受控脉冲穿孔等离子弧焊接(PAW)过程中,小孔形状随焊接电流动态变化,经历“形成—长大—缩小—闭合”的变化过程.本文在对受控脉冲PAW瞬态温度场进行数值模拟的基础上,通过分析焊接熔池表面的受力状态,建立了小孔形状的模型,考虑了盲孔(小孔深度小于工件厚度)和穿透小孔2类情况.对焊接熔池内三维小孔在一个脉冲周期内的变化过程进行了数值计算.进行了受控脉冲PAW工艺实验,验证了穿孔持续时间的数值分析结果. During controlled pulse perforation plasma arc welding (PAW), the shape of the small hole changes dynamically with the welding current and undergoes the process of “formation-growth-reduction-closure” Based on the numerical simulation, the model of the hole shape is established by analyzing the stress state of the welding pool surface, taking into account the blind hole (the hole depth is less than the thickness of the workpiece) Numerical simulation of the variation of three-dimensional small holes in a single pulse cycle was carried out. The controlled pulsed PAW process was used to verify the numerical results of perforation duration.