基于纵向磁场控制的大直径空心螺柱焊接工艺  

Large diameter hollow stud welding process based on longitudinal magnetic field control

作　　者：张德库[1] 何思源 殷宏宇 王克鸿[1] ZHANG Deku;HE Siyuan;YIN Hongyu;WANG Kehong(Nanjing University of Science and Technology,Nanjing,210094,China)

机构地区：[1]南京理工大学,南京210094

出　　处：《焊接学报》2021年第9期74-80,I0005,共8页Transactions of The China Welding Institution

基　　金：国防科技创新特区资助项目(18-H863-03-ZD-007-004-02)。

摘　　要：采用电弧螺柱焊方法对外径20 mm、内径10 mm的空心螺柱与45钢板材进行焊接,研究了旋弧磁场对接头显微组织特征及力学性能的影响.结果表明,在纵向旋弧磁场作用下,电弧中电荷受洛伦兹力作用呈螺旋运动,接头外观成形得到改善.受磁场控制的电弧持续搅拌熔池,改善了焊接热循环条件,影响了熔池凝固结晶过程.接头中先共析铁素体呈有规律的网状分布,珠光体也变得细化.接头温度梯度减小使得固态相变时间增长,母材侧热影响区马氏体数量显著下降,热影响区宽度变小.但旋弧磁场电流过大时焊接过程飞溅倾向明显增大,焊缝中气孔增多.在焊接时间1400 ms、焊接电流800 A、旋弧磁场电流0.43 A时,电弧在空心螺柱端面充分燃烧,接头抗剪强度可达到325 MPa.The arc stud welding method was used to weld 45 steel plate and hollow stud with outer diameter of 20 mm and inner diameter of 10 mm.Effects of the rotating arc magnetic field on microstructure and mechanical properties were studied.The results show that with the longitudinal rotating arc magnetic field,the charge in the arc moved spirally under the action of Lorentz force,which extended outward to some extent and the appearance of the joint was improved.The thermal cycle condition of joint was improved thanks to the continuous stirring of molten pool by controlled arc,and the solidification and crystallization of molten pool was affected.The proeutectoid ferrite showed a regular network distribution and the pearlite became fine.For the decrease of joint temperature gradient,the solid-state phase transition time increased,the martensite content in the heat affected zone of the parent metal of 45 steel side decreased significantly and the width of HAZ became smaller.When the rotating arc magnetic field current was too large,the spatter tendency increased obviously as well as the porosity in the weld increased.When the welding time of 1400 ms,the welding current of 800 A and the rotating arc current of 0.43 A,the arc was fully burned at the full end face of the hollow stud,the shear strength of joints can reach 325 MPa.

关 键 词：电弧螺柱焊 空心螺柱 旋弧磁场 电弧 

分 类 号：TG430[金属学及工艺—焊接]