Application and optimisation of the plasma-arc welding process with a powder filler metal in the case of the manufacture of joints on X6CrNiMoTi 17-12-2

摘要

The initial situation was characterised by problems in production by means of welding technology in the case of structures which have tightly limited space and are difficult to manufacture with conventional welding processes. For the basic investigations, sample welds were manufactured on plates using the plasma-arc welding process with filler metals in powder form. This technique was to be used in order to weld joints on X6CrNiMoTi17-12-2 (material number 1.4571). The weld specimens to be investigated were joined together in a butt joint. In this respect, the welding process had to be tested and assessed under various gases with the classifications I1 (Ar 4.6), R1 (Ar W5) and SI3 (Ar/He 11) according to DIN EN 439. Furthermore, the penetration behaviour was to be shown on the basis of macrographs and the changes in the material on the basis of microsections. This was followed by measures for the optimisation of the welding quality (in particular, of the weld surface) and of the deposition of the filler metal in order to increase the economic efficiency. These goals were achieved by modifying the powder/shielding-gas nozzle of the torch.