Due to the coupled filler material and energy supply in gas metal arc welding (GMAW) processes, these processes have limited productivity as a result of heat-induced residual stresses and distortion. To increase productivity and decrease heat input, conventional GMAW processes can be combined with an auxiliary hot wire. The disadvantage of hot-wire processes is the small process window due to the required melt pool contact to maintain resistance heating and the magnetic blow effect of the hot-wire current. In this paper, the development of a GMAW hot-wire process with upstream ohmic preheating of the filler wire (between two current nozzles) is presented. Besides an increase of the deposition rate and consequently of the productivity, a decoupling and specific control of the material and energy input depending on the application is aimed at. By reducing the heat input into the base material, the influence on the mechanical-technological properties will be reduced and the development of residual stresses and distortion minimized. Furthermore, by preventing the magnetic arc blow caused by the hot-wire current, the process behavior will be improved, thus increasing its productivity and robustness. The potential of the process is demonstrated using selected welding tests.
|Number of pages||8|
|Journal||Welding in the world|
|Publication status||Published - Aug 2023|