Change search
Link to record
Permanent link

Direct link
BETA
Alternative names
Publications (10 of 44) Show all publications
Ni, P., Tanaka, T., Suzuki, M., Nakamoto, M. & Jönsson, P. (2019). A Kinetic Model of Mass Transfer and Chemical Reactions at a Steel/Slag Interface under Effect of Interfacial Tensions. ISIJ International, 59(5), 737-748
Open this publication in new window or tab >>A Kinetic Model of Mass Transfer and Chemical Reactions at a Steel/Slag Interface under Effect of Interfacial Tensions
Show others...
2019 (English)In: ISIJ International, ISSN 0915-1559, E-ISSN 1347-5460, Vol. 59, no 5, p. 737-748Article in journal (Refereed) Published
Abstract [en]

A new kinetic model was developed to predict the dynamic change of the interfacial oxygen content and the steel/slag interfacial tension. This model mainly describes the following interfacial physicochemical phenomena: i) Silica decomposition and oxygen adsorption at the interface, ii) Oxygen and aluminum reactions at the interface, iii) Oxygen desorption from the interface, iv) Silica mass transfer from the slag to the interface, v) Dissolution of the formed alumina into the slag and its transfer in slag and vi) Blockage on the silica mass transfer, to come in contact with the steel, by the accumulation of the formed alumina at the interface. With this model, the dynamic changes of the interfacial oxygen contents under different aluminum contents in steel and different slag viscosities were predicted. Overall, the interfacial oxygen content was found to increase with a decreased aluminum content and a decreased slag viscosity. Furthermore, the aluminum reaction rate can significantly influence the interfacial oxygen content as well as the interfacial tension. In addition, the model captured the fast increase of the interfacial tension after passing the minimum value point for the system of a high -Al content steel and a low viscous slag, which is in agreement with the experimental observations. Furthermore, a parameter study was carried out to show the influence of various parameters on the dynamic interfacial phenomena.

Place, publisher, year, edition, pages
IRON STEEL INST JAPAN KEIDANREN KAIKAN, 2019
Keywords
steel-slag interfacial tension, mass transfer, thermodynamics and kinetics, interfacial reactions, dynamic modeling
National Category
Metallurgy and Metallic Materials
Identifiers
urn:nbn:se:kth:diva-254046 (URN)10.2355/isijintemational.ISIJINT-2018-496 (DOI)000469406900001 ()
Note

QC 20190813

Available from: 2019-08-13 Created: 2019-08-13 Last updated: 2019-08-13Bibliographically approved
Liu, Y., Ersson, M., Liu, H., Jönsson, P. G. & Gan, Y. (2019). A Review of Physical and Numerical Approaches for the Study of Gas Stirring in Ladle Metallurgy. Metallurgical and materials transactions. B, process metallurgy and materials processing science, 50(1), 555-577
Open this publication in new window or tab >>A Review of Physical and Numerical Approaches for the Study of Gas Stirring in Ladle Metallurgy
Show others...
2019 (English)In: Metallurgical and materials transactions. B, process metallurgy and materials processing science, ISSN 1073-5615, E-ISSN 1543-1916, Vol. 50, no 1, p. 555-577Article, review/survey (Refereed) Published
Abstract [en]

This article presents a review of the research into gas stirring in ladle metallurgy carried out over the past few decades. Herein, the physical modeling experiments are divided into four major areas: (1) mixing and homogenization in the ladle; (2) gas bubble formation, transformation, and interactions in the plume zone; (3) inclusion behavior at the steel-slag interface and in the molten steel; and (4) open eye formation. Several industrial trials have also been carried out to optimize gas stirring and open eye formation. Approaches for selecting criteria for scaling to guarantee flow similarity between industrial trials and physical modeling experiments are discussed. To describe the bubble behavior and two-phase plume structure, four main mathematical models have been used in different research fields: (1) the quasi-single-phase model, (2) the volume of fluid (VOF) model, (3) the Eulerian multiphase (E-E) model, and (4) the Eulerian-Lagrangian (E-L) model. In recent years, the E-E model has been used to predict gas stirring conditions in the ladle, and specific models in commercial packages, as well as research codes, have been developed gradually to describe the complex physical and chemical phenomena. Furthermore, the coupling of turbulence models with multiphase models is also discussed. For physical modeling, some general empirical rules have not been analyzed sufficiently. Based on a comparison with the available experimental results, it is found that the mathematical models focusing on the mass transfer phenomenon and inclusion behaviors at the steel-slag interface, vacuum degassing at the gas-liquid interface, dissolution rate of the solid alloy at the liquid-solid interface, and the combination of fluid dynamics and thermodynamics need to be improved further. To describe industrial conditions using mathematical methods and improve numerical modeling, the results of physical modeling experiments and industrial trials must offer satisfactory validations for the improvement of numerical modeling.

Place, publisher, year, edition, pages
SPRINGER, 2019
National Category
Materials Engineering
Identifiers
urn:nbn:se:kth:diva-243935 (URN)10.1007/s11663-018-1446-x (DOI)000456070300052 ()2-s2.0-85056988962 (Scopus ID)
Note

QC 20190313

Available from: 2019-03-13 Created: 2019-03-13 Last updated: 2019-03-13Bibliographically approved
Nabeel, M., Alba, M., Karasev, A., Jönsson, P. G. & Dogan, N. (2019). Characterization of Inclusions in 3rd Generation Advanced High-Strength Steels. Metallurgical and materials transactions. B, process metallurgy and materials processing science, 50(4), 1674-1685
Open this publication in new window or tab >>Characterization of Inclusions in 3rd Generation Advanced High-Strength Steels
Show others...
2019 (English)In: Metallurgical and materials transactions. B, process metallurgy and materials processing science, ISSN 1073-5615, E-ISSN 1543-1916, Vol. 50, no 4, p. 1674-1685Article in journal (Refereed) Published
Abstract [en]

Samples taken from laboratory-produced 3rd generation advanced high-strength steels, solidified at a low cooling rate, have been investigated to study the characteristics of non-metallic inclusions. Two steels, containing 2 and 5 pct Mn content, were produced for this purpose. A higher number of total inclusions were observed in 5 pct Mn steel. The four main types of inclusions observed were Al2O3, AlN, MnS, and AlSiMn-oxide. These classes were divided into subclasses according to variations in their chemistry. The major subclasses of AlN inclusions are either plate-like or regular in shape and have different size distributions. Thermodynamic calculations suggest that plate-like AlN inclusions are formed at the initial stage of solidification, while faceted/regular-shaped inclusions are precipitated toward the end of solidification. Moreover, it was found that the size of nitride inclusions is related to their N content. This phenomenon is discussed from the viewpoint of nucleation theory.

Place, publisher, year, edition, pages
Springer, 2019
National Category
Metallurgy and Metallic Materials
Identifiers
urn:nbn:se:kth:diva-255553 (URN)10.1007/s11663-019-01605-0 (DOI)000475698700016 ()2-s2.0-85066623028 (Scopus ID)
Note

QC 20190808

Available from: 2019-08-08 Created: 2019-08-08 Last updated: 2019-08-08Bibliographically approved
Liu, Y., Ersson, M., Liu, H., Jönsson, P. & Gan, Y. (2019). Comparison of Euler-Euler Approach and Euler–Lagrange Approach to Model Gas Injection in a Ladle. Steel Research International, 90(5), Article ID 1800494.
Open this publication in new window or tab >>Comparison of Euler-Euler Approach and Euler–Lagrange Approach to Model Gas Injection in a Ladle
Show others...
2019 (English)In: Steel Research International, ISSN 1611-3683, E-ISSN 1869-344X, Vol. 90, no 5, article id 1800494Article in journal (Refereed) Published
Abstract [en]

The gas injection in a ladle using a porous plug is simulated using both the Euler-Euler and Euler-Lagrange approaches. The effects of various forces, bubble sizes, and bubble injection frequencies on the flow pattern are modeled. For predicting axial velocity and turbulent kinetic energy, the Euler-Lagrange approach fits better than Euler-Euler approach with the measured data. In the Euler-Euler approach, differences in axial velocities and turbulent kinetic energies for various bubble sizes mainly appears in the plume zone. In the Euler-Lagrange approach, different bubble sizes with the same injection frequency have a small impact on the turbulence dissipation. Furthermore, the turbulent dispersion from the gas phase to the liquid phase has an important effect on the plume structure and spout eye formation. For both modeling, the smaller the bubble diameter is, the larger the axial velocity and turbulent kinetic dissipation are in the central zone. For the bubble coalescence and breakup, according to the comparison of two modeling approaches, the Euler-Lagrange approach is more accurate in predicting the flow pattern for gas injection with a porous plug in the ladle.

Place, publisher, year, edition, pages
Wiley-VCH Verlagsgesellschaft, 2019
Keywords
bubble coalescence and breakup, ladle, mathematical modeling, porous plug, Coalescence, Computational fluid dynamics, Flow patterns, Kinetics, Ladles, Lagrange multipliers, Mathematical models, Turbulent flow, Bubble coalescence, Euler-Euler approach, Injection frequencies, Lagrange approach, Turbulence dissipation, Turbulent dispersion, Turbulent kinetic energy, Kinetic energy
National Category
Materials Engineering
Identifiers
urn:nbn:se:kth:diva-252488 (URN)10.1002/srin.201800494 (DOI)2-s2.0-85062368543 ()2-s2.0-85062368543 (Scopus ID)
Note

QC 20190712

Available from: 2019-07-12 Created: 2019-07-12 Last updated: 2019-08-09Bibliographically approved
Bölke, K., Ersson, M., Andersson, N. A. I., Imris, M. & Jönsson, P. (2019). Experimental Determinations of Mixing Times in the IronArc Pilot Plant Process. METALS, 9(1), Article ID 101.
Open this publication in new window or tab >>Experimental Determinations of Mixing Times in the IronArc Pilot Plant Process
Show others...
2019 (English)In: METALS, ISSN 2075-4701, Vol. 9, no 1, article id 101Article in journal (Refereed) Published
Abstract [en]

IronArc is a newly developed technology and an emerging future process for pig iron production. The long-term goal with this technology is to reduce the CO2 emissions and energy consumption compared to existing technologies. The production rate of this process is dependent on the stirring, which was investigated in the pilot plant process by measuring the mixing time in the slag bath. Moreover, slag investigations were done both based on light optical microscope studies as well as by Thermo-Calc calculations in order to determine the phases of the slag during operation. This was done because the viscosity (which is another important parameter) is dependent on the liquid and solid fractions of the slag. The overall results show that it was possible to determine the mixing time by means of the addition of a tracer (MnO2 powder) to the slag. The mixing time for the trials showed that the slag was homogenized after seconds. For two of the trials, homogenization had already been reached in the second sample after tracer addition, which means <= 8 s. The phase analysis from the slag indicated that the slag is in a liquid state during the operation of the process.

Place, publisher, year, edition, pages
MDPI, 2019
Keywords
IronArc process, Ironmaking, pig iron production, mixing time, CO2 reduction, slag investigation
National Category
Materials Engineering
Identifiers
urn:nbn:se:kth:diva-246292 (URN)10.3390/met9010101 (DOI)000459738500100 ()2-s2.0-85060686372 (Scopus ID)
Note

QC 20190325

Available from: 2019-03-25 Created: 2019-03-25 Last updated: 2019-05-13Bibliographically approved
Ratnasari, D. K., Yang, W. & Jönsson, P. (2019). Kinetic Study of an H-ZSM-5/Al MCM-41 Catalyst Mixture and Its Application in Lignocellulose Biomass Pyrolysis. Energy & Fuels, 33(6), 5360-5367
Open this publication in new window or tab >>Kinetic Study of an H-ZSM-5/Al MCM-41 Catalyst Mixture and Its Application in Lignocellulose Biomass Pyrolysis
2019 (English)In: Energy & Fuels, ISSN 0887-0624, E-ISSN 1520-5029, Vol. 33, no 6, p. 5360-5367Article in journal (Refereed) Published
Abstract [en]

The use of H-ZSM-S and Al MCM-41 in a two-stage system of mesoporous and microporous catalysts has been proved to improve the quality of bio-oil. Information about biomass pyrolysis kinetics is important to evaluate biomass as a feedstock for fuel or chemical production as well as efficient design and control of thermochemical processes. In this study, the catalytic pyrolysis kinetics of lignocellulose biomass with a mixed catalyst of H-ZSM-5 and Al-MCM-41 at different ratios is analyzed. The derived activation energies are determined using the Coats-Redfern model and an Avrami mechanism for first order chemical reactions (A1, F1). Bench-scale experiments as well as quantifications of the resulted benzene, toluene, and xylene (BTX) yields have also been investigated. The thermogravimetric analysis DTG results show that the presence of catalyst mixtures has significant effects on the fractions of volatile matter from lignocellulose biomass. Reactivity profiles have been obtained in the temperature range of 180 to 360 degrees C. The results show that the energy activation for lignocellulose biomass at a heating rate of 10 K min(-1) is 134.64 kJ mol(-1) and that the value decreases when using catalysts. However, when the heating rate is increased, the activation energy from the catalytic experiments is 6.3-66.0% higher than that from the biomass pyrolysis experiment. This is due to the production of coke. Overall, a H-ZSM-5/Al MCM-41 ratio of 3:1 is found to be the best catalyst ratio in cracking hemicellulose and cellulose compared to other catalyst mixtures that were studied. The same catalyst ratio also attains the best interaction, in terms of a BTX product selectivity. The optimum activity of this catalyst mixture is reached at a temperature of 500 degrees C.

Place, publisher, year, edition, pages
American Chemical Society (ACS), 2019
National Category
Chemical Process Engineering
Identifiers
urn:nbn:se:kth:diva-255323 (URN)10.1021/acs.energyfuels.9b00866 (DOI)000472800900065 ()2-s2.0-85066907499 (Scopus ID)
Note

QC 20190807

Available from: 2019-08-07 Created: 2019-08-07 Last updated: 2019-08-07Bibliographically approved
Sidorova, E., Karasev, A., Kuznetsov, D. & Jönsson, P. (2019). Modification of Non-Metallic Inclusions in Oil-Pipeline Steels by Ca-Treatment. METALS, 9(4), Article ID 391.
Open this publication in new window or tab >>Modification of Non-Metallic Inclusions in Oil-Pipeline Steels by Ca-Treatment
2019 (English)In: METALS, ISSN 2075-4701, Vol. 9, no 4, article id 391Article in journal (Refereed) Published
Abstract [en]

Corrosion rate in different steel grades (including oilfield pipeline steels) is determined by the presence of non-metallic inclusions (NMI) in steels. Specifically, the effect of different inclusions on the quality of steels depends on their characteristics such as size, number, morphology, composition, and physical properties, as well as their location in the steel matrix. Therefore, the optimization and control of NMI in steels are very important today to obtain an improvement of the material properties of the final steel products. It is well known that a Ca-treatment of liquid steels in ladle before casting is an effective method for modification of non-metallic inclusions for improvement of the steel properties. Therefore, the NMI characteristics were evaluated in industrial steel samples of low carbon Ca-treated steel used for production of oil-pipelines. An electrolytic extraction technique was used for extraction of NMI from the steel samples followed by three-dimensional investigations of different inclusions and clusters by using SEM in combination with EDS. Moreover, the number and compositions of corrosion active non-metallic inclusions were estimated in hot rolled steel samples from two different heats. Finally, the corrosion resistance of these steels can be discussed depending on the characteristics of non-metallic inclusions present in the steel.

Place, publisher, year, edition, pages
MDPI, 2019
Keywords
oil-pipeline steel, Ca-treatment, non-metallic inclusions, electrolytic extraction, corrosion
National Category
Materials Engineering
Identifiers
urn:nbn:se:kth:diva-252645 (URN)10.3390/met9040391 (DOI)000467637000008 ()2-s2.0-85064179266 (Scopus ID)
Note

QC 20190610

Available from: 2019-06-10 Created: 2019-06-10 Last updated: 2019-06-10Bibliographically approved
Du, H., Karasev, A., Sundqvist, O. & Jönsson, P. (2019). Modification of Non-Metallic Inclusions in Stainless Steel by Addition of CaSi. METALS, 9(1), Article ID 74.
Open this publication in new window or tab >>Modification of Non-Metallic Inclusions in Stainless Steel by Addition of CaSi
2019 (English)In: METALS, ISSN 2075-4701, Vol. 9, no 1, article id 74Article in journal (Refereed) Published
Abstract [en]

The focus of this study involved comparative investigations of non-metallic inclusions in 316L stainless steel bars without and with Ca treatments. The inclusions were extracted by using electrolytic extraction (EE). After that, the characteristics of the inclusions, such as morphology, size, number, and composition, were investigated by using a scanning electron microscope (SEM) in combination with an energy dispersive X-ray spectroscopy (EDS). The following four types of inclusions were observed in 316L steels: (1) Elongated MnS (Type I), (2) MnS with hard oxide cores (Type II), (3) Undeformed irregular oxides (Type III), and (4) Elongated oxides with a hard oxide core (Type IV). In the reference sample, only a small amount of the Type III oxides (Al2O3-MgO-MnO-TiOx) existed. However, in Ca-treated 316L steel, about 46% of the observed inclusions were oxide inclusions (Types III and IV) correlated to gehlenite and to a mixture of gehlenite and anorthite, which are favorable for the machinability of steel. Furthermore, untransformed oxide cores (Al2O3-MgO-MnO) were also found in the inclusions of Type IV. The mechanism leading to different morphologies of oxide inclusions is also discussed.

Place, publisher, year, edition, pages
MDPI, 2019
Keywords
stainless steel, Ca treatment, non-metallic inclusion, electrolytic extraction
National Category
Materials Engineering
Identifiers
urn:nbn:se:kth:diva-246294 (URN)10.3390/met9010074 (DOI)000459738500073 ()2-s2.0-85060092047 (Scopus ID)
Note

QC 20190325

Available from: 2019-03-25 Created: 2019-03-25 Last updated: 2019-03-25Bibliographically approved
Bai, H., Ersson, M. & Jönsson, P. (2019). Numerical study of an application of a divergent reverse TurboSwirl nozzle in the billet continuous casting process. Ironmaking & steelmaking, 46(2), 148-158
Open this publication in new window or tab >>Numerical study of an application of a divergent reverse TurboSwirl nozzle in the billet continuous casting process
2019 (English)In: Ironmaking & steelmaking, ISSN 0301-9233, E-ISSN 1743-2812, Vol. 46, no 2, p. 148-158Article in journal (Refereed) Published
Abstract [en]

The swirling flow has widely been investigated for liquid steel flowing in the continuous casting process. In this paper, a new design of the submerged entry nozzle (SEN) is applied by using a reverse TurboSwirl device with a divergent nozzle. This divergent reverse TurboSwirl nozzle (DRTSN) is shown to gain a more beneficial flow pattern compared to the straight nozzle. A stronger swirling flow can be obtained at the SEN outlet, which leads to a calmer flow field and an appropriately active meniscus flow that could improve the heat and mass transfer near the meniscus. The swirl number in the SEN is independent of the casting speed, while a lower casting speed yields a lower maximum wall shear stress. The DRTSN is connected to the tundish by an elbow and a horizontal runner. A longer horizontal runner supplies a more uniform velocity profile and a more symmetrical flow pattern.

Place, publisher, year, edition, pages
TAYLOR & FRANCIS LTD, 2019
Keywords
Swirling flow, TurboSwirl, divergent nozzle, SEN, billet continuous casting
National Category
Fluid Mechanics and Acoustics
Identifiers
urn:nbn:se:kth:diva-244514 (URN)10.1080/03019233.2017.1360433 (DOI)000458159900006 ()2-s2.0-85027106950 (Scopus ID)
Note

QC 20190402

Available from: 2019-04-02 Created: 2019-04-02 Last updated: 2019-04-02Bibliographically approved
Ni, P., Tanaka, T., Suzuki, M., Nakamoto, M. & Jönsson, P. (2018). A kinetic model on oxygen transfer at a steel/slag interface under effect of interfacial tension. ISIJ International, 58(11), 1979-1988
Open this publication in new window or tab >>A kinetic model on oxygen transfer at a steel/slag interface under effect of interfacial tension
Show others...
2018 (English)In: ISIJ International, ISSN 0915-1559, E-ISSN 1347-5460, Vol. 58, no 11, p. 1979-1988Article in journal (Refereed) Published
Abstract [en]

A kinetic model was developed to predict the dynamic change of the oxygen content in the sub-interface region as well as the dynamic change of the interfacial tension between molten steel and slag. The dynamic steel/slag interfacial phenomena are very complex, where the combined effect of thermodynamics and kinetics on the interfacial tension needs to be accounted for. As a first step, the current model only considers the SiO2 decomposition, oxygen adsorption and desorption at the steel/slag interface to realize the modeling of the dynamic change of the steel/slag interface phenomena. The oxygen desorption rate was derived based on the slope of the interfacial tension change over oxygen content. Specifically, the oxygen change with time in a sub-interface was predicted by the current model. The oxygen desorption rate was found to have an important influence on the dynamic change of the oxygen content in the sub-interface region. Furthermore, a low slag viscosity was found to increase the oxygen content at the interface due to the fast supply of SiO2 from the slag bulk to the interface. In addition, the equilibrium constant for the oxygen adsorption at an interface due to the interfacial tension effect increases the oxygen content in the sub-interface region.

Place, publisher, year, edition, pages
Iron and Steel Institute of Japan, 2018
Keywords
Dynamic modeling, Interfacial tension, Mass transfer, Steel-slag interface, Thermodynamics, Desorption, Dynamic models, Equilibrium constants, Kinetic parameters, Kinetic theory, Oxygen supply, Silica, Silicon alloys, Slags, Steel foundry practice, Surface tension, Current modeling, Interface phenomena, Interfacial phenomena, Kinetic modeling, Oxygen adsorption, Oxygen desorption, Steel slag interface, Thermodynamics and kinetics, Gas adsorption
National Category
Materials Engineering
Identifiers
urn:nbn:se:kth:diva-247092 (URN)10.2355/isijinternational.ISIJINT-2018-303 (DOI)000452244600004 ()2-s2.0-85056835487 (Scopus ID)
Note

QC 20190404

Available from: 2019-04-04 Created: 2019-04-04 Last updated: 2019-04-04Bibliographically approved
Organisations
Identifiers
ORCID iD: ORCID iD iconorcid.org/0000-0001-9775-0382

Search in DiVA

Show all publications