尖角磁场极性对双钨极氩弧焊电弧形态和焊缝特征的影响

针对双钨极氩弧焊(T-TIG)存在的电弧压力小、焊缝熔深浅等问题，引入不同极性的外加尖角磁场辅助T-TIG焊方法.分别采用高速摄像机和红外摄像仪研究不同极性的尖角磁场对电弧形态和焊缝特征的影响规律，并构建物理模型以揭示尖角磁场与电弧等离子体间的相互作用机制.结果表明，外加尖角磁场影响着T-TIG电弧形态和焊缝温度场，两种极性的尖角磁场都对其热影响区组织有细化作用.其中，在正极性的尖角磁场作用下，T-TIG电弧形态变化程度更大，焊缝温度场更加集中，焊缝熔深比未加磁场时增加37.1%，同时能量利用效率提高31.6%.

Influence of cusp magnetic field polarity on arc shape and weld characteristics of twin-electrode TIG welding

Aiming at the problems of low arc pressure and shallow weld penetration in twin-electrode TIG (T-TIG) welding, a T-TIG welding method assisted by cusp magnetic fields with different polarities is introduced. A high-speed camera and an infrared camera were used to study the influence of cusp magnetic fields of different polarities on arc shape and weld characteristics, and a physical model was constructed to reveal the interaction mechanism between cusp magnetic fields and arc plasma. The results show that the external cusp magnetic field affects the shape of the T-TIG arc and the temperature field of the weld, and the cusp magnetic fields of both polarities can refine the structure of the heat-affected zone. Among them, under the action of a positive cusp magnetic field, the T-TIG arc shape changes more greatly, the weld temperature field is more concentrated, the penetration depth of the weld is increased by 37.1% compared with that without a magnetic field, and the energy utilization efficiency increases by 31.6%.