2．25Cr-1Mo-0．25V纯净钢简体锻件的工艺与性能

为了制造千吨级煤液化反应容器，满足更高温度(482℃)和更高的强度等级(σ0．2≥415MPa)，减少筒体锻件的重量，在原采用的2．25Cr-1Mo钢的基础上，开发出了加V钢。针对煤液化装置(或大型热壁加氢反应器)用2．25Cr-1Mo-0．25V纯净钢筒体锻件的特点及理化性能要求，分析了冶炼、锻造、热处理等工序的难点，在进行大量的国内、外资料查寻以及材料和工艺试验的基础上，制定出并实施了制造工艺，经过筒体锻件的解剖及理化检验，证明所采用的工艺方法是非常有效的，完全满足煤液化装置用钢2．25Cr-1Mo-0．25V的质量要求。     

2.25Cr-1Mo-0.25V钢制加氢反应器用埋弧焊焊材试验研究

通过对2.25Cr-1Mo-0.25V钢用国产与进口埋弧自动焊焊材,用模拟件进行焊接试验,从焊接工艺性、化学成分、硬度、力学性能以及回火脆化等各项性能进行对比分析,结果表明,在相同的焊接参数和热处理条件下,国产焊材焊接工艺性良好,各项力学性能与进口同类焊材相当,能够满足2.25Cr-1Mo-0.25V钢焊接技术要求.     

2.25Cr-1Mo-0.25V钢加氢反应器的研制

2.25Cr-1Mo-0.25V钢是当前设计温度454℃以上高压临氢设备首选用材，具有强度高、抗氢侵蚀能力强、抗氢脆性能显著、回火脆化倾向小、抗氢致剥离性能优良等特点。本文通过首台产品研制，介绍了2.25Cr-1Mo-0.25V钢锻焊结构热壁加氢反应器制造技术。     

2.25Cr-1Mo-0.25V钢焊接材料的再热裂纹敏感性试验方法探讨

在再热裂纹Gleeble试验的基础上,提出一种采用高温拉伸试验机对2.25Cr-1Mo-0.25V钢焊接材料进行再热裂纹敏感性测试的方法。采用该方法测得的断面收缩率(ROA值)大于Gleeble的试验结果。用其他低合金钢板作为试板时,若坡口面未堆焊2.25Cr-1Mo-0.25V过渡层,则依据该方法制作的试样杂质元素含量相对较高,试验得到的ROA值较低。     

热壁加氢反应器的现场组焊技术

介绍新疆独山子石化公司60×104t/a加氢裂化装置中,采用2.25Cr-1Mo-0.25V钢制造的热壁加氢反应器的现场组焊技术,同时介绍了现场组装、焊接、无损检测、焊后热处理和水压试验等各工序中的质量控制要点。     

2.25Cr-1Mo-0.25V钢大直径封头拼缝的性能试验

通过对2.25Cr-1Mo-0.25V钢大直径封头采用埋弧焊(交流)方法拼接后整体热成形,再经正火(水加速冷却)+回火恢复材料性能热处理和模拟焊后热处理后的性能试验,表明封头拼缝的力学性能、抗回火脆化敏感性和高温持久试验均满足ASME BPVC.Ⅷ.2及API 934-A规范要求。同时,对封头本体拼缝取样进行各项性能检验,证明该封头拼缝的制造工艺合理可行。     

90°弯管先堆焊后热成形技术

研究了2.25Cr-1Mo-0.25V钢90°弯管整体热成形制作技术。采用试验件模拟堆焊、热成形和调质处理过程,检验试验件的尺寸、母材及耐蚀层的性能,供加氢反应器设计和制造单位参考。     

2.25Cr-1Mo-0.25V钢埋弧自动焊焊材对比试验

通过对三组埋弧自动焊焊材的对比试验，选出用于2.25Cr-1Mo-0.25V钢埋弧自动焊最合适的焊丝与焊剂。     

2.25Cr-1Mo-0.25V钢加氢反应器焊接工艺改进及优化措施

为了满足工业生产需求,要求制造耐高温高压》腐蚀性能优良的加氢反应器.主要分析了2.25Cr-1Mo-0.25V钢加氢反应器主体材料成分及焊接要点,介绍了在设备制造过程中焊接工艺参数》焊接方法的选用及注意事项,在反应器制造的各个环节提出了工艺改进及优化措施,通过对焊接接头进行夏比冲击试验和拉伸试验,结果表明接头性能符合标准要求,并对主体焊缝进行RT检测,一次探伤合格率达97％以上,有效减少了裂纹的产生,为加氢反应器的成功制备提供了参考.     

二次热循环对2.25Cr-1Mo-0.25V钢再热裂纹敏感性的影响

通过对2.25Cr-1Mo-0.25V钢及其焊缝金属进行不同二次热循环下的Gleeble试验,证实经过二次热循环后,2.25Cr-1Mo-0.25V钢母材的断面收缩率(ROA值)在各种焊后热处理温度下均有显著的提高,再热裂纹敏感性由原来的稍敏感降低为不敏感;对于焊缝金属来说,经过FG(R)-WM和IC(R)-WM的二次热循环模拟后,其ROA值均较CG(R)-WM有所提高,再热裂纹敏感性有所降低;而SC(R)-WM的模拟对其再热裂纹敏感性的影响不大。     

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.