摘 要作为一种新型窄间隙电弧焊技术，摇动电弧窄间隙 GMAW 焊具有变形小、成本低、结构紧凑、效率高以及方向性好等特点，解决了传统弧焊侧壁未熔合的问题，因此成为目前窄间隙焊工业的首选。但是，该焊接工艺涉及工艺参数较多，匹配不当仍会出现侧壁未熔合等缺陷，从而阻碍了摇动电弧窄间隙GMAW 焊的推广。焊接过程中焊接温度场对焊缝的尺寸、形状、成型、组织、力学性能具有重要影响，因此对摇动电弧窄间隙 GMAW 焊温度场的研究有利于深入了解它的成型机理，有助于该工艺的优化。目前摇动式电弧窄间隙焊接技术的研究主要集中在工艺设备方面，涉及内部机理的研究相对较少，对其内部成型机制缺乏足够的理解。随着计算机技术的发展，数值模拟技术已经成为焊接机理研究及工艺优化的重要手段。本文从电弧摇动特性和接头几何特征对电弧热流分布特点影响方面，通过建立摇动电弧窄间隙 GMAW 焊有限元数值分析模型，对焊件的焊接温度场进行模拟计算并分析该热场分布特征，结果表面：模型能够合理的反映动温度场的动态特性，且焊缝横断面形状主要参数与实验得出的结果基本吻合，从而验证了该数值模型的准确性。当摇动频率从 2.0Hz 增大到 2.5Hz 时，侧壁的热输入也增大，焊接过程中峰值温度升高，但熔池形态变化过程大体一致，焊缝横断面底部相差不大，变为有明显的“双峰”特征。58974
毕业论文关键词: 摇动电弧，窄间隙焊，热源模型，温度场，数值分析
Abstract As one kind of new narrow gap arc welding technology, undulation electric arcnarrow gap GMAW welds has distorts small, the cost low, the structure compact, theefficiency high as well as the directivity good and so on the characteristics, has solvedthe traditional arc welding sidewall fusion problem, therefore becomes the presentnarrow gap to weld the industry the first choice. But, this welding craft involves thecraft parameter to be many, does not match when still could appear flaws and so onsidewall fusion, thus has hindered the promotion which undulation electric arc narrowgap GMAW welded. In the welding process welds the temperature field to the weldedjoint size, the shape, the formation, the organization, mechanics performance has theimportant influence, therefore to undulates electric arc narrow gap GMAW to weldthe temperature field the research to be advantageous to understood thoroughly itsformation mechanism, is helpful to this craft optimization.At present undulates the type electric arc narrow gap welding technology theresearch mainly to concentrate in the process unit aspect, involves internal mechanismrelatively the research few, lacks the enough understanding to its internal formationmechanism. Along with the computer technology development, the value simulationtechnology already became the important method which the welding mechanismresearch and the craft optimized. This article from the electric arc undulationcharacteristic and the attachment geometry characteristic to the electric arc heat flowdistribution characteristic influence aspect, welds the finite element numericalanalysis model through establishment undulation electric arc narrow gap GMAW,carries on the analog computation to the weld welding temperature field and analyzesthis hot field distribution characteristic, finally surface: The model can the reasonablereflection move the temperature field the dynamic characteristic, also the welded jointcross section shape main parameter and the experiment obtains the result tallies change process is roughly consistent, the welded joint cross section base differencedoes not change for has “the split-blip” obviously the characteristic.Key words: swing arc; narrow gap welding; heat source model; temperature field;numerical simulationbasically, thus has confirmed this numerical model accuracy. When the undulationfrequency increases from 2Hz to 2.5Hz, the sidewall hot piping enters also increases,in welding process peak value temperature increment, but the molten pool shape 摇动电弧窄间隙GMAW焊温度场数值分析:http://www.751com.cn/cailiao/lunwen_63999.html