Thick wall stainless-steel pipes are used for building pipelines for the transfer of media under extreme conditions, therefore high-quality joints need to be welded to meet the necessary requirements and standards. The purpose of this bachelor thesis was to optimize the parameters for the automatic welding of austenitic stainless tubes, in combination with TIG and MIG welding process for the needs in nuclear power plants. The influence of process parameters on weld filling in multilayer welding was examined and welding times for different welds were compared. The results of tensile test, radiographic analysis, macro analysis and weld defects that appeared are presented. We found out that by automatic welding of pipes we can assure repeatable quality welds and shorten the welding time up to fivefold in comparison to manual welding.