Changyu Ren, Caide Huang, Lifeng Zhang, and Ying Ren, In situ observation of the dissolution kinetics of Al2O3 particles in CaO–Al2O3–SiO2 slags using laser confocal scanning microscopy, Int. J. Miner. Metall. Mater., 30(2023), No. 2, pp.345-353. https://dx.doi.org/10.1007/s12613-021-2347-6
Cite this article as:
Changyu Ren, Caide Huang, Lifeng Zhang, and Ying Ren, In situ observation of the dissolution kinetics of Al2O3 particles in CaO–Al2O3–SiO2 slags using laser confocal scanning microscopy, Int. J. Miner. Metall. Mater., 30(2023), No. 2, pp.345-353. https://dx.doi.org/10.1007/s12613-021-2347-6
Changyu Ren, Caide Huang, Lifeng Zhang, and Ying Ren, In situ observation of the dissolution kinetics of Al2O3 particles in CaO–Al2O3–SiO2 slags using laser confocal scanning microscopy, Int. J. Miner. Metall. Mater., 30(2023), No. 2, pp.345-353. https://dx.doi.org/10.1007/s12613-021-2347-6
Cite this article as:
Changyu Ren, Caide Huang, Lifeng Zhang, and Ying Ren, In situ observation of the dissolution kinetics of Al2O3 particles in CaO–Al2O3–SiO2 slags using laser confocal scanning microscopy, Int. J. Miner. Metall. Mater., 30(2023), No. 2, pp.345-353. https://dx.doi.org/10.1007/s12613-021-2347-6
The dissolution kinetics of Al2O3 in CaO–Al2O3–SiO2 slags was studied using a high-temperature confocal scanning laser microscope at 1773 to 1873 K. The results show that the controlling step during the Al2O3 dissolution was the diffusion in molten slag. It was found that the dissolution curves of Al2O3 particles were hardly agreed with the traditional boundary layer diffusion model with the increase of the CaO/Al2O3 ratio of slag. A modified diffusion equation considering slag viscosity was developed to study the dissolution mechanism of Al2O3 in slag. Diffusion coefficients of Al2O3 in slag were calculated as 2.8 × 10−10 to 4.1 × 10−10 m2/s at the temperature of 1773–1873 K. The dissolution rate of Al2O3 increased with higher temperature, CaO/Al2O3, and particle size. A new model was shown to be vAl2O3=0.16×r1.580×x3.52×(T−Tmp)1.11 to predict the dissolution rate and the total dissolution time of Al2O3 inclusions with various sizes, where vAl2O3 is the dissolution rate of Al2O3 in volume, μm3/s; x is the value of CaO/Al2O3 mass ratio; R0 is the initial radius of Al2O3, μm; T is the temperature, K; Tmp is the melting point of slag, K.
The removal of inclusions is always a key issue for the clean steel production [1–5]. Typically, the steel cleanness was mainly dependent on the size distribution, morphology, and composition of inclusions [6–8]. The size distribution of inclusions was particularly important for the steel quality. Large inclusions were harmful for the steel performance [9–11]. During the refining process, the removal of inclusions involved floating, passing through the steel/slag interface, and the absorption of inclusion particles by the slag [11–13]. It was necessary to improve the dissolution kinetics of inclusions to remove inclusions from the molten steel as soon as possible.
Dissolution kinetics of inclusions are mainly investigated by four methods, including dip test [14–18], confocal scanning laser microscope (CSLM) [17–27], single hot thermocouple technique (SHTT) [28], and phase field model (PFM) [29–32]. In the dip test, an oxide cylinder [15–16], crucible [18], and large particles [14,17] were dipped in slag for a period of time. The dissolution rate is obtained by comparing the beginning and end states of the oxide material. Compared with other research methods, the relative movement between inclusions and slag can be simulated by stirring Mo rod in the molten slag. Park et al. [18] studied the dissolution of Al2O3 crucible in the slag with FetO. Li et al. [16] investigated the thickness of the product layer around the Al2O3 rod and found that the rate controlling step is the diffusion in the product layer. Due to advantages of accurate temperature control and in-situ observation, the CSLM has been widely used in steel investigations involving crystallization [33–35], precipitation [36], agglomeration [36–38], and inclusion transformation [39–40], etc. Recently, the dissolution kinetics of inclusion particles in slags were investigated using CSLM [17–27], which can observe the dissolution process of various inclusions in real time. In addition, Kim et al. [28] studied the dissolution of inclusions by SHTT for the first time. Compared with CSLM technique, some additional samples can be added to the molten slag during the dissolution process after reaching the experimental temperature. To verify the dissolution of inclusions in the above experiments, the PFM method is applied. Liu et al. [31] first used the oxide PFM developed by Heulens et al. [32] to study the dissolution of Al2O3 inclusions. Then the oxide PFM was improved by Mu and Xuan [29–30] to study the dissolution of various inclusions. The PFM simulation results are in good agreement with the results obtained by CSLM experiments.
In the previous CSLM studies, researchers mainly focused on the dissolution of inclusion particles with the same size. However, various inclusion sizes of inclusions lead to a large difference in the dissolution time, which is seriously related to the removal efficiency of inclusions. Fox et al. [41] reported that the total dissolution time of ZrO2 particles with a radius of 100 and 275 μm are 270 and 1400 s, respectively. There is a non-linear correlation between the total dissolution time and the inclusion size. To better predict the dissolution time of inclusions with various sizes, it is necessary to quantify the effect of particle size. Moreover, reported slags in previous studies are mainly CaO–Al2O3–SiO2 with high SiO2 content. In Al-killed steels, a large number of Al2O3 inclusions are generated after the Al deoxidation [9,42–43]. Considering deoxidation and desulfurization during the secondary refining, the CaO–Al2O3–SiO2 slags with a high CaO/Al2O3 mass ratio of 1.2–2.0 and a low SiO2 content of 5wt%–15wt% is widely used. However, the high melting point and low viscosity of the CaO–Al2O3-rich refining slags increase the difficulty of capturing the dissolution process of Al2O3 inclusions. There is little CSLM study for the dissolution of Al2O3 inclusions in CaO–Al2O3-rich refining slags. Therefore, it is of great importance to understand the Al2O3 dissolution in the widely used slag with the low SiO2 content using CSLM.
For the determination of the dissolution mechanism of inclusions in the molten slag, the shrinking core model (SCM) [44] and the diffusion equation [45–47] are widely applied. In SCM, there are two controlling steps including the chemical reaction and the boundary layer diffusion. For the diffusion equation, a complicated mathematical model named Lattice-Boltzmann model (LBM) was proposed [48]. However, the application of LBM is limited due to the large calculation.
In the current study, the dissolution process of Al2O3 in CaO–Al2O3–SiO2 slags with the CaO/Al2O3 mass ratio of 1.0–1.8 and the C/S of 6.0 was in-situ observed at 1773, 1823, and 1873 K using CSLM. Slag properties are summarized, and the effect of CaO/Al2O3 ratio on the dissolution mechanism of Al2O3 was discussed. To better understand the influence of the particle size, sixteen experiments with an inclusion radius of 71–546 μm were conducted. Then a model of the dissolution rate of Al2O3 particles in CaO–Al2O3–SiO2 slags was developed considering the effect of CaO/Al2O3 ratio, particle size, and temperature.
2.
Experimental
Dissolution experiments for Al2O3 in CaO–Al2O3–SiO2 slags were carried out by a CSLM (VL2000DX-SVF18SP, Lasertec, Japan). The working principle of CSLM has been reported widely [19–20]. In the current study, high purity copper particles (99.9wt%, 1356.5 K) were melted in CSLM to calibrate the temperature, showing a (25 ± 5) K temperature difference between the sample surface and the R-type thermocouple.
Slags were prepared by mixing SiO2 (>99.5%, Sinopharm), Al2O3 (>99.5%, Sinopharm), and CaO (＞98.0%, Sinopharm) powders, and melting at 1903 K under the inert atmosphere for 1 h. The composition of slags in these dissolution experiments was determined by X-ray fluorescence (XRF) spectroscopy. After XRF analysis, slags were ground and compacted in Pt crucibles (5 mm inner diameter × 4 mm height) using a hydraulic press. The particle size of slag was larger than 37 μm measured by scanning electron microscope. To ensure the homogenization of slags, prepared slags were premelting in a Pt crucible in CSLM before dissolution experiments. The composition of the slag does not change after premelting in CSLM. Compositions and physicochemical properties of each slag, including temperature (T), the solubility of Al2O3 in slag, viscosity of slag (η), density of slag (ρ), and solubility factor (k0), are listed in Table 1. The slag viscosity and the solubility of Al2O3 in slag were calculated by FactSage 7.0 [49]. The density of slag was obtained by the Mills model [50].
Table
1.
Compositions and physicochemical properties of slags
Studies for Al2O3 dissolution were carried out as shown in Fig. 1(a). An Al2O3 particle (99.9%) was placed at the center of the slag surface in a Pt crucible and then the sample was heated rapidly up to the experimental temperature under the argon atmosphere. To eliminate the effect of Al2O3 dissolution on the slag composition, the Al2O3 particle constituted less than 0.5% of the weight of the slag. The sample was heated to 50 K below the experimental temperature at a heating rate of 1000 K/min. Then the temperature was elevated to the experimental temperature at a lower heating rate of 200 K/min to obtain a more accurate reaction start time and to avoid the temperature overshoot. The time reaching experimental temperature was defined as time zero.
Fig.
1.
Schematic of the in-situ observation of the Al2O3 dissolution: (a) experimental set up; (b–e) CSLM images at 80 s, 107 s, 180 s, and 242 s. Temp. is temperature.
Fig. 1(b)–(e) illustrates a group of images of the Al2O3 in the slag with a C/A of 1.2 and a C/S of 6.0 (Slag 2) at 1773 K. The images were processed using Image J to obtain the area of inclusions, and then an equivalent circular diameter of the Al2O3 particle was obtained by the inclusion particle area analysed by Image J, assuming that the Al2O3 particle remained spherical during the dissolution process. Each experiment was conducted twice to reduce errors introduced by particle shape, particle location in the slag during dissolution, etc. The particle radii were basically equal in repeated experiments, with a difference of no more than 10 microns. The results of CSLM experiments were summarized in Table 2. Experiments Nos. 3–22 studied the effect of temperature and Al2O3 particle size on the dissolution of Al2O3, and experiments Nos. 1–2, 8–9, and 23–28 were used to discuss the effect of slag composition on the dissolution of Al2O3.
Table
2.
Statistics of the results of CSLM experiments
Slag
No.
T / K
r0 / μm
t0 / s
Slag
No.
T / K
r0 / μm
t0 / s
1
1
1773
208
1852
2
15
1773
375
782
2
203
1981
16
416
926
2
3
1773
71
82
17
473
1121
4
82
110
18
546
1575
5
104
169
19
1823
249
231
6
126
189
20
240
234
7
154
259
21
1873
237
92
8
195
351
22
236
113
9
207
458
3
23
1773
207
362
10
243
451
24
197
305
11
257
626
4
25
1773
205
249
12
295
763
26
203
252
13
301
556
5
27
1773
203
147
14
312
592
28
208
137
Note: r0 is the initial radius of the Al2O3 particle, t0 is the total dissolution time of the particle in slag.
3.
Dissolution mechanism of Al2O3 in various slags
The dissolution mechanism of inclusions in the slag is usually described using the SCM [44] and the diffusion equations [45–47]. In the SCM, there are two controlling steps. For the chemical reaction control, there is a linear relationship between the total dissolution time and the radius of the particle, as given in Eq. (1). Another possible controlling step is the boundary layer diffusion shown in Eq. (2).
t0=ρpr0bkΔC
(1)
t0=ρpr202bΔCD
(2)
where t0 is the total dissolution time, s; ρp is the density of the Al2O3 particle, kg/m3; r0 is the initial radius of the Al2O3 particle, μm; b is the stoichiometric number which equals 1; k is a constant for the first order reaction, m/s; ΔC is the driving force which equals to the concentration difference of Al2O3 in bulk slag and slag at saturation, kg/m3; D is the diffusion coefficient of Al2O3 in slags, m2/s.
In the current study, particle volume instead of radius was applied to characterize the evolution of the dissolving particles. Converted equations are given as Eqs. (3) and (4), respectively.
VV0=(1−tt0)3
(3)
VV0=(1−tt0)1.5
(4)
where V is the volume of the particle at t, μm3; V0 is the volume of the initial particle, μm3; t is the dissolution time, s.
Compared to the boundary layer diffusion controlling step in the SCM, the diffusion in the molten slag takes place in a larger range. In this case, two approximations were proposed as invariant interface approximation and invariant field approximation, which are illustrated as Eqs. (5) and (6), respectively [45]. Dissolution curves predicted by the Eq. (6) is consist with which predicted by the boundary layer diffusion control model in SCM. Therefore, only Eq. (5) was applied to study the dissolution of Al2O3. The solubility factor k0 is defined as Eqs. (7) and (8) [45].
drdt=−k0DR−k0√Dπt
(5)
drdt=−k0DR
(6)
k0=cs−cbcp−cs
(7)
c=ρ⋅m
(8)
where r is the radius of Al2O3 particle, μm; cs, cb, and cp are the Al2O3 concentrations of the saturated slag, that of the bulk slag, and that of the particle, kg/m3; c is the Al2O3 concentrations of the slag, kg/m3; ρ is the density of slag, kg/m3; m is the mass fraction of Al2O3, wt%, and for cp, m = 100wt%.
Fig. 2 illustrates the comparison between normalized dissolution curves for Al2O3 particles in slags with the C/A of 1.0–1.8 and various controlling models. Solid, dotted, and dashed-dotted lines represent the results predicted by the chemical reaction control, the boundary layer diffusion control, and the diffusion in the molten slag models, respectively. The results show that the Al2O3 dissolution curve has a preferable agreement with the predicted curve of the diffusion in the molten slag model. At the beginning of the Al2O3 dissolution, the boundary layer around inclusions is hardly formed. The steep concentration gradient results in a faster dissolution rate than the prediction using SCM. The concentration gradient gradually slows down and the surface area of the particle decreases throughout the dissolution process of Al2O3 particles, lowering the dissolution rate of the particle. Under the above discussion about the contact area and the concentration gradient, the controlling step is better described by the diffusion in the molten slag model.
Fig.
2.
Comparison of normalized dissolution curves for Al2O3 particles in different slags at 1773 K and three controlling models: (a) Slag 1; (b) Slag 2; (c) Slag 3; (d) Slag 4; (e) Slag 5.
There is a difference between the dissolution curves of Al2O3 particles in various slags. For example, the observed dissolution curve for Slag 1 is closer to the dissolution curve obtained by the diffusion in the boundary layer compared with results of Slag 4. The C/A of Slags 1 to 5 increases gradually, leading to an increase of the solubility of Al2O3 in slag as shown in Table 1. During the dissolution process, a concentration profile is formed in the boundary layer around the Al2O3 particle. The concentration gradient decreases and the boundary layer is extended. As Fig. 3 shows, the thickness of the boundary layer increases with the higher concentration difference of Al2O3 in bulk slag and saturated slag. Therefore, it is concluded that dissolution curves of Al2O3 particles are hardly predicted by the traditional boundary layer diffusion with the increase of the C/A of slag. When the concentration difference tends to zero, controlling steps of the dissolution can be considered using the boundary layer diffusion model.
Fig.
3.
Assumed concentration distribution for the particle dissolution in slags with different initial concentration of Al2O3. cAl2O3, i.e., c, is the concentration of Al2O3 in the slag, kg/m3; c2 and c1 are the initial concentration of Al2O3 in two bulk slags with the same viscosity, and c2 > c1, kg/m3
The difference between the observed and predicted dissolution curves in Fig. 2 is explained by the effect of slag viscosity on the boundary layer. Ahrendts and Kabelac [51] reported that the boundary layer thickness between the particle/slag interface increases with the larger slag viscosity, leading to a gentle concentration gradient. Thus, Feichtinger et al. modified Eq. (5) by introducing a dimensionless factor f in Eq. (9) [22]:
drdt=−k0DR−fk0√Dπt
(9)
The factor f increases with a higher slag viscosity. Fig. 4 [22] illustrates the assumed concentration distribution for the particle dissolution in slags. For the high viscosity slag in Fig. 4(a), there is a steep concentration gradient when the dissolution begins. During the dissolution process, the concentration gradient gradually decreases in the extended boundary layer, decreasing the dissolution rate of SiO2. The slag viscosity tended to infinity for f = 1. The concentration gradient changed during the dissolution process. Therefore, the controlling step of dissolution can be completely described as the diffusion in the molten slag. For the low viscosity slag in Fig. 4(b), the SiO2 particle can move fast in the good fluidity slag. The concentration gradient reaches the steady state in a short time. The dissolution curve is mainly affected by the contact surface between the particle and the slag. The concentration gradient is constant throughout the dissolution for f = 0. In this case, the diffusion in the boundary layer is the controlling step.
Fig.
4.
Assumed concentration distribution for the particle dissolution in slags: (a) high viscosity; (b) low viscosity. S. Feichtinger, S.K. Michelic, Y.B. Kang, and C. Bernhard, J. Am. Ceram. Soc., vol. 97, 316-325 (2014) [ 22]. Copyright Wiley-VCH Verlag GmbH & Co. KGaA. Reproduced with permission. t1 and t2 represent the early and late stages of the same dissolution process; c′s, c′b, and c′p are the SiO2 concentrations of the saturated slag, that of the bulk slag, and that of the particle, kg/m3.
The dissolution of Al2O3 can be calculated using Eq. (9). The factor k0 is calculated by Eq. (7), and related parameters of slag are given in Table 1. The factor f is obtained by fitting the observed dissolution pattern with the modified model as shown in Fig. 5. Fig. 6 illustrates the correlation between the viscosity of slag and the factor f at 1773 K. The fitted equation is obtained as Eq. (10). Based on the modified diffusion model, diffusion coefficients are calculated using Eq. (9), as listed in Table 3. The range of diffusion coefficients is from 2.8 × 10−10 to 4.1 × 10−10 m2/s.
Fig.
5.
Normalized dissolution curves for Al2O3 particles in different slags at 1773 K compared with various controlling models and modified model: (a) Slag 1; (b) Slag 2; (c) Slag 3; (d) Slag 4; (e) Slag 5.
4.
Influencing factors on the dissolution of Al2O3 inclusions in slag
4.1
Temperature
A series of experiments in the slag with a C/A of 1.2 and a C/S of 6.0 (Slag 2) were conducted at 1773, 1823, and 1873 K. Selected Al2O3 particles was in the radius from 236–257 μm to eliminate the effect of particle size. Fig. 7 illustrates the relationship between the equivalent volume and the total dissolution time. Average dissolution times at 1773, 1823, and 1873 K are 539, 233, and 103 s, respectively. The dissolution time gradually decreased with increasing temperature, which is exhibited in Fig. 8. The dissolution rate of Al2O3 particles increases with a higher temperature, and the relationship between the dissolution rate and temperature is shown as Eq. (11). It is generally believed that the reaction between the particle and slag was a first-order reaction. For the chemical reaction control model, the first-order rate constant (k) increases with an increase of temperature as shown in Eq. (12) [52]. The same pattern is found in the diffusion coefficient for the boundary layer diffusion control model, as Eq.(13) [52].
Fig.
7.
Evolution of Al2O3 particles volume in Slag 2.
where vAl2O3 is the dissolution rate of Al2O3 in volume, μm3/s; Tmp is the melting point of slag, K.
k=A1e−Q1/(RT)
(12)
D=A2e−Q2/(RT)
(13)
where A1 and A2 are pre-exponential constants; Q1 and Q2 are the activation energy, J/mol; R is the gas constant, J·mol−1·K−1.
In addition, the slag viscosity decreased with higher temperature. Valdez et al. [53] found that the total dissolution rate has an inverse ratio with the slag viscosity. The low slag viscosity improves the fluidity of slag, leading to a larger dissolution rate of inclusions in slag.
4.2
CaO/Al2O3 mass ratio
The effect of C/A on the dissolution rate of Al2O3 in slag was investigated. The initial radius was in the range of 195–208 μm. In Fig. 9, the dissolution rate rise from 1.90 × 104 to 2.57 × 105 μm3/s with the increase of C/A from 1.0 to 1.8. Besides, the concentration gradient is larger in slags with a higher C/A, resulting in a larger dissolution driving force. On the other hand, the viscosity of slag decreases with higher CaO content in slag, which promotes the absorption of Al2O3 inclusions. It is clear that there is a non-linear relationship between the dissolution rate and C/A, as shown in Eq. (14).
Fig.
9.
Effect of C/A on the dissolution rate of Al2O3 particles in slag.
Fig. 10 shows the effect of particle size on the dissolution rate of Al2O3 particles in slag. The dissolution rate of Al2O3 particles increased with the larger initial radius of particles. On the one hand, it is easier to reach a stable and slight concentration gradient around the larger Al2O3 particle. The stable and slight concentration gradient reduces the driving force for the dissolution, thereby inhibiting the dissolution of inclusions. On the other hand, the contact area of large inclusions and the molten slag is larger, increasing the dissolution rate. According to experimental results, the dissolution rate of Al2O3 in slag is mainly affected by the latter case. The dissolved amount per unit time is larger for a single Al2O3 particle with larger size. There is a non-linear relationship between the particle size and total dissolution time, and the quantitative relationship between the dissolution time and the size of Al2O3 inclusions can be determined, as Eq. (15).
Fig.
10.
Effect of particle size on the dissolution rate of Al2O3 particles in slag
4.4
Prediction of the total dissolution time of Al2O3
It is of great importance to determine the dissolution time of Al2O3 with various size and slag compositions. In the current study, it is confirmed that temperature, C/A of slag, and particle size have an important effect on the dissolution of Al2O3. To predict the dissolution rate of Al2O3, a new dissolution model was obtained as shown in Eq. (16). Based on Eq. (16), the total dissolution time of Al2O3 inclusions with various sizes was calculated by Eq. (17), as illustrated in Fig. 11. The predicted dissolution time of Al2O3 inclusions with various sizes was useful for the numerical simulation of non-metallic inclusions removal. It was clear that high temperature, high C/A, and small size promoted the dissolution of inclusions.
Fig.
11.
Prediction of the total dissolution time of Al2O3 particles with various initial radii in CaO–Al2O3–SiO2 slags: (a) 1773 K, (b) 1823 K, and (c) 1873 K.
Dissolution kinetics of Al2O3 in CaO–Al2O3–SiO2 slags at the temperature from 1773 to 1873 K was studied by CSLM. The dissolution mechanism was determined by the diffusion equation.
(1) The controlling step of the Al2O3 dissolution was the diffusion in the molten slag. With the increase of the C/A of slag, dissolution curves of Al2O3 particles were hardly predicted by the traditional boundary layer diffusion.
(2) A modified diffusion model was applied to consider the effect of slag viscosity on the dissolution of Al2O3 inclusions. Diffusion coefficients of Al2O3 in slag were calculated as 2.8 × 10−10 to 4.1 × 10−10 m2/s at the temperature of 1773–1873 K.
(3) The dissolution rate of Al2O3 increased with a higher temperature, C/A, and particle size. A new dissolution model was obtained considering the effect of temperature, C/A, and particle size. Moreover, the total dissolution time for Al2O3 inclusions with various sizes was calculated.
Acknowledgements
This work was financially supported by the National Nature Science Foundation of China (Nos. U1860206 and 51725402), the Science and Technology Program of Hebei, China (Nos. 20311006D and 20591001D). The authors are also grateful for support from the High Steel Center (HSC) at North China University of Technology, University of Science and Technology Beijing (USTB), and Yanshan University, and the Beijing International Center of Advanced and Intelligent Manufacturing of High Quality Steel Materials (ICSM), USTB.
L.F. Zhang and B.G. Thomas, State of the art in evaluation and control of steel cleanliness, ISIJ Int., 43(2003), No. 3, p. 271. DOI: 10.2355/isijinternational.43.271
[2]
L.F. Zhang. Non-metallic Inclusions in Steels: Industrial Practice, Metallurgical Industry Press, Beijing, 2019.
[3]
L.F. Zhang. Non-metallic Inclusions in Steels: Fundamentals, Metallurgical Industry Press, Beijing, 2019.
[4]
C. Gu, W.Q. Liu, J.H. Lian, and Y.P. Bao, In-depth analysis of the fatigue mechanism induced by inclusions for high-strength bearing steels, Int. J. Miner. Metall. Mater., 28(2021), No. 5, p. 826. DOI: 10.1007/s12613-020-2223-9
[5]
W. Xiao, Y.P. Bao, C. Gu, M. Wang, Y. Liu, Y.S. Huang, and G.T. Sun, Ultrahigh cycle fatigue fracture mechanism of high-quality bearing steel obtained through different deoxidation methods, Int. J. Miner. Metall. Mater., 28(2021), No. 5, p. 804. DOI: 10.1007/s12613-021-2253-y
[6]
L.F. Zhang and B.G. Thomas, State of the art in the control of inclusions during steel ingot casting, Metall. Mater. Trans. B, 37(2006), No. 5, p. 733. DOI: 10.1007/s11663-006-0057-0
[7]
A.L.V. da Costa e Silva, Non-metallic inclusions in steels – origin and control, J. Mater. Res. Technol., 7(2018), No. 3, p. 283. DOI: 10.1016/j.jmrt.2018.04.003
[8]
J.J. Wang, L.F. Zhang, G. Cheng, Q. Ren, and Y. Ren, Dynamic mass variation and multiphase interaction among steel, slag, lining refractory and nonmetallic inclusions: Laboratory experiments and mathematical prediction, Int. J. Miner. Metall. Mater., 28(2021), No. 8, p. 1298. DOI: 10.1007/s12613-021-2304-4
[9]
M. Jiang, J.C. Liu, K.L. Li, R.G. Wang, and X.H. Wang, Formation mechanism of large CaO–SiO2–Al2O3 inclusions in Si-deoxidized spring steel refined by low basicity slag, Metall. Mater. Trans. B, 52(2021), No. 4, p. 1950. DOI: 10.1007/s11663-021-02230-6
[10]
Y. Liu, X. Zhang, P. Wang, and D.Z. Li, Investigation on inclusions in non-oriented silicon steels, Metall. Mater. Trans. B, 51(2020), No. 1, p. 22. DOI: 10.1007/s11663-019-01735-5
[11]
L.F. Zhang, S. Taniguchi, and K.K. Cai, Fluid flow and inclusion removal in continuous casting tundish, Metall. Mater. Trans. B, 31(2000), No. 2, p. 253. DOI: 10.1007/s11663-000-0044-9
[12]
F. Yuan, A.J. Xu, and M.Q. Gu, Development of an improved CBR model for predicting steel temperature in ladle furnace refining, Int. J. Miner. Metall. Mater., 28(2021), No. 8, p. 1321. DOI: 10.1007/s12613-020-2234-6
[13]
H.X. Yu, D.X. Yang, J.M. Zhang, G.Y. Qiu, and N. Zhang, Effect of Al content on the reaction between Fe−10Mn−xAl (x = 0.035wt%, 0.5wt%, 1wt%, and 2wt%) steel and CaO−SiO2−Al2O3−MgO slag, Int. J. Miner. Metall. Mater., 29(2022), No. 2, p. 256. DOI: 10.1007/s12613-021-2298-y
[14]
L.X. Zhang, M. Chen, M.Y. Huang, N. Wang, and C. Wang, Dissolution kinetics of SiO2 in FeO–SiO2–V2O3–CaO–MnO–Cr2O3–TiO2 system with different FeO contents, Metall. Mater. Trans. B, 52(2021), No. 4, p. 2703. DOI: 10.1007/s11663-021-02214-6
[15]
G.J. Chen, S.P. He, and Q. Wang, Dissolution behavior of Al2O3 into tundish slag for high-Al steel, J. Mater. Res. Technol., 9(2020), No. 5, p. 11311. DOI: 10.1016/j.jmrt.2020.07.107
[16]
Z.R. Li, B.R. Jia, Y.B. Zhang, S.P. He, Q.Q. Wang, and Q. Wang, Dissolution behaviour of Al2O3 in mould fluxes with low SiO2 content, Ceram. Int., 45(2019), No. 3, p. 4035. DOI: 10.1016/j.ceramint.2018.11.082
[17]
G. Tripathi, A. Malfliet, B. Blanpain, and M.X. Guo, Dissolution behavior and phase evolution during aluminum oxide dissolution in BOF slag, Metall. Mater. Trans. B, 50(2019), No. 4, p. 1782. DOI: 10.1007/s11663-019-01590-4
[18]
Y.J. Park, Y.M. Cho, W.Y. Cha, and Y.B. Kang, Dissolution kinetics of alumina in molten CaO–Al2O3–FetO–MgO–SiO2 oxide representing the RH slag in steelmaking process, J. Am. Ceram. Soc., 103(2020), No. 3, p. 2210. DOI: 10.1111/jace.16879
[19]
S. Sridhar and A.W. Cramb, Kinetics of Al2O3 dissolution in CaO–MgO–SiO2–Al2O3 slags: In situ observations and analysis, Metall. Mater. Trans. B, 31(2000), No. 2, p. 406. DOI: 10.1007/s11663-000-0059-2
[20]
J. Liu, M. Guo, P.T. Jones, F. Verhaeghe, B. Blanpain, and P. Wollants, In situ observation of the direct and indirect dissolution of MgO particles in CaO–Al2O3–SiO2-based slags, J. Eur. Ceram. Soc., 27(2007), No. 4, p. 1961. DOI: 10.1016/j.jeurceramsoc.2006.05.107
[21]
J.H. Park, J.G. Park, D.J. Min, Y.E. Lee, and Y.B. Kang, In situ observation of the dissolution phenomena of SiC particle in CaO–SiO2–MnO slag, J. Eur. Ceram. Soc., 30(2010), No. 15, p. 3181. DOI: 10.1016/j.jeurceramsoc.2010.07.020
[22]
S. Feichtinger, S.K. Michelic, Y.B. Kang, and C. Bernhard, In situ observation of the dissolution of SiO2 particles in CaO–Al2O3–SiO2 slags and mathematical analysis of its dissolution pattern, J. Am. Ceram. Soc., 97(2014), No. 1, p. 316. DOI: 10.1111/jace.12665
[23]
Y. Lee, J.K. Yang, D.J. Min, and J.H. Park, Mechanism of MgO dissolution in MgF2–CaF2–MF (M = Li or Na) melts: Kinetic analysis via in situ high temperature confocal scanning laser microscopy (HT-CSLM), Ceram. Int., 45(2019), No. 16, p. 20251. DOI: 10.1016/j.ceramint.2019.06.298
[24]
M. Sharma and N. Dogan, Dissolution behavior of aluminum titanate inclusions in steelmaking slags, Metall. Mater. Trans. B, 51(2020), No. 2, p. 570. DOI: 10.1007/s11663-019-01762-2
[25]
K.Y. Miao, A. Haas, M. Sharma, W.Z. Mu, and N. Dogan, In situ observation of calcium aluminate inclusions dissolution into steelmaking slag, Metall. Mater. Trans. B, 49(2018), No. 4, p. 1612. DOI: 10.1007/s11663-018-1303-y
[26]
T.L. Tian, Y.Z. Zhang, H.H. Zhang, K.X. Zhang, J. Li, and H. Wang, Dissolution behavior of SiO2 in the molten blast furnace slags, Int. J. Appl. Ceram. Technol., 16(2019), No. 3, p. 1078. DOI: 10.1111/ijac.13120
[27]
C.Y. Ren, L.F. Zhang, J. Zhang, S.J. Wu, P. Zhu, and Y. Ren, In situ observation of the dissolution of Al2O3 particles in CaO–Al2O3–SiO2 slags, Metall. Mater. Trans. B, 52(2021), No. 5, p. 3288. DOI: 10.1007/s11663-021-02256-w
[28]
Y. Kim, Y. Kashiwaya, and Y. Chung, Effect of varying Al2O3 contents of CaO–Al2O3–SiO2 slags on lumped MgO dissolution, Ceram. Int., 46(2020), No. 5, p. 6205. DOI: 10.1016/j.ceramint.2019.11.088
[29]
W.Z. Mu and C.J. Xuan, Phase-field study of dissolution behaviors of different oxide particles into oxide melts, Ceram. Int., 46(2020), No. 10, p. 14949. DOI: 10.1016/j.ceramint.2020.03.023
[30]
C.J. Xuan and W.Z. Mu, A phase-field model for the study of isothermal dissolution behavior of alumina particles into molten silicates, J. Am. Ceram. Soc., 102(2019), No. 11, p. 6480. DOI: 10.1111/jace.16509
[31]
J.J. Liu, J. Zou, M.X. Guo, and N. Moelans, Phase field simulation study of the dissolution behavior of Al2O3 into CaO–Al2O3–SiO2 slags, Comput. Mater. Sci., 119(2016), p. 9. DOI: 10.1016/j.commatsci.2016.03.034
[32]
J. Heulens, B. Blanpain, and N. Moelans, A phase field model for isothermal crystallization of oxide melts, Acta Mater., 59(2011), No. 5, p. 2156. DOI: 10.1016/j.actamat.2010.12.016
[33]
Z.J. Wang and I. Sohn, A review of in situ observations of crystallization and growth in high temperature oxide melts, JOM, 70(2018), No. 7, p. 1210. DOI: 10.1007/s11837-018-2887-z
[34]
I. Sohn and R. Dippenaar, In-situ observation of crystallization and growth in high-temperature melts using the confocal laser microscope, Metall. Mater. Trans. B, 47(2016), No. 4, p. 2083. DOI: 10.1007/s11663-016-0675-0
[35]
D.C. Fu, G.H. Wen, X.Q. Zhu, J.L. Guo, and P. Tang, Modification for prediction model of austenite grain size at surface of microalloyed steel slabs based on in situ observation, J. Iron Steel Res. Int., 28(2021), No. 9, p. 1133. DOI: 10.1007/s42243-020-00513-x
[36]
Q.R. Tian, G.C. Wang, D.L. Shang, H. Lei, X.H. Yuan, Q. Wang, and J. Li, In situ observation of the precipitation, aggregation, and dissolution behaviors of TiN inclusion on the surface of liquid GCr15 bearing steel, Metall. Mater. Trans. B, 49(2018), No. 6, p. 3137. DOI: 10.1007/s11663-018-1411-8
[37]
Y.G. Wang and C.J. Liu, Agglomeration characteristics of various oxide inclusions in molten steel containing rare earth element under different deoxidation conditions, ISIJ Int., 61(2021), No. 5, p. 1396. DOI: 10.2355/isijinternational.ISIJINT-2020-684
[38]
W.Z. Mu and C.J. Xuan, Agglomeration mechanism of complex Ti–Al oxides in liquid ferrous alloys considering high-temperature interfacial phenomenon, Metall. Mater. Trans. B, 50(2019), No. 6, p. 2694. DOI: 10.1007/s11663-019-01686-x
[39]
X.J. Zhao, Z.N. Yang, and F.C. Zhang, In situ observation of the effect of AIN particles on bainitic transformation in a carbide-free medium carbon steel, Int. J. Miner. Metall. Mater., 27(2020), No. 5, p. 620. DOI: 10.1007/s12613-019-1911-9
[40]
J. Guo, X.R. Chen, S.W. Han, Y. Yan, and H.J. Guo, Evolution of plasticized MnO–Al2O3–SiO2-based nonmetallic inclusion in 18wt%Cr−8wt%Ni stainless steel and its properties during soaking process, Int. J. Miner. Metall. Mater., 27(2020), No. 3, p. 328. DOI: 10.1007/s12613-019-1945-z
[41]
A.B. Fox, M.E. Valdez, J. Gisby, R.C. Atwood, P.D. Lee, and S. Sridhar, Dissolution of ZrO2, Al2O3, MgO and MgAl2O4 particles in a B2O3 containing commercial fluoride-free mould slag, ISIJ Int., 44(2004), No. 5, p. 836. DOI: 10.2355/isijinternational.44.836
[42]
J.H. Park and L.F. Zhang, Kinetic modeling of nonmetallic inclusions behavior in molten steel: A review, Metall. Mater. Trans. B, 51(2020), No. 6, p. 2453. DOI: 10.1007/s11663-020-01954-1
[43]
S. Lyu, X.D. Ma, Z.Z. Huang, Z. Yao, H.G. Lee, Z.H. Jiang, G. Wang, J. Zou, and B.J. Zhao, Formation mechanism of Al2O3-containing inclusions in Al-deoxidized spring steel, Metall. Mater. Trans. B, 50(2019), No. 5, p. 2205. DOI: 10.1007/s11663-019-01644-7
[44]
O. Levenspiel, Chemical Reaction Engineering, 3rd ed., John Wiley & Sons, Inc., the United States of America, 1999.
[45]
M.J. Whelan, On the kinetics of precipitate dissolution, Met. Sci. J., 3(1969), No. 1, p. 95. DOI: 10.1179/msc.1969.3.1.95
[46]
H.B. Aaron, D. Fainstein, and G.R. Kotler, Diffusion-limited phase transformations: A comparison and critical evaluation of the mathematical approximations, J. Appl. Phys., 41(1970), No. 11, p. 4404. DOI: 10.1063/1.1658474
[47]
L.C. Brown, Diffusion-controlled dissolution of planar, cylindrical, and spherical precipitates, J. Appl. Phys., 47(1976), No. 2, p. 449. DOI: 10.1063/1.322669
[48]
F. Verhaeghe, S. Arnout, B. Blanpain, and P. Wollants, Lattice-Boltzmann modeling of dissolution phenomena, Phys. Rev. E, 73(2006), No. 3, art. No. 036316. DOI: 10.1103/PhysRevE.73.036316
[49]
C.W. Bale, P. Chartrand, S.A. Degterov, G. Eriksson, K. Hack, R. Ben Mahfoud, J. Melançon, A.D. Pelton, and S. Petersen, FactSage thermochemical software and databases, Calphad, 26(2002), No. 2, p. 189. DOI: 10.1016/S0364-5916(02)00035-4
[50]
K.C. Mills and B.J. Keene, Physical properties of BOS slags, Int. Mater. Rev., 32(1987), No. 1, p. 1. DOI: 10.1179/095066087790150296
[51]
J. Ahrendts and S. Kabelac. Technische thermodynamik, [in] H. Czichos and M. Hennecke, eds., Hütte - Das Ingenieurwissen, Springer Berlin, Heidelberg, 2012, p. 925.
[52]
B.J. Monaghan and L. Chen, Dissolution behavior of alumina micro-particles in CaO–SiO2–Al2O3 liquid oxide, J. Non Cryst. Solids, 347(2004), No. 1-3, p. 254. DOI: 10.1016/j.jnoncrysol.2004.09.011
[53]
M. Valdez, G.S. Shannon, and S. Sridhar, The ability of slags to absorb solid oxide inclusions, ISIJ Int., 46(2006), No. 3, p. 450. DOI: 10.2355/isijinternational.46.450
NIU Sitong, CHENG Guoguang, ZHANG Jian, TONG Fusheng.
Foaminess of Refining Slags System
[J]. International Journal of Minerals, Metallurgy and Materials, 1997, 4(2): 30-30.
Yi Wang, Jian-xun Fu, Deepoo Kumar, et al. State-of-art of in situ observations of inclusion agglomeration at steel/Ar and steel/slag interfaces: a review of recent development on experimental and theoretical studies. Journal of Iron and Steel Research International, 2025.
DOI:10.1007/s42243-024-01410-3
2.
Bin Guo, Jujin Wang, Lifeng Zhang. Dissolution Kinetics of Al2O3, CaAl4O7, and MgAl2O4 Inclusions Into CaO–Al2O3–SiO2 Slags with Varying MgO Content. Metallurgical and Materials Transactions B, 2025, 56(1): 1029.
DOI:10.1007/s11663-024-03412-8
3.
Guang Wang, Muhammad Nabeel, Wangzhong Mu, et al. In-situ confocal microscopy study on dissolution kinetics of calcium aluminate inclusions in CaO–Al2O3–SiO2 type steelmaking slags. Journal of Iron and Steel Research International, 2025.
DOI:10.1007/s42243-024-01397-x
4.
Yu-die Gu, Ying Ren, Li-feng Zhang. In-situ observation on dissolution of CaO–SiO2–Al2O3 complex inclusions in refining slag. Journal of Iron and Steel Research International, 2025.
DOI:10.1007/s42243-024-01405-0
5.
Zhijie Guo, Yanhui Sun, Hongyu Wang, et al. Effect of Al2O3 and CaO/SiO2 ratio in slag on the cleanliness of bearing steel GCr15. Ironmaking & Steelmaking: Processes, Products and Applications, 2024.
DOI:10.1177/03019233241256418
6.
Yao-xin Du, Yan-wu Dong, Zhou-hua Jiang, et al. Dissolution kinetics and reaction mechanism of Al2O3 in molten CaF2–CaO–Al2O3 slag. Journal of Iron and Steel Research International, 2024, 31(4): 861.
DOI:10.1007/s42243-023-01112-2
7.
Guojun Chen, Ying Ren, Minghui Wu, et al. <i>In-Situ</i> Observation of the Modification Behavior of Alumina Inclusions in a Calcium-treated Steel. ISIJ International, 2024, 64(8): 1263.
DOI:10.2355/isijinternational.ISIJINT-2024-049
8.
Fereshteh Falah Chamasemani, Florian Lenzhofer, Roland Brunner. Deep learning revealed statistics of the MgO particles dissolution rate in a CaO–Al2O3–SiO2–MgO slag. Scientific Reports, 2024, 14(1)
DOI:10.1038/s41598-024-71640-8
9.
Zhiyin Deng, Xiaomeng Zhang, Guangyu Hao, et al. Dissolution behavior of Al2O3 inclusions into CaO–MgO–SiO2–Al2O3–TiO2 system ladle slags. International Journal of Minerals, Metallurgy and Materials, 2024, 31(5): 977.
DOI:10.1007/s12613-023-2817-0
10.
Yifan Zhao, Zhiyuan Li, Shijie Li, et al. A review of in-situ high-temperature characterizations for understanding the processes in metallurgical engineering. International Journal of Minerals, Metallurgy and Materials, 2024, 31(11): 2327.
DOI:10.1007/s12613-024-2891-y
11.
Daniel Marian Ogris, Susanne Michelic, Ernst Gamsjäger. Dissolution of Oxide Particles in Multi-component Slags Governed by Diffusive and Convective Fluxes. Metallurgical and Materials Transactions B, 2024, 55(5): 3451.
DOI:10.1007/s11663-024-03175-2
12.
Héléna Verbeeck, Vincent Feyen, Inge Bellemans, et al. Multi-phase-field modeling of the dissolution behavior of stoichiometric particles on experimentally relevant length scales. Computational Materials Science, 2024, 245: 113288.
DOI:10.1016/j.commatsci.2024.113288
13.
Haixin Yang, Ying Ren, Jinshu Wang, et al. <i>In-situ</i> Observation of Precipitation and Growth of MnS Inclusions during Solidification of a High Sulfur Steel. ISIJ International, 2024, 64(14): 2020.
DOI:10.2355/isijinternational.ISIJINT-2024-195
14.
Zhongyan Xie, Yubao Liu, Ying Ren, et al. Effect of Cerium Addition on Microstructure and Mechanical Properties of the Ductile Iron. steel research international, 2024, 95(12)
DOI:10.1002/srin.202400458
15.
Li Zhang, Wanlin Wang, Lei Zhang, et al. A comparison study on the dissolution mechanism of Al2O3 inclusion on fluorine-bearing and fluorine-free molten mold fluxes. Ceramics International, 2023, 49(16): 27176.
DOI:10.1016/j.ceramint.2023.05.262
16.
Xufeng Wang, Fangfang Li, Qiangqiang Wang, et al. Dissolution behavior of AlN in CaO–Al2O3–BaO–CaF2–Li2O system mold fluxes. Journal of Materials Research and Technology, 2023, 26: 2229.
DOI:10.1016/j.jmrt.2023.08.038
17.
Lan Gou, Hong Liu, Ying Ren, et al. Concept of Inclusion Capacity of Slag and Its Application on the Dissolution of Al2O3, ZrO2 and SiO2 Inclusions in CaO–Al2O3–SiO2 Slag. Metallurgical and Materials Transactions B, 2023, 54(3): 1314.
DOI:10.1007/s11663-023-02763-y
18.
Siyue Dong, Rui Wang, Likui Xie, et al. Effect of P and Ti on the agglomeration behavior of Al2O3 inclusions in Fe–P–Ti alloys. High Temperature Materials and Processes, 2023, 42(1)
DOI:10.1515/htmp-2022-0294
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