Advanced Ceramic Filtering Materials: a Contribution to Clean Steel Technologies
Institute of Ceramic, Glass and Construction Materials, Technical University of Freiberg, 09599 Freiberg/Germany
Revision 05.04.2017, 08.05.2017
Volume 9, Issue 4, Pages 117 - 120
Non-metallic inclusions in cast metal parts remarkably influence their performance during application. It is well known that size, type and distribution of non-metallic inclusions in metals distinctly influence their fracture toughness, tensile strength, ductility and fatigue. For the last three decades ceramic foam filters have been applied successfully in steel foundries for metal products with superior properties. Excellent operating filter systems fulfil two basic functions which are a) removing impurities on millimetre, micron as well as submicron scale, and b) promoting a non-turbulent melt filling of the mould if they are applied correctly during operation especially in means of time dependent interactions according to the filter material contribution. At present, the formation mechanism as well as the kinetics of observed in situ layers on filters in contact with steel melt and their influence on the deposition of inclusions from the steel melt is a main focus of the Collaborative Research Center 920 of the German Research Foundation in Freiberg. In terms of this presentation the contribution of different in situ formed layers as a function of their chemistry, porosity, time of interaction with the steel melt and the kind of treatment of the steel will be demonstrated and discussed in case of functional surface filter coatings as well as coatings on crucibles. Theoretical models are proposed which confirm the experimental results in a special steel casting simulator as well as in real trials in a foundry.
ceramic filters, clean steel technology
 Zhang, L.; Thomas, B.G.: Inclusions in continuous casting of steel. Proc. of XXIV National Steelmaking Symposium. Morelia, Mich, Mexico, 26–28 Nov. 2003, 138–183  Wasai, K.; Mukai, K.; Miyanaga, A.: Observation of inclusion in aluminium deoxidized iron. ISIJ Int. 42 (2002)  459–466  Aneziris, C.G.; Ansorge, A.; Jaunich, H.: New approaches of carbon bonded foam filters for filtration of large castings. cfi/Ber. DKG 85 (2008)  E100–E103  Aneziris, C.G.; et al.: Reactive filters for steel melt filtration. Adv. Engin. Mater. 15 (2013) [1–2] 46–59  Dudczig, S.; et al.: Characterization of carbon bonded alumina with active or reactive coatings in a steel casting simulator. Ceram. Int. 40 (2014) 16727–16742  Roungos, V.; Aneziris, C.G.; Berek, H.: Novel Al2O3-C refractories with less residual carbon due to nanoscaled additives for continuous steel casting applications. Adv. Engin. Mater. 14 (2012)  255–264  Zienert, T.; et al.: Interface reactions between liquid iron and alumina-carbon refractory filter materials. Ceram. Int. 41 (2015)  Part A 2089–2098  Schmidt, A.; et al.: Functionalised carbonbonded filters with an open porous alumina coating: Impact of time on interactions and steel cleanliness. To be published in special issue in: Adv. Engin. Mater. 2017, 18. DOI: 10.1002/adem.201700170  Storti, E.; et al.: Comparison of carbon-bonded alumina filters with addition of nanomaterials in contact with a steel melt. To be published in Proc. UNITECR (2017)  Storti, E.; et al.: Short-time performance of MWCNTs-coated Al2O3-C filters in a steel melt. J. Europ. Ceram. Soc. 36 (2016) 857–866
Göller Verlag GmbH