低温用3.5Ni钢管的焊接性试验研究

在工期紧张无法进行焊后热处理的情况下,通过焊接试验,制定合适的焊接工艺,将3.5Ni低温钢管焊接线能量控制在18kJ/cm以内,并采用焊后氩弧重熔工艺,控制焊缝粗晶组织的出现,从而保证接头的低温冲击韧性。     

浅析氩电联焊工艺在压力管道焊接施工中的缺陷控制

在使用氩电联焊工艺对压力管道进行焊接时,应该科学地应用电焊机,从而实现打底和填充工作,从而把各种缺陷控制在合理的范围内。这项工艺的适用范围较广,并且施工效率较高。本文对氩电联焊工艺的原理和实施流程进行简单介绍,探究功能工艺的应用价值,总结在压力管道焊接施工中氩电联焊工艺控制缺陷的模式。     

特大型圆锥滚子轴承支柱保持架氩弧焊接技术

分析特大型圆锥滚子轴承支柱焊接保持架目前普通电弧焊接存在的问题,改进采用氩弧焊接方法,并对保持架倒角进行改进。通过工艺对比验证了支柱氩弧焊接的优越性,支柱氩弧焊接无焊渣飞溅,焊帽质量更好,满足了强度要求,并对焊接的检测进行了说明。     

35CrMo法兰与Q345管材的焊接工艺

采用氩电联焊的方法焊接35CrNo和Q345（16Mn）钢。此类异种钢的焊接要注意焊前预热和焊后热处理。按正确的工艺焊接，焊后检验合格。     

20钢含硫天然气管线焊接工艺应用研究

本文从降低成本、缩短进料周期等角度出发,根据前线施工单位具体情况,灵活应用,提出以国产J427焊条替代进口焊条,采用氩电联焊方法进行了20钢含硫管线的焊接。焊接接头经应力腐蚀试验等检测后完全满足标准要求,其工艺已应用于现场施工,大大降低了生产成本,取得了令人满意的效果。     

中小径薄壁管氩弧自动焊设备研究与应用

对氩弧自动焊设备及中小径薄壁管氩弧自动焊工艺进行了研究,通过焊接试验表明,氩弧自动焊设备操作简单,焊接过程稳定,可以提高产品质量和生产效率,降低焊工劳动强度及制造成本,可在中小径薄壁管焊接生产中广泛应用。     

LD10CS、LF6y_2铝合金的熔化极脉冲弧焊接

本文介绍应用熔极脉冲弧焊接(M1G-PAW)方法焊接LD10 CS、LF6Y_2铝合金的工艺。文中从焊接热输入、焊接变形、接头的机械性能和金相组织等方面对T1G与M1G作了比较。采用M1GPAW时,对不同厚度的材料采用氦-氩和纯氩等不同保护气体,并采用不同的熔滴过渡方式(分别采用射流、介射流、半短路三种过渡方式)通过工艺试验制订出一系列工艺参数。将五十年代陈旧的埋弧焊设备改装为简易的脉冲焊机是挖潜、革新和改造的具体措施。     

LD10CS、LF6y_2铝合金的熔化极脉冲弧焊接

本文介绍应用熔极脉冲弧焊接(M1GPAW)方法焊接LD10 CS、LF6Y_2铝合金的工艺。文中从焊接热输入、焊接变形、接头的机械性能和金相组织等方面对T1G与M1G作了比较。采用M1GPAW时,对不同厚度的材料采用氦-氩和纯氩等不同保护气体,并采用不同的熔滴过渡方式(分别采用射流、介射流、半短路三种过渡方式)通过工艺试验制订出一系列工艺参数。将五十年代陈旧的埋弧焊设备改装为简易的脉冲焊机是挖潜、革新和改造的具体措施。     

大型轴流压缩机机壳焊接工艺及变形控制

分析了大型轴流压缩机焊接机壳的结构特点,选择(Ar)80%+(CO2)20%富氩混合气体保护焊的焊接工艺方法,并按标准进行了相关工艺试验,通过合理的拼装顺序有效控制了机壳的焊接变形,焊后各项指标达到设计要求。     

N06600镍基管材的焊接工艺探析

介绍N06600材料的特点,通过有害气体对镍基材料焊接时的影响、等分析该材料的焊接性能。详细叙述N06600镍基管道的焊接工艺,如焊材的选择,焊封底焊接方法等,并提出提高焊接质量的措施。焊接流动性、焊接熔深坡口的选择,钨极氩弧     

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...     

Quantum Cooperative Robotics and Autonomy

The intersection of Quantum Technologies and Robotics Autonomy is explored in the present paper.The two areas are brought together in establishing an interdisci...     

考虑进油孔有限长滑动轴承油膜力的近似解析解

针对具有进油孔的有限长滑动轴承油膜力求解问题,采用变分原理和分离变量法,求得了有限长滑动轴承油膜压力分布的近似解析表达式。将油膜压力分布的近似解析表达式在油膜存在区域上进行积分,即得到了油膜力。将提出的计算有限长滑动轴承油膜力方法与无限长轴承模型、有限元方法的计算结果进行了比较,发现了提出的方法与有限元方法的计算结果很接近。最后,研究了进油孔位置和进油压力对油膜存在区域、油膜力等的影响,研究结果表明进油孔位置和进油压力对油膜存在区域和油膜力有较大的影响。     

三绕组变压器的双绕组等效建模及在Matpower中的应用

针对实际电网存在着大量的三绕组变压器,但国际上一些著名商业软件,如BPA仿真软件、Matpower这一权威潮流计算开源软件,均只提供双绕组变压器模型,限制了其在具有三绕组变压器的电力系统中的应用的问题,潮流计算是自主开发的电力系统各种应用软件的核心模块,因此依托国际权威开源程序进行二次开发,是一种较好的选择。对Matpower要求的数据格式进行了归纳,对变压器的一般的等值电路及带理想变压器的等值电路和带标幺值的等值电路进行了分析研究,提出了三绕组变压器转换为双绕组等效模型的建模方法,使得原先只适应双绕组变压器的潮流计算软件可以适用于三绕组变压器电网的潮流计算;最后以Matpower软件为例进行了案例计算,并用PSASP仿真软件进行对比验证。研究结果证明,所提出的建模方法是有效的。     

On the Relation of Load to Average Gap in the Contact Between Surfaces with Longitudinal Roughness

A computer simulation model for the contact between longitudinally-oriented rough surfaces has been formulated. This model closely duplicates the actual surf ace contact deformation behavior by taking into account the elastic interactions between the asperities. There were no assumptions made about the shapes, or any deformation behavior of the asperities, except for their obeying the laws of elasticity. The plastic deformations on the high asperity peaks were taken into account by setting a ceiling on their contact pressures at the material hardness value. The simulations used real surface profiles which were digitized from unworn circumferentially ground steel surfaces. Each pair of these profiles was mathematically combined to form an equivalent rough profile pressing against an infinitely rigid flat and having the appropriately adjusted elastic modulus. A total of 28 different pairs of profiles were used in the simulations. Each contacting pair was subjected to 30 different load levels and the local contact pressures and deformations were calculated. The contact simulations yielded some important mathematical relationships between parameters, such as the real area of contact, average gap, and average asperity load through statistical curve fitting. Two analytical functions were generated to relate the average load to average gap and the real area of contact to load.     

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.     

电站锅炉模糊风险评价方法研究与应用

针对电站锅炉风险等级评价问题,将模糊综合评价技术应用到电站锅炉风险等级评价中。开展了电站锅炉失效影响因素及模糊评价因素的重要程度分析,建立了一套科学合理适于在线评价的电站锅炉风险评价体系,提出了模糊综合评价技术与改进的模糊层次分析法相结合的模糊风险评价方法,利用改进的模糊层次分析法计算了指标体系中各层指标权重。对某一台电站锅炉的实际运行工况影响子因素进行了模糊风险评价,采用模糊合成算子进行模糊综合运算得到电了站锅炉运行工况影响子因素的评价向量。研究结果表明:电站锅炉的运行工况影响子因素的风险评价等级为第6级,失效可能性等级为小,该电站锅炉运行工况良好。     

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....     

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.