外加轴向磁场K-TIG横焊电弧形态及焊缝成形

Transverse welding arc shape and joint formation in K-TIG welding under axial magnetic field

深熔K-TIG焊是一种单面焊双面成形的高效焊接技术,在中厚板材制造中得到广泛的应用。为探究磁场影响电弧形态的机理,采用数字图像处理技术对不同磁场强度下的电弧形态进行了研究。结果表明,轴向磁场对电弧上部和电弧下部呈现不同的作用效果,电弧上部的挺度大于电弧下部的,在相同焊接工艺参数下,电弧上部受磁场影响的波动幅度比电弧下部小,磁场强度对电弧的影响呈现非线性关系,深熔K-TIG焊电弧属于自由电弧,形成的熔池面积较大,在横焊工艺中,熔池因重力效应而出现下淌,进而影响焊缝成形。文中提出了一种通过磁场辅助抑制熔池下淌的方法,通过轴向磁场与熔池的电流相互作用,产生与重力方向相反的电磁力,进而抑制熔池下淌,轴向磁场适用于改善K-TIG横焊焊缝成形。

Deep penetration K-TIG welding is an efficient welding technology widely used in the manufacturing of medium and thick plates.To investigate the mechanism of magnetic field affecting the arc shape,digital image processing technology was used to study the arc shape under different magnetic field strengths.The results showed that the axial magnetic field had different effects on the upper and lower parts of the arc,with the upper part exhibiting greater stiffness than the lower part.Under the same welding parameters,the fluctuation amplitude of the upper arc affected by the magnetic field was smaller than that of the lower arc,and the effect of magnetic field strength on the arc exhibited a nonlinear relationship.The K-TIG welding arc belongs to a free arc,and the formed molten pool area is relatively large.In the transverse welding process,the molten pool flows downward due to the effect of gravity,which affects the formation of the weld.To solve this problem,a method of using magnetic field to assist in suppressing the downward flow of the molten pool was proposed.By the interaction between the axial magnetic field and the current of the molten pool,an electromagnetic force opposite to the direction of gravity was generated to suppress the downward flow of the molten pool.Therefore,the axial magnetic field is suitable for improving the formation of K-TIG transverse welds.