Horizontal Belt Casting of Steel - Resource-conserving Production of New High-Performance Materials
Dipl.-Ing. Ulrich Grethe (Spokesperson)
Dipl.-Kfm. Burkhard Dahmen*
Prof. Dr.-Ing. Karl-Heinz Spitzer** Salzgitter Flachstahl GmbH, Salzgitter
*SMS Siemag AG, Hilchenbach and Düsseldorf
**Institute for Metallurgy, Clausthal University of Technology
Steel has great potential as both a traditional as well as an innovative material. One example of the many uses of the new special steels is the manufacture of highly fuel-efficient cars. Yet how are these new steels produced and how can they be produced sustainably and more efficiently than in the conventional processes?
Dr. Ulrich Grethe, Burkhard Dahmen and Prof. Dr. Karl-Heinz Spitzer have found the solution. They are responsible for the development of a new steel casting process that needs far less energy and raw materials than in the past. At the same time, the innovative method is especially cost-effective - and above all presents an opportunity to expand considerably the useful range of steel properties. Ulrich Grethe is CEO of Salzgitter Flachstahl GmbH, Burkhard Dahmen is CEO of SMS Siemag AG, Karl-Heinz Spitzer is the chair for Metallurgical Process Engineering at the Institute of Metallurgy at Clausthal University of Technology.
Steel is both a traditional material as well as ultra modern and, due to its outstanding and versatile properties, demand is very high in many fields of industry. The best example is in automotive engineering. To respond to the challenges such as a further lowering of fuel consumption in vehicles, industry has come to rely on innovative special steels such as high strength and ductility (HSD®) steel: it contains a higher percentage of manganese which makes the steel a ductileand extremely hard. The material makes it possible to manufacture even safety-critical components such as seats, door impact bars and bumpers much lighter. However, these types of steel cannot be produced by means of conventional casting technologies, such as continuous casting.
Yet in the innovative process, the nominees have jointly developed a production method capable of producing innovative special steels in industrial quantities. In horizontal belt casting, also known as Belt Casting Technology (BCT), the steel is not cast as it usually is in blocks up to 30 cm thick, the ingot slabs, which then have to undergo further processing at the expenditure of a lot of time and energy to obtain the required final shape. Instead, the process yields thin, cast strips 1 to 2 centimeters thick which already have the material thickness required for many applications. In this process, steel is cast onto a moving, reusable transport belt that is cooled from below by water.
The new process has a number of advantages: horizontal casting onto a moving belt minimizes stresses in the hot steel as it solidifies when it is most susceptible to cracking. Since the thin strips cool down relatively quickly, the steel also has better material properties overall. It is this that makes the industrial large-scale production possible of many new steel materials with extraordinary properties, like the HSD steels. The process also needs much less energy than the conventional continuous casting route. This also reduces carbon dioxide emissions that are harmful to the environment. The energy requirement can be reduced by over 60% during casting and hot rolling. At the same time, the investment in the building of BCT plant is approximately only one third of that for a conventional plant.
To demonstrate the production capability of horizontal belt casting in the steel industry, SMS Siemag AG has built a first industrial-scale pilot plant for Salzgitter Flachstahl AG in Peine near Hanover. The plant whose construction was funded by the Federal Ministry for the Environment, Nature Conservation and Nuclear Safety started operations in December 2012 and is capable of producing around 40,000 tons of steel per year. In the mean time, it has impressively proven the stability and reliability of the horizontal belt casting process in several dozen casting trials.
The pilot plant gives both companies the opportunity to further improve and sell the innovative and as yet unrivaled technology during normal production. Interest is great. In Germany, the innovative and sustainable process is expected to help save and create countless jobs for the future in the steel industry and in sectors with a high demand for steel, such as metal processing, the automotive industry or in manufacturing and engineering.
Research associate at the Institute of Metallurgy of TU Clausthal
PhD under Prof. Dr.-Ing. K. Schwerdtfeger at the Institute of Metallurgy of TU Clausthal
Doctoral thesis: "Mathematische Modellierung zum elektromagnetischen Rühren beim Stranggießen" (mathematical modeling of electromagnetic stirring in continuous casting)
1985 – 2002
Senior assistant professor at TU Clausthal
Habilitation at TU Clausthal in metallurgy
Post-doctoral thesis: "Mathematische Modelle zur Entwicklung und Optimierung metallurgischer Prozesse" (mathematical models for developing and optimizing metallurgical processes)
Full professor for Metallurgical Process Technology (C4) at TU Clausthal
Collaboration in professional associations and committees