calcium modification of spinel inclusions in aluminum
Modification of oxide inclusions by addition of Ca
Thus calcium aluminates form instead of Al2O3 inclusions in Al-deoxidized steels. In Si-deoxidized steels mullite (Al6Si2O13) transforms into gehlenite (Ca2Al AlSiO7 ) or anorthite (CaAl2Si2O8). Figure 1 Compositions of different oxide inclusions precipitated in aluminum (a)
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Calcium Modification of Spinel Inclusions in Aluminum
Calcium treatment is a well-established way to modify solid alumina inclusions to liquid or partially liquid calcium aluminates. Spinels (Al2O3·xMgO) can also form in liquid steel after aluminum
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Thermodynamic Analysis on Precipitation of Nonmetallic
In order to make nonmetallic inclusions with low melting point and improve the fatigue resistance of gear steel thermodynamic analysis on precipitation of nonmetallic inclusions CaO(MgO)-Al2O3 system was investigated in this paper. The complex deoxidation equilibria of strong deoxidizing elements such as aluminum calcium magnesium and so on were calculated accurately with the second order
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Calcium-Aluminum-rich Inclusions Major Unanswered
Calcium-Aluminum-rich Inclusions Major Unanswered Questions 227 titanium. Their primary minerals are notably deficient in volatile components such as iron alkalis and water. These minerals include many of the same phases encountered in synthetic high temperature ceramic materials and phase equilibrium diagrams pertinent to ceramic systems.
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Inclusion Evolution during Modification of Alumina
The production of clean steel involves the controlling elimination or modification of nonmetallic inclusions. In Al-killed steels alumina is the main type of inclusion. Calcium treatment by wire feeding is commonly used to modify solid alumina inclusions to calcium aluminates which exists in a fully or partially liquid phase.
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Inclusion Evolution during Modification of Alumina
The production of clean steel involves the controlling elimination or modification of nonmetallic inclusions. In Al-killed steels alumina is the main type of inclusion. Calcium treatment by wire feeding is commonly used to modify solid alumina inclusions to calcium aluminates which exists in a fully or partially liquid phase.
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Characteristics of Inclusions in Low Carbon Al-Killed
The process of change of oxide inclusions was alumina → spinel type → calcium aluminate. For Heat-1 after calcium treatment the average composition of oxide inclusions was still out of the liquid zone while that of Heat-2 was changed to the expected liquid area.
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Calcium-Aluminum-rich Inclusions Major Unanswered
Calcium-Aluminum-rich Inclusions Major Unanswered Questions 227 titanium. Their primary minerals are notably deficient in volatile components such as iron alkalis and water. These minerals include many of the same phases encountered in synthetic high temperature ceramic materials and phase equilibrium diagrams pertinent to ceramic systems.
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A Kinetic Model for the Modification of Al2O3 Inclusions
Laboratory-scale experiments for the modification of Al 2 O 3 inclusions by calcium treatment in high-carbon hard wire steel were performed and the compositions and morphological evolution of inclusions were studied. The kinetics of the modification of Al 2 O 3 inclusions by calcium treatment were studied in high-carbon hard wire steel based on the unreacted shrinking core model considering
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Modification and Minimization of Spinel(Al2O3·xMgO
Calcium treatment 17 18 is a countermeasure to avoid harmful alumina or spinel inclusions by modifying them to harmless liquid calcium aluminate inclusions. Calcium modification of Ti-bearing inclusions in steel contributes to the production of high-quality steel with fewer defects caused by inclusions 19 and it prevents nozzle blockage by
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Modification and Minimization of Spinel(Al2O3·xMgO
Calcium treatment 17 18 is a countermeasure to avoid harmful alumina or spinel inclusions by modifying them to harmless liquid calcium aluminate inclusions. Calcium modification of Ti-bearing inclusions in steel contributes to the production of high-quality steel with fewer defects caused by inclusions 19 and it prevents nozzle blockage by
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Calcium modification of alumina and spinel inclusions in
Modification of spinel inclusions Readily modified to liquid / partially liquid inclusions Partial removal of MgO (Mg enters liquid steel) upon calcium treatment Similar transient path to alumina (CaS forms first then reacts to give modification) Mg returned to solution upon Ca treatment spinels can reappear upon reoxidation
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Deoxidation and Inclusion Control in Stainless Steel
13 V. Neerav C.P. Petrus J.F. Richard Calcium Modification of Spinel Inclusions in Aluminum-Killed Steel Reaction Steps J. Metallurgical and Materials Transactions B. 43 (2012) . DOI 10.1007/s
Get PriceModification of Alumina and Spinel Inclusions by Calcium
Dec 01 2011 · Successful modification of alumina and spinel inclusions by calcium was demonstrated 85 86 . It was observed that these modification mechanisms proceed through transient phase (CaO CaS) formation. In the case of spinels preferential reduction of MgO part was also observed during calcium modification of spinels.
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Control of complex inclusions in high- strength ship plate
focuses on the modification and removal of the Al2O3 inclusions in steel. " " " " " " " " MgO·Al2O3 spinel inclusions are often found in steel that has been treated by aluminum deoxidation. The thermodynamic conditions for MgO·Al2O3 spinel inclusions and their formation were calculated using FactSage software. The MgO-Al2O3 phase
Get Price(PDF) MECHANISM AND KINETICS OF TRANSFORMATION OF
Few works have been done on the kinetics of inclusion modification.Since 1970 s Hilty and Farrell et studied the effect of Ca on the nozzle clogging and inclusion modification. The different kind of calcium aluminates were found in their experiments and the sequence of alumina inclusion modification A1203 => CA => CA ==> CA ==> CA was
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Calcium-aluminum-rich inclusions in enstatite chondrites
Porous Calcium-aluminum-rich Inclusions-Two porous CAIs both in ALHA77295 (Table 2) have spinel-rich cores completely surrounded by secondary Na-Al-rich rims (Fig. 3a e). The spinel is near-endmember MgA1204 with no more than 0.01 atom per formula unit Ti
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A plagioclase–olivine–spinel–magnetite inclusion from
Calcium–aluminum-rich inclusions (CAIs) are rare in CK chondrites. Only one inclusion from Karoonda has been de-scribed. This contains the unusual mineral assemblage fassaite– hercynite–olivine (MacPherson and Delaney 1985). Maralinga seems to contain more CAIs than the average CK chondrite.
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Characteristics analysis of inclusion of 60Si2Mn–Cr spring
The experimental observation and thermodynamic analysis showed that calcium treatment cannot entirely modify large-size MgO·Al 2 O 3 spinel inclusions into homogeneous CaO–MgO–Al 2 O 3 inclusions but formed a liquid xCaO·yAl 2 O 3 layer on its surface. When the Al content was 0.05 mass Mg Ca and O in molten steel could be
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Control of complex inclusions in high- strength ship plate
focuses on the modification and removal of the Al2O3 inclusions in steel. " " " " " " " " MgO·Al2O3 spinel inclusions are often found in steel that has been treated by aluminum deoxidation. The thermodynamic conditions for MgO·Al2O3 spinel inclusions and their formation were calculated using FactSage software. The MgO-Al2O3 phase
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THE EVALUATION OF NON- METALLIC INCLUSIONS IN
Solid alumina inclusions in aluminum-killed steels which is always big size cluster can be modified to calcium-aluminate which is much smaller compact spherical inclusions by calcium addition (Figure 1-1)9 10. Figure 1-1 Modification of alumina inclusions by calcium (a) alumina cluster18 (c) compact calcium aluminate 10.
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MacSphere Modeling of inclusion evolution in Ladle
The kinetic model is further extended to model the modification of spinel inclusions by calcium treatment. Coupling the model for inclusions modification to a multi component kinetic model for the slag-steel reactions in the ladle furnace allowed prediction of the change of average composition of inclusions which was subsequently verified using
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Inclusion Evolution during Modification of Alumina
The production of clean steel involves the controlling elimination or modification of nonmetallic inclusions. In Al-killed steels alumina is the main type of inclusion. Calcium treatment by wire feeding is commonly used to modify solid alumina inclusions to calcium aluminates which exists in a fully or partially liquid phase.
Get PriceModification of Alumina and Spinel Inclusions by Calcium
Successful modification of alumina and spinel inclusions by calcium was demonstrated 85 86 . It was observed that these modification mechanisms proceed through transient phase (CaO CaS) formation. In the case of spinels preferential reduction of MgO part was also observed during calcium modification of
Get PriceCalcium-Aluminum-Rich Inclusions from Enstatite Chondrites
Aug 25 2000 · The primary mineral assemblages and initial26Al/27Al ratios of rare calcium-aluminum–rich inclusions (CAIs) from enstatite (E) chondrites are similar to those of CAIs from other chondrite classes. CAIs from all chondrite classes formed under oxidizing conditions that are much different from the reducing conditions under which the E chondrites formed.
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CALCIUM-ALUMINUM-RICH INCLUSIONS (CAIs)
Calcium-Aluminum-rich Inclusions in Unequilibrated Enstatite Chondrites A Preliminary Petrologic and Isotopic Study #1391 We determined spinel/liquid D s for Ti and V for average type B CAI composition at the C-CO buffer curve.
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Deoxidation and Inclusion Control in Stainless Steel
13 V. Neerav C.P. Petrus J.F. Richard Calcium Modification of Spinel Inclusions in Aluminum-Killed Steel Reaction Steps J. Metallurgical and Materials Transactions B. 43 (2012) . DOI 10.1007/s
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Calcium Modification of Spinel Inclusions in Aluminum
Apr 10 2012 · Calcium treatment is a well-established way to modify solid alumina inclusions to liquid or partially liquid calcium aluminates. Spinels (Al 2 O 3 · x MgO) can also form in liquid steel after aluminum deoxidation. Like alumina the spinels can be modified readily to liquid inclusions by a calcium treatment.
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Effect of calcium treatment on inclusions in Si-Mn-killed
Sep 01 2020 · On the other hand the modification of Al 2 O 3 inclusions in Al-killed steels by calcium treatment has been widely studied to lower the melting temperature of inclusions and avoid the
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