摘要
将纵向磁场应用于98%Ar+2%O2和80%Ar+20%CO2保护的射流过渡MAG焊,借助高速摄像手段研究外加纵向磁场对MAG焊电弧形态及运动特征的影响规律,揭示纵向磁场对MAG焊电弧的作用本质在于压缩电弧。通过分析液流束末端的液态金属的受力情况,确立纵向磁场作用下MAG焊的熔滴过渡机制。试验结果表明,外加纵向磁场使得相对'静态'的锥形MAG焊电弧转变为高速旋转的螺旋状电弧,并且随着励磁电流的增大,电弧旋转角速度加快、可见弧长缩短、电弧电场强度提高。同时外加纵向磁场的引入还能够降低焊接电流、提高熔滴过渡频率和焊丝熔化系数。外加纵向磁场对射流过渡MAG焊接过程稳定性的影响特点与所采用的保护气体的物理性质相关。
Applying the longitudinal magnetic field to the process of streaming transfer MAG welding with 98%Ar＋2%O2 and 80%Ar＋20%CO2 shielded gases,the influence of the longitudinal magnetic field on arc shape and motion character is researched by means of a high speed camera.It is revealed that the essential effect of the outer longitudinal magnetic field on MAG welding arc is arc constriction.Through analyzing the force of the liquid metal on the end of liquid metal jet,the drop transfer mechanics under the effect of the longitudinal magnetic field is proposed.The result shows that the application of the longitudinal magnetic field can change arc shape from pyramidal and static to spiral and rotational with high speed.With the increment of exciting current,the angular velocity of arc is accelerated and arc length is shortened and electric-field intensity is raised.Also the application of the longitudinal magnetic field can decrease the welding current and increase the transfer frequency of molten drop and the melting coefficient of wire.The stability of MAG welding process is affected by the outer longitudinal magnetic field and the physics nature of shield gas.
出处
《机械工程学报》
EI
CAS
CSCD
北大核心
2010年第14期95-100,共6页
Journal of Mechanical Engineering
关键词
纵向磁场
电弧形态
熔滴过渡
Longitudinal magnetic field Arc shape Drop transfer
