场效应管逆变式方波交流MIG焊接电源的研制

Study on the MOSFET inverter type square wave AC MIG welding power souroe

交流MIG焊接方法过去认为是不能实现的。近年来在直流MIG焊接法研究中发现磁偏吹的不良作用严重影响了MIG焊接质量及其在厚板深坡口和角缝焊接中的应用。因而作者提出了用交流电源实现MIG焊接的方法克服磁偏吹。本文提出了交流MIG焊接电弧控制法,详细介绍了作者研制成的方波交流MIG焊接电源,主要是方波交流逆变器。论述了元器件选择、保护及为实现电弧稳定而采取的一些措施,初步实现了方波交流MIG焊接,并对方波频率、正负极性比率及电流反向速度对焊接电弧稳定性的影响得到了定性认识,为进一步发展交流MIG焊接打下了基础。

For several decades only DC MIG is considered to be applicable for practice,it was found, however, that aoblow, often happens in DC MIG process, partinlarly in deep groove welding, is seriously detrimental to the quality of the weld. In order to overcome the shortcome a project for developping AC MIG process was proposed by the authors. In present papaer.the control method for AC MIG process and the power source for realizing it,mainly a square wave invertor.are described. Measures for stablizing the arc, the electronic circuit, the devices used and its protection circuit are discussed. Effects of square wave frequency, polarity ratios and current rising rate at the transient point on the stability of the arc are studied and introduced. Results of present study laid down a good foundation for further developping the AC MIG welding process.