Sheffield Forgemasters makes global leap in welding technology

A breakthrough in electron beam welding technology has Josh Welton pondering this process’s potential in large nuclear and non-nuclear fabrication projects.

We rarely open our browsers to breaking news related to welding, yet here we are!

Sheffield Forgemasters, a steelmaker in England’s Yorkshire region, recently announced a "global leap in welding technology" capable of significantly reducing the time and cost of producing small nuclear reactors, central to the U.K.'s energy strategy.

The successful development of local electron beam welding (LEBW) makes it possible to weld very thick steel sections for nuclear use. Unlike electron beam welding (EBW), where the entire weldment must fit in a full containment vacuum welding chamber, LEBW only needs to cover the section that is being welded. And this distinction is a big deal when talking about big pieces.

I’m no EBW expert, but here are the basics. A particle gun (awesome) shoots electrons into a vacuum—where free electrons can exist—which are then sped up by electrical fields. This electron beam can generate enormous power via the flow (current) and acceleration (voltage). The beam is pushed through magnetic lenses, which focus and shape it. Due to the incredible amount of control, the beam can be adjusted to weld from a consistent penetration depth of nearly 0 up to 200 mm. That’s, like, 8 in. thick! The beam is kinetic energy, and while it needs a very tight fit-up, it doesn’t require any filler metal. The focused beam allows for deep penetration and remarkably little width. There’s no wasted energy, resulting in a tiny heat-affected zone (HAZ).

Much of the funding for U.K. government-owned Sheffield Forgemasters to develop LEBW was provided by government programs explicitly looking to create and deploy full-size small modular reactors (SMR) across the U.K. Instead of being built on-site, an SMR is built in a factory and shipped for assembly. The goal is to deploy these reactors in 2030 and for them to provide 25% of the U.K.’s total power by 2050.

For this purpose, adding the L to LEBW is critical. There’s not a lot of information out there yet besides a press release heavy on quotes and light on details, but I would assume the most significant part of LEBW is the ability to weld outside of a full-containment vacuum chamber.

The vacuum chamber serves a few purposes. It not only allows for the free electrons, but it is also necessary for the vaporization of metal. The chamber takes care of the fumes and, super importantly, the radiation this process creates. EBW isn’t new, but until now you could only weld what could fit inside a chamber. On an SMR, four nuclear-grade welds are needed on 8-in.-thick, 10-ft.-dia. material. My guess is that much of the development of LEBW focused on creating a legit vacuum chamber that attaches to the weldment instead of engulfing it whole.

In the Sheffield Forgemasters announcement, Senior Development Engineer and Project Lead Michael Blackmore said, "The implication of this technology within the nuclear industry is monumental, potentially taking high-cost welding processes out of the equation.

"Not only does this reduce the need for weld inspections, because the weld joint replicates the parent material, but it could also dramatically speed up the rollout of SMR reactors across the U.K. and beyond; that's how disruptive the LEBW breakthrough is."

Despite weaving through all the tech/industry-bro keywords, he’s not wrong, at least according to their info. Those four welds would typically take a year. Sheffield Forgemasters did them in 24 hours.

Sheffield Forgemasters, a steelmaker in England’s Yorkshire region, recently announced a "global leap in welding technology" capable of significantly reducing the time and cost of producing small nuclear reactors, central to the U.K.'s energy strategy.

As the process continues to evolve, there’s the potential for large nuclear and non-nuclear fabrications. Think anything from defense to specialized constructions to energy, wherever massive welds are required. What was once previously impossible or prohibitively time-consuming may no longer be.

The LEBW process allows for consistent, zero-defect welds of nearly any depth from 0 to 200 mm. There’s no filler, so the welded metal will be the same as the base material. From thin to thick, if it works like Sheffield claims, it will be a “disruptive game-changer” to the fabrication industry.