Abstract
The various factors influencing the selection of mould powder compositions are discussed in this chapter. Mould powders contain two types of component (i) the minerals which form the slag film and (ii) Carbon which controls the melting rate. Both are vital to the successful performance of the mould powder. The composition of the mould powder is determined by the mould dimensions, the casting conditions and the steel grade being cast. Empirical rules have been developed to provide the required values of the powder consumption (Q reqs ), the viscosity (ηreq) and the break temperature (T reqbr ) for satisfactory casting (i.e. free from longitudinal cracking and sticker break-outs). More than 85% of mould powders conform to these empirical rules. However, other factors can also influence the powder selection process. These include
-
(i)
Increasing the slag viscosity or the interfacial tension to reduce slag entrapment.
-
(ii)
Increasing the interfacial tension to minimise scaling of the steel surface.
-
(iii)
Minimising carbon pick-up (especially for LC and ULC steels).
-
(iv)
Providing both support in the mould and optimal heat transfer when casting round billets.
-
(v)
Providing reasonable heat transfer in mould configurations with corners acting as heat sinks.
-
(vi)
Handling the large amounts of Al2O3 formed when casting high-Al steels whilst maintaining good lubrication throughout the casting.
-
(vii)
Handling Ti-stabilised steels which form either TiN or Ti(CN) in the slag pool (which has low solubility in mould slag) or CaO·TiO2 (which has a high Tliq).
-
(viii)
Reducing the fluoride content of slag to minimise environmental and health concerns.
All of these problems are discussed in detail and possible solutions are outlined.
This is a preview of subscription content, log in via an institution.
Abbreviations
- D C :
-
Diameter of carbon particles (m)
- f :
-
Frequency (Hz or cpm)
- f* :
-
fraction of powder forming slag
- Q s :
-
Powder consumption (kgm−2)
- q :
-
Heat flux density (Wm−2)
- R* :
-
(Surface area/Volume)—mould (m−1)
- s :
-
stroke (m)
- T :
-
Temperature (°C)
- T br :
-
Break or Solidification temperature
- t :
-
Thickness of mould (m) or time (s)
- V c :
-
Casting speed (m min−1)
- w :
-
Width of mould (m)
- η :
-
Slag viscosity (dPas)
- ρ :
-
Density (kg m−3)
- EMBr:
-
Electromagnetic braking
- IR:
-
Infrared radiation
- LC:
-
Low-carbon steel
- MC:
-
Medium-carbon steel
- SEN:
-
Submerged entry nozzle
- ULC:
-
Ultra-low-carbon steel
- A:
-
Al2O3
- C:
-
CaO
- F:
-
FeO
- Fl:
-
CaF2
- M:
-
MgO
- S:
-
SiO2
- T:
-
TiO2
References
H Harada, E Anzai, E Takeuchi, Canad. Met. Quart., 39, (3), 307, (2000).
S Ogibayashi, T Mizoguchi,T Kajatani, Intl. Workshop on Thermophys. Data for the Development of Mathematical models of solidification. Gifu City, Japan (1995).
AB Fox, PhD Thesis, “Mould fluxes- their properties and performance” Imperial College, London, (2003).
KC Mills, S Sridhar, AS Normanton, ST Mallaband, Proc. Brimacombe Conf., Vancouver, (2000) p. 781.
S Sridhar, KC Mills, V Ludlow, ST Mallaband, Proc. 3rd Europ. Conf. Continuous Casting, Madrid, 1998 (UNESID, Madrid, 1998) p. 807.
F Neumann, J Neal, MA Pedroza, AH Castiliejos E, FA Acosta G, Proc. 79th. Steelmaking Conf., 1996 (ISS, Warrendale, PA) p. 249.
M Wolf, Proc. 2nd Europ. Conf. Continuous Casting, Dusseldorf, 1994, (VDEh, Dusseldorf, 1994) p. 78.
S Ogibayashi, Y Yamaguchi, T Mukai, T Takahashi, Y Mimura, K Koyama, Y Nagano, T Nakano, Nippon Steel Technical Report, 34, 1, (1987).
KC Mills, AB Fox, ISIJ Intl., 43, 1479, (2003).
K Tsutsumi, S Murakami, S Nishioka, Tetsu-to-Hagane, 84, 617, (1998).
PE Ramirez-Lopez, KC Mills, PD Lee, B Santillana, Met. Mater. Trans., B, 43B, 109, (2012).
SN Singh, KE Blazek, J Metals, 26 (10), 17, (1974).
Thermocalc see www.thermocalc.com.
MB Santillana, PhD Thesis, Thermo-mechanical properties and cracking during solidification of thin slab cast steel. Univ. Delft, NL (2013) Chapter 3.
J Miettinen, AA Howe, Ironmaking and Steelmaking, 27, 212, (2000).
KE Blazek, O Lanzi, P Gano, D Kellogg, Proc. AISTech., 2007, (AIST, Warrendale, PA, 2007) PR-351–141 – 2007.
M Wolf, W Kurz, Met. Mater. Trans., 12, 85, (1981).
M Wolf, Proc. METEC Congress’94;. 2nd Europ. Conf. Continuous Casting, Dusseldorf, 1994, (VDEh, Dusseldorf, 1994) vol. 1, pp 78.
T Mukongo, C Pistorius, A Garbers-Craig, Ironmaking and Steelmaking, 31, 135, (2004).
R Koldewijn, Unpublished Corus Internal Rept. (2007) cited in KC Mills, J Kromhout, A Hamoen, R Boom, Proc. Admet Conf., Dnipropetrovsk, 2007, (Natl. Metall. Acad. Ukr., Dnipropetrovsk, 2007) vol. 2, p. 174.
T Mallaband (Metallurgica, UK) Unpublished results cited by AB Fox, ref. [3].
PE Ramirez- Lopez, PN Jalali, J Bjorkvall, U Sjostrom, C Nilsson, ISIJ Intl., 54, 342, (2014) and Proc. 8th Europ. Conf. Continuous Casting, Graz, Austria, 2014 (ASMET, Vienna, 2014).
E van Vliet, DW van der Plas, SP Carless, A A Kamperman, AE Westendorp, Proc. 7th Europ. Conf. Cont. Casting, Dusseldorf, 2011, (VDEh, Dusseldorf, 2011) Session 4.
M Kawamoto, K Nakajima, T Kanazawa, K Nakai, ISIJ Intl., 34, 593, (1994).
C Lefebvre, JP Radot, JN Pontoire, Y Roux, Revue de Metallurgie, CIT, 94, 489, (1997).
B. Debiesme, J Radot, D Coulombet, C Lefebvre, Y Roux, C Demarval, US Patent No 5 876, 482 (1999) and US Patent No 6, 328, 781 (2001).
S Terada, S Kaneo, T Ishikawa, Y Yoshida, Proc. 74th Steelmaking Conf., Washington, DC, 1991, (ISS, Warrendale, PA, 1991) p. 635.
J Macho, G Hecko, B Golomowski, M Frazee, McMaster Iron & Steelmaking Symp. “Thinner slab casting”, 2005, (McMaster Univ., Hamilton, Ont., 2005) p. 131.
LC Hibbeler, BG Thomas, Proc. AISTech 2013, (AIST, Warrendale, PA, 2013) p. 1215.
S Feldbauer, AW Cramb, Proc. 79th Steelmaking Conf., 1996 (ISS, Warrendale, PA, 1996) p. 595.
K Tsutsumi, K Watanabe, M Suzuki, M Nakada, T Shiomi, Proc. 7th Intl. Conf. Molten slags, fluxes and salts, Cape Town, 2004, (SAIMM, Johannesburg, 2004) p. 803.
J Yoshida,T Ohmi, M Iguchi, ISIJ Intl., 45, 1160, (2005).
K Tsutsumi, K Watanabe, J Kubota, S Hatori, Y Miki, T Suzuki, T Omoto, Proc. 7th Europ. Cont. Casting Conf., Dusseldorf, 2011, (VDEH, Dusseldorf, 2011) Session p. 1.
K Watanabe, K Tsutsumi, M Suzuki, H Fujita, S Hatori, T Omoto, ISIJ Intl., 54, 865, (2014).
J Kromhout, PhD thesis, Mould powders for high speed continuous casting of steel. Univ. of Delft, NL (2011), p. 99.
M Kawamoto, Paper presented at International Workshop on “Thermo-physical data for the development of mathematical models of solidification” Gifu City, Japan, (1995).
M Hanao, Y Tsukaguchi, M Kawamoto, Proc. 4th Intl. Congress Science and Technol., Gifu, 2008, (ISIJ, Tokyo, 2008) p. 694.
R Nishimachi, Y Ogura, SEAISI Quarterly, 25, (4), 44, (1996).
H Tai, M Morashita, T Miyake, Proc. 3rd Europ. Conf. Continuous Casting, Madrid, 1998, (UNESID, Madrid, 1998) p. 447.
K Blazek, HB Yin, G Skoczylas, M McClymonds, M Frazee, Proc. EEEC-METEC Dusseldorf, 2011 (VDEh, Dusseldorf, 2011).
JW Cho, KE Blazek, MJ Frazee, HB Yin, JE Park, SW Moon, ISIJ Intl., 53, 62, (2013).
GH Wen, S Sridhar, P Tang, X Qi, YQ Liu, ISIJ Intl., 47, 1117, (2007).
Q Liu, GH Wen, JZ Li, XJ Fu, P Tang, W Li, Ironmaking and Steelmaking, 41, 292, (2014).
JK Park, JW Cho, KH Moon, SH Lee, KH Kim, HS Jeong, Proc. 7th Intl. Conf. Clean Steel, Balatonfured, Hungary, 2007, (Hung. Min. Metall. Soc., Budapest 2007), p. 264.
H Nakada, K Nagata, ISIJ Intl., 46, 441, (2006).
LY Chen, GH Wen, CL Yang, F Mei, CY Shi, P Tang, Ironmaking and Steelmaking, 42, 105, (2015).
N Takahira, N Hanao, Y Tsukaguchi, ISIJ Intl., 53, 818, (2013).
Q Wang, YJ Lu, SP He, KC Mills, Z Li, Ironmaking and Steelmaking, 38, 297, (2011).
MC Bezerra, CA Valadares, IP Rocha, JP Bulota, MC Carboni, IL Scripnic, CR Santos, K Mills, D Lever, Proc. 36th Steelmaking Seminar, Porto Allegre, RS- Brazil, 2005, (ABM, Sao Paulo, 2005). p. 190 available on line at www.carboox.com/pdf/fluxante_2007.pdf.
AB Fox, KC Mills, D Lever, C Bezerra, C Valadares, I Unamono, J Laraudogoitia, J Gisby, ISIJ Intl., 45, 1051, (2005).
AB Fox, K Mills, D Lever, M C Bezerra, CA Valadares, I Unamono, J Laraudogoitia, J Gisby, Proc. 36th Steelmaking Seminar, Vittoria ES- Brazil, 2005, (ABM, Sao Paulo, 2005) p. 222, available on line at www.carboox.com/pdf/paper2005sfs.pdf,
Z Li, K Mills, MC-Bezerra, Proc. 35th Seminar de Fusao Refino e Solidificao Metals, Salvador, Brazil, 2004 (ABM, Sao Paulo, 2004) p. 281.
Y Nakamura, T Ando, K Kurata, M Ikeda, Trans. ISIJ, 26, 1052, (1986).
DW Bruce, NS Hunter, Proc. 2nd Intl. Conf. Continuous Casting, Dusseldorf, 1994, (VDEh, Dusseldorf, 1994) p. 156.
Q.Wang, SP He, KC Mills, Proc. 4th Intl. Conf. Cont. Casting Steel in Developing Countries, Beijing, China (2008). (Chinese Soc. Metals, Beijing, 2008), p. 715.
MM Wolf, Ironmaker & Steelmaker, 2000, (Jan), 22, (2000).
MM Wolf, Ironmaker & Steelmaker, 2000, (Feb.), 65, (2000).
MM Wolf, Ironmaker & Steelmaker, 2000, (March), 69, (2000).
MM Wolf, Ironmaker & Steelmaker, 2000, (April), 58, (2000).
MM Wolf, Ironmaker & Steelmaker, 2000, (May), 78, (2000).
MM Wolf, Ironmaker & Steelmaker, 2000, (June), 22, (2000).
MM Wolf, Ironmaker & Steelmaker, 2000, (July), 63, (2000).
MM Wolf, Ironmaker & Steelmaker, 2000, (Aug), 75, (2000).
MM Wolf, Ironmaker & Steelmaker, 2000, (Sept), 90, (2000).
MM Wolf, Ironmaker & Steelmaker, 2000, (Oct), 114, (2000).
MM Wolf, Ironmaker & Steelmaker, 2000, (Nov), 67, (2000).
MM Wolf, Ironmaker & Steelmaker, 2000, (Dec), 45, (2000).
H Nakato, S Takeuchi, T Fujii, T Nozaki, N Washio, Proc. 74th Steelmaking Conf., 1991, (ISS, Warrendale, PA, 1991) p. 639.
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
Copyright information
© 2017 Springer International Publishing AG
About this chapter
Cite this chapter
Mills, K.C., Däcker, CÅ. (2017). Selection of Mould Fluxes and Special Mould Fluxes for Continuous Casting. In: The Casting Powders Book. Springer, Cham. https://doi.org/10.1007/978-3-319-53616-3_10
Download citation
DOI: https://doi.org/10.1007/978-3-319-53616-3_10
Published:
Publisher Name: Springer, Cham
Print ISBN: 978-3-319-53614-9
Online ISBN: 978-3-319-53616-3
eBook Packages: Chemistry and Materials ScienceChemistry and Material Science (R0)