Analysis of Inclusion Behavior in a Ladle Refining Process by a Newly Developed Coagulation Model

Fuchigami, Katsuhiro; Wakoh, Masamitsu; Imamura, Naochika; Endoh, Koichi; Kiyose, Akito; Sawada, Ikuo

doi:10.2355/tetsutohagane1955.85.5_368

Cited by 12 publications

(8 citation statements)

References 6 publications

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“…In the alumina clusters from the cast slab, on the other hand, multi-crystalline alumina with a grain size of [5][6][7][8][9][10] μm, which grew during casting, was observed, but no metallic iron particles were detected inside these samples (Case VI). On the basis of the observation shown in Chapter 3.1 and Chapter 3.2, the characteristics of the alumina clusters before and after casting were summarized in Table 2. 4.…”

Section: Inner Structure Of Alumina Clustersmentioning

confidence: 99%

“…2) To optimize these processes, computer simulations concerning the evolution and removal behavior of alumina inclusions in molten steel are of great assistance, [3][4][5][6][7][8][9][10][11][12][13] as is basic research about the nucleation and growth of deoxidation products. [14][15][16][17][18][19][20][21][22][23] The coagulation coefficient of alumina particles strongly affects the collision growth rate of alumina clusters larger than 1 μm; however, as the reported values for the coefficient vary widely between 0.03 and 0.7, [3][4][5][6][7][8][9][10][11][12][13] it is still difficult to interpret the experimental results, although the Brownian motion, the van der Waals force and other forces related to fluid dynamics were taken into consideration. We think that the coagulation behavior must also depend on the liquidcapillary force of a very small amount of liquid iron oxide bridging the solid alumina particles and working as a "binder" because of its good wettability, in addition to the abovementioned forces.…”

Section: Introductionmentioning

confidence: 99%

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Influence of Unstable Non-equilibrium Liquid Iron Oxide on Clustering of Alumina Particles in Steel

et al. 2013

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Alumina clusters extracted from molten steel and from a cast slab at our plant were analyzed by SEM and TEM. It was found that a small amount of liquid FeO could accelerate the clustering of alumina inclusions in aluminum-killed steel because of the strong liquid-capillary negative pressure of liquid FeO. The sources of the FeO are most likely oxygen contamination from ferroalloy additives, residual steel adhering to the refractory surfaces of ladles and vessels, and air entrainment.

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Section: Inner Structure Of Alumina Clustersmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Influence of Unstable Non-equilibrium Liquid Iron Oxide on Clustering of Alumina Particles in Steel

et al. 2013

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“…5,6) Clustering of non-metallic inclusions in liquid steel has been intensively studied, mainly focusing on influencing factors, such as inclusion type, temperature, holding time, stirring and initial oxygen content. [7][8][9][10][11][12] Clustering was found to occur easily among inclusions that are not wetted by liquid steel. This suggests that clustering is related to the interfacial properties of inclusions and liquid steel.…”

Section: Introductionmentioning

confidence: 99%

Effect of Alumina Morphology on the Clustering of Alumina Inclusions in Molten Iron

et al. 2016

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Clustering of alumina inclusions during liquid processing of steel significantly influences its cleanliness and mechanical properties. We have therefore studied the effect of alumina inclusion morphology on their clustering behavior in molten iron. Alumina inclusions were extracted from iron samples taken at 1 min after Al addition. Dendritic, spherical, plate-like, faceted and clustered alumina inclusions were identified and their clustering degrees were measured. The clustering degree increases in the order of spherical, dendritic, plate-like and faceted inclusions. To explain this, attractive force between two alumina particles with different shape combinations, i.e., sphere-sphere (S-S), sphere-plane (S-P), plane-plane (P-P), was calculated based on the theory of spontaneous cavitation. The attractive force is influenced significantly by particle shape. S-S type has the smallest attractive force and the shortest acting length. P-P type has the largest attractive force and the longest acting length. This explains that spherical inclusions have the lowest clustering degree. The lower clustering degree of plate-like inclusions, compared with faceted inclusions, is due to that molten iron wets plate-like inclusions better.

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“…By calculating the rupture energy of a cavity bridge, Zheng et al [4] demonstrated that a faceted inclusion has the strongest attractive force, which was reflected in a plate-like, dendritic and spherical shape. Also Fuchigami et al [5] developed an agglomeration model by combining a coagulation calculation and flow simulation of liquid steel, where coagulation of alumina and slag-origin oxide inclusions were considered [5]. In this model, agglomeration frequency Z (m −3 ·s −1 ) was estimated by:…”

Section: Introductionmentioning

confidence: 99%

Agglomeration Behavior of Non-Metallic Particles on the Surface of Ca-Treated High-Carbon Liquid Steel: An In Situ Investigation

Tanaka

Pahlevani

Sahajwalla

2018

Metals

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The agglomeration behavior of non-metallic inclusion is a critical phenomenon that needs to be controlled as it has a direct relationship with the performance of produced steel. Although the agglomerates can be potential points for serious defects in every grade of steel, they are likely to be more serious in high-carbon steel due to the low ductility of these grades of steels as well as their usage in severe conditions. Confocal scanning laser microscopes (CSLM) have been used by different researchers to investigate the agglomeration behavior of non-metallic particles at the interface of liquid steel and Ar gas, in situ. In recent decades, the agglomeration of Al 2 O 3 particle in and on the surface of low-carbon steel has been widely investigated. However, there are very few studies focussing on non-Al 2 O 3 inclusions which are included in a Ca-treated high-carbon steel. In this study, the agglomeration behaviors of sulfide/sulfide and sulfide/oxide particles on the surface of liquid high-carbon steel have been investigated in detail using CSLM. Agglomerations on the liquid surface are governed by capillary forces similar to the Al 2 O 3 particle but this study demonstrates that agglomeration forces among non-Al 2 O 3 particles on the surface of re-melted high-carbon samples are lower than pure-Al 2 O 3 on the surface of low-carbon steel. Despite this, they show similar or longer acting lengths than pure-Al 2 O 3 .

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Analysis of Inclusion Behavior in a Ladle Refining Process by a Newly Developed Coagulation Model

Cited by 12 publications

References 6 publications

Influence of Unstable Non-equilibrium Liquid Iron Oxide on Clustering of Alumina Particles in Steel

Influence of Unstable Non-equilibrium Liquid Iron Oxide on Clustering of Alumina Particles in Steel

Effect of Alumina Morphology on the Clustering of Alumina Inclusions in Molten Iron

Agglomeration Behavior of Non-Metallic Particles on the Surface of Ca-Treated High-Carbon Liquid Steel: An In Situ Investigation

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