TIG电弧载流区温度的低扰动静电探针差动分析

采用低扰动静电探针差动分析对TIG电弧载流区进行诊断，通过测定的饱和离子电流求解不同焊接电流和弧长下载流区温度分布.结果表明，低扰动静电探针差动分析测定的载流区温度变化特征与辐射光谱测量结果一致，但探针对电弧的冷却扰动导致差动分析测定的温度值低于光谱诊断的测量结果；电弧载流区温度分布宽度沿电弧轴线由阴极向阳极增加，载流区截面中心附近温度最高，并向电弧边缘减小，且阴极附近存在一个高温区；随着焊接电流的减少，温度分布宽度和载流区最高温度均减小，阴极附近高温区沿电弧轴向收缩；弧长增大会使载流区温度分布宽度增加，但最高温度基本不变.

Differential analysis for temperature distribution diagnostics of arc current-carrying region with low disturbance electrostatic probe

The differential analysis of low disturbance electrostatic probe was developed for local micro-measurement of TIG arc current-carrying region temperature. The temperature of TIG arc current-carrying region can be solved by ion saturation current of electrostatic probe. Furthermore the temperature distribution in different welding current and arc length can be also obtained. The results show that the variation trend of TIG arc current-carrying region temperature acquired by probe, which agrees with results of spectroscopic method; because of cool disturbance of probe, the temperature solved by ion saturation current is lower than temperature measured by spectroscopic method; the distribution width of TIG arc current-carrying region temperature reduce to the smallest near cathode along the arc axial direction; the temperature rises to maximum at the center of TIG arc current-carrying region cross section along arc radial direction, and there is a region with higher temperature near cathode; when the welding current decreased, the highest temperature of TIG arc current-carrying region would be lowered, meanwhile the current-carrying region temperature distribution width reduced, and then the high temperature region near cathode tends to shrink along arc axis; the longer arc length cause spatial range of charged particles enlarged, this gives arise to expand distribution width of TIG arc current-carrying region temperature, but the highest temperature of TIG arc current-region would not change.