LowCostEB - Reducing the cost of electron beam welding for improved productivity of heavy manufacturing sectors

**_The demand for 'thick section' steel structures, primarily in power generation, is strong & growing._**

Globally 79% of electricity is generated by thermal processes, in which conventional power plants provide over 62% of global electricity supply and the remaining 17% is by nuclear fission processes and this is expected to increase (IEA, 2015). Thermal power plants make use of a large number of thick section (\\\>20mm) components for many parts of the primary circuit; pump and valve bodies, ancillary systems and other safety critical components. Furthermore, off-shore wind demand in the UK requires \>1,000 structures (towers and foundations) or 1m tonnes of steel p.a. to be cost-effectively fabricated.

The fabrication of large metallic structures typically requires high-integrity, thick section, welding; often for structures that are for safety critical applications (e.g. pressure vessels/steam raising plant, aerospace parts, etc). Arc-based welding techniques are first choice for simple engineering steels, but there are limitations in applying these processes to high performance advanced alloys and other materials. Arc-based processes can only weld to a depth of ~2-3mm, and thus multi-pass welding is needed; this increases manufacturing time (sometimes requiring tens or hundreds of passes per welded joint), costs and increases the chance of weld defects and the amount of inspection and re-work needed.

**_To reduce cost this manufacturing time needs to be significantly reduced._**

Electron beam (EB) welding 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).

CVE has over the last 7 years developed and has begun commercialising the 'EBFlow' system; which creates a local-vacuum process head, targeting off-wind fabrication, and reduces this welding time from 6,000hrs to <200hrs, equivalent to a reduction in cost of over 85%.

**_The LowCostEB project will use this approach (and learning) to remove the requirement for a vacuum chamber and dedicated shielding through the application of low-cost 'local-chamber' system._**

This project will deploy a team comprising Cambridge Vacuum Engineering (CVE) who develop bespoke power beam welding solutions for high integrity fabrications, TWI (an RTO specialising in welding and performance testing) and Stainless Metalcraft (an example end-user fabricator).

The consortium will develop and evaluate of the LowCostEB system to improve material utilisation, develop designs for maximising manufacturing efficiency, and establish fabrication methods maximising the economic and production benefits.