磁场和活性焊联合作用对焊接熔池形态的影响

为了研究磁场和活性焊联合作用对焊接熔池中液态金属流动形态的影响，文中建立了移动热源作用下镁合金TIG焊三维瞬态数学模型. 利用fluent软件及其二次开发功能，模拟了单独磁场、单独活性焊和两者联合作用对焊接熔池温度场和速度场的影响. 模拟结果表明，在单独磁场作用下,熔池中液态金属呈顺时针定向旋转运动，速度场呈不对称双峰分布，最大速度偏向熔池一侧；在单独活性焊作用下,熔池中液态金属形成由外向内的对流模式，从而冲刷熔池底部增加熔深；在两者联合作用下流体流动较为复杂，熔池表面附近液态金属流动主要受表面张力的影响，熔池内部主要受外加电磁力的影响.

Impact on welding pool shape under combined effect of magnetic field and active agent

In order to study the combined effect of magnetic field and active welding influence on the welding pool of liquid metal flow pattern, the paper established the moving heat source under the action of three-dimensional transient mathematical model of magnesium alloy TIG welding. By using fluent software and its secondary development function to simulate the welding pool temperature field and velocity field under the effect of single magnetic field, single active welding and the combined effect of both. The simulation results show that liquid metal in the welding pool was directed clockwise rotation under the effect of single magnetic field, velocity field presented asymmetrical bimodal distribution，maximum speed biased the pool side. Under the effect of single active welding liquid metal in the welding pool formed outside-in convection mode, which scour the bottom of the pool to increase penetration. The fluid flow is more complex under the combined effect of magnetic field and active agent. The liquid metal flow near the pool surface is mainly affected by surface tension. The liquid metal flow inside the pool is mainly affected by external electromagnetic force.