Mould Fluxes Viscosity and Surface Tension Influence on the Wear Mechanisms of Al₂O₃-C Nozzle

Abstract:

A deep understanding of the mould flux effect on the wear mechanisms of Al₂O₃-C nozzles (AG) is relevant to avoid premature damage and to decrease the cost of black refractories in the industry. In this paper, a post mortem study on a nozzle was carried out to identify the causes of the wear mechanisms during the continuous casting of billets. Physical properties such as viscosity and surface tension of the mould fluxes were determined at operation temperature (1550oC), in order to correlate with microstructural results obtained by light and scanning electron microscopy (SEM). Also dihedral angle φ measurements were carried out at high magnification by SEM. Applying EDS analysis the infiltrated mould flux chemical composition was determined. The study was completed by EBSD. The EBSD technique contributed to increase the knowledge on wear mechanisms because of the possibility of identifying and localizing phases together with crystalline condition. The phases, the grain orientations and the properties of grain boundaries, have a large influence on the corrosion behaviour. Therefore, it is essential to have a characterization technique that can provide information such as: grain size, orientation, misorientation angle and the present phases. In this context, EBSD can provide relevant information on crystallographic and structural analysis of AG nozzle including the insert of ZrO₂-C.

• Periodical: Advances in Science and Technology (Volume 92)
• Pages: 226-231
• DOI: https://doi.org/10.4028/www.scientific.net/AST.92.226
• Online since: October 2014
• Authors: Elena Brandaleze*, Valeria Peirani, Martina Ávalos
• Keywords: EBSD, Mould Fluxes, Nozzle, Physical Properties, Wear

References

[1] N. Eustathopoulus, R. Parra and M. Sánchez, Role of capillarity in corrosion of refractories by melts, in: C. Díaz, C. Landolt, T. Utigard (Eds. ), Copper 2003 - The Hermann Schwarse Symposium on Copper Pyrometallurgy, Vol.: 5, Book 2, 2003, pp.457-471.

[2] E. Brandaleze, E. Benavidez, V. Peirani, L. Santini, C. Gorosurreta, Impact of free fluor fluxes on nozzle wear mechanisms, Advances Science and Technology, 70 (2010) 205-210.

DOI: 10.4028/www.scientific.net/ast.70.205

[3] W.E. Lee, S. Zhang, Melt corrosion of oxide and oxide-carbon refractories, International Materials Reviews, 44 (1999) 77-104.

DOI: 10.1179/095066099101528234

[4] K.C. Mills, L. Yuan, R.T. Jones, Estimation the physical properties of slags, The Journal of The Southern African Institute of Mining and Metallurgy 111 (2011) 649-657.

[5] J.K. Farrer, J.R. Michael, C.B. Carter, EBSD of ceramic materials, in: A. J. Schwartz, M. Kumar, B. L. Adams (Eds), Electron Backscatter Diffraction in Materials Science, Ch. 24, 2000, pp.299-318.

DOI: 10.1007/978-1-4757-3205-4_24

[6] E. Benavidez, M.V. Peirani, M. Ávalos, E. Brandaleze, Effects of viscosity and surface tension of free fluorine fluxes on the wear mechanisms of Al2O3-C nozzle, UNITECR 2013 Proceeding, (2013) 483-488.

DOI: 10.1002/9781118837009.ch89

[7] A.J. Dzermejko, Carbonaceous Refractories, in: C. A. Schacht (Eds. ), Refractories Handbook – Marcel Dekker, Inc., Ch. 8, 2004, pp.457-471.

DOI: 10.1201/9780203026328.ch8