SMS Mevac GmbH (Essen, Germany):

Tembergen D., Mag. Eng., Chief Metallurgist and Head of Metallurgical Dept., dieter.tembergen@sms-mevac.com
Eichert T., Mag. Eng., Senior Metallurgist and Commissioning Supervisor

During the past two decades remarkable changes have occurred in the field of steelmaking, especially in ladle metallurgy. These changes have led to today’s “state-of-the-art” steel refining technology. The result has enabled steelmakers to meet the demands being made by customers for higher quality with new process steps. In particular, vacuum treatment plays a crucial role in achieving the lowest levels of C and S as well as the removal of dissolved gases, such as H and N. One type of vacuum degassing process is based on liquid steel recirculation which is generally known as the RH process. This process has been industrially applied for more than 50 years. The second most common degassing process is known as “Tank Degassing” (VD process). The main differences of both processes will be analyzed and compared in this paper.In more than 80% of the cases the optimal degasser choice, whether it is RH or VD, is obvious. This choice is typically made on the basis of the type of melting furnace, the production program, the metallurgical operations and targets, and according to the metallurgical background and experience of the steelmaker. In about 20% of the cases, both concepts can be applied with regard to the above-mentioned criteria. In these cases, all the individual characteristics like material flow, productivity, the share of vacuum-treated steel in the total production, the available ladle freeboard, the layout situation or the location of the steelmaker’s plant must be discussed in correlation in order to arrive at an optimum solution. Strategic criteria such as the competitors‘ situation, steelmaker’s consultants or a future production strategy lead to a final decision in only less than 5% of projects. However, in all cases, SMS has the relevant know-how and experience to advise a steelmaker on which ladle metallurgy systems should be combined for their steelmaking plant and their production plans.

1. Arnold, H.; Kappel, H. J.; Tembergen, D.; Eichert, T.: Behandlung von Stahl in der Vakuummetallurgie, Techn. Seminar DGM, Fortbildung Vakuummetallurgie, Hanau, Germany, 2003.
2. Eichert, T. et al.: Traditional brands live on in the field of secondary metallurgy, MPT Intern. 25 (2002) No. 5, p. 52/58. 
3. Tembergen, D.; Dittrich, R.; Mayer-Kortwig, J.: Aspects of production of micro-alloyed high-strength and HIC resistant line pipe steels, Proc. METEC InSteelCon 2011, 28 June — 02 July 2011, Düsseldorf, Germany.
4. Odenthal, J.; Tembergen, D.: Verbesserte Stahl umlauf-Simulation beim RH Prozess, Verlag Stahleisen GmbH, Düsseldorf, Stahlinstitut VDEh, Düsseldorf, 2009.
5. Knopp, I.; Liebig, H.; Tembergen, D.: Betriebs erfahrungen mit der neuen RH-Anlage im Stahlwerk der ThyssenKrupp Steel AG, Techn. Symposium of SMS Mevac, 2004, Moscow, Russia.
6. Ahrenhold, F.; Liebig, H.; Schütz, K.-H.; Tember gen, D.: Installation of a second 265-t RH degasser at the Beeckerwerth steel plant at ThyssenKrupp Steel, ABM Conf., 12–19 May 2003, Belo Horizonte, Brazil.
7. van Poucke, N.; Eichert, T.: Use of the Mesid lance in the RH degasser at Sidmar steel plant, CISA Internat. Steel Congr., Sept. 2002, Beijing, P. R. China.
8. Lachmund, H. et al.: Metallurgical measures for the achievement of ultra-low carbon contents at Dillinger Hüttenwerke, Proc. 84^th ISS Steelmaking Conf., 25–28 March 2001, Baltimore, USA.
9. Jungreithmeier, A.; Pissenberger, E.; Posch, W.: High-quality steel production at voestalpine Stahl GmbH in Linz, Proc. 4th Europ. Oxygen Steelmaking Conf. (EOSC), 12–15 May 2003, Graz, Austria.