Numerical Analysis of Metal Transfer Phenomena
Numerical Analysis of Metal Transfer Phenomena
复制标题
金属转移现象的数值分析
DOI：
10.2207/qjjws.30.1
复制
发表时间：
2012
期刊：
影响因子：
--
通讯作者：
Y. Hirata
中科院分区：
文献类型：
--
作者：
K. Kadota;Y. Hirata
GMA焊接过程中的熔滴过渡模式随焊接参数的不同而不同：电流、电压、保护气体、焊丝等，本质上受熔体物理性质和电磁力的影响。然后利用所建立的计算模型对液体传递过程的时间变化进行了数值研究。数值计算结果与圆柱形喷嘴水滴传递的实验结果吻合较好。数值分析表明，液体的传递方式取决于液滴尖端的压力平衡。当液体流动产生的动压低于表面张力引起的毛细管压力时，发生球状传递。相反，当液体流动的动态压力较高时，会发生喷雾传递。在液体中有电流流动的情况下，电磁力对液滴的传递模式和液滴脱落有显著影响。对于从直径1.2 mm的喷嘴流出的液体，利用低碳钢的物理性质进行的计算结果表明，电流大于250A时产生的电磁力使传递方式由球状转变为喷雾。而在纯Ar气体保护的实际GMAW中，转移模式在230A左右改变，熔滴剥离行为既受电磁力的空间分布变化，也受电磁力时间变化的影响。
Metal transfer modes in GMA welding process are different from welding variables: current, voltage, shielding gas, electrode wire and etc. Essentially they are influenced by physical properties of molten metal and electro-magnetic force. Then we numerically investigated the time-change of liquid transfer process using calculation model developed. The numerical result agreed very well with experimental result of water drop transfer from cylindrical nozzle. Numerical analysis shows that liquid transfer modes depend on the pressure balance at the tip of drop. When the dynamic pressure induced by liquid flow is lower than capillary pressure due to surface tension, globular transfer occurs. In contrast, when the dynamic pressure of liquid flow is higher, spray transfer occurs. In the case that the electrical current flows in the liquid, electro-magnetic force significantly influences on the transfer mode and the drop detachment. As for liquid flow-out from the nozzle of 1.2 mm in diameter, calculated results with use of physical properties of molten mild steel show that electro-magnetic force induced by higher current than 250 A changes the transfer mode from globular to spray. Whereas in real GMAW with pure argon gas shielding the transfer mode changes at around 230 A. The behavior of drop detachment is varied by both spatial distribution and time-change of the electro-magnetic force.
影响因子：
4.1
作者：
BRACKBILL, JU;KOTHE, DB;ZEMACH, C
通讯作者：
ZEMACH, C