CF-62钢焊接工艺试验研究

本文综合介绍了《大型球罐用CF钢的应用研究》课题协作组各有关成员单位,采用国产超低氢焊条新结607CF施焊国产CF-62钢及日本WEL-TEN62CF钢时所进行的各种焊接参数选择的试验研究结果,以及根据球罐的焊接特点采用已选择的较佳焊接工艺规范进行的焊接工艺评定及焊接接头韧性试验结果。结果表明,采用新结607CF焊条在室温下施焊CF钢,当焊接层间温度控制在200℃以下,焊接线能量在10～40kJ/cm范围内,焊后及焊后消除应力热处理状态下不同焊接位置(平焊、横焊、立焊)的工艺评定绪果均合格;焊接接头各部位的-40℃冲击功均大于等于2.8kgf·m(标准值)且富裕量较大;其余焊接接头韧性(COD、J积分、NDT温度、da/dN等)数值也均较理想。此外,本文还针对球罐组装焊接过程中碳弧气刨清根及焊缝返修工艺进行了较系统的试验。     

焊后热处理对P91钢和TP347H钢焊接接头综合力学性能的影响

对P91钢和TP347H钢焊接接头在焊态和720,760,800℃和1050℃×2h空冷等焊后热处理工艺下进行了拉伸、弯曲、冲击、硬度等常规力学性能试验和高温持久强度试验研究。研究结果表明,合适的热处理规范工艺可以提高P91＋TP347H异质焊接接头的拉伸及弯曲性能,对冲击性能及硬度也没有大的影响。经热处理后的焊接接头比未经热处理的试样具有更好的高温持久性能。得出了P91＋TP347H异种钢焊接的最佳工艺方案是采用TIG焊,并进行焊前预热和焊后进行760℃×2h空冷时效处理。     

焊接参数对T92/S30432异种钢焊接接头室温力学性能的影响

研究了焊接工艺参数对T92/S30432异种钢焊接接头室温力学性能的影响,并获得了最佳的焊接工艺。结果表明:层间温度、焊接层数、焊丝类型和焊接接头坡口角度对接头强度的影响不大;但低层间温度和多层多道焊可以提高T92钢侧热影响区的韧性;与ERNiCr-3焊丝相比,ERNiCrMo-3焊丝填充的接头T92钢侧热影响区具有较高含量的铁素体,从而使其冲击功下降;焊接接头冲击韧性随坡口角度增大而先增大后减小,并在35°时达到最高;焊后热处理温度为760℃时接头具有最高的强度和韧性;T92/S30432异种钢较佳的焊接工艺是采用ERNiCr-3焊丝和较低层间温度,并严格控制焊层厚度且采用温度为760℃的焊后热处理。     

焊后热处理对ASTM4130钢焊接粗晶区韧性的影响

采用焊接热模拟试验研究了焊后热处理不同保温时间对ASTM4130钢焊接粗晶区组织和韧性的影响,同时分析了预热温度对粗晶区焊后热处理效果的影响。试验结果表明,经640℃不同保温时间的焊后热处理,ASTM4130钢粗晶区未发现再热脆化现象;随着保温时间的延长,冲击功先升高后降低,在保温时间为2．0h时达到峰值;在焊后热处理工艺相同的情况下,提高预热温度冲击功却稍有降低。试验证明：预热温度200℃,焊后热处理工艺为640℃×1．5h,粗晶区可获得良好的强韧性匹配。     

100mm EH36-Z35钢CO2焊+埋弧焊焊接工艺及应用

提出一种100 mm厚EH36-Z35船用高强度钢板对接,采用不对称"X"坡口、焊缝背面不清根、正面CO2焊打底一道,其余焊道埋弧焊的组合焊焊接工艺。对其进行焊接工艺试验,并在深海采矿船EH36-Z35船用高强度钢厚板对接缝应用;工艺试验与现场应用结果表明,焊接接头性能良好、质量稳定,改善施工环境,提高焊接效率。     

转炉大齿轮焊接

针对中碳调质钢35CrMo焊接性较差和齿圈的工作特点,选用力学性能低于母材的E4316焊条,焊前在200～250℃整体预热以减缓焊接接头的冷却速度,施焊过程中控制层间温度保持在200～250℃。通过改进焊接工艺的方法,制定了较为合理的装配顺序和焊接工艺,及时进行焊后热处理消除焊接残余应力,控制了焊接变形和裂纹的形成,取得了很好的效果。     

装甲钢复合热源搅拌摩擦焊接过程数值模拟

装甲钢属于高强度特种钢,因其强度高、硬度好的特性被国内外学者的大量研究,但焊接时容易因为工艺操作不当而产生缺陷。如何避免裂纹、变形的产生成为装甲钢焊接技术研究的一个重要课题。采用复合热源搅拌摩擦焊进行焊接,运用有限元技术,参数化编程语言,对装甲钢的电弧热源与搅拌摩擦复合焊接技术进行数值模拟,得到不同时间点的焊接温度场。结果表明,预热电流为30 A,电压为20 V,焊速50 mm/min,预热温度200℃的工艺参数更适合该钢的焊接。     

ASTMA765钢焊接接头低温性能

针对离心压气机壳用ASTM A765钢的低温工况,研究了改性材料的焊接工艺及焊后热处理工艺。研究了拉伸性试验、低温冲击试验和金相观察、焊接参数和焊后热处理工艺对焊接接头性能的影响。试验结论显示,采用HS09MnNiDR焊丝焊接的ASTM A765钢可满足-46℃低温工况的使用要求。     

1Ni9钢在乙烯压缩机上的应用

阐述了-150℃工作的1Ni9低温用钢进行的焊接、热处理试验及焊接工艺评定等工作;并针对材料的焊接性能和产品特性设计了焊接叶轮的坡口型式及焊接工艺。完成了焊接力学性能试验、评价焊接材料,完成了工艺性试验、通过试验测定焊接收缩性能、制定焊接收缩量、评定-150℃焊接接头性能及焊接性能,确定产品叶轮焊接及焊后热处理工艺。     

15Cr1Mo1V阀体与WB36配管焊接方法

介绍了15Cr1Mo1V阀体与WB36配管材料的特性,提出了特殊的焊接工艺,解决了异种钢焊接性能较差的工艺问题。     

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.     

Fifth International Summer School on Screw-Theory Based Methods in Robotics

正3-11 September,2014University of Bologna,Bologna,Italy www.summerscrews.org summerscrews2014.ing.unibo.it SUMMER 20SCREWS 14In 2014,our screw-theory school comes to the world's oldest university.In early September,Summer Screws'14 will gather six experts in the application of screw theory in robotics and up to 40 participants at the University of Bologna,Bologna,Italy.The school will teach attendees how to apply existing methods and empower them to develop new ones in their own research.The basic theoretical notions will be introduced in a rigorous manner,emphasizing examples,applications,and exercises.Scholarships are available.     

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。     

INDUSTRIAL ENGINEERING AND VISUALISATION-A PRODUCT DEVELOPMENT PERSPECTIVE

Taking the actual project of teaching and researching process for example, the relationship between the industrial engineering and product development is discussed. And use the novel visualization technology to support the industrial engineering and product development. How to use the new computer modeling and simulating technologies to support the product development and industrial engineering, is introduced especially. The support includes both domestic products and industrial systems. The visualization and computer technologies take a very important role in some system or multi-direction modeling, those technologies mentioned above can help the industrial engineers study the effect of design on the whole life circle, including the producing steps. So the engineers can avoid making the wrong decision which may cause bad effects on the whole industrial engineering.     

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.