TY - JOUR
T1 - Transient behavior of inclusion chemistry, shape, and structure in Fe-Al-Ti-O Melts
T2 - Effect of titanium source and laboratory deoxidation simulation
AU - Wang, Cong
AU - Nuhfer, Noel Thomas
AU - Sridhar, Seetharaman
N1 - Funding Information:
Financial support from the Center for Iron and Steelmaking Research, Carnegie Mellon University, is gratefully acknowledged. The fruitful discussions with J. Lehmann, W. Tiekink, and P. Kaushik are greatly appreciated.
PY - 2009/12
Y1 - 2009/12
N2 - In the present study, laboratory-scale deoxidation experiments in a vacuum-induction furnace (VIF) were carried out to elucidate the evolution of inclusions during transient stages after a titanium addition. Three different titanium sources (Fe-70 wt pct Ti, Fe-30 wt pct Ti, and titanium granules) were employed and the results were compared in terms of the inclusion chemistry, structure, and morphology. It was found that, immediately after titanium additions to an aluminum-killed melt, titanium-containing inclusions, which are either single-phase or dual-phase particles having a certain amount of titanium and are contrary to melt equilibrium predictions, were formed. Analysis by transmission electron microscope (TEM) suggested that these inclusions could be Al2TiO5. The change in the inclusion chemistry was accompanied by a shift in the inclusion morphology from spherical to irregular. With time, the inclusion chemistry shifted back toward the thermodynamically stable Al2O3, but the change in morphology remained. The temporary Al2TiO5 inclusions were formed as a result of local high content of titanium immediately after and at the vicinity of the titanium addition. When comparing the different titanium sources, it was found that they can be ranked as Ti > Fe-70 pct Ti > Fe-30 pct Ti, in terms of the amount of titanium-containing inclusions produced during the transient stage.
AB - In the present study, laboratory-scale deoxidation experiments in a vacuum-induction furnace (VIF) were carried out to elucidate the evolution of inclusions during transient stages after a titanium addition. Three different titanium sources (Fe-70 wt pct Ti, Fe-30 wt pct Ti, and titanium granules) were employed and the results were compared in terms of the inclusion chemistry, structure, and morphology. It was found that, immediately after titanium additions to an aluminum-killed melt, titanium-containing inclusions, which are either single-phase or dual-phase particles having a certain amount of titanium and are contrary to melt equilibrium predictions, were formed. Analysis by transmission electron microscope (TEM) suggested that these inclusions could be Al2TiO5. The change in the inclusion chemistry was accompanied by a shift in the inclusion morphology from spherical to irregular. With time, the inclusion chemistry shifted back toward the thermodynamically stable Al2O3, but the change in morphology remained. The temporary Al2TiO5 inclusions were formed as a result of local high content of titanium immediately after and at the vicinity of the titanium addition. When comparing the different titanium sources, it was found that they can be ranked as Ti > Fe-70 pct Ti > Fe-30 pct Ti, in terms of the amount of titanium-containing inclusions produced during the transient stage.
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U2 - 10.1007/s11663-009-9267-6
DO - 10.1007/s11663-009-9267-6
M3 - Article
AN - SCOPUS:72149101253
SN - 1073-5615
VL - 40
SP - 1005
EP - 1021
JO - Metallurgical and Materials Transactions B: Process Metallurgy and Materials Processing Science
JF - Metallurgical and Materials Transactions B: Process Metallurgy and Materials Processing Science
IS - 6
ER -