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calcium aluminate inclusions in steel process

A Kinetic Model for the Modifiion of Al2O3 Inclusions

The diffusion of Al in the inclusion layer was the limiting link in the inclusion modifiion process. The Ca concentration in molten steel had the greatest influence on the inclusion modifiion time. The modifiion time for inclusions tended to be longer in the transformation of higher CaO-containing calcium aluminate.

Kim, Tae Sung; Holappa, Lauri; Park, Joo Hyun Influence of

1 Influence of calcium aluminate flux on reoxidation behaviour of molten steel during continuous casting process Tae Sung Kima, Lauri Holappab and Joo Hyun Parka a Department of Materials Engineering, Hanyang University, Ansan 15588, Korea b School of Chemical Engineering, Aalto University, Espoo, Finland CONTACT Joo Hyun Park ; [email protected]

Some aspects of non-metallic inclusions during vacuum

Large nuer of steel samples were collected and examined. Liquid calcium aluminate inclusions with low SiO2 and high SiO2 were often found with spinel inclusions before vacuum degassing. Laboratory experiments showed that spinel would react with the dissolved Ca in the liquid steel forming calcium aluminate inclusions.

Inclusion modifiion in steel castings using automated

INCLUSION MODIFIION IN STEEL CASTINGS USING AUTOMATED INCLUSION ANALYSIS SEM and EDS images of spherical a) CaS and b) calcium aluminate inclusions from the sample collected after Ca-treatment in the ladle in the acid practice, samples collected at various stages of the casting process, for plant A with no calcium-treatment and plant

MODIFIION OF OXYGEN AND SULPHUR INCLUSIONS IN …

The calcium aluminates are of different shape and have a lower content of calcium. Most of aluminates had a sulphidic ring of type (Ca,Mn)S – Figure 1. The form of sulphides forming the inclusions case and their chemical compositions depend on the content of sulphur and calcium in steel. By low calcium content,

Inclusion evolution after calcium addition in Ti-bearing

Meanwhile, calcium could also modify solid titanium aluminate inclusions to spherical ones similarly, but there were a nuer of multilayer inclusions in molten steel at the initial stage. Different calcium treatment level should be adopted in different titanium content steel production process. As for the production practice, to achieve the

Inclusion Evolution during Modifiion of Alumina

For small size inclusions in Al-killed Ca-treated steel plates, calcium aluminate inclusions, with low melting temperature, were elongated during the hot rolling process, even if they were covered

Accepted manuscript of high sulfur AL killed steel - TU Delft

Keywords: Inclusion, Aluminium killed steel, Calcium aluminates, Oxy-sulphides, High sulphur, Billet. 1. Introduction The clogging of SEN ( Submerged entry nozzle) due to the deposition of inclusions, such as alumina is a long-witnessed problem in the continuous casting of aluminium-killed low-carbon steels[1]. Inclusions in steels are very

Modifiion of Alumina and Spinel Inclusions by Calcium

Steel Cleanliness plays a crucial role in determining steel properties such as toughness, ductility, formability, corrosion resistance and surface quality. The production of clean steel often involves the elimination or chemical and morphological modifiion of oxide and sulfide inclusions. Along with deteriorating the steel properties, solid inclusions can affect steel castability through

A Kinetic Model for the Modifiion of Al2O3 Inclusions

Mar 09, 2021· limiting link in the inclusion modifiion process. The Ca concentration in molten steel had the greatest influence on the inclusion modifiion time. The modifiion time for inclusions tended to be longer in the transformation of higher CaO-containing calcium aluminate. The modifiion

Transient Inclusion Evolution During Modifiion of

saturated liquid calcium aluminate inclusions. Several samples from industrial heats were also analyzed, and a typical example is given in this paper. For the industrial sample, the heat size was 200 metric tons, and the amount of calcium silicide injected (for calcium treat-ment) was 170 kg. The steel composition of the indus-

Evolution of Mgo·Al2O3 Based Inclusions in Alloy Steel

mechanism of liquid calcium aluminate inclusions from MgO·Al2O3 spinel, and found that spinel reacted with the dissolved Ca forming a liquid calcium aluminate phase. Pretorius et al [10] studied the modifiion of spinel inclusions by Ca- treatment in LCAK steel by industrial experiments and showed the feasibility for the

DISSOLUTION KINETICS OF CALCIUM ALUMINATE IN …

Inclusion removal is critical for the production of clean steel. A better understanding of removal processes require knowledge of the effect of process parameters on dissolution kinetics. The present research focuses on the kinetics of calcium aluminate inclusion dissolution in relevant steelmaking slags that contain CaO, Al 2 O 3 and SiO 2.

A Kinetic Model for the Modifiion of Al2O3 Inclusions

Mar 09, 2021· limiting link in the inclusion modifiion process. The Ca concentration in molten steel had the greatest influence on the inclusion modifiion time. The modifiion time for inclusions tended to be longer in the transformation of higher CaO-containing calcium aluminate. The modifiion

Clean Steel: Part Three :: Total Materia Article

The addition of calcium to steel which contains such inclusions changes the composition of these inclusions from pure alumina to CaO-containing calcium aluminates. As it can be see from Figure 1, the, melting point of the calcium aluminates will decrease as the CaO content increases, until liquid oxide phases occur at about 22% of CaO, i.e

Experimental and Numerical Study of Calcium Treatment of Steel

In order to diminish the harmful effects of aluminate inclusions and improve the castability of molten steel, calcium treatment is widely used in Aluminum killed steels. However, calcium treatment gives irregular results. Even with many efforts done to understand the behavior of calcium in liquid steel, it is not yet accurately predicted. Therefore, the mechanism by which the calcium dissolves

Modifiion of non-metallic inclusions to improve the

It was found that calcium aluminate inclusions had a more deleterious effect on the fatigue properties of steel than alumina inclusions. In calcium modified steels, at lifetimes of more than 5x105 cycles, fatigue cracks always initiated from calcium aluminate inclusions, which were partly or completely debonded from the matrix.

Inclusion Evolution during Modifiion of Alumina

ify solid alumina inclusions to calcium aluminates, which exists in a fully or partially liquid phase. Liquid inclusions can improve steel castability, but make inclusions size larger during hot rolling process if these inclusions have not been completely removed before casting, which can significantly

Modifiion of Alumina and Spinel Inclusions by Calcium

Steel Cleanliness plays a crucial role in determining steel properties such as toughness, ductility, formability, corrosion resistance and surface quality. The production of clean steel often involves the elimination or chemical and morphological modifiion of oxide and sulfide inclusions. Along with deteriorating the steel properties, solid inclusions can affect steel castability through

The effective modifiion of spinel inclusions by Ca

metallic inclusions in steel.”2 • “astrophic plugging of calcium-treated steels seems to correlate with the presence of spinel.”3 • solid spinel inclusions into liquid inclusions by “Spinel, just like alumina inclusions, deteriorates the final quality of steel products because it …

(PDF) Evolution of Inclusions in Magnesium–Calcium-Treated

Magnesium–calcium treatment can effectively balance the castability of molten steel and the control on inclusion size, which is an inclusion modifiion approach with appliion prospect. In

Clean Steel: Part Three :: Total Materia Article

The addition of calcium to steel which contains such inclusions changes the composition of these inclusions from pure alumina to CaO-containing calcium aluminates. As it can be see from Figure 1, the, melting point of the calcium aluminates will decrease as the CaO content increases, until liquid oxide phases occur at about 22% of CaO, i.e

Mechanism and kinetics of transformation of alumina

Sep 08, 2006· After calcium treatment, the inclusions are restricted mainly to calcium aluminates (CaO-Al2O3) and the sulphur in the steel is associated with these inclusions as calcium sulphide. The topic of the present study concerns the basic mechanism and kinetics of the transformation process of alumina inclusions in steel when calcium is introduced

A Kinetic Model for the Modifiion of Al2O3 Inclusions

Mar 09, 2021· limiting link in the inclusion modifiion process. The Ca concentration in molten steel had the greatest influence on the inclusion modifiion time. The modifiion time for inclusions tended to be longer in the transformation of higher CaO-containing calcium aluminate. The modifiion

(PDF) Evolution of Inclusions in Magnesium–Calcium-Treated

Magnesium–calcium treatment can effectively balance the castability of molten steel and the control on inclusion size, which is an inclusion modifiion approach with appliion prospect. In

Inclusion Evolution during Modifiion of Alumina

The production of clean steel involves the controlling, elimination, or modifiion 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.

Experimental and Numerical Study of Calcium Treatment of Steel

In order to diminish the harmful effects of aluminate inclusions and improve the castability of molten steel, calcium treatment is widely used in Aluminum killed steels. However, calcium treatment gives irregular results. Even with many efforts done to understand the behavior of calcium in liquid steel, it is not yet accurately predicted. Therefore, the mechanism by which the calcium dissolves

Liquid Inclusion Collision and Agglomeration in Calcium

Aug 11, 2021· This work addresses conflicting results in the literature regarding liquid inclusion agglomeration. To assess whether liquid calcium aluminates do agglomerate in liquid steel, laboratory experiments were performed: melting electrolytic iron, deoxidizing the melt with aluminum and subsequently calcium treating the deoxidation products (alumina and magnesia-alumina spinel inclusions).

Steelmaking additive composition - SCHWER; JOHN W.

In the process of steelmaking utilizing electric furnace, basic oxygen furnace, AOD furnace or open hearth furnace means, the improvement consisting of the addition to the molten steel of a steelmaking additive composition consisting essentially of from about 40 to 70 wt% CaO, 20 to 50 wt% Al 2 O 3 from bauxite or mixtures of calcium aluminate

Some aspects of non-metallic inclusions during vacuum

Large nuer of steel samples were collected and examined. Liquid calcium aluminate inclusions with low SiO2 and high SiO2 were often found with spinel inclusions before vacuum degassing. Laboratory experiments showed that spinel would react with the dissolved Ca in the liquid steel forming calcium aluminate inclusions.

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