双丝脉冲MIG焊接电弧光谱诊断及热源耦合机理分析

搭建了双丝脉冲MIG焊接试验系统，为了分析研究双丝脉冲MIG焊接的热源耦合机理以及电弧温度场，采用光谱技术对其电弧进行了诊断分析，采用中空探针法进行等离子体的辐射采集，得到电弧等离子体的光信号，利用Boltzmann图法计算了双丝脉冲MIG焊接电弧等离子体的电子温度，得出了电弧等离子体的电子温度分布规律，并结合电信号采集和高速摄像技术对电弧进行了综合分析。研究创新之处在于结合了电弧的高速摄像图片信息和电弧等离子体的光信号对双电弧耦合机理进行分析，对电弧温度场进行了较为直观的分析研究。试验结果表明，在本试验条件下焊接过程实现了推挽式输出，实现了一脉一滴的过渡方式;两个电弧在焊接过程中在磁场的作用下相互吸引，向中心发生了偏移，在双电弧的几何中心形成了新的热源中心，并且电弧发生上飘现象;双电弧电子温度整体呈倒V型分布，在双电弧几何中心位置，距工件表面3 mm的位置电弧电子温度最高，为16 887.66 K，比最低温度11 963.63 K高大约4 900 K。

Arc Spectrum Diagnostic and Heat Coupling Mechanism Analysis of Double Wire Pulsed MIG Welding

A double wire pulsed MIG welding test system was built in the present paper, in order to analyze the heat-coupling mechanism of double wire pulsed MIG welding, and study arc temperature field. Spectroscopic technique was used in diagnostic analysis of the arc, plasma radiation was collected by using hollow probe method to obtain the arc plasma optical signal. The electron temperature of double wire pulsed MIG welding arc plasma was calculated by using Boltzmann diagram method, the electron temperature distribution was obtained, a comprehensive analysis of the arc was conducted combined with the high speed camera technology and acquisition means of electricity signal. The innovation of this paper is the combination of high-speed camera image information of arc and optical signal of arc plasma to analyze the coupling mechanism for dual arc, and a more intuitive analysis for arc temperature field was conducted. The test results showed that a push-pull output was achieved and droplet transfer mode was a drop in a pulse in the welding process; Two arcs attracted each other under the action of a magnetic field, and shifted to the center of the arc in welding process, so a new heat center was formed at the geometric center of the double arc, and flowing up phenomenon occurred on the arc; Dual arc electronic temperature showed an inverted V-shaped distribution overall, and at the geometric center of the double arc, the arc electron temperature at 3 mm off the workpiece surface was the highest, which was 16 887.66 K, about 4 900 K higher than the lowest temperature 11 963.63 K.