BGH Edelstahl Siegen GmbH (Siegen, Germany):

Hellermann R., Dr. Eng., Head of Casting Shop
Hippenstiel F., Dr. Eng., Dr. Econ., Head of Technological Direction
Hofmann N., Mag. Eng., Quality Control and Provision Technology

Knöllinger Flo-Tec GmbH (Hillscheid, Germany):
Schönbrenner W., Head of Sales Dept.
Seitz P., Bach. Eng., Engineering and Development Dept., e-mail: paul.seitz@knoellinger.de

Due to increasing demands for steel products, the steel manufacturers work on several measures to reduce the risk of reoxidation during steelmaking. One important point is answering the key question with respect to ingot casters: the oxygen pick-up at the slide gate and the gap between slide gate and trumpet of the runner channel of an ingot casting system. Recently, developments were made and practical tests with a gastight slide gate valve were carried out. The paper gives an overview of the development work to create a gas-tight version of a three-plate system and of the handling experience at a steel plant. Putting into practice the gas-tight ladle three-plate slide gates developed and manufactured by Knöllinger Flo-Tec company allows to improve consequently the production process of high-quality steels. Two aspects are very important in this connection: from one side, reproducible precision of metallurgical processes relating to operating jet screening increases, but from other side, the effect of secondary oxidation is substantially weakened. The new slide gate system provides lowering of quality expenses and rising of added value. The first prototype of this system has been manufactured in 2010 and had positive feedbacks since that time. At present time, all four metallurgical plants have been moved completely to the new sliding gate system. Gastight two-plate slide gate system for continuous casting is under testing to provide consequent development of this innovation.

1. Fauland, H.-P.; Hochörtler, J.; Perko, J.: Optimization of ingot casting — the road to highest quality, 1. Intern. Conf. on Ingot Casting, Rolling and Forging, Aachen, 3. – 7. Juni 2012.
2. Zhang, L.; Rietow, B.; Thomas, B.; Eakin, K.: Large inclusions in plaincarbon steel ingots cast by bottom teeming, ISIJ Intern. 46 (2006) Nr. 5, S. 670/79.
3. Tezanos, J.; Elvira, R.; Postigo, C.; Llanos, M.: Steel making process for increasing the fatique life continuous grain flow monoblock crankshafts, Proc. 16^th Intern. Forgemasters Meeting (IFM), Sheffield, Großbritanien, 15. – 19. Okt. 2006, S. 139/48.