Weldability of Additive Manufactured Pipe Features for Fusion Component Replacement
The current strategy for joining ITER diverter cooling pipes is to conduct semi-automated autogenous Tungsten Inert Gas (TIG) welding on thin-walled pipes using an inserted flat washer filler ring. In this approach, the positioning of the filler ring and the alignment the pipe stubs so far can only be achieved manually. However, it has limitations for future maintenance because human interventions may be limited or completely prohibited in contaminated environments, requiring the need for remotely operated tools and systems. In addition, maintenance of cooling pipes will involve cutting and rewelding of the parts, however, components have limited lifespan for reuse. Additive manufacturing (AM) is an advanced technique provides one potential way to overcome the limitations. This work investigates the use of AM method to deposit material as an alternative approach to using filler rings, which a flange feature was firstly built on the pipe end using laser blown power direct energy deposition (DED). Thereafter, semi-automated autogenous TIG welding was conducted on the AM modified pipe stubs. The results suggest that using AM produced part is able to produce compliant pipe joins, implying possible improvements to maintenance strategies for future fusion power plants and experimental devices.