Steel tomography research awarded EU grant

Materials World magazine
1 Jun 2016

An EU Horizon 2020 grant is enabling the development of an innovative steel production tool, as Simon Frost reports. 

Dr Manuchehr Soleimani, a researcher in tomographic imaging at the University of Bath, UK, has been awarded an EU Horizon 2020 grant to lead a three-year project, named ‘Shell-Thick’, developing an induction tomography system intended to reduce defects by monitoring the cooling and solidification of molten steel. 

Induction tomography works by transmitting a time-varying magnetic field and measuring the inducted voltage on receiving sensor arrays. These voltages depend on the electromagnetic properties of the metal, which can be imaged using induction tomography inverse equations. 

Soleimani explained to Materials World, ‘Our induction tomography will provide information about various layers of the steel during the solidification process. This data can then be used in the control loop of the solidification process, where a number of parameters can be controlled, such as the rate of metal flow and speed of casting.’ 

A contactless ‘bracelet’ around the billet continuously takes real-time, non-destructive measurements of molten steel as it cools and solidifies, providing an image of its structural composition based on its electrical conductivity. The method is being developed in the hope it will improve the quality, safety, productivity, costs and, ultimately, competitiveness of the UK and EU steel industry. 

Critical cooling

‘There are several different types of defects that can occur during cooling,’ said Soleimani. ‘Hot tears and hot spots are the main metallurgical defects – hot tears occur because the metal is weak when it is hot and the residual stresses in the material can cause the process to fail as it cools. Hot spots are areas on the surface that are hard because they cooled quicker than other areas.’ 

Current state-of-the-art methods for real time measurement, such as infrared imaging, are only able to provide information on the outer layer of the billet, said Soleimani. ‘When it comes to internal structure mapping and imaging, there is no current solution. This project will challenge our induction tomography to be able to work beyond metal layers, providing information on the inner layers, too.’ 

Over the three years of the Shell-Thick project, Soleimani aims to build an industry-standard tomography device based on the prototype his team has developed. ‘This will be the first step, in parallel with developing the mathematics of the imaging process. The new imaging software will be tested in the lab until an industrial-standard system is complete – then we can begin field tests.’ 

The work will be carried out in collaboration with Fundacion Tecnalia Research & Innovation, Spain, and Italian steel companies Ferriere Nord and Ergolines Lab. 

Dr Manuch Soleimani will lead the three-year project to develop a commercial induction tomography system based on this prototype. 

To read our report on Dr Soleimani’s work in landmine detection, see Materials World, October 2015. 

William Cook partners with AMRC

The UK’s largest steel castings group, William Cook, has partnered with the University of Sheffield Advanced Manufacturing Research Centre (AMRC), following last year’s acquisition of Castings Technology International, which led to the creation of AMRC Castings. 

William Cook, which manufactures extreme specification engineering steels chiefly for energy, transport and defence applications, recently won a £30m contract with General Dynamics, UK, to supply parts for the British Army’s future fleet of vehicles. 

The new partnership will allow William Cook to use the AMRC’s research facilities and training centre, with the potential for advanced apprentices and higher-level trainees to gain industrial experience and contribute new ideas. Newly-founded AMRC Castings specialises in titanium, reactive metals, alloys and superalloys, and is currently building a unique facility for developing large-scale titanium aerospace engine and structural components. 

Professor Keith Ridgway CBE, AMRC’s Executive Dean, said, ‘William Cook has invested substantially in research and technology that has allowed it to move into more challenging, higher value markets. By mobilising AMRC Castings’ expertise, we hope to help the group build on that achievement by further increasing its competitiveness and expanding into more technically advanced areas.’