Numerical Simulation of MIG Weld Pool in Switch Back Welding
Numerical Simulation of MIG Weld Pool in Switch Back Welding
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MIG 焊池折回焊数值模拟
DOI：
10.2207/qjjws.25.372
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发表时间：
2007
期刊：
影响因子：
--
通讯作者：
K. Oshima
中科院分区：
文献类型：
--
作者：
Y. Kaneko;Y. Maekawa;S. Yamane;K. Oshima
提出了在单面多层焊时，使第一层焊缝背面焊道稳定的翻转焊方法。在所提出的焊接方法中，焊炬运动对于控制焊池是重要的，即，焊枪像开关一样前后移动。研究焊接过程中熔池的行为对获得最佳的焊接工艺参数（如焊接速度、焊接电流、焊接前、后移距离等）具有重要意义。为了找到最佳的焊接参数，数值模拟是有用的方法，而不是焊接实验。由于厚板焊接的数值模型中考虑了熔敷金属，使得数值分析变得复杂。为了简化分析，作者对薄板焊接的数值模拟进行了讨论，因为可以将熔敷金属的影响降到最低。根据试验结果，确定了开背焊的数值模型。其次，研究了温度随行进速度和后退距离的变化规律。如果在反向焊接中移动速度恒定，则焊接熔池尺寸有时会变大。在这种情况下，由于焊接熔池中的流动，可能发生烧槽。当向前移动的行进速度快于向后移动时，熔池长度变得比恒定行进速度的情况短。此外，如果向后距离大于转回焊接的向前距离的一半，则作者可以获得连续的背面焊道，而不管诸如弧长变化的干扰，即，增加了焊池的稳定性。采用转底焊的方法，有利于在连续焊中形成稳定的背面焊道。
The authors proposed the switch back welding method to make the stable back beads in the first layer weld during one side multilayer welding. In the proposed welding method, the torch motion is important to control the weld pool, i.e., the welding torch is moved backward and forward like switch back. It is important to investigate the behavior of the weld pool to get the optimum welding parameters such as the traveling speed, the forward distance, the backward distance, the welding current and so on. There are many welding parameters. In order to find the optimum welding parameters, the numerical simulations are useful method instead of the welding experiments. Since the deposited metal is considered in the numerical models of the welding in the thick plates, the numerical analysis becomes complicated. In order to simplify the analysis, the authors discussed the numerical simulations of the welding in the thin metal plates because the effect of the deposited metal can be minimized.First, the fundamental welding experiments were carried out in MIG welding. By using the experimental results, the numerical models in the switch back welding are determined. Next, the behaviors of the temperature are investigated under the change of the traveling speed and the backward distance. If the traveling speed is constant in the switch back welding, the weld pool size may sometimes become big. In this case, the burn trough may take place due to the flow in the weld pool. When the traveling speed of the forward movement is faster than backward movement, the weld pool length becomes shorter than the case of the constant traveling speed. Moreover, if the backward distance is longer than half of the forward distance of the switch back welding, the authors can obtain continuous back bead regardless of the disturbance such as the variation of the arc length, i.e., the stability of the weld pool is increased. The switch back welding method is useful to make the stable back bead in the MIG welding.