外加磁场作用下TIG焊电弧的光谱分析

发布时间：2018-06-25 04:04

本文选题：外加磁场 + 电弧行为　；参考：《沈阳工业大学》2015年硕士论文

【摘要】：在TIG焊接生产中，氩气可以很好地隔绝旁边空气，本身又不溶于金属，不和金属反应；焊接电弧还有自动清除工件表面氧化膜的作用。因此，可成功地焊接易氧化、氮化、化学活泼性强的有色金属、不锈钢和各种合金，在核电站及航空航天等领域也被广泛应用。但TIG焊接存在着电弧能量易发散、熔深浅、熔敷速度小、生产率较低，一旦焊接速度过快时，又会出现驼峰或咬边等缺陷。为了改善TIG焊接技术，本文提出了一种外加纵向磁场来控制电弧运动的方法，实验证明它改变电弧的形状，改善焊缝的熔深和熔宽，还可以控制熔池金属液体的流动、传热规律等。本文对电弧压力受磁场影响进行了细致研究，分析了磁感应强度，磁场频率对焊接电弧影响规律，并分析其作用机理，对焊接电弧行为的研究具有重要的理论意义和巨大的实际应用价值。本文利用自制分裂阳极装置对电弧热量进行测试，得出了磁场频率对热量分布的影响规律；利用自制水冷铜阳极电弧压力进行测试，得出了磁感应强度和磁场频率对压力分布的影响规律；利用高速摄像对电弧形态进行拍摄，得出了纵向磁场对电弧形态的影响规律；采用光谱诊断的方式计算不同磁场参数下电弧温度，实验结果表明：外加磁场作用下的电弧比自由电弧相比性能显著提高。当焊接电流为95A，磁感应强度为35mT，磁场频率为1550Hz左右时，电弧温度比自由电弧的温度从13391.42K提升到14136.34K，热量分布系数提高了14%左右，电弧旋转半径明显减小，形态由原来的锥形被压缩成为圆柱状。通过焊缝成形实验可知，对焊接电弧施加纵向磁场，焊缝成形良好，通过调节磁场参数，，可以显著增大熔深，使焊缝组织结构细小均匀，明显细化晶粒。
[Abstract]:in that TIG welding production , the argon gas can well insulate the air beside itself , and is insoluble in metal , and does not react with the metal ;
In order to improve the TIG welding technology , this paper presents a method for controlling the arc motion by adding longitudinal magnetic field .

In this paper , a self - made split anode device is used to test the arc heat , and the influence law of the magnetic field frequency on the heat distribution is obtained .
The influence of magnetic induction intensity and magnetic field frequency on pressure distribution was obtained by using self - made water - cooled copper anode arc pressure .
The influence of the longitudinal magnetic field on the arc shape is obtained by taking the high - speed camera to shoot the arc shape .
The arc temperature under different magnetic field parameters is calculated by means of spectral diagnosis . The experimental results show that the arc temperature is higher than that of free arc . When the welding current is 95A , the magnetic induction intensity is 35mT and the magnetic field frequency is about 1550 Hz , the temperature of the arc is increased from 13391 . 42K to 14136 . 34K , the heat distribution coefficient is increased by about 14 % , and the radius of arc rotation is obviously reduced , and the shape is compressed into cylindrical shape by the original taper .

According to the welding forming experiment , the longitudinal magnetic field is applied to the welding arc , the welding seam is good , the penetration depth can be remarkably increased by adjusting the parameters of the magnetic field , the structure of the welding seam tissue is fine and uniform , and the crystal grains are obviously refined .
【学位授予单位】：沈阳工业大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TG444.74

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