SPECIAL ASPECTS OF WELDING OF ALUMINUM ALLOYS COMPONENTS FOR NUCLEAR PLANTS

The article presents the techniques and processing technologies that allow improvement of quality of welded joints of small-sized aluminum alloys components for nuclear plants. The authors give the description of standard designs and sizes of such components and show the characteristic feature of welding of small-sized components for nuclear plants – the splash formation. The article describes an experiment when the component temperature was measured during the splash. Other features of welding of aluminum alloys components are concerned with the presence of oxide film on their surfaces. It causes the defects disturbing the welded joints continuity. The authors considered the methods and processing technology that allow reduction of the probability of splash formation during the welding of edge and girth seams. The application of pulse laser welding was considered to be the most effective method. To remove the oxide film out of the throat area, the authors suggested making a cavity in the groove mounting seat. The authors found out that the best effect when welding the ampoules with a wall thickness of 1 mm is achieved in case of the groove depth of 1 mm. UDGI-161 slope controller, a special-purpose welding equipment, was used for the same purpose. The authors proved experimentally that, when using the UDGI-161, the number of oxide inclusions and pores of rejection size is reduced by half. The experiment determined the dependence of the component extension out of the collet insert on the quality of welded joint. The authors considered the possibility of reducing the growth of pores when welding aluminum through the molted state time reduction when using pulse laser welding. The article presents the equipment allowing to perform pulse laser welding under vacuum conditions.