Experimental Study of Characteristics of Long Seam Welding With CO₂ Laser(Invited Paper)

In this paper, the influences of both axial and off-axial protection on weld penetration were investigated during long seam welding of stainless steel with a CO₂ laser. The results showed that the weld penetration obviously decreased with the increase of welding length in axial protection. On the other hand, the weld penetration hardly changed with the change of welding length in the welding with off-axial protection. The thermal lens effect of light path system on weld penetration was not obvious. Further analysis shows that the poor control of plasma in axial protection is the reason why the weld penetration decreases with the increase of welding length. The negative effect of plasma on the weld penetration can be avoided by using the discontinuous welding in axial protection.