The influence of different calcium‐based additions on desulphurisation and inclusion characteristics

Andersson, Matts; Berlin, Dean; Jönsson, Pär G.; Löwnertz, Martin

doi:10.1034/j.1600-0692.2001.300303.x

Cited by 5 publications

(2 citation statements)

References 3 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Dois minutos após a injeção de CaSi, as inclusões de cálcio-aluminatos apresentam um tamanho que se mantém constante com o tempo. Essa distribuição de tamanhos foi observada nos experimentos em laboratório conduzidos por outros autores, (11,12) e também em amostras coletadas na planta (7) . O aumento do diâmetro médio nas amostras F se deve à precipitação dos compostos de (Ca,Mn)S na superfície das inclusões durante a solidificação lenta, como mostram os mapas de raios X (Item 3.3).…”

Section: Distribuição De Tamanhos Das Inclusões Via Mevunclassified

Estudo Experimental Do Tratamento De Inclusões Com Cálcio Em Escala Laboratorial

Bielefeldt

Marcon

Vilela

2008

TMM

View full text Add to dashboard Cite

O cálcio (ou ligas a base de cálcio) é muito importante na metalurgia de muitos tipos de aço. Esse elemento é adicionado para promover a desoxidação, dessulfuração, controle da forma de inclusões e para o aumento da lingotabilidade dos aços no lingotamento contínuo. Apesar da importância do uso do cálcio na metalurgia dos aços, o conhecimento acerca do seu comportamento termodinâmico e cinético continua sendo tópico de estudo. Os objetivos deste trabalho são: 1) avaliar a evolução da composição química de inclusões modificadas com a adição de cálcio no banho ao longo do tempo de um aço para construção mecânica (SAE 8620); e 2) consolidar uma metodologia para estudo de inclusões em escala laboratorial. Foram executadas corridas em um forno elétrico resistivo com capacidade de até 8 kg de aço. As matérias-primas utilizadas foram: ferro com alta pureza, ferroligas, alumínio e CaSi. Na análise química do aço foram considerados os elementos de liga de rotina de produção, bem como o teor de cálcio e oxigênio total. Nas análises de inclusões foram avaliadas: composição química, morfologia, distribuição de fases e tamanho via MEV/EDS. Observou-se a modificação química das inclusões com a adição de cálcio, formando diferentes tipos de cálcio-aluminatos, como previsto. Devido à presença de enxofre verifica-se a formação de sulfetos de cálcio e manganês associados aos cálcio-aluminatos.

show abstract

Section: Distribuição De Tamanhos Das Inclusões Via Mevunclassified

Estudo Experimental Do Tratamento De Inclusões Com Cálcio Em Escala Laboratorial

Bielefeldt

Marcon

Vilela

2008

TMM

View full text Add to dashboard Cite

show abstract

“…= 35 ppm in the steel. Though adding Ca wire or CaSi powder into the steel can modify the shape and defonnability of inclusions [43,44], this method is rare to be used to produce tire cord steels. Ca is very reactive , and it is only effective after the steel has been deoxidized and if slag entrainment, especially with FeO and MnO, can be avoided .…”

Section: Steel Plants Processes and Techniquesmentioning

confidence: 99%

State of the Art in the Control of Inclusions in Tire Cord Steels - a Review

Zhang

2006

steel research international

View full text Add to dashboard Cite

The control of inclusions in tire cord steels and techniques used in the production process are extensively reviewed. Inclusion and segregation requirements for the tire cord steel are discussed. The deformability of an inclusion is significantly affected by its AI203 content. Inclusions containing 20% AI20 3 has best deformability. The undeformable inclusions can be avoided by controlling the dissolved aluminum in the steel. Low basicity slags favour the generation of deformable inclusions. When the basicity R (=CaO/Si0 2 ) = 0.8-1.5, the dissolved aluminum in the steel should be 1-5ppm to achieve 20% AI 203 in inclusions. With R=1.0-1.4, in order to control [AI] in the range of 1-5ppm, the slag should contain approximately 8% A120 3. The technologies to control inclusions in tire cord steels are reviewed including steel deoxidizer choice, steel refining method, slag carry over from BOF to the ladle, ladle stirring practice, control of nitrogen pickup and caster curvature. Control methods to decrease the central segregation in the tire cord steel are briefly reviewed, such as electromagnetic stirring during continuous casting.The work presents theoretical fundamentals of the process of refining molten steel from liquid non-metallic inclusions, using the method of filtration with ceramic filters -the thermodynamic precondition for the absorption of liquid non-metallic inclusions on the surface of a ceramic filter. The theoretical consideration has been supported by the results of laboratory tests on the filtration of steel which was previously reduced with complex deoxidants giving liquid products of deoxidization. The filtration process of steel melts reduced with complex deoxidants of type AI-Mn-Si has proved to be more efficient. The deoxidation products were identified on the filtration surface of the ceramic filters.

show abstract

Modelling of Manganese Sulphide Formation during Solidification, Part I: Description of MnS Formation Parameters

Diederichs

Bleck

2006

steel research international

View full text Add to dashboard Cite

Precipitations of second phases in steel grades influence the mechanical properties of the material significantly. Manganese sulphides especially affect the ductility propert ies at high as well as at low testing temperatures. For a sufficient appreciation of the influence of MnS precipitates on the propert ies, a proper knowledge about the parameters in regard to the size and distribution of MnS precipitates is necessary. This paper proposes a model to describe the solidif ication of a medium carbon steel grade , the micro-segregation of manganese und sulphur and the subsequent precipitation of MnS. Especially for the calculat ion of the mean radius of globular MnS precipitates after solidification, a new approach is presented regarding the MnS size as a function of the manganese and sulphur content , the cooling rate during solidification and the secondary dendrite arm spacing. The model is validated by means of quench tests in combination with light-optical and scanning electron microscopic evaluations of the size distribution of MnS precipitates as well as EDX analysis for the composition of the formed sulphide phase.

show abstract

The influence of different calcium‐based additions on desulphurisation and inclusion characteristics

Cited by 5 publications

References 3 publications

Estudo Experimental Do Tratamento De Inclusões Com Cálcio Em Escala Laboratorial

Estudo Experimental Do Tratamento De Inclusões Com Cálcio Em Escala Laboratorial

State of the Art in the Control of Inclusions in Tire Cord Steels - a Review

Modelling of Manganese Sulphide Formation during Solidification, Part I: Description of MnS Formation Parameters

Contact Info

Product

Resources

About