Investigation of Viscosity's Effects on Continuous Casting of Steel Mold Powders Containing B<sub>2</sub>O<sub>3</sub>, Li<sub>2</sub>O, TiO<sub>2</sub>, Fe<sub>2</sub>O<sub>3</sub>, ZnO and Na<sub>2</sub>O
- 1 Department of Materials Engineering, Najaf Abad Branch, Islamic Azad University, Isfahan, Iran
- 2 Department of Materials Engineering, Najaf Abad Branch, Islamic Azad University, Isfahan, Iran
- 3 Department of Materials Engineering, Najaf Abad Branch, Islamic Azad University, Isfahan, Iran
- 4 Department of Materials Engineering, Najaf Abad Branch, Islamic Azad University, Isfahan, Iran
Abstract
Mold powders are mainly formed of such oxides as SiO 2 , CaO, Al 2 O 3 , Na 2 O along with F and C. One of the main constitutional composes of mold powders is F, which is utilized in chemical composition of mold powders due to its features of controlling viscosity and producing desired lubrication between solidified steel shell and mold. However, the emission of F through such compositions as HF (g) causes health and environmental problems. The purpose of this research is to decrease, and subsequently substitute, F in chemical composition of a lubricating high speed powder, which is used in continuous casting of steel industry. A combination of Fe 2 O 3 and TiO 2 compositions to substitute F in chemical composition of a fluorine-free mold powder was used to meet the purposed of this research. In addition, nine powder samples (A-I) with laboratory scale were prepared. In order to evaluate the samples’ viscosity behavior, groove viscometer test and image analysis software was used and to evaluate the crystalline behavior of samples C and G, XRD and SEM analyses were conducted. The results of these analyses demonstrated that the fluorine-free sample, due to its viscosity resemblance in comparison with molten reference powder and through creation of such crystalline phases as Perovskite (CaTiO 3 ) and Fayalite (Fe 2 SiO 4 ), will result in viscosity control of the mold powder and therefore optimizing continuous casting conditions. Finally, it is possible to derive that this sample may be an appropriate substitution for the reference powder being utilized in steel continuous casting industry.
- E. T. Turkdogan, “Fundamentals of Steelmaking,” Cambridge University Press, Cambridge, 1996, pp. 138-179.
- M. Mueller, W. Willenborg, K. Hilpert and L. Singheiser, “Structural Dependence of Alkali Oxide Activity in Coal Ash Slags,” VII International Conference on Molten Slags, Fluxes and Salts, Cape Town, 25-25 January 2004.
- M. Nakamoto, J. Lee and T. Tanaka, “A Model for Estimation of Molten Silicate Slag,” ISIJ International, 2005, Vol. 45, No. 5, 2005, pp. 651-656. doi:10.2355/isijinternational.45.651
- S. Sridhar, “Estimation Models for Molten Slag and Alloy Viscosities,” JOM Journal of the Minerals, Metals and Materials Society, Vol. 54, No. 11, 2005, pp. 46-48.
- R. F. Brooks, A. T. Dinsdale and P. N. Quested, “The Measurement of Viscosity of Alloys—A Review of Methods, Data and Models,” Measurement Science and Technology, Vol. 16, No. 2, 2005, pp. 354-362. doi:10.1088/0957-0233/16/2/005
- Q. Shu and J. Zhang, “Viscosity Estimatin for Slags Containing Clacium Fluoride,” Journal of University of Science and Technology Beijing, Vol. 12, No. 3, 2005, p. 221.
- P. V. Riboud and M. Larrecq, “Fundamental Study of the Behavior of Casting Powders, ISIJ International, Vol. 36, 1996, pp. 522-525.
- C. Orrling, A. W. Cramb, A. Tilliander and Y. Kashiwaya, “Observations of the Melting and Solidification Behavior of Mold Slags,” Iron and Steelmaker, Vol. 27, No. 1, 2000, pp. 53-63.
- S. Feldbauer, I. Jimbo, A. Sharan, K. Shimizu, W. king, J. Stepanek, J. Harman and A. W. Cramb, “Physical Properties of Mold Slags That Are Relevant to Clean Steel Manufacture,” Proceedings of 78th Steelmaking Conference, Nashville, 2-5 April 1995, pp. 655-667.
- K. C. Mills, S. Sridhar, A. S. Normanton and S. T. Mallaband, “Mould Flux Behavior in Continuous Casting,” The Brimacombe Memorial Symposium, Vancouver, 1-4 October 2000, pp. 781-794.
- P. V. Riboud, Y. Roux, L. D. Lucas and H. Gaye, “Improvement of Continuous Casting Powders,” Fachber Huttenprax Metallweiterverarb, Vol. 19, No. 10, 1981, pp. 859-869.
- G. Urbain, F. Cambier, M. Deletter and M. R. Anseau, “Viscosity of Silicate Melts,” Transactions and Journal of British Ceramics Society, Vol. 80, No. 4, 1981, pp. 139-141.
- E. T. Turkdogan, “Physicochemical Properties of Molten Slags and Glasses,” Metals Society, London, 1983, p. 11.