考虑金属蒸汽的钨极惰性气体保护焊电弧与熔池交互作用三维数值分析

发布时间：2018-06-05 17:31

本文选题：钨极惰性气体保护焊 + 金属蒸汽　；参考：《物理学报》2015年10期

【摘要】：基于局域热平衡状态假设并考虑金属蒸汽的作用,建立了钨极惰性气体保护焊电弧与熔池交互作用的三维数学模型.电弧等离子体的热力学参数和输运系数由温度和金属蒸汽浓度共同决定,并使用第二黏度近似简化处理金属蒸汽在氩等离子中的输运过程.在考虑熔池流动时,主要考虑了浮力、电磁力、表面张力和等离子流拉力的作用.通过对麦克斯韦方程组、连续性方程、动量守恒方程、能量守恒方程和组分输运方程的耦合求解,得到了金属蒸汽在电弧中的空间分布、电弧和熔池的温度场、速度场和电流密度分布等重要结果.通过与未考虑金属蒸汽的结果对比,研究了熔池上表面产生的金属蒸汽对电弧等离子体行为的影响,以及电弧等离子对熔池行为的影响.结果表明,金属蒸汽主要富集在熔池上表面附近;金属蒸汽对电弧等离子体有明显的收缩作用,而对等离子速度和电势影响较小;金属蒸汽的出现对熔池上表面速度分布和剪切力分布以及熔池形貌并无明显影响.求解结果与已有的实验结果和计算结果符合良好.
[Abstract]:Based on the assumption of local thermal equilibrium and taking into account the effect of metal vapor, a three-dimensional mathematical model of the interaction between arc and pool of tungsten inert gas welding is established. The thermodynamic parameters and transport coefficients of arc plasma are determined by temperature and metal vapor concentration, and the second viscosity is used to simplify the transport process of metal vapor in argon plasma. The effects of buoyancy, electromagnetic force, surface tension and plasma current tension are considered in the consideration of molten pool flow. By coupling the Maxwell equations, the continuity equations, the momentum conservation equations, the energy conservation equations and the component transport equations, the spatial distribution of metal vapor in the arc, the temperature field of the arc and the melting pool are obtained. Some important results, such as velocity field and current density distribution, are obtained. The effect of metal vapor on the behavior of arc plasma and the effect of arc plasma on the behavior of molten pool were studied by comparing with the results without taking into account the metal vapor. The results show that the metal vapor is mainly concentrated near the upper surface of the molten pool, and the metal vapor has obvious shrinkage effect on the arc plasma, but has little effect on the plasma velocity and potential. The appearance of metal vapor has no obvious influence on the surface velocity distribution, shear force distribution and weld pool morphology. The results agree well with the experimental results and the calculated results.
【作者单位】：兰州理工大学材料科学与工程学院;省部共建有色金属先进加工与再利用国家重点实验室;
【基金】：国家自然科学基金(批准号:51074084,51205179) 甘肃省自然科学基金(批准号:1010RJZA037)资助的课题~~
【分类号】：TG444.74

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