横向交变磁控DP-TIG焊电弧熔池特性研究

外加交变磁场可改善大电流高速焊接时的焊缝成形缺陷,为获得不同励磁参数对DP-TIG(deep penetration,TIG)焊接电弧和熔池特性的影响,在横向交变磁场作用下,对12 mm的Q345B板进行了DP-TIG焊接试验.通过高速摄像系统观察电弧形态,采用小孔法测量电弧压力,基于金相腐蚀法分析熔池截面.结果表明:与无磁场作用时的DP-TIG电弧相比,在横向交变磁场作用下,DP-TIG电弧形态发生明显变化,电弧压力峰值随交变频率的增大先降低后增大,熔池截面形态由指状向锅底状过渡,且镍基堆焊时,焊缝表层铁含量在5%以内,焊材被稀释程度较低.

Study on arc and pool characteristics of DP-TIG welding with additional transverse alternating magnetic field

The defects of weld profiles in large-current and high-speed welding can be improved by adding alternating magnetic field. In order to obtain the influence of different magnetic excitation parameters on the arc and pool characteristics of DP-TIG (deep penetration TIG) welding, the DP-TIG welding experiment of 12 mm Q345B plate was carried out with additional transverse alternating magnetic field. The arc shapes were observed by a high-speed camera system, the arc pressures were measured through the small hole method, and the weld pool section profiles were analyzed based on the metallographic corrosion method. The results show that, compared with DP-TIG welding without magnetic field, the arc shape of DP-TIG welding with additional transverse alternating magnetic field changes obviously, the peak value of arc pressure first decreases and then increases with the increase of alternating frequency, and the weld pool section profile transits from finger-shape to pot-bottom-shape. In addition, the iron content in the weld surface of Ni-based overlay welding is less than 5%, and the dilution degree of welding material is low.