An investigation on laser-arc hybrid welding of one-pass full-penetration butt-joints for steel bridge members

For investigating effectiveness of laser-arc hybrid welding for fabrication of steel bridge members, a series of experiments were conducted. One-pass full-penetration butt-joints with steels for bridge high performance structures (SBHS400) with a thickness of 15 mm were joined by the laser-arc hybrid welding. Six passes were required for fabricating the same dimensional full-penetration joints by the arc welding. The time for fabrication by the hybrid welding was around 2% of that of the arc welding. Welding processes by the hybrid welding and the arc welding were simulated by a thermal elastic–plastic analysis. The magnitude of out-of-plane deformation by the hybrid welding was around 5% of that of the arc welding. The width of tensile residual stress region by the hybrid welding was around 50% of that of the arc welding. The hybrid welding might show the higher effectiveness compared to the conventional arc welding from the viewpoints of controlling the welding distortion, residual stress, and welding time.