摘要
研究了熔滴过渡频率为50Hz的脉冲熔化极氩弧焊接(GMAW-P)过程中熔滴冲击在熔池自由表面上引起的动态波动行为。利用波动理论建立了熔滴冲击在熔池自由表面上形成的波动的瞬态数值模型,推导出了控制方程并给出了初始条件和边界条件,编制程序进行了数值计算,得到了熔池自由表面的位移和速度的动态变化,以及波动的平均传播速度。研究结果表明,熔池波动的最大波幅为2.3mm,能够引起电弧对熔池热输入的极大改变。波动的持续周期为0.008s,连续的2次熔滴冲击在熔池自由表面上引起的波动不会导致波的干涉和谐振。波的平均传播速度为1.20m.s-1,波动能够促进熔池前部的熔化,而对尾部的焊道波纹成形无影响。实验结果与模拟结果的对比表明,熔池自由表面形成波动的持续周期和最大波幅与实测值吻合良好,而波的传播速度有少许差别。
The dynamic wave behaviors caused by droplet impingement on the free surface of a weld pool in pulsed gas metal arc welding（GMAW-P）with a 50 Hz droplet transfer frequency are investigated in this article.By using the wave theory a transient numerical model is established to describe the wave on weld pool free surface resulted from droplet impingement.The governing equation,initial condition and boundary condition are given,and then numerical analyses are performed based on a written program.The transient variation of displacement and velocity of weld pool free surface are obtained,and the average wave speed is got as well.Predicted results show that the max amplitude of waves on weld pool surface is 2.3mm,which could greatly change the heat input from arc to weld pool.The lasting cycle of wave is 0.008s,so no interference and resonance occur on weld pool surface between two waves caused by two neighboring droplet impingements,respectively.The average wave speed is 1.20m.s-1,and the wave could improve the metal to melt but has no influence on weld bead formation.Comparison between experimental results and predicted ones indicates that both the duration and max amplitude are in good agreement,while there is a little difference in wave speed.
出处
《青岛科技大学学报（自然科学版）》
CAS
北大核心
2013年第4期407-413,共7页
Journal of Qingdao University of Science and Technology:Natural Science Edition
基金
山东省高等学校科技计划项目(J12LA16)
