Introduction
Experimental methods
Metal sample preparation
Exp. no. | Ti addition (mass%) | Sampling time (min) | Dissolved oxygen content (ppm) | Dissolved Ti content (ppm) | Undissolved Ti content (ppm) |
---|---|---|---|---|---|
1 | 0.03%Ti (initial oxygen: 157 ppm) | 1 | 130 | 302 | 33 |
5 | 103 | 254 | 20 | ||
2 | 0.1%Ti (initial oxygen: 168 ppm) | 1 | 132 | 519 | 139 |
3 | 111 | 434 | 75 | ||
30 | 60 | 313 | 73 | ||
3 | 0.2%Ti (initial oxygen: 133 ppm) | 1 | 112 | 1990 | 203 |
3 | 68 | 2000 | 116 | ||
10 | 57 | 1567 | 164 |
Inclusion characterization
Results and discussion
Chemical composition of inclusion
Ti addition (mass %) | FeO% in inclusion | Criteria of inclusion state at temperature 1600 °C | |
---|---|---|---|
Single inclusion | Cluster | ||
0.03 | > 81 | – | Liquid |
0.1 | > 48 | < 7 | Liquid + solid |
0.2 | < 3 | Solid |
Thermodynamic consideration of critical Ti content
T (K) | log K(1) | log K(2) | log K(3) |
\( e_{\text{Ti}}^{\text{Ti}} \)
|
\( e_{\text{O}}^{\text{Ti}} \)
|
\( e_{\text{Ti}}^{\text{O}} \)
|
\( e_{\text{O}}^{\text{O}} \)
|
\( r_{\text{O}}^{\text{Ti}} \)
|
\( r_{\text{Ti}}^{\text{O}} \)
|
---|---|---|---|---|---|---|---|---|---|
1873 | − 5.938 | − 16.191 | − 9.810 | 0.0448 | − 0.533 | − 1.596 | − 1.534 | 0.0385 | − 0.355 |
Theoretical analysis of solid TiOx coalescence behavior
Coalescence coefficient of turbulent collision
Attraction force due to wettability
Agglomeration of the oxide particles at the surface of the molten alloy
Initial sintering of inclusions in melt
Sample | Inclusion | γs (N/m) | δ3 (m3) | r (µm) | x (µm) |
---|---|---|---|---|---|
0.2%Ti | TiOx | ~ 1.60 [56] | ~ 1.66 × 10−29 [57] | 1.70 ± 0.32 | 1.17 ± 0.31 |
0.06%Al [34] | Al2O3 | 0.935 [58] | 1.38 × 10−29 [59] | 1.42 ± 0.39 [29] | 0.85 ± 0.26 [29] |