Henry Granjon prize competition 2001 winner, category a joining and fabrication technology: Development of laser-GMA hybrid- and hydra welding processes for shipbuilding

Coupling gas shielded metal arc welding with laser beam welding ("hybrid process") has been shown to be one possibility of making use of the specific advantages of both processes. The arc, in addition to the laser beam, supplies heat to the weld metal in the upper weld region, giving the weld pool its typical U-shape. The mutual influences exerted by the processes can differ in intensity and form as a function of the arc or laser process and the process parameters. The heat to which the weldment is exposed as a result of the hybrid process can be kept low comparable to the laser process. Either laser or arc character may predominate, depending on the selected power input ratio. Further advantages can be achieved by coupling the laser beam with two gas metal arcs ("Hydra Welding Process"). Samples of Hybrid and Hydra welds are shown. The welded materials are as well high strength steels for shipbuilding and steel constructions as austenitic steels in material thicknesses up to 20 mm. The welds were mainly butt joints, but fillet joints were also used. Expansion of the possible uses and operative capability of the laser-GMA Hybrid- and Hydra Welding Process will increase productivity, flexibility and, consequently, competitiveness.