氧化铝生产中带加热管束压煮器现场改造

为确保压煮器的使用安全,提高设备的经济效益,对接管焊缝处和热影响区接管焊缝已得到处理但焊缝内部未融合、未焊透等仍未得到修复的缺陷进行了局部现场改造,改造后设备运行性能符合工艺要求。     

前处理电泳印痕解决经验浅谈

介绍了采取无磷前处理和高泳透力电泳工艺生产时车身出现的印痕问题,从板材、设备、材料以及工艺方面对该问题进行了分析验证,并提出了解决措施。     

水声透声橡胶防水涂层

一、前言提高水声换能器的水密性能,特别是保持换能器在水下长期工作时的良好绝缘状态,是个比较复杂的问题。本世纪七十年代中期,我们开始研制液体聚氨酯透声橡胶。由于该种橡胶灌胶工艺简单,硫化时不用高温高压,利于换能器特别是结构复杂的换能器的密封工艺要求,而且透声性能很好,与氯丁橡胶相当,所以聚氨酯透声橡胶的应用发展很快,目前     

压力管道未焊透超声波检测的探头选择

未焊透是压力管道中最常见的危害性缺陷,超声波检测是压力管道检验中发现和评价未焊透的主要手段。闸述了压力管道未焊透超声波检测的现状和存在的主要问题,认为斜探头参数的合理选择是保证检测质量的关键。分析了斜探头晶片尺寸、探头频率、折射角(K值)、斜探头前沿长度对超声波检测可靠性的影响,计算出典型参数的平面单晶横波探头的声场特性值,提出了压力管道未焊透超声波检测横波探头的选择原则。     

透波用三维中空复合材料研究进展

介绍了透波用三维中空织物的成型工艺,包括手糊成型、真空导流成型及高效率连续化生产工艺,并综述了透波用三维中空织物的力学性能和透波性能研究进展。指出中空复合材料具有高比强度、刚性、韧性、耐腐蚀性等,可为现代工业制造产品创造更高的附加价值,并且随着导弹、天线罩等产品对透波性能的要求,使得具有特殊结构的三维中空织物复合材料在这些领域具有很大应用前景。随着三维中空织物复合材料的广泛应用,其成型工艺将不断被更新。     

栲胶脱硫工艺运行总结

阐述了湿法栲胶脱硫工艺在预脱硫工序中的工艺原理、过程及生产运行中工艺指标的合理控制方法。通过优化工艺,保证了硫化氢的脱除效率和溶液的再生,满足了生产要求。总结湿法栲胶脱硫在生产运行中出现的问题,就部分主要问题的解决方法进行了讨论。     

重型大管径长输管道焊接技术及应用

通过香港屯门海底排污管工程的现场组对焊接 ,总结了一套行之有效的焊接工艺 ,克服了重型大管径长输管道焊接时易出现裂纹和未焊透等缺陷。     

节能高效商用车车身涂装工艺的设计与应用

针对目前商用车车身涂装工艺的高能耗、环境不友好、生产效率低等问题，对商用车车身涂装材料和工艺进行优化选型。采用硅烷处理剂、高泳透力电泳涂料、“湿碰湿”涂装用胶、高固面漆等新材料，设计出一套节能高效的商用车车身涂装新工艺。     

大型甲醇合成气及循环气压缩机组选用总结

论文重点总结了神华新疆68万吨／年煤基新材料项目甲醇合成气及循环气压缩机组在设计、制造中存在的问题,并结合国内同类型设备在运行中存在的问题,重点分析了压缩机功率超负荷的原因;工艺气中石腊对压缩机的影响;如何提高干气密封可靠性;透平空冷如何防冻的问题,结合工艺包供应商的建议提出新疆项目的解决思路,为以后类似装置的设计选型及生产运行提供参考。     

年产7万 t 聚丙烯扩能闪蒸工艺优化选择

年产7万 t 聚丙烯扩产至年产10万 t ,闪蒸及装置未改造,为满足扩能生产,降低消耗,对闪蒸装置工艺进行优化选择,达到扩能生产规模,丙烯消耗达到工艺要求.     

浅谈压力容器中的角接接头

本文讨论的是角接接头在设计，制造中应注意的一些问题。     

Fracture Mechanics of Linearly Welded Wood Joints: Effect of Wood Species and Grain Orientation

The energy release rates of beech, oak and pine wood specimens welded by linear friction were determined using double cantilever beam (DCB) tests. The influence of grain orientation both in welding along the wood longitudinal direction as well as in end-grain-to-end-grain welding to give butt joints was determined. The analysis of results was done with the experimental compliance method, based on linear-elastic fracture mechanics. The energy release rates obtained varied considerably according to wood grain orientation, wood species and welding cycle used. In many cases, the energy release rates obtained with the recently developed 150 Hz/faster weld technology were in the range as obtained for adhesive-bonded wood joints. Some cases also gave energy release rates higher than adhesive-bonded joints. Welding of butt joints by end-grain-to-end-grain welding was achieved, although the joints presented much lower energy release rates. In butt joints there appeared to be no significant difference in the energy release rates obtained for the three different timber species used.     

应力腐蚀开裂的断裂参量研究

根据焊接接头应力腐蚀开裂行为的特点,采用焊接接头力学不均匀性模拟试样,用断裂力学的 K 因子方法和 COD 方法进行研究。结果表明,焊接接头区域硬化层宽度 h 增加时,应力腐蚀裂纹扩展速率 da/dt 显著增加。     

聚乙烯及其复合管道安全检测与评价方法

聚乙烯及其复合管道广泛应用于油气输送、城市燃气等能源领域,其安全性至关重要。焊接接头的安全检测及评价是聚乙烯及其复合管道系统安全的关键技术。介绍了聚乙烯管道焊接接头的无损检测原理及方法、冷焊检测技术以及缺陷分类与失效模式三方面内容。对电熔和热熔焊接接头分别采用超声相控阵和耦合聚焦技术进行超声检测,并给出了缺陷剖切与检测结果的对比图。提出了物理概念清晰、工程应用方便的冷焊超声检测方法。将电熔接头中的缺陷分为熔合面缺陷、孔洞、结构畸变和过焊。分别对含不同类型和大小缺陷的电熔接头进行力学性能测试,发现电熔接头存在三种典型的失效模式,即沿电熔套筒壁贯穿裂纹失效、熔合面失效以及沿电阻丝所在平面贯穿裂纹失效。根据试验测试与理论分析结果,提出了相应的安全评定方法。所提出的方法,填补了国内外在聚乙烯管道安全检测与评价方法方面的技术空白,提高了燃气管道的本质安全性。     

Enhancing the Exterior Performance of Wood Joined by Linear and Rotational Welding

Application of rosin, a wood derived, non-toxic, natural, inexpensive and easily and abundantly available natural material, to the wood faces to be joined by either linear vibration welding or rotational dowel welding has shown to greatly enhance the water resistance of welded wood joints. The method of application has been shown to have a marked effect on the results, with the application and drying of a diluted rosin solution to the wood surfaces before welding yielding the best results. The considerable improvement in water resistance does not still allow classification of the joints as fully exterior grade. However, dowel welding can now be used for protected exterior joints due to a combination of rosin waterproofing and joint geometry. Welded dowel joints holding together for longer than 455 days immersion in water indicate this to be the case. Rosin-treated linear vibration joints held together well in excess of 30 days but retained a measurable strength, in the best case, only up to 18 days water immersion. The wood anatomy and chemical reasons for the effect of rosin were determined by X-ray microdensitometry and CP–MAS ¹³C-NMR analysis.     

Diode Laser Welding of Polyethylene

A high-power diode laser (HPDL) was used to weld high-density polyethylene (HDPE) sheets. Laser-welded joints were fabricated with different values of laser power and scan speed. Hot-tool welding was also employed to fabricate joints to make a comparison between this consolidated technology and HPDL welding. Initially, laser heating tests were carried out to study the laser–material interaction. Furthermore, welding tests were carried out and tensile mechanical tests were performed to characterize joints and sound specimens. A similar material behavior was recognized for all the specimens. While the laser process resulted in lower strength and ductility, in comparison to the tool-welding process, the aesthetics of the laser-welded joints were remarkable. The best values of the process parameters were individuated for the laser welding and were used to fabricate a closed structure having sharp edges. The same geometry cannot be obtained by any other welding technology.     

塑料感应焊接技术

感应焊接是一门简单、快捷、可靠的塑料焊接技术。该技术是通过感应加热向设计接头精确输出能量,接头处的植入材料选择吸收能量、熔化和流动以填满接头。塑料感应焊接商业应用已有三十多年历史,在焊接压力容器和其它高要求零件（需高强度和外形美观的结构、密封接头）方面获得了持续成功。感应焊最初之所以大受欢迎是因为它有效地解决了低表面能聚合物如聚丙烯和聚乙烯的焊接问题,过去的十年里其使用范围已扩展到覆盖全系列工程塑料及难以用其它方法焊接的高填充复合物。本文论及感应焊接原理及过程、植入物、焊接设备、工艺参数、焊接性、接头设计、特点、应用、最新进展。     

Relationship of welding technology to degree of plasticization in the PVC films

The influence of the degree of plasticization on optimum heat-sealing or high-frequency welding conditions has been studied for plasticized PVC films with different quantities of DOP plasticizer. Two equations were obtained that relate the parameters of the welding process (time and temperature, or time and specific anodic current) with the degree of PVC film plasticization. The equations allow calculation of welding conditions needed to obtain maximum strength of welded joints. One describes the durability of lap joints; the other of T-joints.     

Hot plate welding of plastics: Factors affecting weld strength

Welded joints were made under a range of conditions in polypropylene, glass fiber reinforced polypropylene and poly (methylmethacrylate) bars. Melt flow in the weld was investigated by microscopy and by contact microradiography, and weld strengths were measured by tensile tests. The fracture toughness of the weld zone was determined by tests on double edge notched specimens. The study shows that weld strength is strongly affected by hot plate temperature, heating time and melt flow during welding. Insufficient heating or melt flow results in incomplete bonding. Excessive melt flow produces strong transverse orientation. Both reduce strength, but in different ways, which can be distinguished by fracture mechanics tests.     

乙烯裂解炉对流段 P91炉管焊接工艺评定及其应用

对于P91钢,焊前预热是必要的,通过试验研究了焊接线能量对P91钢焊接接头冲击韧性的影响,焊接线能量控制在12～15kJ／cm以内,控制层问温度,能获得良好的焊接接头。根据焊接接头的力学性能检验,规定回火参数[P]等于21是合理的。并依此制定工艺,成功地完成了该钢种在三台乙烯裂解炉中的焊接应用。