PAW+TIG电弧双面焊接小孔形成过程的数值模拟

综合考虑影响等离子弧小孔形成的等离子流力、重力、表面张力等力学因素，建立了等离子电弧＋钨极电弧（PAW＋TIG）双面焊接时小孔形成过程的数学模型，并与焊接传热的控制方程耦合，采用数值模拟技术，定量分析了小孔形成的动态过程，根据数值分析结果，将小孔的形成过程分为开始焊接到熔透，熔透到开始穿孔，开始穿孔到小孔形态稳定三个阶段，熔池的最小跨距可作为小孔建立的评价指标。小孔的形成是热、力共同作用的结果。

NUMERICAL SIMULATION OF KEYHOLE FORMATION DURING PAW+TIG DOUBLE-SIDED ARC WELDING

The mathematic model of keyhole formation in double-side arc welding is established through considering all influencing dynamic factors, such as plasma arc pressure, gravity and surface tension. With the numerical simulation technology, the dynamic process of keyhole formation is quantitatively analyzed by coupling the keyhole model with the governing equations of heat transfer. According to the numerical analysis results, the keyhole formation may be divided into three stages: from welding start to penetration, from penetration to perforation and from perforation to stable keyhole state. The minimum span in the weldpool may be regarded as the evaluation criterion of keyhole formation. The keyhole formation results from the common actions of heat and forces.