Improvement of Gap Bridging Ability in CO₂ Laser-GMA Hybrid Welding

Chae, Hyunbyung; Kim, Cheolhee; Kim, Jeong-Han; Rhee, Sehun

Journal of KWJS 2006;24(5):49-56.
Published online January 4, 2007.

조선용 강재의 CO₂레이저 GMA 하이브리드 용접에서 갭 브리징 능력 향상기술 개발

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Improvement of Gap Bridging Ability in CO₂ Laser-GMA Hybrid Welding

Hyunbyung Chae, Cheolhee Kim, Jeong-Han Kim, Sehun Rhee

Abstract

For laser welding in shipbuilding industry, gap bridging capability is one of the most important characteristics to achieve the high productivity and good weld quality. Recently, laser-GMA hybrid welding process is regarded as a distinctive method to overcome the tight gap tolerance with improving the productivity. In this study, the influence of process parameters on the bead formation was experimentally analyzed and the relationship between the process parameters and geometric imperfections was investigated. It was revealed that undercut, excessive weld metal, excessive penetration and incompletely filled groove were the major geometric imperfections. The optimized wire feeding and arc pressure were necessary to ensure the gap bridging ability. The approach to select the process parameters was conducted for butt welding with up to 2㎜ joint gap, in which the sound weld beads were generated without changing the welding speed.

Key Words: Shipbuilding, Gap bridging capability, Laser-GMA hybrid welding, Geometric imperfection