纵向磁场对CO_2焊接电弧及焊缝成形的影响

Influence of longitudinal magnetic field on welding arc and formation of weld bead in CO_2 welding

为了促进CO_2焊接的发展,降低焊接飞溅率与改善焊缝成形显得至关重要.在具有不同磁场强度与磁场频率的外加纵向磁场作用下,通过高速摄像技术观测了焊接电弧形态,同时测量了焊缝熔宽和熔深的变化.结果表明,当励磁电流为1 A、励磁频率为50 Hz时,焊接电弧由最初的锥形变为钟罩形,并按一定方向旋转,焊接电弧的刚性和稳定性得到了增强,因而焊接效果较好.随着磁场参数的增加,焊缝的熔宽与熔深先增加后减小.因此,通过采用一定范围内的磁场参数,可以达到有效改善焊缝成形并降低焊接飞溅的效果.

In order to promote the development of CO2welding, it is very important to reduce the welding spatter rate and improve the formation of weld bead. Under the action of external longitudinal magnetic field with different intensities and frequencies, the morphologies of welding arc were observed with high speed camera technology. Meanwhile, the changes of weld width and penetration were measured. The results show that when the excitation current is 1 A and the excitation frequency is 50 Hz, the shape of welding arc changes from cone shape to bell shape, and the welding arc rotates according to a certain direction, which will improve the stiffness and stability of welding arc and thus the welding effect is better. With increasing the magnetic field parameters, the weld width and penetration of weld bead first increase and then decrease. Therefore, to control the magnetic field parameters in a certain range can effectively improve the formation of weld bead and reduce the welding spatter.