Enabling high productivity cost effective welding for the power sector (HiWeld)

The demand for ‘thick section’ steel structures in power generation is strong & growing – primarily driven by need for off-shore wind towers and foundations structures – with UK demand for 1,000 structures or 1m tonnes of steel p.a. The fabrication of structures is limited by the welding time (and cost); to produce a typical 40m long monopile (60mm thick) takes ~6,000 hrs. CVE has developed the ‘EbFlow’ system which reduces this welding time to <200 hrs, equivalent to a reduction in cost of over 85%. However, to date, this has only been successfully achieved using proprietary ‘HTUFF’™ steel supplied by the Nippon steel from Japan. This steel alloy is able to overcome HAZ toughness which is by product of the rapid welding approach. Owing to Nippon having a monopoly supply position, this has prevented and serious market investment and uptake of the approach. The HiWeld project aims to integrate induction heating into the EbFlow system, to overcome this issue by applying a localised heat-treatment – allowing standard grades of C-Mn steel to be used for structures. Critically, standard S355 steel can be supplied by any UK, European or Worldwide supplier; unlocking a key market barrier to adoption of the EbFlow process. This development will enable >£10m of systems to be deployed by CVE within 3-5 years of project completion, potentially reducing the cost of off-shore wind structures by 3-5% (LCOE prediction).