SA335P91/10CrMo910异种钢的焊接工艺研究

当前,在国内外大型电厂的建设过程中,SA335P91钢已得到了广泛的应用,这就不可避免地出现了SA335P91钢种与其他耐热钢种的连接。本文结合具体的施工情况,详细介绍了SA335P91/10CrMo910异种钢焊接的施工方法以及焊接工艺,并通过多个工程焊接施工实践证明,其工艺是可行的,希望对电力建设各施工单位同类型钢种的焊接提供一定的借鉴。     

石化装置用SA335P91厚壁炉管焊接工艺研究

分析了SA335P91厚壁炉管焊接的冷裂敏感性 ,研究了焊接线能量和层间温度对P91钢的焊接接头冲击韧性的影响 ,并规定了手工氩弧焊的焊接线能量上、下限值和合理的层间温度     

浅谈P91＋12Cr1MoV异种钢超厚壁大径管焊接工艺

首次对SA335-P91＋12Cr1MoVG钢超厚壁大径管异种钢进行施焊,通过设置合理的焊接方法、工艺控制及焊接过程中的注意事项,使机组的运行正常,其结果表明此种工艺是可行的。     

耐热钢P5与不锈钢304H的焊接

对于SA335P5耐热钢弯头与SA312TP30 4H不锈钢管的异种钢焊接 ,根据使用工况等可以采用不同的焊接工艺方案。本文介绍了通过在SA335P5耐热钢弯头端堆焊过渡层 ,进行热处理和探伤后再与SA312TP30 4H不锈钢管的焊接 ,从而兼顾了耐热钢需要焊后热处理及不锈钢需保持防腐性能和抗晶间腐蚀的问题 ,通过焊接试验结果表明 :制定的焊接工艺已成功地用于乙烯裂解炉对流段的制造。     

SA335／P91钢焊接接头热处理工艺性分析

SA335／P91钢是在SA335／P9钢的基础上，添加Nb、V等合金，控制N含量得到的马氏体钢，具有高温强度高、抗蠕变性及抗氧化性能高等优点。因此，SA335／P91钢在国外大容量的机组中的过热器、高温再热器集箱及主蒸汽管道中得到了广泛的应用，在20世纪90年代我国在大容量机组中也开始使用。     

《金属加工(热加工)》2014年第4期要目

正常减压塔复合钢板焊接裂纹的原因分析新型焊丝组合在纵骨流水线上的试验及应用GB/T 5117—2012《非合金钢及细晶粒钢焊条》的主要变化异种金属的手工钨极氩弧焊铝合金管道焊接气孔原因及克服措施埋弧焊在LNG低温储罐底板焊接中的应用2.0MW风力发电机后底座的焊接工艺评定及应用SA335P91/10CrMo910异种钢的焊接工艺研究     

SA-335 P91钢全位置窄间隙热丝TIG焊接工艺及接头性能研究

针对SA-335 P91钢大口径管环缝,采用轨道式全位置热丝TIG焊机进行了窄间隙焊接。将整条环缝均分为16个区域,根据不同位置熔池受力状态对各区的焊接工艺参数进行修正设置,并对所获焊接接头的组织和性能进行了研究。所获焊缝和热影响区的组织均为回火马氏体,焊接接头的拉伸、弯曲、冲击等力学性能均满足要求。结果表明,窄间隙热丝TIG焊接工艺参数合理,分区修正设置恰当,能够满足SA-335 P91钢大口径管全位置焊接要求。     

SA—335MP11钢焊接工艺及分析

介绍了SA—335M P11钢的焊接性以及进行工艺试验的情况,对试验结果进行了分析,并对锅炉中此种材质的集箱筒体焊接工艺进行了分析,为以后进行相关材料的焊接工作积累了宝贵的经验。     

P91钢的焊接特点及工艺

随着P91钢的大量使用,制定出符合该钢材特点的焊接工艺规范直接用于生产建设中,有很好的经济效益和社会效益.结合热电厂300MW机组安装工程,主要介绍了P91钢的性能特点以及其在焊接过程中容易出现的焊缝性能和热影响区性能的劣化问题,分析了P91钢焊接性.制定了P91钢的焊接工艺、热处理工艺以及在实际焊接操作过程中经常遇到的问题以及预防方法.通过采取合适的预热温度、焊接工艺方法和焊后热处理工艺,可以解决P91钢焊接过程中易出现的焊缝性能和热影响区性能的劣化问题,保证焊口的质量并使焊缝、熔合区及其热影响区能够获得较好的性能,满足其在火电厂中的高温运行要求.     

SA-335P91钢管热弯制造技术

对SA335P91钢的主要性能进行了介绍,并对热弯管工艺特点进行了分析,通过中频感应加热弯管和弯后热处理工艺试验,确定出满足材料使用性能和质量要求的中频感应加热弯管工艺,提出了制造中需控制的重要尺寸要素。     

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.     

ANGULAR DISTORTION ALLOWABLE VALUE AND ASSESS METHOD OF WELD ON COKE TOWER

A graph as the new engineering method for estimate the safety of bulging deformation of coke tower is proposed. Through stresses analysis of circumferential weld of coke tower and comparing the stresses produced by pressure with heat stress of steady state, residual stress, bending stress produced by both itself weight and wind loads, it showed that the stresses produced by pressure on the angle distortion are the main factor of equivalent stress of the combined stress. After comparing four kinds of stress controlling conditions, the relation to stress with depth of angular distortion, grade of curvature of angular distortion and half of region of angular distortion has been inferred. Graph of deformation allowable value of coke tower for different condition by angular distortion and half of region of angular distortion has been plotted. The five steps for its engineering use have been explained. The lighter the grade of curvature is, the larger of bulge allowance, may be, and the bigger of depth of angular distortion may pose too. For the coke tower with a popular structure of Dg 5 400 mm×28 mm, the result by graph is nearly more than the result of two formulas formed by other research, the error is less than 7.0%. But, the graph can be easily applied to different size of angular distortion.