外加稳态磁场作用下的焊接电弧数值仿真

摘要

为了揭示外加静态磁场对焊接电弧形态及传热传质的影响规律,建立了焊接电弧的数值模型,对比分析了普通熔积、外加纵向磁场作用以及横向磁场作用下的电弧传热传质过程.结果显示:相比普通熔积,外加纵向磁场作用下,靠近基板的位置电流密度和温度减小,电弧的温度和压强峰值减小,中心处出现负压;外加横向磁场作用下,电孤整体偏向一侧,电孤中心的电流密度、温度和电弧压强都小于未施加外加磁场情况.外加磁场对电弧形态及传热传质的改变,将导致电弧和金属之间的热和力相互作用改变,从而使得熔池的传热传质过程相应的发生改变.%To reveal the influence of static magnetic field on the shape,heat and mass transfer of welding arc,the numerical model of a welding arc is established to compare and analyze its heat and mass transfer processes in the conventional welding,external longitudinal magnetic field and transverse magnetic field-assisted welding.The analysis results show that the longitudinal magnetic field can decrease the current density and temperature of the welding arc near its substrate.In addition,the peak temperature and pressure of the welding arc are reduced and the negative pressure appears at the center of the welding arc under the external longitudinal magnetic field.The transverse magnetic field makes the welding arc inclined to one side;the current density,temperature and arc pressure at the center of the welding arc are smaller when no external longitudinal magnetic field is applied.The changes in arc shape,heat transfer and mass transfer result in the heat and force interaction between welding arc and metal and further result in changes in heat and mass transfer processes of the molten pool.