Modeling the coagulation and removal of nonmetallic inclusions during the injection of an inert gas into a melt

Chichkarev, E. A.

doi:10.1007/s11015-010-9286-1

Cited by 4 publications

(3 citation statements)

References 4 publications

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“…Cleanliness of steel can be determined by the size, distribution, shape, and number density of NMIs. Various techniques are available to reduce and control NMIs, such as filtration of the melt, inert gas stirring [10], flux and slag absorption [11], inclusion modification [12], dissolved oxygen control, and the use of a protective atmosphere [13,14].…”

Section: J Min Metall Sect B-metall 55 (3) B (2019) 381 -395mentioning

confidence: 99%

The effect of electroslag remelting on the cleanliness of CrNiMoWMnV ultrahigh-strength steels

Ali

Porter

Kömi

et al. 2019

J min metall B Metall

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The cleanliness of ultrahigh-strength steels (UHSSs) without and with electroslag remelting (ESR) using a slag with the composition of 70% CaF 2 , 15% Al 2 O 3 , and 15% CaO was studied. Three experimental heats of UHSSs with different chemical compositions were designed, melted in an induction furnace, and refined using ESR. Cast ingots were forged at temperatures between 1100 and 950 °C, air cooled, and their non-metallic inclusions (NMIs) were characterized using field emission scanning electron microscopy and laser scanning confocal microscopy. Thermodynamic calculations for the expected NMIs formed in the investigated steels with and without ESR were performed using FactSage 7.2 software while HSC Chemistry version 9.6.1 was used to calculate the standard Gibbs free energies (G°). As a result of ESR the total impurity levels (TIL% = O% + N% + S%) and NMI contents decreased by as much as 46 % and 62 %, respectively. The NMIs were classified into four major classes: oxides, sulphides, nitrides, and complex multiphase inclusions. ESR brings about large changes in the area percentages, number densities, maximum equivalent circle diameters, and the chemical composition of the various NMIs. Most MnS inclusions were removed although some were re-precipitated on oxide or nitride inclusions leading to multiphase inclusions with an oxide or nitride core surrounded by sulphide, e.g. (MnS.Al 2 O 3) and (MnS. TiN). Also, some sulphides are modified by Ca forming (CaMn)S and CaS.Al 2 O 3. Some nitrides like TiN and (TiV)N are nucleated and precipitated during the solidification phase. Al 2 O 3 inclusions were formed as a result of the addition of Al as a deoxidant to the ESR slag to prevent penetration of oxygen to the molten steel.

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Section: J Min Metall Sect B-metall 55 (3) B (2019) 381 -395mentioning

confidence: 99%

The effect of electroslag remelting on the cleanliness of CrNiMoWMnV ultrahigh-strength steels

Ali

Porter

Kömi

et al. 2019

J min metall B Metall

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“…Inert gas injection is one of the most effective ways to remove the inclusions by enhancing bubble adherence and agitating turbulence flow to improve inclusion collision and flotation. [2][3][4] Clusters formed by the agglomeration of small inclusions are more readily floated to the melt surface or steel/slag interface. However, it is more detrimental if these clusters remain in the solidified steel.…”

Section: Introductionmentioning

confidence: 99%

Inertial Force on Floating Inclusion Particles at the Interface of Liquid Steel and Inert Gas

Qiu¹,

Malfliet²,

Guo³

et al. 2021

ISIJ Int.

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To predict the clustering of inclusions at the liquid steel and inert gas interface, it is essential to calculate the pairwise attractive (inertial) force on the inclusions correctly. In most of the studies, the inertial force is calculated from three successive inter-particle distances with a certain time interval, in which the inertial force is assumed to be identical at the first two distances. Considering the nature of the attractive force, a new iteration scheme is proposed where the inertial force is assumed to be non-identical from point to point. However, both the identical and non-identical force schemes tend to give an unreasonably oscillating force when the measured inter-particle distance is less accurate. Moreover, the curve fitting function is also considered in this study including the use of polynomial, exponential, sum of sines, rational, Gaussian functions and Fourier series. Among these functions, the 4th order polynomial and the 2nd order sine are the most robust functions in predicting the inertial force on particles, even when the measured distance is less accurate.

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“…Solid inclusions of alumina and silicon that are poorly wetted by liquid steel can be affectively removed together with gas bubbles. The rate of removal of nonmetallic inclusions of different sizes from a melt is significantly influenced their flotation by bubbles of the inert gas [14,15] The main goal of experiments was determine the influence of volume and duration of inert gas blowing in to the steel in electric induction furnace on the content of non-metallic inclusions in the liquid steel.…”

Section: Introductionmentioning

confidence: 99%

Influence of Blowing of Argon on the Cleanness of Steel

Pribulová

2012

Archives of Foundry Engineering

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The mechanical properties of steel components are controlled by the chemical composition and mechanical treatment to which the steel is submitted. Non-metallic inclusions have a very high influence on the steel quality but secondary metallurgy enables to reduce their content in the steel. Possibilities of secondary metallurgy are relatively extensive but financial situation in Slovak foundries does not enable to make investments in secondary metallurgy in the near future. Accessible means for influencing of steel quality is injection of an inert gas. Main goal of experiments described in the article was verify the influence of blowing of argon into the steel in an electric induction furnace on its cleanness. Duration and flow-rate of argon blowing have a very clearly influence on the final content of non-metallic inclusions. Minimum time of argon blowing necessary for reducing of content of non-metallic inclusions in one tonne electric induction furnace was more than 6 minutes and recommended argon flow rate was 10 litters per minute.

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Modeling the coagulation and removal of nonmetallic inclusions during the injection of an inert gas into a melt

Cited by 4 publications

References 4 publications

The effect of electroslag remelting on the cleanliness of CrNiMoWMnV ultrahigh-strength steels

The effect of electroslag remelting on the cleanliness of CrNiMoWMnV ultrahigh-strength steels

Inertial Force on Floating Inclusion Particles at the Interface of Liquid Steel and Inert Gas

Influence of Blowing of Argon on the Cleanness of Steel

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