Assessment of Al Deoxidation Equilibrium in Liquid Iron

Itoh, Hiroyasu; Hino, Mitsutaka; Ban-Ya, Shiro

doi:10.2355/tetsutohagane1955.83.12_773

Cited by 163 publications

(87 citation statements)

References 11 publications

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“…In most investigations [2][3][4][5][6][7][8][9][10] on thermodynamic aspects of deoxidation equilibrium in Fe-Ni alloys, the effect of nickel on the activity coefficients of oxygen and deoxidizing elements in liquid iron have been evaluated by using their experimental results in Fe-Ni melts. For self-interaction parameters of aluminum and oxygen and the interaction parameter between aluminum and oxygen which were required in their evaluation, they employed the values reported by Sigworth et al 11,12) or recommended by JSPS, 13) both of which are based on liquid iron.…”

Section: Introductionmentioning

confidence: 99%

Aluminum Deoxidation Equilibrium in Liquid Fe-36%Ni Alloy.

et al. 2002

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For thermodynamic prediction, the deoxidation equilibrium of aluminum in Fe-36%Ni alloy was investigated by employing a cold crucible under an Ar gas atmosphere at 1 773 K. The interaction parameters between aluminum and oxygen by taking liquid Fe-36%Ni alloy as the basis (i.e., solvent) are evaluated as follows: within the composition range of [Al]Ͻ1 mass%. The equilibrium constant for reaction 2Al ϩ3O ϭAl 2 O 3(s) was obtained in the temperature range of 1 773 to 1 973 K by using data from the present study and from previous works reported:log K AO ϭ0.58Ϫ24 460/T The deoxidation equilibrium of aluminum in Fe-36%Ni can thus be thermodynamically described in the range of [Al]Ͻ1 mass% using both the first and second order interaction parameters as well as the equilibrium constant determined in this study.KEY WORDS: deoxidation equilibrium; equilibrium constant; interaction parameter; aluminum; nickel; deoxidation product, inclusion; cold crucible.teraction parameter between aluminum and oxygen based on liquid i.e., by investigating deoxidation equilibrium for aluminum in Fe-36%Ni under H 2 /H 2 O gas mixture at 1 973 K and the result is given in Table 1. However, their work was confined to a narrow range in low aluminum concentrations.The objective of the present study is to obtain the thermodynamic data of aluminum deoxidation equilibrium over a wide range of aluminum content covering up to 1 mass% Al in Fe-36%Ni alloy at 1 773 K. Liquid Fe-36%Ni is chosen as a base melt to avoid a separate consideration of nickel on other elements. The equilibrium constant as well as the first order and second order interaction parameters have been determined at 1 773 K. Experimental ProcedureElectromagnetic levitation-melting technique using a cold crucible was employed to study aluminum deoxidation equilibrium in liquid Fe-36%Ni. The cold crucible is a copper crucible constructed in segments, each of which is water-cooled (flow rate: 20 l/min). A high frequency current (20 kW and 170 kHz) was applied to the coil surrounding the crucible.This non-contact levitation melting enables to avoid any contamination or side effect which could otherwise result from a container like alumina crucible. Furthermore, inclusion particles, which are deoxidation products, are completely exposed on the surface of the molten metal and accumulated at the bottom of the metal in the form of a thin film by gravity. Therefore, metal and oxide are perfectly separated from each other and hence all oxygen and aluminum existing in the metal can be regarded as solute, not in the form of oxide.The experimental apparatus is shown in Fig. 1. Gas purification trains and gas flow meters are also constructed. The melt temperature was measured using a two-color optical pyrometer calibrated preliminarily against a thermocouple (Pt-30%Rh/Pt-6%Rh).Nickel and iron of electrolytic grade and high purity aluminum (99.99 mass%) were used in preparing alloys. Master alloys of Fe-36%massNi and Fe-36%massNi-1%massAl were made in an alumina crucible using an induction fur...

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Section: Introductionmentioning

confidence: 99%

Aluminum Deoxidation Equilibrium in Liquid Fe-36%Ni Alloy.

et al. 2002

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“…Table 3 shows the Gibbs free energy of chemical reactions involved in the present work. Table 3 Free energy data of reactions considered in the present work [4,5,6,7] Reaction…”

Section: Resultsmentioning

confidence: 99%

The Evolution and Thermodynamic Analysis of Inclusions in Gear Steel after Magnesium Treatment

Xu¹,

Yang²,

Cheng³

et al. 2017

Proceedings of the 2017 International Conference on Manufacturing Engineering and Intelligent Materials (ICMEIM 2017)

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Abstract.The influence of different magnesium content on the inclusions in steel was studied under the condition of the same molten steel at 1873 K. The results show that, after the magnesium treatment, the tiny MgO•Al 2 O 3 inclusions could become the nucleus of MnS in solidification of liquid steel, which weakens the large number of MnS precipitates in grain boundaries. The change of the oxide core in the composite sulfides with the increase of magnesium content is: Al 2 O 3 →MgO•Al 2 O 3 →MgO•Al 2 O 3 +MgO→MgO+MgS.This evolution mechanism can provide certain reference for the application of magnesium treatment in production practice.

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“…(8) were reassessed by Itoh et al, 29) Fujiwara et al 30) and Kang et al. 31) Ca-O equilibrium constants of Eq.…”

Section: Rate Constant Of Nitrogen Removal Reactionmentioning

confidence: 99%

Effect of Changes in Sulfur and Oxygen Concentration on Change in Nitrogen Concentration in Liquid Steel during CaO^|^ndash;CaSi Powder Blowing under Reduced Pressure

Numata¹,

Higuchi²

2012

ISIJ Int.

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In this paper, 1 500 kg scale experiments of CaSi mixed CaO powder top blowing onto the Al killed steel were carried out under reduced pressure. And the effects of CaSi alloy ratio in the mixture on reactions of desulfurization and nitrogen removal were examined. Aluminum decreasing rate decreased and rate constant of desulfurization and nitrogen removal increased with increasing CaSi mixing ratio to flux. It is supposed from the above that deoxidation and desulfurization reaction can simultaneously occur by blowing the mixture of CaSi and CaO powder and the effect of calcium mixing powder on desulfurization can be explained by promotion of CaO desulfurization and CaS formation. It is suggested that lower oxygen and sulfur activity due to reaction between molten steel and powder with CaSi increased rate constant of nitrogen removal.

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Assessment of Al Deoxidation Equilibrium in Liquid Iron

Cited by 163 publications

References 11 publications

Aluminum Deoxidation Equilibrium in Liquid Fe-36%Ni Alloy.

Aluminum Deoxidation Equilibrium in Liquid Fe-36%Ni Alloy.

The Evolution and Thermodynamic Analysis of Inclusions in Gear Steel after Magnesium Treatment

Effect of Changes in Sulfur and Oxygen Concentration on Change in Nitrogen Concentration in Liquid Steel during CaO^|^ndash;CaSi Powder Blowing under Reduced Pressure

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