Hybrid laser/GMA welding of components for wagon construction

The object of the conducted investigations into hybrid laser/GMA welding was to portray the technological and, above all, economic potentials on T‑joints in particular with the objective of the full connection produced in one pass. After the proof of the strength properties in the full-scale fatigue test, a specimen fabrication process was defined as another main focal point in order to assess the process stability and the reproducibility of the parameters. Within the framework of a customer project relating to the manufacture of passenger carriages, beam subassemblies were selected from the region of the base frame according to the fabrication possibilities existing at SLV Halle GmbH. The requirements on the jig configuration were oriented not only to the exact positioning of the subassembly but also primarily to the robot accessibility and to the completion of as many welds as possible in one clamping operation. The fabrication of beam subassemblies was begun after the end of the authorisation procedure with the execution of the procedure qualification test necessary for the relevant joint types and any repair work. A batch size of 40 double‑T beams was fabricated with double fillet welds in fully connected joints over a weld length of 800 mm. In this respect, flawless full-penetration welding was proven for the demanded weld length using a subsequent ultrasonic test.

The experience gathered and problems solved within the framework of the specimen fabrication are available as fundamental know-how for further implementation operations.