Inclusion Modification by Calcium Treatment.

Higuchi, Yoshihiko; Numata, Mitsuhiro; Fukagawa, Shin; Shinme, Kaoru

doi:10.2355/isijinternational.36.suppl_s151

Cited by 68 publications

(38 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…The CaO and CaS contents in the inclusions decreased gradually as the dissolved calcium vaporized and decreased with the time. [9] A similar effect was calculated for when the oxygen content in steel was 20 ppm, and the CaS formed when the calcium content was 20 ppm (aluminum 100 ppm and sulfur 250). With the same aluminum and sulfur contents, the CaS saturation occurred already when the calcium was around 10 ppm and the oxygen level was 10 ppm.…”

Section: Introductionmentioning

confidence: 99%

Transformation of Alumina Inclusions by Calcium Treatment

Lind¹,

Holappa²

2010

Metall Mater Trans B

View full text Add to dashboard Cite

The objectives of this study were to investigate reactions of calcium with Al 2 O 3 by different model experiments both on the laboratory and on the industrial scale. Experiments with solid Al 2 O 3 and CaO were performed between 1350°C and 1600°C. Reaction rate constants were determined based on scanning electron microscopy/energy dispersive spectroscopy (SEM/EDS) observations of reaction products and weight measurements of the Al 2 O 3 reacted via dissolution of the CaO bearing phases from the specimens after the annealing period. The results showed that the formation of calcium aluminate phases proceeded rapidly at temperatures greater than 1405°C when a liquid calcium aluminate was formed. In the lowest temperature range (1350°C-1405°C), when the formation of liquid phase ceased, the reaction rate was several orders of magnitude lower. Industrial trials including Ca-alloy injection into steel, sampling and SEM/EDS analyses, as well as an inclusion rating in the samples show the concept of rapid transformation of the alumina inclusions with Ca treatment.

show abstract

Section: Introductionmentioning

confidence: 99%

Transformation of Alumina Inclusions by Calcium Treatment

Lind¹,

Holappa²

2010

Metall Mater Trans B

View full text Add to dashboard Cite

show abstract

“…Higuchi et al 13) developed the mathematical model of the kinetics which considered the evaporation rate of calcium and the reaction rate between inclusions and the molten steel. There are, however, few studies 14,15) on the kinetics of the inclusion composition change during calcium addition and the relationship between the flux-metal reaction rate and inclusion-metal reaction rate.…”

Section: Introductionmentioning

confidence: 99%

Change in Inclusion Composition during CaO Flux Powder Blowing under Reduced Pressure

Numata¹,

Higuchi²

2012

ISIJ Int.

Self Cite

View full text Add to dashboard Cite

To examine the reaction mechanism of the variation of calcium content in inclusions and the molten steel and the effect of flux composition on the reaction, the variations of molten steel content and inclusion content during CaO, 60%CaO-40%CaF2 or 50%CaO-50%CaSi powder blowing onto the molten steel under reduced pressure were investigated with 15 kg scale experiments. From the experimental results, it was found that the inclusion composition was changed from Al2O3 to Al2O3-CaO by CaO flux that did not contain CaSi alloy, and that the reaction path of the inclusion composition was changed remarkably by CaSi alloy in CaO flux. From the experimental results and the chemical thermodynamic calculation, the effects of the flux and CaSi alloy on the change in composition of inclusion and melts were examined.

show abstract

“…[19][20][21][22][23][24][25][26][27] and some models have been proposed. [25][26][27] There are few thermodynamic calculation on the transformation of MgO·Al 2 O 3 spinel inclusions by calcium treatment. 14,16,17) Composite deoxidation by Mg, Al and Ca is considered.…”

Section: Formation Thermodynamics Of Oxide Inclusionsmentioning

confidence: 99%

Characteristics of Inclusions in Low Carbon Al-Killed Steel during Ladle Furnace Refining and Calcium Treatment

Yang

Zhang

Wang³

et al. 2013

ISIJ Int.

172

112

View full text Add to dashboard Cite

A plant trial of the productions of LCAK steel was performed, and characteristics of inclusions during LF refining and calcium treatment were investigated. Besides, thermodynamic diagram among magnesium, aluminum, and oxygen as well as calcium, magnesium, aluminum, and oxygen in the steel melt were studied to understand the fundamentals of inclusion modification by calcium treatment in LCAK steel. Furthermore, the change mechanisms of oxide inclusions and the precipitation of calcium sulfide were discussed. The experimental results showed that oxide inclusions were partly changed along with the path of Al2O3→MgO·Al2O3→(MgO·)CaO·Al2O3, which was a little different from the thermodynamic calculation results due to the limited kinetic conditions. Calcium treatment somehow modified the inclusions, however, many large inclusions were generated, and the modification effect would be dramatically decreased by the formation of large amount of CaS inclusions, which appeared with three main distribution forms. The formation of inclusions after calcium treatment were discussed based on the thermodynamic analysis. In order to reach the target of modification, sulfur concertration in steel should be reduced to a small amount to decrease the formation of CaS.

show abstract

Inclusion Modification by Calcium Treatment.

Cited by 68 publications

References 0 publications

Transformation of Alumina Inclusions by Calcium Treatment

Transformation of Alumina Inclusions by Calcium Treatment

Change in Inclusion Composition during CaO Flux Powder Blowing under Reduced Pressure

Characteristics of Inclusions in Low Carbon Al-Killed Steel during Ladle Furnace Refining and Calcium Treatment

Contact Info

Product

Resources

About