42／00－RSZ轴承内轴局部淬火工艺

４２／００－ＲＳＺ双列深沟球轴承是正时齿带涨紧器的关键部件，材料为ＧＣｒ１５钢，轴承内轴与外圈装配成成品后，需将内输带孔的一端铆接在一个金属板上，为此，该端应有足够的塑韧性，且硬度不宜过高，另一端则要求高硬度。曾对内轴采用高频感应加热淬火、控制气氛连续淬火炉加热淬火，均不能满足技术要求、采用盐浴局部加热淬火、整体回火后，带孔端研度低于３０ＨＲＣ，另一端硬为６１～６５ＨＲＣ，且金相组织符合要求。     

20Cr2Ni4A大型低速重载硬齿面齿轮热处理工艺的研究

本文通过对２０Ｃｒ２Ｎｉ４Ａ钢制造的大型低速重载硬齿面齿轮的加工工艺性分析、确立了先渗碳淬火，后插入孔健槽的工艺方案。在热处理工艺上采取了高温装炉快速加热淬火及内孔局部保护法，使齿轮及齿缘达到ＪＢ－ＺＱ４０３９－８８有ＪＢ／ＺＱ４０４０－８８的要求，同时使内孔（轮幅）硬度降低到ＨＲＣ４０以下，保证顺利害怕行键槽工序；渗碳后增加了低温退火工序，淬火后进行两次低温回火，使渗碳层的金相组织达到了要求，加     

一种新型多元素莱氏体抗磨蚀铸钢

发展了一种抗磨蚀多元系莱氏体铸钢ＺＧ９３Ｌ，经淬火、回火后，抗拉强度近５５０ＭＰａ，硬度为６０ＨＲＣ以上，其抗磨蚀性比０Ｃｒ１３Ｎｉ４Ｍｏ钢高１．５倍，是一种适于制造水轮机顶盖及护板用的耐磨蚀新钢种。     

直齿圆柱齿轮冷精锻实用化工艺研究

以实用化为目标,对１５＾＃钢、４５＾＃钢、２０ＣｒＭｎＴｉ直齿圆柱齿轮冷精锻工艺进行系统研究,提出了闭式镦挤－约束孔分流两步成形实用化工艺方案和基于变位理论和齿形模修正设计方法。     

不同喷涂方法制备WC—Co涂层性能的研究

介绍超音速火焰、等离子，氧乙炔火焰三种喷涂方法，在钢基体上喷涂钴包碳化钨粉末所制备涂层的工艺性能，结合强度，耐磨性能和机理。结果表明，三种喷涂方法都可制备ＷＣ－Ｃｏ金属陶瓷涂层；超音速火焰喷涂涂层的性能最好，其耐磨性能与硬质合金ＹＴ５相当；氧乙炔火焰喷涂层具有一定的耐磨性能。     

不同喷涂方法制备WC－Co涂层性能的研究

介绍超音速火焰、等离子、氧乙炔火焰三种喷涂方法，在钢基体上喷涂钴包碳化钨粉末所制备涂层的工艺性能、结合强度、耐磨性能和机理。结果表明，三种喷涂方法都可制备ＷＣ－Ｃｏ金属陶瓷涂层；超音速火焰喷涂涂层的性能最好，其耐磨性能与硬质合金ＹＴ５相当；氧乙炔火焰喷涂涂层具有一定的耐磨性能。     

淬火温度和回火工艺对4Cr5Mo2V钢高温耐磨性能的影响

将4Cr5Mo2V钢在1 000～1 090℃下淬火,并通过不同温度2次回火处理将相同淬火温度下试验钢的回火硬度分别调整至55,52 HRC,研究了淬火温度和回火工艺对显微组织、冲击韧性和高温(350℃)耐磨性能的影响。结果表明：回火硬度相同时,淬火温度过高或过低均会降低试验钢的韧性而加剧磨损表面材料剥落,从而降低耐磨性能;相同回火硬度下,1 030℃淬火条件下试验钢的韧性和高温耐磨性能最好,1 090℃淬火条件下最差;淬火温度相同时,较低温度回火试验钢因具有较高回火硬度,能够起到支撑表面氧化层的作用,其耐磨性能比较高温度回火时好;4Cr5Mo2V钢的推荐热处理工艺为1 030℃×30 min油淬+560℃×2 h×2次回火。     

我国热作模具钢性能数据集(续Ⅹ)

(1 0 )　 4Ｃｒ5ＭｏＳｉＶ钢 (Ｈ1 1 )4Ｃｒ5ＭｏＳｉＶ钢是国外早期研制含 5 %Ｃｒ系的典型热作模具钢 ,主要用于铝合金压铸模 ,后来变化为六种成分。这类钢常用工作硬度为 4 4 5 0ＨＲＣ ,在受较大冲击力时硬度可降至 4 0 4 4ＨＲＣ ,作为铝合金压铸模时硬度可提高至 5 2ＨＲＣ。 4Ｃｒ5ＭｏＳｉＶ钢的特点是合金元素含量较低、空淬温度较低、淬火变形小、有较好的抗氧化性、抗冷热疲劳和耐铝的冲蚀性。在我国被列入ＧＢ12 99标准 ,是成熟的应用量较大的热作模具钢。其淬透性较好 ,15 0ｍｍ以下截面的模具可以空冷淬硬。在相近的硬度条…     

15MnVN代替15MnMoVNRe提高屈服强度和表面淬火硬度的研究

本文采用与工件等效截面的试样，利用１５ＭｎＶＮ钢，经调质和表面淬火后，成功地代替了１５ＭｎＭｏＶＮＲｅ钢，其屈服强度达到了Ｑ／ＣＧ０５－８０《低合金高强度结构钢技术条件》中ＱＪ６０的要求，表面淬火后硬度达到４０－４５ＨＲＣ，有效硬化层深度达到３．８ｍｍ，为１５ＭｎＶＮ钢的使用开辟了一条新途径。经采用试样的工艺方法，三种斗刃的热处理亦获得了满意的结果。     

GCr15钢贝氏体淬火及其在铁路轴承上的应用

研究了ＣＧｒ１５钢的等温淬火工艺及其在铁路轴承上的应用，结果表明，与常规淬火相比，在工件滚动接触疲劳寿命和耐磨性相机的情况下，等温淬火有优良的冲击韧性。铁路轴承采用等温淬火工艺是行之有效的。为了获得较好的力学性能，加热温度推荐为８５０－８７０℃，等温时间为２２０－２４０℃，等温时间为２２０－２４０℃，等温时间有待进一步研究。     

Minimal Realization of Linear Graph Models for Multi-physics Systems

An engineering system may consist of several different types of components,belonging to such physical"domains"as mechanical,electrical,fluid,and thermal.It is t...     

INTEGRAL EQUATION METHOD＇S APPLICATION IN HOLE-EDGE STRESS OF COMPOSITE MATERIAL PLATE WITH DIFFERENT SHAPED HOLES

The strength of composite plate with different hole-shapes is always one of the most important but complicated issues in the application of the composite material. The holes will lead to mutations and discontinuity to the structure. So the hole-edge stress concentration is always a serious phenomenon. And the phenomenon makes the structure strength decrease very quickly to form dangerous weak points. Most partial damage begins from these weak points. According to the complex variable functions theory, the accurate boundary condition of composite plate with different hole-shapes is founded by conformal mapping method to settle the boundary condition problem of complex hole-shapes. Composite plate with commonly hole-shapes in engineering is studied by several complex variable stress fimction. The boundary integral equations are founded based on exact boundary conditions. Then the exact hole-edge stress analytic solution of composite plate with rectangle holes and wing manholes is resolved. Both of offset axis loadings and its influences on the stress concentration coefficient of the hole-edge are discussed. And comparisons of different loads along various offset axis on the hole-edge stress distribution of orthotropic plate with rectangle hole or wing manhole are made. It can be concluded that hole-edge with continuous variable curvatures might help to decrease the stress concentration coefficient; and smaller angle of outer load and fiber can decrease the stress peak value.     

Non-monotonic material contrast in scanning ion and scanning electron images

30 keV Ga⁺ focused ion beam induced secondary electron (iSE) imaging was used to determine the relative contrast between several materials. The iSE signal compared from C, Si, Al, Ti, Cr, Ni, Cu, Mo, Ag, and W metal layers does not decrease with an increase in target atomic number Z₂, and shows a non-monotonic relationship between contrast and Z₂. The non-monotonic relationship is attributed to periodic fluctuations of the stopping power and sputter yield inherent to the ion–solid interactions. In addition, material contrast from electron-induced secondary electron (eSE) and backscattered electron (BSE) images using scanning electron microscopy (SEM) also shows non-monotonic contrast as a function of Z₂, following the periodic behavior of the stopping power for electron–solid interactions. A comparison of the iSE and eSE results shows similar relative contrast between the metal layers, and not complementary contrast as conventionally understood. These similarities in the contrast behavior can be attributed to similarities in the periodic and non-monotonic function defined by incident particle–solid interaction theory.     

Application of Feature Extraction through Convolution Neural Networks and SVM Classifier for Robust Grading of Apples

This paper proposes a novel grading method of apples,in an automated grading device that uses convolutional neural networks to extract the size,color,texture,an...     

分布动态载荷识别的抗噪处理

针对正交多项式频域法在用多种响应对矩形薄板进行载荷识别中抗噪性较差的问题,综合运用平均法、矩阵预处理和奇异值截断法等方法对之进行改善,并引入空间映射的思想,将该方法的应用范围拓展为复杂的模型.利用仿真算例,证实了该方法具有较好的抗噪性.     

基于MELTAC-N平台的核电厂安全级DCS环网研究与测试

针对工程实践中环网通讯相关问题的处理缺乏理论基础及国产化安全级DCS平台的开发缺乏成熟经验借鉴问题,对基于MELTAC-N平台核电厂安全级DCS环网的软硬件实现进行了研究。提出了安全级DCS环网双环网冗余设计、光切换开关设计等硬件设计方法,以及以RPR协议为基础,采用全数据收发策略的软件设计方法。在CPR1000安全级DCS平台上对安全级DCS环网的可靠性及实时性进行了评价,并进行了容错能力、响应时间及响应时间稳定性测试验证实验。结果表明,基于MELTAC-N平台安全级DCS环网软硬件设计具有较好的容错能力及响应时间稳定性。     

Short-Term Relay Quality Prediction Algorithm Based on Long and Short-Term Memory

The fraction defective of semi-finished products is predicted to optimize the process of relay production lines, by which production quality and productivity ar...     

End-to-End Multiview Gesture Recognition for Autonomous Car Parking System

The use of hand gestures can be the most intuitive human-machine interaction medium.The early approaches for hand gesture recognition used device-based methods....     

The laboratory simulation of abrasive wear

Abrasive wear has long been recognised as one of the most potentially serious tribological problems facing the operators of many types of plant and machinery; several industrial surveys have indicated that wear by abrasion can be responsible for more than 50% of unscheduled machine and plant stoppages. Locating the operating point of a tribological contact in an appropriate operational ‚map’︁ can provide a useful guide to the likely nature and origins of the surface degradation experienced in use, though care must be exercised in choosing the most suitable parameters for the axes of the plot. Laboratory testing of materials and simulations of machine contacts are carried out for a number of purposes; at one level for the very practical aims of ranking candidate materials or surface hardening treatments in order of their wear resistance, or in an attempt to predict wear lives under field conditions. More fundamentally, tests may be aimed at elucidating the essential physical mechanisms of surface damage and loss, with the longer term aim of building an analytical and predictive model of the wear process itself. In many cases, component surface damage is brought about by the ingress of hard, particulate matter into machine bearing or sealing clearances. These may be running dry although, more usually, a lubricant or service fluid is present at the interface. A number of standardised wear test geometries and procedures have been established for both two- and three-body wear situations, and these are briefly described. Although abrasive wear is often modelled as following an ‚Archard’︁ equation (i.e. a linear increase in material loss with both load and time, and an inverse dependence on specimen hardness) both industrial experience and laboratory tests of particularly lubricated contacts show that this is not always the case: increasing the hardness differential in an abrasively contaminated lubricated pair may not always reduce the rate of damage to the harder surface.     

Limits of topographic measurement by the scanning tunnelling and atomic force microscopes

Parameters describing the topographic character of a surface (height, surface wavelength, slope and curvature) can be derived from equivalent sinusoidal profiles. The response of a surface-measuring instrument may be modelled in terms of instrument parameters such as stylus radius, and scanning range and resolution. The performance of the instrument may then be mapped as a zone in amplitude-wavelength (AW) space to show the sinusoidal profiles it is capable of measuring. In a first-order analysis the STM and AFM are considered as equivalent to contact-stylus instruments with a notional stylus radius equal to the tip radius plus the gap. Comparisons between different instruments and types of instrument are readily made by mapping in AW space. The error arising from convolution of the sinusoidal profile with that of the finite tip may be quantified and plotted as contours in AW space.