Dörrenberg Edelstahl GmbH (Engelkirchen, Germany):

Kühnemund M., Mag. Eng.

Induga GmbH & Co. KG (Simmerath, Germany):

Hauck A., Dr. Eng.

Otto Junker GmbH (Simmerath, Germany):

Schmitz W., Dr. Eng., e-mail: sz@otto-junker.de

Secondary metallurgical treatment of molten steel in the ladle has been state of the art for a long time. In order to compensate temperature losses during such treatment steps or to be able to obtain the required pouring temperature precisely, many ladle treatment stations are provided with a heating capability which in most cases is three-phase electric arc heating. The present paper describes the successful use of plasma heating as an alternative heating method offering essential advantages especially for small treatment units. Another outstanding technical benefit is that it eliminates the time-related carburization effect that is an inevitable characteristic of conventional ladle heating systems. It is shown that with the new plasma ladle furnace, the process steps can be shortened and the product quality can be improved at Dörrenberg Edelstahl, success was also achieved in rising the efficiency of technological process. Mechanical and electrical equipment of the works is described, technological routes for proposed and conventional scheme are compared. It is evident that plasma technology has substantial advantages comparing with threephase electric arc furnaces, especially for the ladles with relatively small volume. Therefore, it should be very interesting for small-size shops manufacturing special steels, as well as for more and more frequently erected micro-mills with melting in induction furnaces.

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