循环氢脱硫塔制造中的腐蚀试验

用国产16MnR（HIC）抗氢钢制造循环氢脱硫塔的过程中，通过对板材、锻件、焊接接头做腐蚀试验的结果，证明能够满足设计要求的试验数据，即该材料在酸性气体中具有一定的抗氢、抗硫化物的特性。     

循环氢脱硫塔制造中的腐蚀试验

用国产16MnR(HIC)抗氢钢制造循环氢脱硫塔的过程中,通过对板材、锻件、焊接接头做腐蚀试验的结果,证明能够满足设计要求的试验数据,即该材料在酸性气体中具有一定的抗氢、抗硫化物的特性.     

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。     

连铸机辊子锻造工艺的改进

1981年我厂生产小方坯连铸机,其中FL101、21-10辊子(锻件见图所示),按设计要求,用25CrMo4材料制造。该原材料是本厂铸钢车间15t电炉冶炼提供的1.27t六角钢锭。锻件重量290kg,最大直径270mm。我厂工艺部门为该辊子编制的工艺是:开坯锻造→热送去氢退火→成品锻造→常规退火四道工序。生产任务下达到锻压车间后,我们对该工艺进行了研究,我们用价值工程的观点,对该工艺进行     

2.25Cr-1Mo-0.25V钢锻件持久性能试验

对2. 25Cr-1Mo-0. 25V钢加氢筒体锻件的高温持久试验及试样的断口形貌进行检测,检测结果表明,随着应力水平的降低,持久时间明显延长;断口形貌规则、均匀,具有良好的持久塑性。经外推法计算,加氢锻件在482℃时的3×104h持久强度极限值为267. 8 MPa。     

电化学充氢条件下夹杂物对管线钢氢致开裂敏感性的影响

对X52、20、X70管线钢在0.5mol·L-1H2SO4溶液中进行电化学充氢试验,研究了钢中夹杂物形态、大小、数量、分布对管线钢氢致开裂(HIC)的影响。结果表明:X52钢的HIC敏感性远小于20钢和X70钢的;20钢中的MnS夹杂物并不是氢致裂纹的必然形核位置,而Al2O3、复合氧化物/铁的碳化物、硅夹杂物则是更为有害的氢致裂纹源;X70钢中以Al2O3、铁的碳化物造成的氢致开裂危害最大;相邻夹杂物形成的裂纹源不断扩展并合成了更大的裂纹。     

回转窑外壳筒体的焊接

琉璃河水泥厂回转窑的窑体直径为4m,长6m。窑体外壳筒体采用厚50mm、32mm、25mm和22mm四种规格的Q235A钢板焊接而成,内有耐火砖衬及换热装置。 窑体外壳筒体总重183t,制造厂分为九个段节供货,现场安装时需要组焊八条环缝。由于筒体的重量及尺寸较大,给组焊和安装带来一定的困     

显微组织对超低碳X80管线钢氢致开裂行为的影响

对超低碳X80管线钢分别进行了正火和淬火处理,采用光学显微镜、扫描电镜、透射电镜和电子背散射衍射技术等手段,研究了显微组织对试验钢氢致开裂(HIC)行为的影响。结果表明:未经热处理的试验钢显微组织为针状铁素体,该组织的抗HIC性能优于正火后多边形铁素体组织和淬火后贝氏体铁素体组织的抗HIC性能;大小角度晶界的均匀分布有利于提高试验钢的抗HIC性能,高密度的小角度晶界可以阻止氢致裂纹扩展。     

125t吊钩桥式起重机主梁的组装焊接

济钢集团石横特殊钢厂Consteel电炉主跨用 2台QD1 2 5 /5 0 /5— 2 2A6吊钩桥式起重机 ,其主梁结构为偏轨箱形梁 ,单件重量为 2 4 1t,截面尺寸为1 770mm× 2 2 0 0mm、总长为 2 2 8m ,材质为Q345A( 1 6Mn)。这种T形钢宽翼缘偏轨箱形梁结构虽然解决了承轨纵向熔透角焊缝制造上的困难 ,但对于这种低合金钢偏轨箱形梁 ,我厂还是第一次制作。如何保证主梁的各项指标达到标准和设计要求 ,是此次制作中的难点。一、主梁相关技术要求及制作难点1 技术要求主梁结构为T形钢宽翼缘偏轨箱形梁结构 ,上下盖板板厚为 1 2mm、主腹板板厚为 1 2mm、…     

氨合成塔大面积的补焊

某化工集团公司合成氨厂,有二台氨合成塔,其中一台多层高压容器是20多年前设计、制造的。 该塔的设计压力为32MPa,操作压力为30.5MPa,壳体设计温度为200℃,其内径为(?)1000mm,壳体由九个层板包扎的筒节和两个锻件组成,内筒钢板为22mm的16Mn,层板为6mm的15MnV,顶部法兰锻件为20MnMo,下封头锻件为18MnMoNb。20MnMo锻件法兰与筒节相连处的壳体壁厚为127mm,壳体高13880mm,设备总高为15400mm,设备总重为58t。     

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...     

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.     

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.     

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。     

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.     

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....     

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.