetime of components subjected to load at high temperature. Creep in metals becomes significant at homologous temperatures in excess of about 0.4, e.g. 1200°C for tungsten, 504°C for titanium, 450°C for iron, and 100°C for aluminium.
物体在重载荷下缓慢的塑性变形,随时间变化的可塑性,材料在恒定载荷或应力下随时间变化的永久变形。应变随时间以随温度升高而增加的速率增加。蠕变可能导致大应变和最终失效,从而限制部件在高温下承受载荷的寿命。当同源温度超过约0.4℃时,金属蠕变变得显著,例如钨为1200℃,钛为504℃,铁为450℃,铝为100℃。
Damage mechanics 损伤机制 The theory of degradation in bodies, particularly fracture by accumulated microstructural damage. Analyses take two approaches: (a) the use of some critical integrated function of stress and strain at which cracking is initiated and propagated; (b) incorporation of damage in the stress–strain curves to reflect weakened material.
物体退化理论,尤其是累积微观结构损伤导致的断裂。分析采用两种方法:(a)使用裂纹开始和扩展时的应力和应变的一些临界积分函数;(b)应力-应变曲线中包含损伤,以反映弱化材料。
Flat head 平头 Flat top surface and a conical bearing surface.
平顶表面和锥形轴承表面。
Cellular materials 蜂窝材料 There are three broad classes of materials that have a sponge-like structure containing many small closed or open (interlinked) pores or cells. Natural cellular materials include bone, cork, sponge, and wood, and have numerous well-known uses. Wide ranges of cellular plastics are produced using blowing or foaming agents, such as air, ammonium carbonate, sodium bicarbonate, etc., to create pores during the processing of thermoplastic or thermosetting polymers. Rigid foams have moderate compressive strength and can be moulded and machined.
有三大类材料具有海绵状结构,包含许多小的封闭或开放(互连)孔或细胞。天然多孔材料包括骨骼、软木、海绵和木材,有许多众所周知的用途。使用发泡剂或发泡剂(如空气、碳酸铵、碳酸氢钠等)生产各种泡沫塑料,以在热塑性或热固性聚合物加工过程中产生孔隙。硬质泡沫具有中等抗压强度,可模制和机加工。
Residual preload 残余预载荷 The tension which remains in an unloaded bolted joint after Relaxation.
松弛后未加载螺栓连接中保持的张力。
Stress corrosion cracking (SCC) 应力腐蚀开裂(SCC) A common form of Stress cracking in which an Electrolyte encourages the growth of a crack in a highly stressed bolt. Only a tiny quantity of electrolyte need be present, at the tip or face of the crack. A time-dependent process in which a metallurgically susceptible material fractures prematurely under conditions of simultaneous corrosion and sustained loading at lower stress levels than would be required in the absence of a corrosive environment. Tensile stress is required at the metal surface and may be a residual stress resulting from heat treatment or fabrication of the metal or the result of external loading. Cracking may be intergranular or transgranular, depending on the combination of alloy and environment.
一种常见的应力开裂形式,其中电解液促使高应力螺栓中的裂纹扩展。在裂纹尖端或表面,只需存在少量电解质。一种随时间变化的过程,其中冶金敏感材料在同时腐蚀和持续加载的条件下过早断裂,其应力水平低于无腐蚀环境时的要求。在金属表面需要拉应力,拉应力可以是金属的热处理或制造或外部负载产生的残余应力。裂纹可能是沿晶开裂或穿晶开裂,这取决于合金和环境的组合。
Conduit 导管 A hollow object, of metal, plastic, glass, ceramic, etc., which is relatively long compared with its lateral dimensions and through which there is fluid flow.
由金属、塑料、玻璃、陶瓷等制成的中空物体,与其横向尺寸相比相对较长,并且有流体流过。
Vickers hardness number 维氏硬度值 (diamond hardness number, DHN, VHN, VPN) (Unit kg/mm² originally, sometimes now Pa) Indentation hardness given by load divided by the surface area of the permanent impression obtained when the indenter is in the form of a square pyramid whose opposite faces make an angle of 136° with one another. The mean length d of the diagonals of the indentation is determined, from which VPN = 0.927(2W/d2) where W is the load, since the base of the pyramid has an area equal to 0.927 times the surface area.
(金刚石硬度值,DHN,VHN,VPN)(最初单位为kg/mm²,有时为Pa)压痕硬度,由载荷除以永久压痕的表面积得出,当压头呈方形棱锥体形式时,其相对面彼此成136°角。确定压痕对角线的平均长度d,其中VPN=0.927(2W/d2),其中W是载荷,因为棱锥底部的面积等于表面积的0.92七倍。
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。
Magnetic materials 磁性材料 Materials in which the magnetic moment of adjacent atoms can adopt either parallel or antiparallel alignment. Ferromagnetism occurs when the magnetic moments adopt parallel alignment. When adjacent magnetic moments cancel due to antiparallel alignment, the material exhibits antiferromagnetism and has no overall magnetic moment. Examples of the latter include ferrous oxide and manganese oxide. The phenomenon of ferrimagnetism occurs when adjacent magnetic moments adopt antiparallel alignment but have unequal magnitude. The region of ferromagnetic or ferrimagnetic material in which the magnetic moments are aligned is known as a magnetic domain and adjacent regions are separated by domain walls. Diamagnetic and paramagnetic materials exhibit weak forms of magnetism that results from independent (uncoupled) alignment of magnetic atomic dipoles induced by an applied magnetic field. Ferromagnetic and ferrimagnetic materials can acquire high degrees of magnetization in relatively weak magnetic fields. They have different hysteresis characteristics and are classified as either hard magnets or soft magnets. Hard magnets retain large magnetization in the absence of an applied magnetic field and are used as permanent magnets. Conventional materials include magnet steels alloyed with tungsten or cobalt. Rare-earth magnets made from alloys of rare-earth elements produce significantly stronger magnetic fields. The most common of these are samarium-cobalt and neodymiumiron-boron permanent magnets. Their strength allows them to be small and used in numerous applications, including cordless tools, disk drives, headphones, toys, and motors for automotive components such as wipers, fans, washers, and windows. Soft magnets may be magnetized and demagnetized relatively easily. When subjected to an alternating magnetic  field the energy loss due to hysteresis is small. Common materials include iron-silicon alloys (known as electrical steels), nickel-iron alloys (permalloy), soft ferrites, and amorphous nanocrystalline alloys, the last of which can be produced in the form of tape by meltspinning. Soft magnets are used to enhance the magnetic flux produced by an electric current.
相邻原子的磁矩可以采用平行或反平行排列的材料。当磁矩采用平行排列时,会产生铁磁性。当相邻磁矩因反平行排列而抵消时,材料表现出反铁磁性,没有总磁矩。后者的实例包括氧化亚铁和氧化锰。当相邻磁矩采用反平行排列但大小不等时,就会出现铁磁现象。磁矩对齐的铁磁或铁磁材料区域称为磁畴,相邻区域由磁畴壁分隔。抗磁和顺磁材料表现出弱磁性形式,这是由外加磁场诱导的磁原子偶极子的独立(非耦合)排列引起的。铁磁性和铁磁性材料可以在相对弱的磁场中获得高磁化度。它们具有不同的磁滞特性,分为硬磁铁和软磁铁。硬磁铁在没有外加磁场的情况下保持较大的磁化强度,用作永磁体。常规材料包括与钨或钴合金化的磁钢。由稀土元素合金制成的稀土磁体产生明显更强的磁场。其中最常见的是钐钴和钕硼永磁体。它们的强度使其体积小,可用于多种应用,包括无绳工具、磁盘驱动器、耳机、玩具和汽车部件(如雨刷、风扇、洗衣机和车窗)的电机。软磁体可以相对容易地磁化和退磁。当受到交变磁场时,由于磁滞引起的能量损失很小。常见材料包括铁硅合金(称为电工钢)、镍铁合金(坡莫合金)、软铁氧体和非晶纳米晶合金,最后一种可以通过熔钉以胶带的形式生产。软磁铁用于增强电流产生的磁通量。
Thermal stresses 热应力 Stresses in metal resulting from nonuniform temperature distribution.
由不均匀温度分布引起的金属应力。
Brittle 脆性材料 A brittle material is one that breaks, often suddenly, with no permanent deformation. Examples of brittle materials are some cast irons, glass, concrete, and some plastics. A bolt is said to be brittle if it will break when stretched only a small amount past its yield point.
脆性材料通常会突然断裂,不会产生永久变形。脆性材料的例子有一些铸铁、玻璃、混凝土和一些塑料。如果螺栓在拉伸时仅超过其屈服点一小部分就会断裂,则称其为脆性螺栓。
Thread insert 螺纹嵌件 (threaded bushing) Either a thin cylinder with an internal thread (and sometimes also an external thread) or a helical coil of wire, pressed or screwed into a hole to accept a bolt or screw. Used in material too soft or a component too thin to be threaded, to change one form of thread to another or to repair a damaged thread.
(螺纹衬套)一种带有内螺纹(有时也有外螺纹)的薄圆柱体或螺旋形线圈,压入或拧入孔中以接受螺栓或螺钉。用于材料太软或部件太薄而无法螺纹连接,用于将一种形式的螺纹更换为另一种形式或修复损坏的螺纹。
Notch depth 缺口深度 The distance from the surface of a notched test specimen to the bottom of the notch. In a cylindrical test specimen, the percentage of the original cross-sectional area removed by machining an annular groove.
从缺口试样表面到缺口底部的距离。在圆柱形试样中,通过加工环形槽去除的原始横截面积的百分比。
Laser sintering 激光烧结 A manufacturing technique by which parts are built layer by layer (each typically 20 μm thick) from plastic or metal (Direct Metal Laser Sintering, DMLS) material in powder form, each layer being sintered by a scanning laser.
一种制造技术,通过这种制造技术,零件由粉末形式的塑料或金属(直接金属激光烧结,DMLS)材料逐层(每个厚度通常为 20 微米)构建,每一层都由扫描激光烧结。
Mechanical alloying 机械合金化 Production of alloys from powders by consolidation, e.g. hotpressing or extrusion, followed by hot and/or cold working and final annealing. Materials such as dispersion-strengthened alloys, high-temperature aluminium alloys, and amorphous alloys can be made in this way.
通过固结(例如热压或挤压)从粉末生产合金,然后进行热和/或冷加工和最终退火。用这种方法可以制造弥散强化合金、高温铝合金和非晶合金等材料。
Milling 铣削 A machining process, typically for metals and plastics, in which a multi-tooth rotary cutter removes material to produce flat or profiled surfaces, slots, grooves, etc. Milling is a machining process in which metal is removed by a rotating multiple-tooth cutter; each tooth removes a small amount of metal with each revolution of the spindle. Because both workpiece and cutter can be moved in more than one direction at the same time, surfaces having almost any orientation can be machined.
一种加工工艺,通常用于金属和塑料,其中多齿旋转刀具去除材料以产生平坦或异形表面、槽、槽等。金属由旋转多齿刀具去除;主轴每转一圈,每个齿都会去除少量金属。因为工件和刀具可以同时在多个方向上移动,所以几乎可以加工任何方向的表面。
Corrosion failure 腐蚀失效 1. The failure of a component or structure after corrosion has reduced the load-bearing area to an unsupportable level. 2. A situation in which a mechanism cannot function owing to corrosion products preventing free movement at joints.
1、部件或结构在腐蚀后失效,使承重面积减少到无法支撑的程度。2.由于腐蚀产物阻止关节处的自由运动,导致机构无法运行的情况。
Centigrade heat unit 摄氏热量单位 (Celsius heat unit, CHU) An obsolete (i.e. non-SI) unit equal to the energy required to increase the temperature of one pound of pure, air-free water from 14.5°C to 15.5°C at a pressure of one standard atmosphere.
(摄氏热量单位,CHU)一个已被淘汰的(即非国际单位制)单位,等于在一个标准大气压的压力下将一磅纯净的无空气水的温度从14.5°C提高到15.5°C所需的能量.
Microstrain 微应变 The strain over a gage length comparable to interatomic distances. These are the strains being averaged by the macrostrain measurement. Microstrain is not measurable by currently existing techniques. Variance of the microstrain distribution can, however, be measured by x-ray diffraction.
与原子间距离相当的标距上的应变。这些是通过宏观应变测量得到的平均应变。现有技术无法测量微应变。然而微应变分布的变化可以通过x射线衍射来测量。
Elastic interactions 弹性相互作用 When a bolt is tightened it partially compresses the joint members ‘‘in its own neighborhood.’’ When nearby bolts are tightened later, they further compress the joint in this region. This allows the first bolt to relax a little (lose a little preload). Tightening bolts on the opposite side of the joint, however, might increase preload in some of the earlier bolts tightened on the near side. These shifts and changes in the elastic energy stored in individual bolts, during assembly, are called elastic interactions.
当螺栓拧紧时,它会“在其自身附近”部分压缩接头构件稍后拧紧附近的螺栓时,进一步压缩该区域的接头。这允许第一个螺栓稍微松弛(失去一点预载)。但拧紧接头另一侧的螺栓可能会增加早期在近侧拧紧的一些螺栓的预载。在装配过程中,储存在单个螺栓中的弹性能量的这些位移和变化称为弹性相互作用。
Cooling curve 冷却曲线 A curve showing the relation between time and temperature during the cooling of a material.
显示材料冷却过程中时间和温度之间关系的曲线。
Machine tool 机床工具 A powered machine, such as a borer, grinder, lathe, milling machine or planer, used for cutting and shaping metal, plastics, composites, etc. (machining). A machining centre is a CNC machine tool working about several axes, having a stock of tools and automatic tool changing ability, which is capable of diverse machining operations under automated control.
一种动力机器,如钻孔机、磨床、车床、铣床或刨床,用于切割和成形金属、塑料、复合材料等(机加工)。加工中心是围绕多个轴工作的CNC机床,具有刀具库存和自动换刀能力,能够在自动化控制下进行各种加工操作。
Oldham coupling 十字联轴节 (double-slider coupling) A device for connecting a pair of misaligned parallel shafts, on the end of each of which are flanges having diametral tenons (tongues) that engage with matching slots spaced at 90° in an intermediate disc. As the coupling rotates, the disc compensates for shaft offset by sliding along each tenon in turn. Low-friction surfaces are requisite and the disc is often made of a polymer. An alternative arrangement has the slots in the flanges and the tenons on the disc.
(双滑块联轴器)一种连接一对未对准平行轴的装置,在每个平行轴的端部有法兰,法兰具有直径榫(舌),与中间盘中间隔90°的匹配槽接合。当联轴器旋转时,圆盘通过依次沿每个榫头滑动来补偿轴偏移。低摩擦表面是必需的,阀盘通常由聚合物制成。另一种布置方式是法兰上的槽和阀盘上的榫头。
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。
Impact loads 冲击载荷 Especially severe shock loads such as those caused by instantaneous arrest of a falling mass, shock meeting of two parts (in a mechanical hammer, for example), or by explosive impact, in which there can be an exceptionally rapid build-up of stress.
特别严重的冲击载荷,例如由下落质量的瞬时停止、两部分的冲击碰撞(例如在机械锤中)或爆炸性冲击引起的冲击载荷,其中可能会出现异常快速的应力积聚。
Water jacket 水套 A casing, typically of sheet metal, surrounding a machine, such as an engine, that requires cooling. Water is circulated through the jacket and a heat exchanger where the heat is removed.
机壳一种机壳,通常由金属板制成,围绕着需要冷却的机器,如发动机。水通过夹套和热交换器循环,在热交换器中热量被去除。
Clearance angle 后角 (relief angle) (Unit °) The angle between the underneath or flank of a cutting tool and the machined surface.
(后角)(单位°)切削刀具的底部或侧面与加工表面之间的角度。
Fluid mechanics 流体力学 The study of fluids in motion (fluid dynamics) or fluid statics where there is no relative motion between fluid particles. Fluid statics concerns primarily the variation of pressure with altitude or depth; it includes aerostatics and hydrostatics. Fluid dynamics includes the topics of aerodynamics, gas dynamics, hydraulics, hydrodynamics and many aspects of acoustics, chemical engineering, flight, lubrication, meteorology, non-Newtonian fluid flow, oceanography, power-plant technology, propulsion, and turbomachinery.
研究运动中的流体(流体动力学)或流体静力学,其中流体粒子之间没有相对运动。流体静力学主要关注压力随高度或深度的变化;它包括空气静力学和流体静力学。流体动力学包括空气动力学、气体动力学、水力学、流体动力学以及声学、化学工程、飞行、润滑、气象学、非牛顿流体流动、海洋学、发电厂技术、推进和涡轮机械的许多方面。
Kinetic friction 动摩擦 (dynamic friction, sliding friction) (Unit N) The sliding resistance to relative motion of two surfaces in contact with each other.
(动摩擦,滑动摩擦)(单位N)两个相互接触的表面相对运动的滑动阻力。
X–Y recorder X-Y记录仪 A device that plots a graph of a variable y against a variable x, both in the form of voltages.
一种绘制变量y和变量x的图形的设备,两者都以伏特数的形式。
Graphitization 石墨化 Formation of graphite in iron or steel. Where graphite is formed during solidification, the phenomenon is called primary graphitization; where formed later by heat treatment, secondary graphitization.
在铁或钢中形成石墨。在凝固过程中形成石墨的现象称为一次石墨化;后来通过热处理,形成二次石墨化。
Vibrometer 测振仪 A device used to measure the motion of a vibrating surface, typically using a contactless laser-based technique.
一种用于测量振动表面运动的装置,通常使用非接触激光技术。
Fracture test 断裂试验 A test in which a specimen is broken and its fracture surface is examined with the unaided eye or with a low-power microscope to determine such factors as composition, grain size, case depth, or internal discontinuities. 1. The recording of load-deflexion (or stress–strain) in a specimen loaded monotonically until it breaks in tension, compression, shear, or torsion. 2. In fatigue, determination of the number of cycles to fracture for a specimen under different patterns of repeated loading. 3. Experiments to determine fracture toughness.
一种试验,其中试样被破坏并用肉眼或低倍显微镜检查其断裂表面,以确定成分、晶粒尺寸、表层深度或内部不连续性等因素。1.记录单调加载试样的载荷偏转(或应力-应变),直到其在拉伸、压缩、剪切或扭转中断裂。2.在疲劳技术中,确定试样在不同重复载荷模式下的断裂循环次数。3.测定断裂韧性的实验。
Depth gauge 深度计 1. A precision instrument, typically consisting of a machine-divided steel rule passing through a hardened-steel cross head, used to measure the depths of slots, holes, shoulders, projections, etc. 2. A device used by divers to indicate the water depth.
1. 一种精密仪器,通常由穿过硬化钢十字头的机器分割钢尺组成,用于测量槽、孔、肩部、突起等的深度。 2. 潜水员用来指示深度的装置水深。
Prevailing torque 有效扭矩 Torque required to run a nut down against the joint when some obstruction, such as a plastic insert in the threads, or a noncircular thread, or other, has been introduced to help the fastener resist vibration loosening. Prevailing torque, unlike normal torque on a nut or bolt, is not proportional to the Preload in the fastener.
当引入了一些障碍物(如螺纹中的塑料插件或非圆螺纹或其他障碍物)以帮助紧固件抵抗振动松动时,将螺母向下压靠接头所需的扭矩。与螺母或螺栓上的正常扭矩不同,主要扭矩与紧固件中的预载不成比例。
Thermodynamics laws 热力学定律 The zeroth, first, second, and third laws of thermodynamics.
热力学第零、第一、第二和第三定律。
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。
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。
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。
Turboblower 涡轮鼓风机 A centrifugal or axial compressor or fan.
离心式或轴流式压缩机或风扇。
Dynamic hardness 动态硬度 (rebound hardness) The resistance of a material to local indentation by a rapidly-moving rigid indenter. In most practical methods the indenter is allowed to fall under gravity on to the surface of the material when the rebound height is a measure of the dynamic hardness.
(回弹硬度)材料对快速移动的刚性压头局部压痕的阻力。在大多数实际方法中,当回弹高度是动态硬度的测量值时,允许压头在重力作用下落在材料表面上。
Acoustic emission 声发射 (stress-wave emission) Sound emitted by some materials when deformed under load. It arises from stress waves emitted by sudden dislocation motion in crystals, slip, crack growth, etc.
(应力波发射)某些材料在负载下变形时发出的声音。它是由晶体中突然的位错运动、滑移、裂纹扩展等发出的应力波引起的。
Principal stress (normal) 主应力(正常) The maximum or minimum value of the normal stressat a point in a plane considered with respect to all possible orientations of the considered plane. On such principal planes the shear stress is zero. There are three principal stresses on three mutually perpendicular planes. The state of stress at a point may be: (1) uniaxial, a state of stress in which two of the three principal stresses are zero; (2) biaxial, a state of stress in which only one of the three principal stresses is zero; or (3) triaxial, a state of stress in which none of the principal stresses is zero. Multiaxial stress refers to either biaxial or triaxial stress.
相对于所考虑平面的所有可能方向,所考虑平面中某点处的法向应力的最大值或最小值。在这样的主平面上,剪切应力为零。在三个相互垂直的平面上有三个主应力。一点的应力状态可以是:(1)单轴,三个主应力中的两个为零的应力;(2)双轴,三个主应力中只有一个为零的应力状态;或(3)三轴,即主应力均不为零的应力状态。多轴应力是指双轴或三轴应力。
Temper embrittlement 回火脆化 Brittleness that results when certain steels are held within, or are cooled slowly through, a certain range of temperature below the transformation range. The brittleness is manifested as an upward shift in ductile-to-brittle transition temperature but only rarely produces a low value of reduction in area in a smooth-bar tension test of the embrittled material. The anomalous reduction in toughness of martensitic stainless steels when tempered in the range 370–600°C. Embrittlement of alloy steels caused by holding within or cooling slowly through a temperature range just below the transformation range. Embrittlement is the result of the segregation at grain boundaries of impurities such as arsenic, antimony, phosphorus, and tin; it is usually manifested as an upward shift in ductile-to-brittle transition temperature. Temper embrittlement can be reversed by retempering above the critical temperature range, then cooling rapidly.
当某些钢保持在低于转变范围的某一温度范围内或缓慢冷却时产生的脆性。脆性表现为延性到脆性转变温度的向上移动,但在脆性材料的平滑棒材拉伸试验中,很少产生较小的面积减小值。马氏体不锈钢在370–600°C范围内回火时的韧性异常降低。合金钢的脆化是由于在低于转变范围的温度范围内保持或缓慢冷却而引起的。脆化是杂质(如砷、锑、磷和锡)在晶界处偏析的结果;它通常表现为韧脆转变温度的上升。回火脆化可以通过在临界温度范围以上重新回火,然后快速冷却来逆转。
Corrosion fatigue 腐蚀疲劳 Cracking produced by the combined action of repeated or fluctuating stress and a corrosive environment at lower stress levels or fewer cycles than would be required in the absence of a corrosive environment.
由重复或波动的应力和腐蚀环境的联合作用产生的开裂,其应力水平低于没有腐蚀环境时所需的应力水平或循环次数更少。
Thermal shock 热冲击 The development of a steep temperature gradient and accompanying high stresses within a structure.
在结构内形成陡峭的温度梯度和伴随的高应力。
Flame hardening 火焰硬化 A process for hardening the surfaces of hardenable ferrous alloys in which an intense flame is used to heat the surface layers above the upper transformation temperature, whereupon the workpiece is immediately quenched.
一种用于硬化可硬化铁合金表面的工艺,其中使用强烈的火焰将表面层加热到转变温度上限以上,然后立即对工件进行淬火。
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。
Poisson’s ratio (ν) 泊松比(ν) The absolute value of the ratio of transverse (lateral) strain to the corresponding axial strain resulting from uniformly distributed axial stress below the proportional limit of the material.
横向(侧向)应变与相应轴向应变之比的绝对值,该比值由低于材料比例极限的均匀分布的轴向应力产生。
Assembly line 流水线 A system of mass production in which work is moved progressively from one operation to another, ultimately to give the final complete product.
一种大规模生产系统,其中工作逐渐从一个操作转移到另一个操作,最终得到完整产品。
Dynamic modulus 动态模量 The ratio of stress to strain under cyclic conditions (calculated from data obtained from either free or forced vibration tests, in shear, compression, or tension).
循环条件下的应力与应变之比(根据在剪切、压缩或拉伸中的自由或强制振动测试中获得的数据计算得出)。
Radial load (Unit N) 径向负荷(单位:N) 1. Centrifugal loading induced in a rotating body. 2. (through-wallthickness load) The radial component of loading arising from internal or external pressurization of a closed vessel. There will also be axial and hoop loading.
1.旋转体中产生的离心载荷。2.(贯穿壁厚载荷)由封闭容器的内部或外部加压产生的载荷的径向分量。还存在轴向和环向载荷。
ASME ASME The American Society of Mechanical Engineers.
美国机械工程师学会。
Transition temperature (Unit K) 转变温度(单位K) (1) An arbitrarily defined temperature that lies within the temperature range in which metal fracture characteristics (as usually determined by tests of notched specimens) change rapidly, such as from primarily fibrous (shear)to primarily crystalline (cleavage) fracture. (2) Sometimes used to denote an arbitrarily defined temperature within a range in which the ductility changes rapidly with temperature. (transition point) 1. The temperature at which the mechanism of fracture in metal alloys having a face-centred cubic crystal structure changes from ductile void growth to brittle cleavage. 2. The temperature at which a material changes from one crystal state to another.
(1) 任意定义的温度,位于金属断裂特性(通常通过缺口试样的试验确定)快速变化的温度范围内,如从主要纤维(剪切)断裂到主要结晶(解理)断裂。(2) 有时用于表示延性随温度快速变化的范围内的任意定义的温度。(转变点)1.具有面心立方晶体结构的金属合金的断裂机制从韧性孔洞生长转变为脆性解理的温度。2.材料从一种晶体状态转变为另一种晶体的温度。
Volume flow rate 体积流率 (volumetric flow rate, , ) (Unit m³/s) The volume of a material, usually a fluid or powder, that flows across a surface or through a pipe or other duct per unit time.
(体积流量)(单位m³/s)单位时间内流经表面或管道或其他管道的材料体积,通常为流体或粉末。
Absolute viscosity 绝对粘度 A measure of the internal shear properties of fluids, expressed as the tangential force per unit area at either of two horizontal planes separated by one unit thickness of a given fluid, one of the planes being fixed and the other moving with unit velocity.
流体内部剪切特性的量度,表示为两个水平面中的任何一个上的单位面积切向力,两个水平面被给定流体的一个单位厚度隔开,其中一个平面固定,另一个以单位速度移动。
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。
Wear 磨损 Damage to a solid surface, generally involving progressive loss of material, due to relative motion between that surface and a contacting surface or substance. The deterioration of a component or structure with time and usage, often impairing the function for which it was designed, owing to abrasion, corrosion, fatigue, friction, etc. during relative motion of parts. The wear factor (K), with unit mm³/N.m, is an empirical dimensional factor that quantifies surface wear due to mechanical frictional contact, and defined by K = /Fs where is the worn volume (in mm³), F is the contact load (in N), and s is the sliding distance (in m).
由于固体表面与接触表面或物质之间的相对运动,对固体表面的损坏,通常涉及材料的渐进损失。部件或结构随时间和使用而劣化,通常由于部件相对运动过程中的磨损、腐蚀、疲劳、摩擦等而损害其设计功能。磨损系数(K),单位为mm³/N.m、 是量化机械摩擦接触导致的表面磨损的经验尺寸因子,由K=/Fs定义,其中是磨损体积(单位:mm³),F是接触载荷(单位:N),s是滑动距离(单位:m)。
Assembly drawing 装配图纸 An engineering drawing that shows how parts are assembled to produce a component or a complete machine. It may include sections to show internal features, dimensions that are critical for assembly, manufacturing information, and part numbers.
显示零件如何组装以生产组件或整机的工程图。它可能包括显示内部特征、对装配至关重要的尺寸、制造信息和零件编号的部分。
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。
Fatigue limit 疲劳极限 The maximum stress that presumably leads to fatigue fracture in a specified number of stress cycles. The value of the maximum stress and the stress ratio also should be stated. Compare with endurance limit.
在指定数量的应力循环中可能导致疲劳断裂的最大应力。还应说明最大应力值和应力比。与耐力极限比较。
Adhesive strength 粘合强度 The strength of an adhesively bonded joint, usually measured in tension (perpendicular to the plane of the bonded joint) or in shear
粘合接头的强度,通常以拉伸(垂直于粘合接头的平面)或剪切测量
Combustion 燃烧氧化 An exothermic chemical reaction in which a fuel and an oxidant, typically air, react together to release a significant quantity of thermal energy in the presence of a flame. In the case of fluid fuels, ignition may be from an electric spark or compression of the
一种放热化学反应,其中燃料和氧化剂(通常是空气)一起反应,在火焰存在的情况下释放大量热能。
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。
Distortion 扭曲 Any deviation from an original size, shape, or contour that occurs because of the application of stress or the release of residual stress.
由于施加应力或释放残余应力而发生的与原始尺寸、形状或轮廓的任何偏差。
Stead’s brittleness 斯特德脆性 A condition of brittleness that causes transcrystalline fracture in the coarse grain structure that results from prolonged annealing of thin sheets of low-carbon steel previously rolled at a temperature below about 705 °C (1300 °F). The fracture usually occurs at about 45° to the direction of rolling.
一种脆性状态,导致粗晶结构中发生穿晶断裂,这是由于之前在低于约705°C(1300°F)的温度下轧制的低碳钢薄板经过长时间退火造成的。断裂通常发生在与轧制方向约45°处。
Accelerated testing 加速测试 A type of testing, for rates of wear, fatigue, corrosion etc., in which failure times are reduced by employing greater loads, more frequent power cycling, higher vibration levels, higher humidity, higher temperatures, greater potential differences etc. than would be encountered in normal operation.
一种测试类型,用于测试磨损率、疲劳率、腐蚀率等,通过采用比正常运行中更大的负载、更频繁的功率循环、更高的振动水平、更高湿度、更高温度、更大的电位差等,减少故障时间。
Physical testing 物理测试 Methods used to determine the entire range of physical properties of a material. In addition to density and thermal, electrical, and magnetic properties, physical testing methods can be used to assess simple fundamental physical properties such as color, crystalline form, and melting point.
用于确定材料整个物理特性范围的方法。除了密度和热、电、磁特性外,物理测试方法还可用于评估简单的基本物理特性,如颜色、结晶形式和熔点。
Ballonet 气囊 An airbag used in a hybrid airship. Helium gas expels air from the ballonet during ascent. Fans draw air in during descent.
混合动力飞艇中使用的安全气囊。氦气在上升过程中将空气从气囊中排出。风扇在下降过程中吸入空气。
Interrupted aging 分段时效 Aging at two or more temperatures, by steps, and cooling to room temperature after each step.
分为两个或两个以上的温度时效,按顺序并在每个步骤后冷却至室温。
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。
Impact strength 冲击强度 The resiliency or toughness of a solid as measured by impact energy.
用冲击能量测量的固体的弹性或韧性。
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。
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。
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。
Crushing strain 压应变 The supposed single strain that results in comminution of a brittle material. The corresponding stress is termed the crushing strength. Neither quantity can be a material constant as they must obey the laws of fracture mechanics and will depend on the type of testpiece, method of loading etc.
导致脆性材料粉碎的假定单应变。相应的应力称为抗压强度。这两个量都不能是材料常数,因为它们必须遵守断裂力学定律,并取决于试件类型、加载方法等。
O-ring (O-ring seal) O形圈(O形密封圈) A toroidal ring of synthetic rubber seated in a groove machined into a flat or cylindrical surface to act as a seal.
一种环形合成橡胶环,位于加工成平面或圆柱表面的凹槽中,起密封作用。
Specific heat capacity 比热容 The heat necessary to raise the temperature of 1 kg of a substance by 1 K. It is measured in J/(kg K).
将1千克物质的温度升高1K所需的热量。单位为J/(kg K)。
Waste heat 废热 1. Heat generated by internal-combustion engines, gas turbines, electrical generators, electrical equipment, and industrial processes that is not used directly but is expelled to the environment, often in hot flue or exhaust gases. 2. Heat generated from waste
1.内燃机、燃气轮机、发电机、电气设备和工业过程产生的热量,这些热量不是直接使用的,而是通过热烟气或废气排放到环境中。2.废物产生的热量
Coefficient of friction (μ) 摩擦系数(μ)  (coefficient of kinetic friction, coefficient of sliding friction, friction coefficient, μ) The ratio of the frictional force F to the normal force N between two surfaces in contact, i.e. μ = F/N. Static friction is when there is no relative sliding; kinetic friction when there is. For structural components sliding on one another, the coefficient of friction is the ratio of the force causing the sliding to the force perpendicular to the sliding component surfaces. The coefficient of friction is dimensionless with values between zero and one. The number characterising the force necessary to slide or roll one material along the€surface of another. If an object has a weight N and the coefficient of friction is μ, then the force F necessary to move it without acceleration along a level surface is F = μN. The coefficient of static friction determines the force necessary to initiate movement; the coefficient of kinetic friction determines the force necessary to maintain movement. Kinetic friction is usually smaller than static friction.
(动摩擦系数、滑动摩擦系数、摩擦系数,μ)两个接触表面之间摩擦力F与法向力N的比值,即μ=F/N。静摩擦是指没有相对滑动时;有摩擦时的动摩擦。对于相互滑动的结构部件,摩擦系数是引起滑动的力与垂直于滑动部件表面的力的比值。摩擦系数是无量纲的,其值介于0和1之间。代表一种材料沿另一种材料的表面滑动或滚动所需的力的数字。如果一个物体的重量为N并且摩擦系数为μ,那么在没有加速度的情况下沿水平表面移动它所需的力F为F=μN。静摩擦系数决定了启动运动所需的力;动摩擦系数决定了保持运动所需的力。动摩擦通常小于静摩擦。两个物体之间的力(F)与将这些物体压在一起的法向力(N)的无量纲比:μ(或f)=(F/N)。
Electrolyte 电解质 The liquid with which the Electrodes of a battery or Corrosion cell are wetted.
润湿电池或腐蚀电池电极的液体。
Creep modulus (Unit Pa) 蠕变模量(单位Pa) The ratio of stress/strain at a chosen strain level obtained from creep tests, often plotted against time to show changes in stiffness.
从蠕变测试中获得的选定应变水平下的应力/应变比,通常随时间绘制以显示刚度的变化。
Centrifugal compressor 离心式压缩机 A compressor in which kinetic energy is added to a fluid by radial acceleration in an impeller and then converted into a pressure increase by flow though a diffuser.
一种压缩机,其中动能通过叶轮中的径向加速度添加到流体中,然后通过扩散器的流动转换为压力增加。
Elastic energy 弹性能 The amount of energy required to deform a material within its elastic range of behavior, neglecting small heat losses due to internal friction. The energy absorbed by a specimen per unit volume of material contained within the gage length being tested. It is determined by measuring the area under the stress-strain curve up to a specified elastic strain. See also modulus of resilience and strain energy.
材料在其弹性行为范围内变形所需的能量,忽略因内耗引起的小热损失。试样在被测标距内每单位体积材料吸收的能量。它是通过测量应力-应变曲线下达到规定弹性应变的面积来确定的。另见弹性模量和应变能。
Pressure surface 压力面 The high-pressure surface of an aerofoil, turbine, or compressor blade. In normal aircraft applications, this is the lower surface of a wing. For applications, such as to high-performance motor vehicles, where the aerofoil is inverted to generate downforce, it is the upper surface.
机翼、涡轮或压缩机叶片的高压表面。在正常的飞机应用中,这是机翼的下表面。对于高性能机动车辆等应用,机翼翻转以产生下压力,它是上表面。
Gas compressor 气体压缩机 A machine which draws in a gas at low pressure and delivers it at high pressure, usually accompanied by a temperature increase. Compressor designs include axial, centrifugal, diaphragm, reciprocating, and rotary (including the blade compressor).
一种在低压下吸入气体并在高压下输送气体的机器,通常伴随着温度升高。压缩机设计包括轴流式、离心式、隔膜式、往复式和旋转式(包括叶片式压缩机)。
Vibrograph 示振器 An instrument that records vibrations in a system over time.
记录系统随时间变化的振动的仪器。
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。
Silky fracture 丝状断口 A metal fracture in which the broken metal surface has a fine texture, usually dull in appearance. Characteristic of tough and strong metals.
一种金属断裂,断裂的金属表面具有精细的纹理,通常外观暗淡。具有坚韧和坚固金属的特征。
Fit 装配 The general term used to signify the range of tightness which may result from the application of a specific combination of allowances and tolerances in the design of mating parts.
通用术语,用于表示配合零件设计中公差和公差的特定组合可能导致的紧密性范围。
Intergranular fracture 沿晶破裂 Brittle fracture of a metal in which the fracture is between the grains, or crystals, that form the metal. Also called intercrystalline fracture.
金属的脆性断裂,断裂位于形成金属的晶粒或晶体之间。又称晶间破裂。
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。
Thermodynamic state 热力学状态 The condition of a system or working fluid according to its properties.
系统或工作流体根据其性质的状态。
Humidify 加湿 To add water vapour to air or another gas to increase its humidity.
将水蒸气添加到空气或其他气体中以增加其湿度。
Weight (W) (Unit N) 重量(W)(单位:N) The force of attraction on a body due to gravity. A body’s weight is the product of its mass and the gravitational field strength at that point. Mass remains constant, but weight depends on the object’s position on the Earth’s surface, decreasing with increasing altitude. If g is the acceleration due to gravity, the weight of a mass m is given by W = mg. On Earth, the acceleration due to gravity is approximately 9.81 m/s², so that the weight of a 1 kg mass is 9.81 N. More generally, the weight is the force exerted on the mass of a body when in the gravitational field of another body.
重力由于重力作用在物体上的吸引力。物体的重量是其质量和该点引力场强度的乘积。质量保持不变,但重量取决于物体在地球表面的位置,随着海拔的升高而减小。如果g是重力引起的加速度,则质量m的重量由W=mg给出。在地球上,重力引起的加速度约为9.81m/s²,因此1千克质量的重量为9.81N。更一般地说,重量是在另一个物体的重力场中施加在物体质量上的力。
Oxidative wear 氧化磨损 A type of wear resulting from the sliding action between two metallic components that generates oxide films on the metal surfaces. These oxide films prevent the formation of a metallic bond between the sliding surfaces, resulting in fine wear debris and low wear rates.
由两个金属部件之间的滑动作用导致的一种磨损,在金属表面上产生氧化膜。这些氧化膜防止在滑动表面之间形成金属结合,导致细磨屑和低磨损率。
Indentation hardness 压痕硬度 The resistance of a material to indentation as determined by hardness testing. The indenter, which may be spherical or diamond shaped, is pressed into the surface of a metal under specified load for a given time. (Unit Pa or, non-SI, kgf/mm²) A measurement of hardness taken by means of an indenter, pressed into a material by a load, which makes a permanent impression. The hardness is given by the load divided by the projected (sometimes surface) area of the indentation. Plasticity theory shows that the hardness is about 2.5–3 times the uniaxial yield stress.
通过硬度测试确定的材料抗压痕的能力。压头可以是球形或菱形,在规定的载荷下压入金属表面一段时间。(单位Pa或,非国际单位制,kgf/mm²)通过压头测量硬度,压入材料,形成永久压痕。硬度由载荷除以压痕的投影(有时是表面)面积得出。塑性理论表明,硬度约为单轴屈服应力的2.5–3倍。
Brake lining 制动衬片 The replaceable friction material that covers a brake shoe in an internally expanding brake.
在内膨胀制动器中覆盖制动的可更换摩擦材料。
Annealing carbon 退火碳 Fine, apparently amorphous carbon particles formed in white cast iron and certain steels during prolonged annealing. Also called temper carbon.
白口铸铁和某些钢在长时间退火过程中形成的细小、明显的无定形碳颗粒。也称为回火碳。
Trepanning 开孔 Trepanning is a machining process for producing a circular hole or groove in solid stock, or for producing a disk, cylinder, or tube from solid stock, by the action of a tool containing one or more cutters (usually single-point) revolving around a center.
开孔是一种机械加工工艺,通过包含一个或多个围绕中心旋转的刀具(通常为单点)的作用,在实心坯料中制造圆孔或凹槽,或从实心坯料生产圆盘、圆柱体或管。
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。
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。
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。
Rotary blower 旋转鼓风机 (rotary compressor) A positive-displacement gas compressor which may be of the blade type, helical-screw type, meshing-lobe type (the Roots blower), or sliding-vane type.
(旋转式压缩机)一种容积式气体压缩机,可以是叶片式、螺旋式、啮合凸角式(罗茨鼓风机)或滑动叶片式。
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。
Screw compressor 螺杆压缩机 A positive-displacement rotary compressor in which gas is progressively compressed by two intermeshing, counter-rotating, helical screws.
一种容积式旋转压缩机,其中气体由两个相互啮合、反向旋转的螺旋螺杆逐渐压缩。
Yield point (Unit Pa) 屈服点(单位Pa) The first stress in a material, usually less than the maximum attainable stress, at which an increase in strain occurs without an increase in stress. Only certain metals—those which exhibit a localized, heterogeneous type of transition from elastic to plastic deformation—produce a yield point. If there is a decrease in stress after yielding, a distinction may be made between upper and lower yield points. The load at which a sudden drop in the flow curve occurs is called the upper yield point. The constant load shown on the flow curve is the lower yield point. (yield strength, yield stress, Rel, Rel) The stress at which the onset of permanent (plastic) deformation (yielding) occurs in a body under increasing loading. In some materials, a yield-point phenomenon occurs in which stress falls on initial yielding and plastic deformation continues without increase in stress as strain increases further. The yield criterion is the combination of normal and shear stresses which produces yielding under multiaxial loading.
材料中的第一应力,通常小于可达到的最大应力,在该应力下应变增加而应力不增加。只有某些金属——表现出从弹性变形到塑性变形的局部、非均匀类型的金属——才会产生屈服点。如果屈服后应力降低,可区分上屈服点和下屈服点。流量曲线突然下降时的荷载称为上屈服点。流量曲线上显示的恒定载荷为较低屈服点。(屈服强度,屈服应力,Rel)在不断增加的载荷下,物体发生永久(塑性)变形(屈服)时的应力。在某些材料中,会出现屈服点现象,即应力在初始屈服时下降,随着应变进一步增加,塑性变形继续,而应力没有增加。屈服准则是在多轴载荷下产生屈服的正应力和剪应力的组合。
Carbonitriding 碳氮共渗 A case hardening process in which a suitable ferrous material is heated above the lower transformation temperature in a gaseous atmosphere of such composition as to cause simultaneous absorption of carbon and nitrogen by the surface and, by diffusion, create a concentration gradient. The process is completed by cooling at a rate that produces the desired properties in the workpiece.
一种表面硬化工艺,在该工艺中,将合适的含铁材料在气体气氛中加热到较低的转变温度以上,使其表面同时吸收碳和氮,并通过扩散形成浓度梯度。该工艺通过以在工件中产生所需性能的速率冷却来完成。
Proportional limit 比例极限 The greatest stress a material is capable of developing without a deviation from straight-line proportionality between stress and strain.
材料能够产生的最大应力不偏离应力和应变之间的直线比例。
Shear test 剪切试验 Any of several tests to obtain shear strength of a metal. Common tests used on mill products include the double-shear test, single-shear test, the blanking shear test (also known as the punching shear test) and the torsion test.
获得金属剪切强度的几种测试中的任何一种。轧机产品上常用的试验包括双剪试验、单剪试验、落料剪切试验(也称为冲切试验)和扭转试验。
Stress-intensity calibration 应力强度校准 A mathematical expression, based on empirical or analytical results, that relates the stress-intensity factor to load and crack length for a specific specimen planar geometry. Also known as Kcalibration.
基于经验或分析结果的数学表达式,该表达式将特定试样平面几何形状的应力强度因子与载荷和裂纹长度联系起来。也称为K校准。
Bimetallic strip 双金属片 A strip formed by welding, riveting or brazing together two metals having different coefficients of expansion, which causes the strip to curl when its temperature changes. Typical combinations are steel and copper or steel and brass.
将两种膨胀系数不同的金属焊接、铆接或钎焊在一起形成的带材,当温度变化时,带材会卷曲。典型的组合是钢和铜或钢和黄铜。
Critical temperature ranges 临界温度范围 Synonymous with transformation ranges, which is the preferred term.
与转换范围同义,这是首选术语。
Carbon restoration 碳修复 Replacing the carbon lost in the surface layer from previous processing by carburizing this layer to substantially the original carbon level. Sometimes called recarburizing.
通过将该层渗碳到基本上原始的碳水平来替换先前处理中在表面层中损失的碳。有时称为再碳化。
Closed-die forging 闭模锻造 The forming of a workpiece by compression within a pair of dies having the female form of the component to be manufactured (closed dies), superfluous metal being expelled as flash where the dies meet.
在一对具有待制造部件的阴模的模具(闭模)内通过压缩形成工件,多余的金属在模具相遇处作为飞边排出。
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。
Computer numerical control (CNC) 计算机数控(CNC) A term relating to machine tools in which the movements of a tool and/or the workpiece are controlled by computer.
与机床相关的术语,其中工具和/或工件的运动由计算机控制。
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。
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°。
Bearing failure 轴承故障 A failure that occurs in a riveted or bolted joint when the transverse load divided by the bearing area results in a stress that leads to permanent plastic deformation.
当横向载荷除以承载面积产生导致永久塑性变形的应力时,铆接或螺栓连接中发生的失效。
Pitch (Unit m) 间距(单位:m) 1. In a cascade of identical turbine or compressor blades, the distance between successive blades measured parallel to the leading edges. 2. For a screw thread, the distance between adjacent thread forms measured parallel to the thread axis. 3. For an aircraft, the vertical relationship between the nose and the horizon. The pitch axis is an axis in the plane of the wings of an aircraft, perpendicular to the centreline, about which the aircraft rotates. Pitch motion is the corresponding up or down movement of the aircraft nose. Pitch attitude is the angle between the centreline of an aircraft and the horizontal. The angle is positive when the nose is above its position when the centreline is horizontal.
1.在相同涡轮或压缩机叶片的叶栅中,平行于前缘测量的连续叶片之间的距离。2.对于螺纹,平行于螺纹轴线测量的相邻螺纹形状之间的距离。3.对于飞机,机头和水平线之间的垂直关系。俯仰轴是飞机机翼平面内垂直于中心线的轴,飞机绕中心线旋转。俯仰运动是飞机机头的相应向上或向下运动。俯仰姿态是飞机中心线与水平线之间的角度。当中心线水平时,当机头高于其位置时,角度为正。
Crank angle (Unit °) 曲柄角度(单位°) The angle between the crank of a slider-crank mechanism and a line from the crankshaft centreline to the piston axis.
曲柄滑块机构的曲柄与曲轴中心线到活塞轴线的直线之间的角度。
J-integral J-积分 A mathematical expression describing a line or surface integral that encloses the crack front from one crack surface to the other, used to characterize the fracture toughness of a material having appreciable plasticity before fracture. The J-integral eliminates the need to describe the behavior of the material near the crack tip by considering the local stress-strain field around the crack front; JIc is the critical value of the J-integral required to initiate crack extension from a preexisting crack.
描述从一个裂纹表面到另一个裂纹正面的线或表面积分的数学表达式,用于表征断裂前具有可观塑性的材料的断裂韧性。J积分通过考虑裂纹前缘周围的局部应力应变场,无需描述裂纹尖端附近材料的行为;JIc是从先前存在的裂纹开始裂纹扩展所需的J积分的临界值。
Mean value 平均值 The average value of a number of data points. Computed by dividing the sum of all data by the number of data points.
多个数据点的平均值。通过将所有数据的总和除以数据点的数量来计算。
Ausforming 形变热处理 Thermomechanical treatment of steel in the metastable austenitic condition below the recrystallization temperature followed by quenching to obtain martensite and/or bainite.
在低于再结晶温度的亚稳态奥氏体条件下对钢进行热机械处理,然后淬火以获得马氏体和/或贝氏体。
Blow moulding 吹塑 The manufacture of hollow polymer objects (e.g. bottles) by expanding, with internal air pressure, a tube sealed at one end (parison) against the walls of a cavity mould.
通过使用内部气压使一端密封的管子(型坯)靠在型腔模具的壁上膨胀来制造中空聚合物物体(例如瓶子)。
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。
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。
Least count 最小计数 The smallest value that can be read from an instrument having a graduated scale. Except on instruments provided with a vernier, the least count is that fraction of the smallest division which can be conveniently and reliably estimated; this fraction is ordinarily one-fifth or one-tenth, except where the graduations are very closely spaced.
可从具有刻度尺的仪器中读取的最小值。除配备游标的仪器外,最小计数是可以方便可靠地估计的最小除法的分数;这个分数通常是五分之一或十分之一,除非刻度间隔非常近。
Acicular ferrite 针状铁素体 A highly substructured non-equiaxed ferrite that forms upon continuous cooling by a mixed diffusion and shear mode of transformation that begins at a temperature slightly higher than the temperature transformation range for upper bainite. It is distinguished from bainite in that it has a limited amount of carbon available; thus, there is only a small amount of carbide present. Ferrite crystallite growing, apparently, as in the course of bainitic transformation. It has a lath-like shape and an increased dislocation
一种高度亚结构的非等轴铁素体,在连续冷却时通过混合扩散和剪切相变模式形成,其开始温度略高于上贝氏体的温度转变范围。它与贝氏体的区别在于它的碳含量有限。因此,仅存在少量碳化物。显然,铁素体微晶在贝氏体转变过程中生长。它具有板条状的形状和增加的位错。
Balancing machine 平衡机 A device that assesses the state of static and dynamic balance of a rotating part, and indicates the magnitude and location of weights to be added to give balance.
一种装置,用于评估旋转部件的静态和动态平衡状态,并指示为获得平衡而添加的砝码的大小和位置。
Bulk velocity 体积速度 (average velocity, V) (Unit m/s) For fluid flow in a pipe or duct, the average flow velocity, given by V = ṁ/ρA where ṁ is the mass flow rate, ρ is the fluid density, and A is the duct cross-sectional area.
(平均速度,V)(单位m/s)对于管道或管道中的流体流动,平均流速,由V=ṁ/ρA给出,其中ṁ是质量流量,ρ是流体密度,A是管道截面积。
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。
Fastener with waisted shank 带腰柄的紧固件 Finished fastener with a shank diameter of ds < d2.
柄径ds
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。
Ductile crack propagation 延性裂纹扩展 Slow crack propagation that is accompanied by noticeable plastic deformation and requires energy to be supplied from outside the body.
缓慢的裂纹扩展,伴随着明显的塑性变形,需要从外部提供能量。
Unit 单位 A numerical indication of the magnitude of a physical quantity. The basic units of mass, length, time, etc. are relative to agreed standards.
物理量大小的数字指示。质量、长度、时间等基本单位与商定的标准相对应。
Bypass flow meter 旁通流量计 (shunt flow meter) A flow meter installed in a pipework bypass which may itself be part of the flow meter. An orifice plate is used to ensure a fraction of the main flow passes through the bypass.
(分流流量计)安装在管道旁路中的流量计,它本身可能是流量计的一部分。孔板用于确保一部分主流通过旁路。
Compressible flow 可压缩流动 A gas flow in which the Mach number M is sufficiently high for the gas density to change significantly. For air, this is when M > 0.3.
马赫数M高到足以使气体密度发生显着变化的气流。对于空气,这是当M>0.3时。
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。
Nut box mechanism 螺母箱机械装置 In a lathe it is used to engage and disengage the lead screw for thread cutting. This comprises a pair of half-nuts capable of sliding in vertical slides in or out of mesh with the lead screw.
在车床中,它用于接合和分离丝杠以进行螺纹切削。这包括一对半螺母,能够在与丝杠啮合的垂直滑动中滑动。
Checks 检查 Numerous, very fine cracks in a coating or at the surface of a metal part. Checks may appear during processing or during service and are most often associated with thermal treatment or thermal cycling.
涂层中或金属零件表面的许多非常细微的裂纹。在加工或服务期间可能会出现检查,并且通常与热处理或热循环有关。
Stress-relaxation curve 应力松弛曲线 A plot of the remaining, or relaxed, stress in a stress-relaxation test as a function of time. The relaxed stress equals the initial stress minus the remaining stress. Also known as a stress-time curve.
应力松弛试验中剩余应力或松弛应力随时间变化的曲线图。松弛应力等于初始应力减去剩余应力。也称为应力-时间曲线。
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。
Guided-bend test 导向弯曲试验 A test in which the specimen is bent to a definite shape by means of a punch (mandrel) and a bottom block.
用冲头(心轴)和底块将试样弯曲成一定形状的试验。
Fog quenching 雾淬 Quenching in a fine vapor or mist.
在细蒸汽或薄雾中淬火。
Pressure (p) (Unit Pa) 压力(p)(单位Pa) In thermodynamics and fluid mechanics, the compressive force exerted by the fluid per unit area. The pressure exerted by a fluid on a surface acts normal to the surface.
在热力学和流体力学中,每单位面积流体施加的压缩力。流体施加在表面上的压力垂直于表面。
Fracture stress 断裂应力 The true normal stress on the minimum cross-sectional area at the beginning of fracture. This term usually applies to tension tests of unnotched specimens.
断裂开始时最小横截面积上的真实正应力。该术语通常适用于无缺口试样的拉伸试验。
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。
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。
Thermodynamic process 热力学过程 A change in equilibrium state undergone by a quantity of matter or a system.
一定量的物质或系统所经历的平衡状态的变化。
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。
Cemented carbides 硬质合金 Sintered mixtures of refractory metal carbides (e.g. tungsten carbide) in a metal matrix binder such as cobalt, nickel, or iron. They have high melting point, toughness, compressive strength, and wear resistance. Applications include use in grinding wheels and papers, cutting tools, drill bits, wire-drawing dies, and ball-point pen tips. Sometimes known as hard metals when the application is to machine tools.
难熔金属碳化物(如碳化钨)在金属基体粘结剂(如钴、镍或铁)中的烧结混合物。它们具有高熔点、韧性、抗压强度和耐磨性。应用包括用于砂轮和纸张、切削工具、钻头、拉丝模和圆珠笔尖。当应用于机床时,有时称为硬金属。
Press quenching 压淬 A quench in which hot dies are pressed and aligned with a part before the quenching process begins. Then the part is placed in contact with a quenching medium in a controlled manner. This process avoids part distortion.
一种淬火方法,在淬火过程开始之前,热模具被压制并与零件对齐。然后将零件以受控方式放置在与淬火介质接触的位置。该过程避免了零件变形。
Quench-age embrittlement 淬火时效脆化 Embrittlement of low-carbon steels resulting from precipitation of solute carbon at existing dislocations and from precipitation hardening of the steel caused by differences in ferrite at different temperatures. Quenchage embrittlement usually is caused by rapid cooling of the steel from temperatures slightly below Ac1 (the temperature at which austenite begins to form), and can be minimized by quenching from lower temperatures.
低碳钢的脆化是由于溶质碳在现有位错处的沉淀和铁素体在不同温度下的差异导致的钢沉淀硬化造成的。淬火脆性通常是由钢从略低于Ac1的温度(奥氏体开始形成的温度)快速冷却引起的,可以通过从较低温度淬火来最小化。
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。
Terminal temperature difference (Unit K) 终端温差(单位K) The temperature difference between the two fluid streams at either inlet or outlet of a heat exchanger.
热交换器入口或出口处两种流体流之间的温差。
Shear joint 剪切接头 A joint which is subjected primarily to loads acting more or less perpendicular to the axes of the bolts.
主要承受或多或少垂直于螺栓轴线的载荷的接头。
Turbulent flow (turbulence) 湍流 Fluid motion characterized by disorderly, rotational (i.e. vortical) three-dimensional velocity fluctuations covering a wide range of frequency and length scales. The pressure, temperature, and other fluid properties also fluctuate and the diffusion of heat, mass, and momentum is greatly enhanced. As are laminar and transitional flow, turbulent flow of a Newtonian fluid is governed by the Navier–Stokes equations which can in principle be solved by direct numerical simulation (DNS) in which all time and length scales of the fluctuating motion are resolved.
流体运动的特点是无序、旋转(即旋涡)三维速度波动,覆盖广泛的频率和长度尺度。压力、温度和其他流体特性也会波动,热、质量和动量的扩散会大大增强。与层流和过渡流一样,牛顿流体的湍流由Navier-Stokes方程控制,该方程原则上可以通过直接数值模拟(DNS)求解,在直接数值模拟中,波动运动的所有时间和长度尺度都可以求解。
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