ASO Siderurgica (Ospitaletto, Italy):

Mercurelli G.
Zani M.
Svanera M.

ALD Vacuum Technologies (Hanau, Germany):
Biebricher U., e-mail: ulrich.biebricher@ald-vt.de
Franz H.

Electroslag remelting (ESR) is a known alternative method for improving the quality of heavy forging ingots in competition with conventional ingot casting. In 2012, a state-of-the-art electroslag remelting furnace producing ingots in sizes from 1 000 to 2 000 mm ingot diameter and total weights of up to 145 t at ASO Siderurgica S.r.l. was brought into production in Italy. Heavy forgings have been produced using multiple electrodes coming from the secondary metallurgical treatment route EAF — LF/VD (electric arc furnace — ladle furnace/vacuum degassing). The ESR furnace is described and first results of investigations on the remelted ingots compared with conventionally cast ingots are given. The results obtained in producing of 1600 mm ingots via ESR technology and conventional technology (electric arc furnace — vacuum degassing — uphill casting) have been compared. The conducted investigations have confirmed the relationships that were already known from technical literature. It was shown that the additional technological stage doesn’t always lead to cost rise (with simultaneous quality improvement). It is recommended to use ESR process in the cases when the required result should be surely achieved with strict requirements to the quality of finished products. Even in the cases when ESR technology id more expensive, it seems to be more preferable in comparison with usual casting, in order to eliminate probability of rejection of finished forging in the end of technological cycle.

1. Verfahren und Vorrichtung zum Herstellen von Metallblöcken nach dem Elektroschlacke Umschmelzverfahren, Patent DE2001128168, 2002.
2. Jauch, R.; Choudhury, A.; Löwerkamp, H.; Regnitter, F.: stahl u. eisen 95 (1975) Nr. 5, S. 408/13.
3. Hoyle, G.: Electroslag processes — principles and practice, Applied Science Publishers Ltd., Essex, Großbritannien, 1983, ISBN 0-85334-164-8.
4. Schumann, R.; Ellebecht, C.: Metallurgical and process problems related to electroslag remelting of forging ingots larger than 40 inch diameter and 150 inch length in single electrode technique, 5^th Int. Symp. on Electroslag and other Special Melting Technologies, Pittsburgh, USA, 16–18. Okt. 1974.
5. May, Μ. J.: Einfluss der Vorgänge beim Gießen und Erstarren auf die Stahleigenschaften, Informationstagung Gießen und Erstarren von Stahl, Luxemburg, Luxemburg, 29. Nov. — 1. Dez. 1977.
6. Scholz, H.; Biebricher, U.; Choudhury, A.: Recent development of technology and equipment design of electroslag remeltig process, Medovar Memorial Sympos., Kiew, Ukraine, 15–17. Mai 2001.