双脉冲TIG焊熔池数值分析

Numerical analysis of double pulsed TIG welding

建立了双脉冲电流下TIG焊熔池的三维非稳态数学模型,通过选择合适的边界条件和热物性参数,强烈耦合控制方程组对双脉冲TIG焊熔池进行数值分析,得到了周期性变化的焊接熔池温度场、流场等分布情况,熔宽、熔深的尺寸大小在周期内的变化规律.结果表明,在双脉冲电流作用下的熔池尺寸大于在平均电流作用下的尺寸,有效的增大了焊接熔池尺寸;熔池尺寸随电流的变化具有一定的滞后性,且在高能脉冲作用时的滞后性较强;在双脉冲电流作用下的熔池内部具有更大的流速,其搅拌作用更强.

A three-dimensional unsteady model of double pulse tangsten inert gas(TIG)welding pool is developed.By choosing appropriate boundary conditions,thermal properties and strongly coupling the control equations,the cyclically change regulations of temperature field,flow field and depth and width of the pool are obtained.The cyclically change regulations of pool size are obtained.The results show that the pool size with double pulse current is larger than that with average currents.The variation of pool size lag behind the pulse current is larger,especially under the action of the high energy pulse current and under the action of the double pulse current.The flow velocity is also larger and the stirring effect is stronger within the pool.