磁控TIG高速焊焊缝成形机理  

Mechanism of weld formation during high speed TIG welding with external magnetic fields

作　　者：常云龙[1] 路林[1] 李英民[1] 杨旭[1] 

机构地区：[1]沈阳工业大学材料学院,沈阳110870

出　　处：《焊接学报》2013年第6期1-4,113,共4页Transactions of The China Welding Institution

基　　金：国家自然科学基金资助项目(51275314);沈阳市重点科技基金资助项目(1071201-1-100);沈阳市科技基金资助项目(F10-205-1-47)

摘　　要：对磁控TIG焊焊缝成形机理进行了理论分析,外加磁场可以改变液态金属表面张力的差值,进而改变熔池的流动方向.当σ/T>0时,焊缝边缘点附近的液态金属向熔池内部流动,焊缝凝固时容易产生咬边;σ/T<0时,液态金属由熔池中心向边缘流动,咬边倾向性很小.分别比较了外加横向直流磁场、横向交流磁场以及纵向交流磁场时的焊接电弧通过焊缝截面的时间.结果表明,外加磁场时TIG焊电弧阳极斑点的有效直径大于无磁场时的电弧阳极斑点有效直径,这将有助于减小表面张力温度系数,从而有助于解决高速焊接时出现的咬边与驼峰等问题.The mechanism of TIG weld formation under external electromagnetic fields was analyzed theoretically. The external magnetic fields could change the difference of surface tension of liquid metal and then change the flow direction of the molten pool. When σ/T>0, the liquid metal around the edge of molten welding pool flew inward and undercut could occur. However, when σ/T<0, the liquid metal flew outward and the trend of forming undercut decreased. The effects of transverse DC magnetic field, transverse AC magnetic field and longitudinal magnetic fields on the time for welding arc penetrating the weld section were compared. The theoretical analysis results show that the effective diameter of the anode spot of TIG welding arc with external magnetic field was larger than that without external magnetic field. TIG welding with external magnetic field could help to reduce the surface tension temperature coefficient and avoid the undercut and bump seam during high speed TIG welding.

关 键 词：外加磁场 电弧特性 焊缝成形 磁压缩 

分 类 号：TG444.2[金属学及工艺—焊接]