Prediction of spatial distribution of the composition of inclusions on the entire cross section of a linepipe steel continuous casting slab

doi:10.1016/j.jmst.2020.05.035

Abstract

Abstract:

In the current study, the transformation in the composition of non-metallic inclusions from the molten steel to the solidified steel was studied and the composition distribution of inclusions on the cross section of a linepine continuous casting slab was predicted. During cooling and solidification of the continuous casting strand, Al₂O₃-CaO inclusions reacted with the bulk steel and transformed to CaS-Al₂O₃-MgO-(CaO) ones in the continuous casting slab. The composition of inclusions on the cross section of the slab varied with locations due to the varied cooling rate. A model was established to predict the distribution of the composition of inclusions on the cross section of the continuous casting slab, coupling solidification and heat transfer of the continuous casting slab, the kinetic mass transfer of the dissolved elements in the solid steel, and thermodynamic calculation of inclusion transformation at different temperatures. The composition transformation of inclusions mainly occurred at the temperature between the liquidus and solidus of the linepipe steel. Inclusions were mainly CaS-Al₂O₃-MgO-(CaO) in slab center and were MgO-Al₂O₃-CaO-CaS within the subsurface of the slab. In the slab, the transformation fraction of inclusions was less than 10 % at corners while it reached 70 % at 50 mm below the surface of the slab.

Key words: Inclusions, Linepipe steel, Continuous casting slab, Mass transfer, Thermodynamics, Kinetics

Qiang Ren, Yuexin Zhang, Ying Ren, Lifeng Zhang, Jujin Wang, Yadong Wang. Prediction of spatial distribution of the composition of inclusions on the entire cross section of a linepipe steel continuous casting slab[J]. J. Mater. Sci. Technol., 2021, 61: 147-158.

Figures/Tables 18

Fig. 1. Dimension of the cooling zones of the entire CC slab.

Table 1 Data of the secondary cooling zones used in the current simulation.

Spray zone	Length (m)	Water flow rate (L/(m² min))
1N	0.7	68.0
1IO	0.24	292.8
2IO	0.56	432.1
3IO	1.11	502.6
4IO	1.56	407.7
5IO	1.92	294.4
6I	3.84	180.2
6O	3.84	270.2
7I	3.84	102.8
7O	3.84	174.8
8I	6.70	122.5
8O	6.70	245.0
Total	19.77	3093.1

Fig. 2. Sampling locations along the thickness of the CC slab.

Fig. 3. Distribution of the composition, size and number of inclusions of (a) the molten steel in tundish, (b) Sample S1 of slab, (c) Sample S5 of slab.

Fig. 4. Elemental mapping of inclusions in (a) the molten steel of tundish and (b) the CC slab.

Table 2 Chemical compositions of the linepipe steel in the current study.

Sample	C (%)	Si (%)	Mn (%)	Alt (%)	T.S (ppm)	T.Ca (ppm)	T.Mg (ppm)	T.O (ppm)
Tundish	0.069	0.204	1.65	0.042	12	10	3	13
Slab	0.070	0.200	1.65	0.037	12	8	3	15

Fig. 5. Statistic composition contours of inclusions along the thickness of the CC slab: (a) MgO, (b) Al2O3, (c) CaO, (d) CaS.

Fig. 6. Distribution of inclusions in slab: (a) Al2O3, MgO, CaO, and CaS contents in inclusions, (b) Number density of inclusions, (c) area fraction of inclusions, (d) number density of large inclusions (> 10 μm).

Fig. 7. Calculated transformation in the composition of inclusions in the linepipe steel during solidification and cooling process. (a) Phases, (b) Average composition, (c) Comparison between the calculation and the measurement.

Fig. 8. Schematic of the scheme of the coupled model to predict the transformation in the composition of inclusions in the steel slab during the CC process.

Fig. 9. Thermal history of steel slab samples S1-S10 during the CC process.

Fig. 10. Schematic of the kinetic model of for the composition transformation of inclusions during solidification and cooling processes of the steel.

Table 3 Diffusivities of Al, Mg, Ca, S, and O in liquid, δ, and γ steel (m2/s) [[78], [79], [80]].

Element	Liquid steel	Δ steel	Γ steel
Al	3.5 × 10^-09	5.9×exp(-241186/(RT))/10000	5.15×exp(-245800/(RT))/10000
Mg	3.5 × 10^-09	0.76×exp(-224430/(RT))/10000	0.055×exp(-249366(RT))/10000
Ca	3.5 × 10^-09	0.76×exp(-224430/(RT))/10000	0.055×exp(-249366/(RT))/10000
S	4.1 × 10^-09	4.56×exp(-214639/(RT))/10000	2.4×exp(-223426/(RT))/10000
O	2.7 × 10^-09	0.0371×exp(-96349/(RT))/10000	5.75×exp(-168454/(RT))/10000

Fig. 11. Calculated evolution in the composition of inclusions in steel samples S1-S10 during solidification and cooling processes: (a) without consideration of element diffusion, (b) with consideration of element diffusion.

Fig. 12. Comparison of measured and calculated composition (a) and transformation fraction (b) of inclusions in the CC slab.

Fig. 13. Simulated temperature profiles on the cross section of slab of (a) 0.8 m, (b) 4.639 m, (c) 10.385 m, and (d) 20.929 m from the meniscus during the CC process.

Fig. 14. Simulated composition transformation fraction profiles of inclusions on the cross section of slab of (a) 0.8 m, (b) 4.639 m, (c) 10.385 m, and (d) 20.929 m from the meniscus during the CC process.

Fig. 15. Simulated composition profiles of inclusions on the cross section of slab of (a) 0.8 m, (b) 4.639 m, (c) 10.385 m, and (d) 20.929 m from the meniscus during the CC process.

References 80

[1]	L. Zhang, Non-Metallic Inclusions in Steels, Metallurgical Industry Press, Beijing, 2019.
[2]	L. Zhang, Non-Metallic Inclusions in Steels: Industrial Practice, Metallurgica lIndustry Press, Beijing, 2020 (in Chinese).
[3]	C.A. Williams, P. Unifantowicz, N. Baluc, G.D.W. Smith, E.A. Marquis, Acta Mater. 61 (2013) 2219-2235.
[4]	D. Zhang, H. Terasaki, Y. Komizo, Acta Mater. 58 (2010) 1369-1378.
[5]	J.H. Shim, Y.J. Oh, Y.W. Suh, Acta Mater. 4 (2001) 2115-2122.
[6]	C. Revilla, B. López, J.M. Rodriguez, Mater. Des. 62 (2014) 296-304. DOI URL
[7]	K. Hashimoto, T. Fujimatsu, N. Tsunekage, K. Hiraoka, K. Kida, E.C. Santos, Mater. Des. 32 (2011) 1605-1611.
[8]	L.M. Wang, Q. Lin, L.J. Yue, L. Liu, F. Guo, F.M. Wang, J. Alloys Compd. 451 (2008) 534-537.
[9]	W. Shi, S. Yang, J. Li, Sci. Rep. 8 (2018) 4830. URL PMID
[10]	F. Pan, J. Zhang, H.L. Chen, Y.H. Su, Y.H. Su, W.S. Hwang, Sci. Rep. 6 (2016) 35843. URL PMID
[11]	C.H.G. Howorth, J. Iron Steel Inst. 2 (1905) 301-319.
[12]	K. Mizuno, H. Todoroki, M. Noda, T. Tohge, Iron Steelmaker 28 (2001) 93-101.
[13]	J.H. Park, Y.B. Kang, Metall. Mater. Trans. B 5 (2006) 791-797.
[14]	Y. Ren, L. Zhang, Ironmak. Steelmak. 45 (2017) 585-591.
[15]	N. Verma, P.C. Pistorius, R.J. Fruehan, M. Potter, M. Lind, S. Story, Metall. Mater. Trans. B 42 (2011) 720-729.
[16]	N. Verma, P.C. Pistorius, R.J. Fruehan, M. Potter, M. Lind, S. Story, Metall. Mater. Trans. B 42 (2011) 711-719.
[17]	Y. Ren, L. Zhang, S. Li, ISIJ Int. 54 (2014) 2772-2779.
[18]	Y. Higuchi, M. Numata, S. Fukagawa, K. Shinme, Tetsu-to-Hagane 82 (1996) 671-676.
[19]	M. Numata, Y. Higuchi, S. Fukagawa, Tetsu-to-Hagane 84 (1998) 159-164.
[20]	Y. Ren, Y. Zhang, L. Zhang, Ironmak. Steelmak. 44 (2016) 497-504.
[21]	Y. Ren, L. Zhang, W. Fang, S. Shao, J. Yang, W. Mao, Metall. Mater. Trans. B 47 (2016) 1024-1034.
[22]	J.H. Park, D. Kim, Metall. Mater. Trans. B 36 (2005) 495-502.
[23]	J.H. Park, S.B. Lee, H.R. Gaye, Metall. Mater. Trans. B 39 (2008) 853-861.
[24]	P. Yan, S. Huang, J.V. dyck, M. Guo, B. Blanpain, ISIJ Int. 54 (2014) 72-81.
[25]	P. Yan, S. Huang, L. Pandelaer, J.V. Dyck, M. Guo, B. Blanpain, Metall. Mater. Trans. B 44 (2013) 1105-1119.
[26]	Y. Ehara, S. Yokoyama, M. Kawakami, Tetsu-to-Hagane 93 (2007) 475-482.
[27]	Y. Ren, L. Zhang, ISIJ Int. 57 (2017) 68-75.
[28]	H. Ling, C. Guo, A.N. Conejo, F. Li, L. Zhang, Metall. Res. Technol. 114 (2017) 111. DOI URL
[29]	H. Ling, F. Li, L. Zhang, A.N. Conejo, Metall. Mater. Trans. B 47 (2016) 1950-1961.
[30]	L. Zhang, S. Taniguchi, Int. Mater. Rev. 45 (2000) 59-82.
[31]	K. Sakata, ISIJ Int. 46 (2006) 1795-1799.
[32]	K. Sasai, Y. Mizukami, ISIJ Int. 40 (2000) 40-47.
[33]	H. Goto, K. Miyazawa, ISIJ Int. 38 (1998) 256-259.
[34]	Y. Ren, L. Zhang, H. Ling, Y. Wang, D. Pan, Q. Ren, X. Wang, Metall. Mater. Trans. B 48 (2017) 1433-1438.
[35]	Y. Liu, L. Zhang, Y. Zhang, H. Duan, Y. Ren, W. Yang, Metall. Mater. Trans. B 49 (2018) 610-626.
[36]	L. Zhang, Y. Liu, Y. Zhang, W. Yang, W. Chen, Metall. Mater. Trans. B 49 (2018) 1841-1859.
[37]	N. Verma, P.C. Pistorius, R.J. Fruehan, M. Potter, M. Lind, S.R. Story, Metall. Mater. Trans. B 42 (2011) 720-729.
[38]	C. Wang, N.T. Nuhfer, S. Ridhar, Metall. Mater. Trans. B 41 (2009) 1006-1021.
[39]	C. Wang, N.T. Nuhfer, S. Sridhar, Metall. Mater. Trans. B 41 (2010) 1084-1094.
[40]	S. Li, L. Zhang, Y. Ren, W. Fang, W. Yang, S. Shao, J. Yang, W. Mao, ISIJ Int. 56 (2016) 584-593.
[41]	W. Yang, C. Guo, L. Zhang, C. Li, H. Ling, Metall. Mater. Trans. B 48 (2017) 2267-2273.
[42]	X. Zhang, W. Yang, H. Xu, Metals 9 (2019) 392.
[43]	Y. Wang, W. Yang, L. Zhang, Steel Res. Int. 90 (2019), 1900027. DOI URL
[44]	Y. Ren, Y. Wang, S. Li, L. Zhang, X. Zuo, S. Lekakh, K. Peaslee, Metall. Mater. Trans. B 45 (2014) 1291-1303. DOI URL
[45]	Y. Chu, W. Li, Y. Ren, L. Zhang, Metall. Mater. Trans. B 50 (2019) 2047-2062.
[46]	Q. Wang, X. Zou, H. Matsuura, C. Wang, Metall. Mater. Trans. B 49 (2018) 18-22.
[47]	M. Li, H. Matsuura, F. Tsukihashi, Metall. Mater. Trans. B 48 (2017) 1-9.
[48]	X. Zhang, S. Yang, C. Liu, J. Li, W. Hao, JOM 70 (2018) 958-962.
[49]	S.J. Kim, H. Tago, K.H. Kim, S. Kitamura, H. Shibata, Metall. Mater. Trans. B 49 (2018) 977-987.
[50]	H. Shibata, K. Kimura, T. Tanaka, S. Kitamura, ISIJ Int. 51 (2011) 1944-1950.
[51]	H. Shibata, T. Tanaka, K. Kimura, S.Y. Kitamura, Ironmak. Steelmak. 37 (2010) 522-528.
[52]	J. Wang, W. Li, Y. Ren, L. Zhang, Steel Res. Int. 90 (2019), 1800600.
[53]	I. Takahashi, T. Sakae, T. Yoshida, Tetsu-to-Hagane 53 (1967) 350-352.
[54]	K. Takano, R. Nakao, S. Fukumoto, T. Tsuchiyama, S. Takaki, Trans. Iron Steel Inst. Jpn. 89 (2003) 616-622.
[55]	Y. Ren, L. Zhang, P.C. Pistorius, Metall. Mater. Trans. B 48 (2017) 2281-2292.
[56]	D. Zhao, H. Li, C. Bao, J. Yang, ISIJ Int. 55 (2015) 2115-2124.
[57]	H. Ling, L. Zhang, JOM 65 (2013) 1155-1163.
[58]	Z. Liu, K. Gu, K. Cai, ISIJ Int. 42 (2002) 950-957.
[59]	T. Matsumiya, H. Kajioka, S. Mizoguchi, Y. Ueshima, H. Esaka, Trans. Iron Steel Inst. Jpn. 24 (2006) 873-882.
[60]	L. Zhang, Y. Wang, JOM 64 (2012) 1063-1074.
[61]	Y. Ren, L. Zhang, W. Chen, JOM 70 (2018) 2968-2979.
[62]	Q. Wang, L. Zhang, JOM 68 (2016) 2170-2179.
[63]	J.H. Shin, Y. Chung, J.H. Park, Metall. Mater. Trans. B 48 (2017) 1-14.
[64]	Y. Ren, Y. Zhang, L. Zhang, Ironmak. Steelmak. 44 (2017) 497-504.
[65]	M.V. Ende, I. Jung, Metall. Mater. Trans. B 48 (2017) 28-36.
[66]	L. Zhang, Y. Ren, H. Duan, W. Yang, L. Sun, Metall. Mater. Trans. B 46 (2015) 1809-1825. DOI URL
[67]	Y.B. Kang, M.S. Kim, S.W. Lee, J.W. Cho, M.S. Park, H.G. Lee, Metall. Mater. Trans. B 44 (2013) 309-316. DOI URL
[68]	A. Harada, N. Maruoka, H. Shibata, S. Kitamura, ISIJ Int. 53 (2013) 2118-2125.
[69]	A. Harada, N. Maruoka, H. Shibata, S. Kitamura, ISIJ Int. 53 (2013) 2110-2117.
[70]	M.A.V. Ende, Y.M. Kim, M.K. Cho, Metall. Mater. Trans. B 42 (2011) 477-489.
[71]	A.N. Conejo, F.R. Lara, M. Macias-Hernandez, R.D. Morales, Steel Res. Int. 78 (2007) 141-150.
[72]	J. Peter, K.D. Peaslee, D.G.C. Robertson, B.G. Thomas, Experimental Study of Kinetic Processes During the Steel Treatment at Two Lmf’s, AISTech, Urbana, 2005, pp. 959-967.
[73]	Z. Liu, B. Li, M. Wu, G. Xu, X. Ruan, A. Ludwig, Metall. Mater. Trans. A 50 (2019) 1370-1379. DOI URL
[74]	Q. Wang, L. Zhang, S. Seetharaman, S. Yang, W. Yang, Y. Wang, Metall. Mater. Trans. B 47 (2016) 1594-1612. DOI URL
[75]	Available from: www.FactSage.com.
[76]	L. Zhang, X. Yang, S. Li, M. Li, W. Ma, JOM 66 (2014) 1711-1720. DOI URL
[77]	J. Zhang, D. Chen, S. Wang, M. Long, Steel Res. Int. 82 (2011) 213-221. DOI URL
[78]	Y. Ueshima, S. Mizoguchi, T. Matsumiya, H. Kajioka, Metall. Mater. Trans. B 17 (1986) 845-859.
[79]	Y.M. Won, B.G. Thomas, Metall. Mater. Trans. A 32 (2001) 1755-1767.
[80]	W. Yamada, T. Matsumiya, A. Ito, Development of Simulation Model for Composition Change of Nonmetallic Inclusions During Solidification of Steels,6th International Iron and Steel Congress (1990) 618-625.