Local vacuum electron beam welding for pressure vessel applications

Abstract

Welding of thick section components such as pressure vessels used in the nuclear industry is traditionally performed using arc welding techniques, requiring multiple weld passes, with interstage non-destructive examination (NDE) and preheating of the component to reduce the risk of hydrogen cracking. Electron beam (EB) welding offers the opportunity to weld thick section components in a single pass and negates the need for interstage NDE, resulting in saving significant time and cost in the fabrication of nuclear vessels. Furthermore, elimination of the preheat step may be possible since the EB process is carried out in a vacuum environment. However, due to the physical size and geometry of nuclear vessels, traditional vacuum chambers would be prohibitively expensive when considering the low volume of output in the nuclear industry. Rolls-Royce and TWI are working on a local vacuum, or 'out of chamber', EB welding system, which eliminates the need of such a vacuum chamber and brings the vacuum to the component, thus making EB welding of nuclear vessels more practical and financially viable.

Future application and prospect of space electron beam processing technology

“…Classical electron beam welding has been widely used in various fields and has good material process adaptability. For example, Aerospace pressure vessels, space propulsion components, big rocket cylinder sections, fighter bearing components, sensors, engine components, gas turbines, and nuclear reactor shells have all been successfully welded using classic electron beam technology [6][7][8][9][10][11] . Electron beam brazing is based on the electron beam with beam spot defocusing and precise trajectory control as the heat source.…”

Surface Manufacturing of Materials by High Energy Fluxes

“…The laser beam processes are usually realized in atmospheric medium. In order to prevent oxidation of the manufactured area, argon is blown over the surface of the manufactured material [16,18].…”

Laser Welding under Vacuum: A Review

“…In addition, the dimensions of the welded part were restricted by the dimensions of the vacuum chamber. A larger vacuum chamber means higher cost and associated pumping time [65]. A lot of trails were carried out to make the electron beam welding release the limitation of vacuum chamber.…”