Wed, 23 July, 2025
The findings from the Innovate UK-funded ‘LowCostEB’ have been published, having also been presented to the International Institute of Welding (IIW) last year.
The project was led by Aquasium Technology Limited (parent of Cambridge Vacuum Engineering) with input from TWI and Stainless Metalcraft (Chatteris) Limited. The objective of LowCostEB was to reduce the cost of component manufacture by using Electron Beam Welding (EBW) to enhance material utilisation and reduce waste. The application of a 'local-chamber' system, removing the need for a vacuum chamber and dedicated shielding for electron beam welding was investigated as an option throughout the project.
The initial target market for LowCostEB were products for the domestic nuclear waste and decommissioning market. This saw the investigation of duplex stainless materials to ascertain how suitable EB welding was for use in the fabrication of safety critical components, and the development of accompanying novel welding solutions for these, as appropriate.
The published paper in particular discusses the phase balance and material performance of the weld solidification product and heat-affected zone (HAZ). EB welding of these materials has traditionally led to an undesirable phase balance due to the rapid cooling rates produced by the low heat input process. However, this paper describes methods of achieving suitable phase balances whilst using the EB process. Both weld and HAZ ferrite levels of between 40 ≤ F% ≤ 70 were achieved in 20mm and 60mm duplex material. This was achieved whilst having no observed negative effect on the other tested material properties where hardness, transverse tensile and Charpy V notch tests were conducted.
Electron beam welding is a well-established and trusted, high integrity, high speed welding process. It can weld from 0.1mm to \>200 mm in a single pass, without costly filler wires, uses less process gas and can reduce fume exposure - and thus can achieve unrivalled productivity improvements (\>1,000x for very thick section fabrications). However, because it needs to be undertaken in a vaccum environment, typically in a large chamber, it can be an expensive technology.
LowCostEB sought to solve the cost issue by delivering a local-vacuum process head that de-risks the electron beam approach, shortens weld times, and reduces costs. The LowCostEB solution also looked to improve material utilisation, maximise manufacturing efficiency, and establish fabrication methods that deliver economic and production benefits.
You can see the full report from this project online, here:
https://rdcu.be/exqcF