【作者】 高辉；

【导师】 焦向东；

【作者基本信息】 北京化工大学 ， 机械设计及理论， 2010， 博士

【摘要】 摩擦叠焊是摩擦焊接技术中的一种,是一种新型的固相连接技术。随着世界范围内海洋石油及天然气资源开发力度的加强,水下油气田开采深度不断加深,海洋深水工程钢结构的连接及其修复技术日渐受到重视。摩擦叠焊焊接接头因其性能优异且焊接质量受环境压力影响较小,在深水钢结构修复领域得到迅速发展。近年来,摩擦叠焊技术在海洋石油国家得到了高度重视。各国针对摩擦叠焊焊接装备、焊接工艺以及该技术在水下连接工程中的应用进行了一系列研究开发工作。在我国,随着海洋石油开采力度的加强和水下工程的发展,迫切要求展开摩擦叠焊技术的研究。目前,摩擦叠焊焊接装备和焊接工艺的研究在国内都还属于空白。因此,本研究中关于摩擦叠焊焊接试验装置及其焊接工艺的研究具有重要的工程价值和理论意义。本文首先根据国外相关研究资料中所提供的摩擦叠焊焊接过程以及影响焊接质量的几个主要焊接工艺参数的范围,提出摩擦叠焊试验装置的设计技术要求。根据技术要求设计了国内第一套摩擦叠焊试验装置。设计工作主要分为：机械系统设计、液压系统设计和电控系统设计。有限元分析结果表明机械系统设计结构合理、安全、可靠。在LY12铝合金摩擦叠焊焊接工艺试验过程中,液压系统能够提供足够的焊接转速、焊接压力和焊接扭矩,满足工艺试验的要求。电控系统结构设计合理,能够实现对焊接过程的控制。为了能够在摩擦叠焊焊接工艺试验过程中监控和采集各项试验数据,本研究针对影响摩擦叠焊焊接质量的几个主要工艺参数,设计开发了一套摩擦叠焊焊接工艺试验数据采集系统。该数据采集系统能够在工艺试验过程中实时采集并存储各项试验数据,人机界面简单明了,易学易用。所有试验数据能够直接存储为Excel格式,便于进行试验后的研究与分析。其次,在完成摩擦叠焊试验装置及摩擦叠焊焊接工艺试验数据采集系统的开发研制的基础上,针对影响摩擦叠焊单元成型焊接质量的几个主要工艺参数,设计并进行了一系列针对LY12铝合金的单元焊接工艺试验。主要内容包括：氩气保护对焊接质量的影响；塞棒转速对焊接质量的影响；塞棒进给速度对焊接质量的影响等。结果表明：在焊接过程中采用氩气进行保护能够有效减少氧化铝的产生,提高单元成型的焊接质量。焊接转速是摩擦叠焊焊接工艺中最重要的焊接参数之一,焊接转速的提高可以有效改善焊接质量。进给速度对焊接质量的影响受焊接转速的制约。在高转速的条件下,提高进给速度有利于提高焊接质量。在转速较低的条件下提高进给速度不利于提高焊接质量。通过以上的大量试验,确定了合理的焊接工艺参数范围并获得了无焊接缺陷的单元填充焊缝。本研究在进行了单元焊接工艺试验后,进一步开展了LY12铝合金叠焊焊缝成型的焊接试验研究,实现了LY12铝合金摩擦叠焊的无缺陷焊接。试验结果表明：在叠焊过程中为了避免钻孔时钻头两侧受力不均匀,采用跳序法进行焊接较为合理。另外,在叠焊焊接过程中对焊接试件进行预热,有利于减小焊接残余应力,提高叠焊焊缝的焊接质量。然后,本研究基于传热学、摩擦学、接触力学等学科的相关理论,通过MSC. Marc有限元计算分析软件建立了摩擦叠焊单元成型焊接初期的热力耦合仿真模型,并对Q235钢材料进行了仿真计算。仿真计算的结果表明：各焊接工艺参数对其焊接过程的影响与LY12铝合金各焊接工艺参数的影响情况基本相同。这说明在摩擦叠焊单元成型焊接过程中各焊接工艺参数对焊接情况的影响规律一般不随材料的变化而变化,只是不同材料的热物性能和力学性能不同导致对各焊接工艺参数的数值大小要求有所不同而已。这为以后开展钢材料的焊接工艺试验奠定了基础。最后,基于摩擦叠焊试验装置在焊接试验过程中体现出的一些缺点和不足,提出了新的针对管道的摩擦叠焊试验装置的设计要求。新的试验装置采用总线通讯的控制方式,除焊接主轴的转动和轴向进给外,其它自由度的运动均采用交流伺服电机驱动,这提高了设备的控制精度和响应速度,设备性能得到了很大的改善。本论文的以上研究内容对我国摩擦叠焊焊接装备及焊接工艺的研究具有重要的意义。更多还原

【Abstract】 Friction stitch welding is a kind of friction welding technology, which belongs to a new type of solid-phase connection technology. With the reinforcement of worldwide offshore oil and gas resource developing, the exploiting depth of underwater oil and gas field increase continually, the connection and repair technology of deepwater engineering steel structure have been paid more attentions day by day. Because the performance of friction stitch welding joint is excellent and there is less effect resulting from environmental pressure on the welding quality, friction stitch welding technology develops rapidly in the repairmen areas of deepwater steel structure. In recent years, friction stitch welding technology has received great attention in the offshore oil countries. They have carried out a series of research and development work for the friction stitch welding equipment, welding process and the application of the technology in underwater connection engineering. In our country, as the strengthening of offshore oil exploitation and the developing of underwater engineering, the requirements of research on friction stitch welding are very urgent. At present, the studies of friction stitch welding equipment and welding process are still non-existent in China. Therefore, in this paper, the study on friction stitch welding test device and welding process has important engineering value and theoretical significance.Firstly, in this paper, the friction stitch welding test device design requirements have been proposed based on the friction stitch welding process and the parameters affecting the welding quality provided by the data from foreign research related. The first set of friction stitch welding test device has been designed meeting the technical requirements. Design work can be divided into mechanical system design, hydraulic system design and electrical control system design. Finite element analysis results show that the design of mechanical system is reasonable, safe and reliable. During the test of friction stitch welding process for LY12 aluminum alloy, the hydraulic system can provide adequate welding speed, welding pressure and welding torque to meet the requirements of process test. The design of electronic control system structure is reasonable; it can achieve the control of welding process.In the friction stitch welding process test, in order to monitor and acquire the parameters, a set of friction stitch welding test data acquisition system has been designed and developed for the process parameters. The data acquisition system can capture and store the test data. Its man-machine interface is simple and easy to learn. All test data can be stored directly as Excel format, which is easy to be researched and analyzed.Secondly, on the basis of friction stitch welding test equipment and friction stitch welding test data acquisition system, a series of LY12 aluminum ally welding process test have been designed and carried out, in order to study the influence of the several key process parameters on the welding quality. The main contents include:influence of argon gas protection on welding quality, influence of rotational speed on welding quality and influence of feed speed on welding quality The results show that:In the welding process, the use of argon gas protection can reduce the production of alumina and improve the welding quality of unit forming. Welding speed is the most important welding parameters for the welding process. The welding quality can be improved through increase the welding speed. The influence of feed speed on welding quality is restricted by the welding speed. Under the condition of high rotational speed, the increase of feed speed will help improve the welding quality. But, under the condition of lower rotational speed, the increase of feed speed can not improve the welding quality. Through a lot of test, a reasonable range of welding parameters have been determined, and a perfect FHPP weld has been acquired.In the study, after test of unit weld process, the experiment of friction stitch welding for LY12 aluminum alloy have been carried out further. The perfect weld of friction stitch welding has been acquired in the experiment. The results show that:the jump continued method is reasonable for friction stitch welding, which can avoid the unbalanced force on both sides of the drill in drilling. Other, the preheating of workpiece for friction stitch welding can help reduce the welding residual stress and improve the weld quality.Then, in the study, based on heat transfer, tribology, contact mechanics and other related theories, the thermal coupled simulation model of FHPP has been established by the finite element analysis software MSC.Marc. And the model Q235 steel material is also simulated. The computed results show that:the influence of welding process parameters is the same as that for LY12 aluminum alloy. It means that the influence variation of welding process parameters on friction unit welding do not change with changes in the material. Just, the different thermal properties and mechanical properties of materials lead to the numerical size requirement of welding process parameters are different. That will lay the foundation for the study of steel material welding process test in the future.Finally, the design requirements of the new pipeline friction stitch welding test equipment have been proposed based on the shortcomings and deficiencies of friction stitch welding test equipment reflected in the welding process experiments. The new test device adapts the bus communication. In addition to the spindle rotation and axial feed, the other movements are driven by AC servo motor, that have improved the control precision and equipment response speed. The equipment performance is improved greatly.The studies in this paper have great significance for the study of friction stitch welding equipment and welding process in our country.更多还原