利用基于背光光源的熔池视觉传感检测系统采集超薄板脉冲微束等离子弧焊焊接过程中熔池轮廓的变化,在平均电流为1.8 A条件下研究基值电流与峰值电流之比(0.29~0.71)、占空比(30%~70%)、脉冲频率(25~100 Hz)对304不锈钢超薄板焊接熔池尺寸和焊缝成形质量的影响。结果表明:在试验条件下采集到的熔池宽度均小于2.5 mm,熔池面积均小于3.5 mm²;在平均电流为1.8 A时,随着基值电流与峰值电流之比、占空比、脉冲频率的增加,熔池的最大宽度和面积均逐渐减小;在不同工艺参数下获得了间断焊缝、连续不等宽焊缝、连续等宽焊缝等3种类型的焊缝,占空比为50%、基值电流与峰值电流之比为0.50,脉冲频率为25,100,500 Hz时所获得的焊缝成形质量最好,为连续等宽焊缝。

The profile change of molten pool during pulsed micro-plasma arc welding of ultra-thin sheets were collected by a backlight-based molten pool visual sensing inspection system. The influence of ratio of base current to peak current(0.29-0.71), duty cycle(30%-70%) and pulse frequency(25-100 Hz) on the weld molten pool size and weld quality of 304 stainless steel ultra-thin sheets under average current of 1.8 A was studied. The results show that under the experimental conditions, the weld pool width and area were less than 2.5 mm and 3.5 mm², respectively. The largest width and area of molten pool gradually decreased with increasing ratio of base current to peak current, duty cycle and pulse frequency. Three different types of welds, including discontinuous welds, continuously non-uniform width welds, and continuously uniform width welds, were obtained under different process parameters. The weld formation quality was the best and the weld was continuously uniform width weld under the duty cycle of 50%, the ratio of base current to peak current of 0.50, and the pulse frequency of 25, 100, 500 Hz.