A new method of assessing a key stage of steel production is set to boost the competitiveness of the UK and EU steel industries.
This is the aim of Dr Manuch Soleimani from Bath University’s department of electronic and electrical engineering who is leading the three-year Shell-Thick project to develop an induction tomography system for assessing the steel solidification process.
It aims to significantly improve the continuous casting process of steel by providing a real-time, non-destructive and reliable method of measuring the molten steel to detect any defects or fails as it solidifies and becomes a market product.
Induction tomography is an emerging non-invasive imaging technique already used in a number of applications, including medical diagnostics, geophysical exploration and civil engineering.
Soleimani, an associate professor at the university, told The Engineer: “Magnetic induction tomography attempts to image the passive electromagnetic properties of an object by measuring the mutual inductances between pairs of coils placed around its periphery.
“Measurements are acquired by passing an alternating current through excitation coils, producing a primary magnetic field.
“This magnetic field interacts with conductive and permeable objects in the medium to produce eddy currents, which, in turn, produce a secondary magnetic field, which is measured by sensing coils.
“As the secondary field depends on the materials present, the measured induced voltage is a non-linear function of the electrical and magnetic properties of the medium, that is, conductivity.”
The system will form a contactless bracelet around a billet of molten steel and take continuous measurements as the steel solidifies.
It will visualise the electrical conductivity of the different states of the solidifying steel and provide an image of its structural composition as it cools.
By enabling industry to continuously monitor and alter the cooling process, the technique should improve the quality, safety, productivity, costs and ultimately competitiveness of the UK and EU steel industries.
Soleimani said he and his team are pioneers in induction tomography and have already developed prototypes in the lab. A prototype would be tested at a factory later this year, he added.
During the project, Soleimani will work with the Fundacion Tecnalia Research & Innovation in Spain, as well as Italian steel industry companies Ferriere Nord and Ergolines Lab.
The project has been awarded a €1.4m (£1.1m) EU Horizon 2020 grant to help develop the technology.
Induction tomography would not solve the problems currently affecting the UK steel industry, but could help make it more competitive in the future, Soleimani said.
“Technology could enable us to be ahead in the production of high quality steel. Considering the cost of energy here and not having the subsidisation as China has, the only way to compete is having high quality products, and this is one step,” he added.
As an undergraduate, I recall being told that In the end its ‘grain-structure’/crystal size’ which determines ultimate strength in steel. The prof who told us that had made two contributions to WWII. The original ‘STEN’ gun was designed and manufactured to be a throw-away item. [they cost 75p -15/- in old money] On the original designs, The cocking post (to retard the mechanism for the next shot and eject the previous cartridge case) had a nasty habit of breaking off: not much fun if the opponants’ gun was still working. Our Prof designed a forging that did the business. Equally important were the ‘pins’ which were used to join the various sections of Bailey (temporary) bridges together. These used to ‘fret and shear and become v difficult to remove. Again, no fun when the opposition was trying to kill you standing for longer than necessary in the open! The replacement, also a forging, again did the business.
Sounds to me rather like a glorification of eddy current crack detection, and nothing particularly new at all.
It’s modern rolling mills and finishing facilities that the UK needs, not more gizmos to monitor the quality of casting. This is fine, but it is tinkering at the edges instead of dealing with fundamental issues of quality and production costs.