Numerical analysis of arc welding phenomena from a unified arc-electrodes model

统一电弧电极模型对电弧焊接现象的数值分析

基本信息

批准号：
13650779
负责人：
USHIO Masao
金额：
$ 2.18万
依托单位：
Osaka University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
2001
资助国家：
日本
起止时间：
2001 至 2003
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-13650779/
关键词：
Tungsten electrode Arc Weld pool TIG welding Numerical analysis Plasma Convective flow Simulation レーザ計測

项目摘要

The development of a numerical model of the process is quite useful for understanding quantitative values of the balances of mass, energy and force in the welding phenomena, because there is still luck of experimentally understanding the quantitative values of them due to the existence of complicated interactive phenomena between the arc plasma and the weld pool. This study was focused on a stationary tungsten inert gas (TIG) welding process for simplification, but the whole region of TIG arc welding, namely, tungsten cathode, arc plasma, work-piece and weld pool was treated in a unified numerical model because of taking the close interaction between the arc plasma and the weld pool into account. Calculations were made for stationary TIG welding at a current of 150 A. The anode was assumed to be a stainless steel, SUS304. The two-dimensional distributions of temperature and velocity in the whole region of TIG welding process were predicted. The weld penetration geometry was also predicted. Furthermore, quantitative values of the energy balance for the various plasma and electrode regions were given. The predicted temperatures of the arc plasma and the tungsten cathode surface were in good agreement with the experiments. There was also approximate agreement of the weld shape with experiment. The calculated convective flow in the weld pool was mainly dominated by the drag force of the cathode jet and the Marangoni force as compared with other two driving forces, namely, the buoyancy force and the electromagnetic force. It was shown that change in the direction of re-circulatory flow in the weld pool led to dramatically different weld penetration geometry.

建立该过程的数值模型对于理解焊接现象中质量、能量和力平衡的定量值非常有用，因为由于存在复杂的交互作用，通过实验来理解它们的定量值仍然是幸运的。电弧等离子体和熔池之间的现象。本研究重点关注固定钨极惰性气体 (TIG) 焊接工艺以进行简化，但 TIG 电弧焊的整个区域，即钨阴极、电弧等离子体、工件和熔池都在统一的数值模型中进行处理，因为考虑到电弧等离子体和熔池之间的密切相互作用。对电流为 150 A 的固定 TIG 焊接进行了计算。假设阳极为不锈钢 SUS304。预测了TIG焊接过程整个区域温度和速度的二维分布。还预测了焊缝熔深几何形状。此外，还给出了各种等离子体和电极区域的能量平衡的定量值。电弧等离子体和钨阴极表面的预测温度与实验吻合良好。焊缝形状也与实验大致一致。与其他两种驱动力（即浮力和电磁力）相比，计算得到的熔池内对流流动主要由阴极射流的曳力和马兰戈尼力主导。结果表明，熔池中再循环流方向的变化导致焊缝熔深几何形状显着不同。