Kinetic model of non-metallic inclusions' precipitation during steel solidification

Lehmann, J.; Rocabois, Philippe; Gaye, Henri

doi:10.1016/s0022-3093(01)00329-5

Cited by 48 publications

(35 citation statements)

References 16 publications

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“…Using the presented model, the size distribution of TiN was obtained, and the predicted amount of evolution fit well with the experimental results. Next, the model was extended to one complex solution for oxides by Lehmann et al [119], which enabled the calculation of composition changes and size evolution. The oxide formation in an Al-Ti alloyed low-carbon steel was calculated.…”

Section: During Solidificationmentioning

confidence: 99%

Modeling Inclusion Formation during Solidification of Steel: A Review

You

Michelic

Presoly

et al. 2017

Metals

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Abstract:The formation of nonmetallic inclusions in the solidification process can essentially influence the properties of steels. Computational simulation provides an effective and valuable method to study the process due to the difficulty of online investigation. This paper reviews the modeling work of inclusion formation during the solidification of steel. Microsegregation and inclusion formation thermodynamics and kinetics are first introduced, which are the fundamentals to simulate the phenomenon in the solidification process. Next, the thermodynamic and kinetic models coupled with microsegregation dedicated to inclusion formation are briefly described and summarized before the development and future expectations are discussed.

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Section: During Solidificationmentioning

confidence: 99%

Modeling Inclusion Formation during Solidification of Steel: A Review

You

Michelic

Presoly

et al. 2017

Metals

View full text Add to dashboard Cite

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“…The frequency factor b is a measure for the number of oxide monomers that can be added to the nucleus per unit time. 18 A parameter G is defined, resulting in:…”

Section: Pbo Nucleationmentioning

confidence: 99%

“…For PbO nucleation in LBE one can assume that the formed nuclei are only consisting of pure PbO, removing the summation from the formula above. Lehmann et al 18 give an overview of different approaches to approximate G. The temperature T (directly and, via the oxygen diffusion coefficient in LBE, indirectly), oxygen concentration C O and the critical radius r c (eqn (10)) all have an influence on the value of G. The Zeldovich factor Z is a measure for the number of oxide monomers needed to change the energy of a critical nucleus by more than k B T, with k B the Boltzmann constant. It also accounts for the possible decay of critical nuclei to smaller sizes.…”

Section: Pbo Nucleationmentioning

confidence: 99%

Nucleation and growth of lead oxide particles in liquid lead-bismuth eutectic

Gladinez

Rosseel

Lim

et al. 2017

Phys. Chem. Chem. Phys.

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a Liquid lead-bismuth eutectic (LBE) is an important candidate to become the primary coolant of future, generation IV, nuclear fast reactors and Accelerator Driven System (ADS) concepts. One of the main challenges with the use of LBE as a coolant is to avoid its oxidation which results in solid lead oxide (PbO) precipitation. The chemical equilibria governing PbO formation are well understood. However, insufficient kinetic information is currently available for the development of LBE-based nuclear technology. Here, we report the results of experiments in which the nucleation, growth and dissolution of PbO in LBE during temperature cycling are measured by monitoring dissolved oxygen using potentiometric oxygen sensors. The metastable region, above which PbO nucleation can occur, has been determined under conditions relevant for the operation of LBE cooled nuclear systems and was found to be independent of setup geometry and thus thought to be widely applicable. A kinetic model to describe formation and dissolution of PbO particles in LBE is proposed, based on Classical Nucleation Theory (CNT) combined with mass transfer limited growth and dissolution. This model can accurately predict the experimentally observed changes in oxygen concentration due to nucleation, growth and dissolution of PbO, using the effective interfacial energy of a PbO nucleus in LBE as a fitting parameter.The results are invaluable to evaluate the consequences of oxygen ingress in LBE cooled nuclear systems under normal operating and accidental conditions and form the basis for the development of cold trap technology to avoid PbO formation in the primary reactor circuit.

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“…Em geral, as barreiras de nucleação para a precipitação de inclusões não-metálicas a partir do liquido são consideradas pequenas [30]. Desta forma, a condição de precipitação é normalmente expressa como a temperatura na qual o produto de solubilidade da inclusão, no liquido, é excedido [17].…”

Section: Formação De Inclusões Não-metálicasunclassified

Segregação Em Aços Alta-Resistência Baixa Liga (Arbl) Para Aplicações Em Serviço Com H2s- Avaliação Por Termodinâmica Computacional

Silva¹

2014

TMM

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ResumoA quantidade, tipo e distribuição de inclusões não-metálicas assim como a segregação de solidificação tem grande importância no desempenho dos aços ARBL empregados na indústria do petróleo em serviço com H 2 S (sour service). Embora o efeito do manganês na segregação e na limpeza interna tenha sido estudado experimentalmente e, parcialmente, através de modelos matemáticos de solidificação, de outros elementos, especialmente o silício, são empregados como adições relevantes nestes aços sem um conhecimento mais preciso de seu comportamento na solidificação, especialmente sob o ponto de vista da segregação. Neste trabalho a extensão da segregação dos principais elementos de liga em aços ARBL para sour service é avaliada através de diferentes modelos de termodinâmica computacional. Em particular, são empregados dois casos limites para comparação: a solidificação em equilíbrio e o caso extremo do modelo de Scheil, em que o liquido é considerado homogêneo e assume-se que não ocorre homogeneização no sólido, durante o processo de solidificação. Modelos considerando a difusão no sólido são aplicados para algumas composições mais interessantes. Os resultados são comparados com dados experimentais disponíveis para alguns aços e alguns elementos e servem como base para uma primeira avaliação do potencial da alteração do projeto destas ligas, sob o aspecto da segregação e limpeza interna. Palavras-chave: Termodinâmica computacional; Sour service; Aços; Solidificação. SEGREGATION IN HSLA STEELS FOR SOUR SERVICE: AN EVALUATION USING COMPUTATIONAL THERMODYNAMICS AbstractThe amount, type and distribution of non-metallic inclusions as well as the solidification segregation, which influences inclusion type and distribution, have great influence on the performance of High Strength Low Alloy (HSLA) steels used in sour service in the oil industry. The effects of manganese, both on segregation and on steel cleanness have been studied through experiments and, to a lesser extent, through mathematical modeling of solidification. However, the effect of some other relevant elements added to these steels, in special those effects caused by solidification segregation, have not been extensively studied. In the present work, the extent of segregation and the probable effect on inclusion distribution of the main elements in HSLA steels used in sour service are evaluated through different computational thermodynamic models. In particular, two limiting cases bound the comparison: equilibrium solidification and the Scheil model, in which no homogenization in the solid phase is assumed. Special attention is given to silicon. For relevant compositions, models considering solid and liquid state diffusion are used. The results are compared with experimental data available for some steel compositions and serve as basis for a first evaluation of the alloy design strategy currently applied to these steels, from the point of view of segregation and internal cleanness.

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Kinetic model of non-metallic inclusions' precipitation during steel solidification

Cited by 48 publications

References 16 publications

Modeling Inclusion Formation during Solidification of Steel: A Review

Modeling Inclusion Formation during Solidification of Steel: A Review

Nucleation and growth of lead oxide particles in liquid lead-bismuth eutectic

Segregação Em Aços Alta-Resistência Baixa Liga (Arbl) Para Aplicações Em Serviço Com H2s- Avaliação Por Termodinâmica Computacional

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