Fatigue strength of hybrid laser-beam/GMA-welded joints with great thicknesses

A research project recently concluded at SLV Halle GmbH dealt with economically viable alternatives for the welding of thick-walled components such as are used, for example, in steel and tank construction as well as in shipbuilding. At present, they are fabricated using the submerged arc welding process with high expenditure on the energy, the filler material and the working time.

Innovative and more efficient welding processes were sought in order to improve the economic viability. Here, the hybrid laser beam / GMA welding available at SLV Halle GmbH offered potential due to a number of materials engineering and design peculiarities compared with conventional welding processes. The evaluation of the welding technology investigations, of the residual stress measurements and simulations as well as of the residual stress analyses indicated that hybrid laser beam / GMA welding constituted an alternative to the conventionally utilised processes because comparable and better joint qualities were achieved. This was also confirmed by the numerous investigations into the fatigue strength. Here, the hybrid-laser-beam/GMA-welded joints achieved longer service lives in comparison. The available results were still to be verified with regard to the applicable set of rules and to the subsequent implementation in a form ready for series production.