Endre søk
Begrens søket
1 - 21 of 21
RefereraExporteraLink til resultatlisten
Permanent link
Referera
Referensformat
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Annet format
Fler format
Språk
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Annet språk
Fler språk
Utmatningsformat
  • html
  • text
  • asciidoc
  • rtf
Treff pr side
  • 5
  • 10
  • 20
  • 50
  • 100
  • 250
Sortering
  • Standard (Relevans)
  • Forfatter A-Ø
  • Forfatter Ø-A
  • Tittel A-Ø
  • Tittel Ø-A
  • Type publikasjon A-Ø
  • Type publikasjon Ø-A
  • Eldste først
  • Nyeste først
  • Skapad (Eldste først)
  • Skapad (Nyeste først)
  • Senast uppdaterad (Eldste først)
  • Senast uppdaterad (Nyeste først)
  • Disputationsdatum (tidligste først)
  • Disputationsdatum (siste først)
  • Standard (Relevans)
  • Forfatter A-Ø
  • Forfatter Ø-A
  • Tittel A-Ø
  • Tittel Ø-A
  • Type publikasjon A-Ø
  • Type publikasjon Ø-A
  • Eldste først
  • Nyeste først
  • Skapad (Eldste først)
  • Skapad (Nyeste først)
  • Senast uppdaterad (Eldste først)
  • Senast uppdaterad (Nyeste først)
  • Disputationsdatum (tidligste først)
  • Disputationsdatum (siste først)
Merk
Maxantalet träffar du kan exportera från sökgränssnittet är 250. Vid större uttag använd dig av utsökningar.
  • 1.
    Abdul Abas, Riad
    et al.
    KTH, Skolan för industriell teknik och management (ITM), Materialvetenskap.
    Jakobsson, Anders
    KTH, Skolan för industriell teknik och management (ITM), Materialvetenskap.
    Hayashi, Miyuki
    KTH, Skolan för industriell teknik och management (ITM), Materialvetenskap.
    Seetharaman, Seshadri
    KTH, Skolan för industriell teknik och management (ITM), Materialvetenskap.
    Studies on Graphitisation of Blast Furnace Coke by X-ray Diffraction Analysis and Thermal Diffusivity Measurements2005Inngår i: Steel research, ISSN 0177-4832, Vol. 77, nr 11, s. 763-769Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    High temperature XRD and thermal diffusivity experiments were employed to investigate the degree of graphitisation in blast furnace coke. The experiments were conducted between room temperature and 1473 K. X-ray diffraction studies were carried out in order to monitor the degree of graphitisation in the coke samples from the same campaign. In these cases, the degree of graphitisation was followed by the changes in the vertical dimension. The degree of graphitisation was found to be dependent on temperature. On the other hand, the graphitisation at each temperature was instantaneous, even at as low a temperature as 973 K and no dependency on time could be noticed. The thermal diffusivities of the coke samples taken from deeper level of the experimental blast furnace were measured using the laser-flash technique. The results from these measurements showed that thermal diffusivities increased with the degree of graphitisation, which in turn, can be affected by the level in the blast furnace at which the coke sample was taken. The present results indicate that the degree of graphitisation as followed by X-ray diffraction analysis as well as thermal diffusivities can be used to trace the thermal history of coke. DSC measurements show that the heat capacity of the coke increases with temperature towards the heat capacity of graphite, which could be due to the increasing the graphitisation degree of the coke.

  • 2.
    Andersson, Annika
    et al.
    KTH, Skolan för industriell teknik och management (ITM), Materialvetenskap, Tillämpad processmetallurgi.
    Andersson, Margareta A.T.
    KTH, Skolan för industriell teknik och management (ITM), Materialvetenskap, Tillämpad processmetallurgi.
    Jönsson, Pär G
    KTH, Skolan för industriell teknik och management (ITM), Materialvetenskap, Tillämpad processmetallurgi.
    A study of some elemental distributions between slag and hot metal during tapping of the blast furnace2004Inngår i: Steel research, ISSN 0177-4832, Vol. 75, nr 5, s. 294-301Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    This paper investigates the distribution of elements between slag and hot metal from a blast furnace through calculation of distribution coefficients from actual production data. First, samples of slag and hot metal tapped from a commercial blast furnace were taken continually at 10-minute intervals for a production period of 68 hours. Distribution coefficients of manganese, silicon, sulphur and vanadium were then calculated from the results of the sample analyses. A major conclusion drawn from examination of the results was that the behaviour of the studied elements was as could be expected when approaching the equilibrium reactions from thermodynamic theory. The distributions of the elements in the slag-metal system showed clear tendencies which did not appear to be influenced by the operational conditions of the furnace. For example, for manganese, vanadium and sulphur, it was found that a higher basicity led to a decreased distribution coefficient L-Mn and L-V, but an increased L-S, which is according to theory. Another observed relationship was that slag basicity increased with an increased carbon content in the hot metal, which indicated that SiO2 was reduced to [Si] when the oxygen potential decreased. Furthermore, it was found that sulphur and silica behaviour likened that of acidic slag components, while the manganese oxide and vanadium oxide behaviour was similar to that of basic slag components.

  • 3. Bohnenkamp, U.
    et al.
    Sandström, Rolf
    KTH, Tidigare Institutioner                               , Materialvetenskap.
    Evaluation of the density of steels2000Inngår i: Steel research, ISSN 0177-4832, Vol. 71, nr 3, s. 88-93Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Data on physical properties of steels have been collected from the open literature and put into a database. The influence of composition on the density of steels has been analyzed. An overview over former studies is given. The steels have been investigated by regression analysis in two groups, i) ferritic and low alloy steels, and ii) austenitic steels. For ferritic steels two models are provided. The first model is based on the assumption that all C is bound in cementite and other solutes are insoluble in cementite, The second model employs the result of a thermodynamic analysis where the amount of cementite and the solubilities in ferrite and cementite were determined with computational thermodynamics. The non-linear effect of Cr and Mn in cementite was computed and regression analysis of the effect of solutes on the density of ferrite was performed. For Ti-stabilized austenitic steels, the amount of TiC and the solubilities were assessed in a thermodynamic analysis. The effect of solutes on the density of austenite was studied by regression analysis. For estimations of the density of steels containing components that are not covered by the regression analysis, the regression coefficients can be supplemented with literature data or theoretically determined values. The results obtained by the present regression analysis are: Cu and Mo increase the density of ferritic steels, and C, Cr, Mn, S, Si, and V decrease it. TiC. C, Cr, Mn, N, Si, and Ti reduce the density of austenitic steels and Cu, Co. Mo, and Ni increase it.

  • 4. Bohnenkamp, U.
    et al.
    Sandström, Rolf
    KTH, Tidigare Institutioner                               , Materialvetenskap.
    Evaluation of the elastic modulus of steels2000Inngår i: Steel research, ISSN 0177-4832, Vol. 71, nr 3, s. 94-99Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Literature data on the physical properties of steels have been collected and put into a database. The elastic modulus of steels has been analyzed as a function of composition. An overview over former studies is given. The steels have been investigated in three groups, martensitic and ferritic steels, ferritic steels separately, and austenitic steels. For the last two groups, a thermodynamic analysis with Thermo-Gale has been performed. Regression analysis on the influence of composition on the elastic modulus was then carried out. The results for ferritic steels reveal that cementite has no effect on the elastic modulus, whereas Cr, Mo, Si, Mn, and Cu increase it. The elastic modulus of austenitic steels is reduced by Ni and Mo and increased by N, NbC, TiC, and Cr. Cr23C6, while statistically significant in the analysis, has no effect on the elastic modulus of austenitic steels, The regression coefficients found can be used to predict the elastic modulus of steels with known composition.

  • 5. Bohnenkamp, U.
    et al.
    Sandström, Rolf
    KTH, Tidigare Institutioner                               , Materialvetenskap.
    Evaluation of the electrical resistivity of steels2000Inngår i: Steel research, ISSN 0177-4832, Vol. 71, nr 10, s. 410-416Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Literature data on the physical properties of sleets have been collected and put into a database. The resistivity of steers has been analyzed as a function of composition and microstructure. An overview over former studies is given. The steels have been investigated in two groups, ferritic steels and austenitic steels. A thermodynamic analysis with ThermoCalc has been performed. Regression analysis on the influence of composition on the resistivity was then carried out. The results for ferritic steels are: Si and Al have the highest elemental resistivity, followed by Mn. Cu, Ni, Mo, and Cr. C precipitated in cementite shows a high coefficient in the analysis when the amount of Fe bound in cementite is not considered separately. C in solution with ferrite shows no significant effect. Cr bound in cementite shows a significant effect but Mn, though present in cementite in comparable amounts, has no significant effect on the resistivity. N and C have the highest elemental resistivity in austenite, followed by the substitutional solutes Nb, Si, Ti, Cu, Ni, Mo, and Cr. The carbides NbC and Tic appear with a higher coefficient in the regression model than can be explained by phase-mixture models providing upper and lower bounds for the resistivity of two-phase alloys. Cr23C6 shows no significant effect. The regression results can be used to predict the resistivity of steels with known composition. The model predicts the resistivity of ferritic steels with a maximum deviation between experimental and computed value of 12 n Omegam and a standard deviation of 5.6 n Omegam. For austenitic steels, the model prediction shows a maximum deviation of 52 mu Omegam and a standard deviation of 20 n Omegam.

  • 6.
    Brandberg, Jenny
    et al.
    KTH, Skolan för industriell teknik och management (ITM), Materialvetenskap, Mikro-modellering.
    Yu, Liang
    KTH, Skolan för industriell teknik och management (ITM), Materialvetenskap, Mikro-modellering.
    Sichen, Du
    KTH, Skolan för industriell teknik och management (ITM), Materialvetenskap, Mikro-modellering.
    Water capacity model of Al2O3-CaO-MgO-SiO2 quaternary slag system2007Inngår i: Steel research, ISSN 0177-4832, Vol. 78, nr 6, s. 460-464Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The focus of the present work was to develop a water capacity model for the quaternary slag system Al2O3-CaO-MgO-SiO2. In the model, a silicate melt was considered to consist of two ion groupings, viz. cation grouping and oxygen ion. The water capacity of a melt is supposed to depend on the interactions between the cations in the presence of oxygen ions. These interactions were determined on the basis of the experimentally measured water solubility data. Only binary interactions were employed in the model. For the system CaO-SiO2, disagreement in the literature data was found. Since the interaction between Ca2+ and Si4+ would play an important role, experiments were carried out to determine the water capacities of some CaO-SiO2 slags. For this purpose a thermogravimetric method was employed. Iso-lines of water capacities at constant MgO contents were predicted by the model and compared with the experimental data from literature. The model calculations agreed well with the experimental results.

  • 7. Eliasson, J.
    et al.
    Sandström, Rolf
    KTH, Tidigare Institutioner                               , Materialvetenskap.
    Proof strength values for austenitic stainless steels at elevated temperatures2000Inngår i: Steel research, ISSN 0177-4832, Vol. 71, nr 07-jun, s. 249-254Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The influence of the alloying elements C, N, Si, Mn, Cr, Ni, Mo, Cu, Ti on proof strength is studied in the temperature range 20-550 degrees C. High temperature data for the proof strength of austenitic stainless steels have been analysed. Using computational thermodynamics the amount of alloying elements in solid solution and the volume fractions of precipitates were assessed. These quantities were then applied in a regression analysis for the high temperature strength. Quantitative relationships for the proof strength as a result of the regression analysis are proposed as a function of temperature. They are to be used in materials design. The interstitial elements showed the largest effect. Si, Ni and Mo increased the strength at all temperatures. Cu and Mn reduced the strength and Cr gave an influence, which varied with temperature.

  • 8. Eriksson, Robert
    et al.
    Tilliander, Anders
    KTH, Tidigare Institutioner, Tillämpad processmetallurgi.
    Jonsson, Lage
    KTH, Skolan för industriell teknik och management (ITM), Materialvetenskap, Tillämpad processmetallurgi.
    Jönsson, Pär
    KTH, Tidigare Institutioner, Materialvetenskap.
    An experimental study of the velocity field during filling of an ingot mould2003Inngår i: Steel research, ISSN 0177-4832, Vol. 74, nr 7, s. 423-430Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    In the present study the velocity field in a 1:3 scale water model of a 4.2-tonne ingot mould was determined using Laser Doppler Anemometry (LDA). The velocity was measured in the horizontal and vertical directions at several different locations along the centre plane of the model. The effect of different volumetric flow rates and water temperatures was also investigated. The reproducibility of the measurements was found to be satisfactory, since the mean velocity at any measurement location had an average difference of around 10% between two fillings. The effect of different volumetric flow rates showed that while decreasing the flow rate, the mean velocity at the bottom turned from an upward direction to a downward direction. At the top of the model the difference between the mean velocities for the different flow rates was less pronounced. An influence of the temperature on the mean velocity could be observed. However, further studies are required to verify this result.

  • 9.
    Fredriksson, Patrik
    et al.
    KTH, Tidigare Institutioner, Materialvetenskap.
    Seetharaman, Seshadri
    KTH, Tidigare Institutioner, Materialvetenskap.
    Thermodynamic activities of FeO in some binary FeO-Containing slags2004Inngår i: Steel research, ISSN 0177-4832, Vol. 75, nr 4, s. 240-246Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    In the present investigation, experimental measurements of the thermodynamic activities of iron oxide in the Al2O3-FeO, CaO-FeO and FeO-SiO2 systems were performed in the temperature range 1823-1873 K by using gas equilibration technique. The molten slag, kept in a Pt-crucible was brought to equilibrium with a gas mixture of known oxygen partial pressure. A part of the Fe from the FeO was reduced during the equilibration and got dissolved in the Pt phase. The samples were quenched after the required equilibration time and the slag phase as well as the platinum crucible was subjected to chemical analysis. The activities of FeO in the slag were calculated from the experimental data using thermodynamic information on the Fe-Pt binary metallic system generated and assessed earlier. The experimental results are compared with earlier thermodynamic studies of the slag systems. Reassessment with the KTH slag model is performed and the results are compared with other thermodynamic models, viz. F*A*C*T(TM) and Thermo-Calc(TM) respectively. The experimental activities predicted by the KTH slag model are in good agreement with the experimental data available in the literature. A general agreement between the various models is also observed.

  • 10.
    Fredriksson, Patrik
    et al.
    KTH, Tidigare Institutioner, Materialvetenskap.
    Seetharaman, Seshadri
    KTH, Tidigare Institutioner, Materialvetenskap.
    Thermodynamic activities of FeO in some ternary FeO-containing slags2004Inngår i: Steel research, ISSN 0177-4832, Vol. 75, nr 6, s. 357-365Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Thermodynamic data concerning FeO-containing slags is of importance in ladle refining of steel. With a view to generate a set of reliable and self-consistent thermodynamic data for these slags, experimental determination of the activities of iron oxide in the Al2O3-FeO-SiO2, CaO-FeO-SiO2 and FeO-MgO-SiO2 systems was carried out using the gas equilibration method involving CO-CO2-Ar gas mixtures in the temperature range 1823-1923 K. The slag samples kept in Pt crucibles were quenched after the equilibration and subjected to chemical analysis. The thermodynamic activities of FeO in the slags were calculated from the experimental data. The results are incorporated into a thermodynamic description of silicate melts developed in the present laboratory. The model is based on a Temkin-Lumsden approach and is able to compute the thermodynamics of higher order systems from the lower order ones. The model was updated with the present results and iso-activity contours of FeO in the three component systems are presented at 1873. The capacity of the model to predict the thermodynamic activites in four-, five-, and six-component slags is demonstrated in the case of steelmaking slags.

  • 11. Jauhiainen, Anu
    et al.
    Jonsson, Lage
    KTH, Skolan för industriell teknik och management (ITM), Materialvetenskap, Tillämpad processmetallurgi.
    Jönsson, Pär
    KTH, Skolan för industriell teknik och management (ITM), Materialvetenskap, Tillämpad processmetallurgi.
    Eriksson, Sven
    The influence of stirring method on hydrogen removal during ladle treatment2002Inngår i: Steel research, ISSN 0177-4832, Vol. 73, nr 3, s. 82-90Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    A mathematical model based on fundamental transport equations for vacuum degassing in an Asea-SKF ladle furnace was developed earlier and predicted hydrogen values from the model were found to agree well with experimental measurements from plant trials. In the present study. the mathematical model was used to predict the hydrogen removal for four different stirring methods: 1-2) combined gas and induction stirring with the inductive stirrer working upwards or downwards and 3-4) gas stirring with two different locations for two porous plugs. Plant data was used as input to the calculations. The hydrogen calculation was validated by simulation of an actual heat and comparison with measured data. After 44 minutes of stirring the predicted and measured hydrogen contents were 1.6 and 1 8 ppm, respectively This agreement was considered satisfactory and the model was then used to study the effect of different stirring methods on hydrogen refining, A change in the stirring method was found to affect the hydrogen refining. Combined gas and induction stirring using downward stirring was found to result in the lowest final hydrogen content in the steel as it rendered the most favourable kinetic conditions for hydrogen refining.

  • 12.
    Kholmatov, Shakvat
    et al.
    KTH, Skolan för industriell teknik och management (ITM), Materialvetenskap, Tillämpad processmetallurgi.
    Takagi, S
    Jönsson, Pär
    KTH, Skolan för industriell teknik och management (ITM), Materialvetenskap, Tillämpad processmetallurgi.
    Jonsson, Lage
    KTH, Skolan för industriell teknik och management (ITM), Materialvetenskap, Tillämpad processmetallurgi.
    Yokoya, Shinichiro
    KTH, Skolan för industriell teknik och management (ITM), Materialvetenskap, Tillämpad processmetallurgi.
    Suppression of Unsteady Fluctuations on the Meniscus with the use of the Swirl Blade during Continious Casting of SteelInngår i: Steel research, ISSN 0177-4832Artikkel i tidsskrift (Annet vitenskapelig)
  • 13.
    Persson, Mikael
    et al.
    KTH, Skolan för industriell teknik och management (ITM), Materialvetenskap.
    Matsushita, Taishi
    KTH, Skolan för industriell teknik och management (ITM), Materialvetenskap.
    Zhang, T.
    KTH, Skolan för industriell teknik och management (ITM), Materialvetenskap.
    Seetharaman, Sesadri
    KTH, Skolan för industriell teknik och management (ITM), Materialvetenskap.
    Estimation of molar volumes of some binary slags from enthalpies of mixings2007Inngår i: Steel research, ISSN 0177-4832, Vol. 78, nr 2, s. 102-108Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    In an effort to interlink the thermo chemical and thermo physical properties of slags, the present workwas undertaken to derive the molar volumes of complex slags from the enthalpies of mixing of thecorresponding slags. As a first step, binary systems of the following oxides were investigated; Al2O3,CaO, FeO, MgO, MnO, and SiO2. An empirical correlation was derived between the enthalpies ofmixing and molar volumes. A comparison of the computed results on the basis of the aboverelationship with the experimental data on molar volumes available in literature shows that theagreement between the calculated results and measured densities is satisfactory in the case of mostof the binary systems, within the limits of experimentally uncertainties. The advantage of the presentapproach is that it would enable prediction of molar volumes of slags that are compatible with thethermodynamic data available.

  • 14.
    Persson, Mikael
    et al.
    KTH, Skolan för industriell teknik och management (ITM), Materialvetenskap.
    Zhang, Jiayun
    Seetharaman, Seshadri
    KTH, Skolan för industriell teknik och management (ITM), Materialvetenskap.
    A Thermodynamic Approach to a Density Model for Oxide Melts2007Inngår i: Steel research, ISSN 0177-4832, Vol. 78, nr 4, s. 290-298Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    In an attempt to estimate the densities of complex slags, a model based on the thermodynamics ofslags developed earlier by the present authors is extended to ternary and multi-component systemsin the present work. The molar volumes of ternary and higher order systems were derived from therelative integral molar enthalpies of mixing of the corresponding slags. The higher order of slagsystems has been predicted by using the parameters from the related binary sub-systems, whichhave been evaluated earlier. Comparisons of calculated results with experimental data on molarvolumes available in literature show a satisfying agreement for a number of systems, within the limitsof experimental uncertainties. The model presents a promising method to compute the molar volumeof slag systems where no experimental data is available using the abundance of thermodynamicdata available. The model would also enable the generation of density data for slags containingAl2O3, CaO, FeO, MgO, MnO, and SiO2 compatible with the corresponding thermodynamic data.

  • 15. Sridhar, S.
    et al.
    Du, S. C.
    Seetharaman, Seshadri
    KTH, Tidigare Institutioner                               , Materialvetenskap.
    Mills, K. C.
    Viscosity estimation models for ternary slags2001Inngår i: Steel research, ISSN 0177-4832, Vol. 72, nr 1, s. 3-10Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Five models to estimate slag viscosity have been compared with the experimental data obtained using the rotating cylinder method. The comparison was made for four ternary silicate systems, viz. FeO-MgO-SiO2, CaO-MnO-SiO2, FeO-MnO-SiO2 and CaO-Feo-SiO2. The KTH model and the model using the Gibbs energy of mixing have been found successful in estimating the slag viscosity. On the other hand, the comparisons of the experimental results with the calculated viscosity using the Riboud, Urbain and NPL models have shown poor agreement. While the limited number of the data points used for parameter optimisation would be one of the reasons for the failure of the Riboud and NPL models when applied for these ternary systems, the description of the slag composition in Urbain's approach could probably explain the disagreement between the estimated and experimental viscosity. Further studies are needed for the KTH model to accommodate fluorides in the model structure.

  • 16.
    Söder, Mats
    et al.
    KTH, Skolan för industriell teknik och management (ITM), Materialvetenskap, Tillämpad processmetallurgi.
    Jönsson, Pär
    KTH, Skolan för industriell teknik och management (ITM), Materialvetenskap, Tillämpad processmetallurgi.
    Jonsson, Lage
    KTH, Skolan för industriell teknik och management (ITM), Materialvetenskap, Tillämpad processmetallurgi.
    Inclusion growth and removal in gas stirred ladles2004Inngår i: Steel research, ISSN 0177-4832, Vol. 75, nr 2, s. 128-138Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    A static modelling approach was used to study the growth and removal of inclusions during gas stirring in a ladle. A mathematical model of a gas-stirred ladle was used to predict the data necessary to calculate growth and removal of inclusions. Results indicated that inclusion growth resulting from laminar shear collisions is negligible in comparison with growth from turbulent and Stokes collisions. Furthermore, the need for a model describing inclusion flotation by spherical-cap bubbles was identified. Since the existing models presented in the literature are only valid for spherical bubbles, a model for the removal of inclusions by spherical-cap bubbles was developed. Inclusion removal to the slag, refractory and by bubble flotation was compared. The mechanism determined to be responsible for the removal of the majority of inclusions larger than 25 μm was Stokes flotation and for the majority of the smaller inclusions, bubble flotation by spherical-cap bubbles (assuming plane contact between the inclusion and the bubble).

  • 17.
    Söder, Mats
    et al.
    KTH, Tidigare Institutioner, Materialvetenskap.
    Jönsson, Pär
    KTH, Tidigare Institutioner, Materialvetenskap.
    Jonsson, Lage
    KTH, Tidigare Institutioner, Materialvetenskap.
    Inclusion growth and removal in gas-stirred ladies2004Inngår i: Steel research, ISSN 0177-4832, Vol. 75, nr 2, s. 128-138Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    A static modelling approach was used to study the growth and removal of inclusions during gas stirring in a ladle. A mathematical model of a gas-stirred ladle was used to predict the data necessary to calculate growth and removal of inclusions. Results indicated that inclusion growth resulting from laminar shear collisions is negligible in comparison with growth from turbulent and Stokes collisions. Furthermore, the need for a model describing inclusion flotation by spherical-cap bubbles was identified. Since the existing models presented in the literature are only valid for spherical bubbles, a model for the removal of inclusions by spherical-cap bubbles was developed. Inclusion removal to the slag, refractory and by bubble flotation was compared. The mechanism determined to be responsible for the removal of the majority of inclusions larger than 25 mum was Stokes flotation and for the majority of the smaller inclusions, bubble flotation by spherical-cap bubbles (assuming plane contact between the inclusion and the bubble).

  • 18.
    Tilliander, Anders
    et al.
    KTH, Tidigare Institutioner, Tillämpad processmetallurgi.
    Jonsson, P. G.
    KTH, Skolan för industriell teknik och management (ITM), Materialvetenskap, Tillämpad processmetallurgi.
    Jonsson, Lage
    KTH, Skolan för industriell teknik och management (ITM), Materialvetenskap, Tillämpad processmetallurgi.
    Effect of Ar/O-2 gas mixtures on heat-transfer and fluid-flow characteristics in AOD nozzles2000Inngår i: Steel research, ISSN 0177-4832, Vol. 71, nr 11, s. 429-434Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    A model of fluid flow and heat transfer in a nozzle used for injection of argon and oxygen in AOD converters was developed earlier. In this study the model was used to determine the effect of changes in the ratio of argon to oxygen in argon-oxygen gas mixtures injected through the nozzle on fluid flow and heat transfer. It was found, for the studied conditions, that the temperature and laminar kinematic viscosity at the nozzle outlet were not dependent on the gas composition. However, the velocity, density, turbulent kinetic energy and dissipation of kinetic energy varied with a change in the fraction of oxygen injected. It is therefore concluded that for use as boundary-condition input data for an AOD converter model (under development), it is important to be able to calculate reliable velocity and turbulence parameter data for gas mixtures of different argon/oxygen ratios.

  • 19. Wang, X. D.
    et al.
    Sichen, Du
    KTH, Tidigare Institutioner                               , Materialvetenskap.
    Li, W. C.
    Seetharaman, Seshadri
    KTH, Tidigare Institutioner                               , Materialvetenskap.
    Slag corrosion of gamma aluminium oxynitride2002Inngår i: Steel research, ISSN 0177-4832, Vol. 73, nr 3, s. 91-96Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Corrosion of gamma-aluminlum oxynitride (AlON) by CaO-MgO-FeO-Al2O3-SiO2 melts corresponding to blast furnace slag was examined from 1693 to 1753 K under static and forced convection conditions. An intermediate layer was observed between the unreacted oxynitride and slag. After a certain time interval, the rate of the growth of this layer was found to be equal to the rate of the dissolution of the layer. Slag corrosion of NON is a strongly thermally activated process, the overall activation energy being 1002 kJ/mol. The rate of corrosion was found to be significantly enhanced by the addition of,,FeO.

  • 20.
    Wu, Liushun
    et al.
    KTH, Skolan för industriell teknik och management (ITM), Materialvetenskap.
    Ek, Mattias
    KTH, Skolan för industriell teknik och management (ITM), Materialvetenskap.
    Song, Minho
    KTH, Skolan för industriell teknik och management (ITM), Materialvetenskap.
    Sichen, Du
    KTH, Skolan för industriell teknik och management (ITM), Materialvetenskap.
    The effect of solid particles on liquid viscosity2011Inngår i: Steel research, ISSN 0177-4832, Vol. 82, nr 4, s. 388-397Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The viscosities of solid-liquid mixtures were experimentally determined for silicon oil-paraffin system at room temperature and solid-liquid oxide mixture at steelmaking temperature. The use of oil-paraffin systems was to confirm the results of high temperature measurements, the experimental conditions being very difficult to control. The silicon oil- paraffin mixtures behaved Newtonian until the particle fraction reached 0.15. At this fraction, the mixture started deviate from Newtonian flow; though some average values could still be collected with very high uncertainty. Liquid-2CaO.SiO2 mixtures and liquid-MgO mixtures were studied at steelmaking temperature with carefully prepared particle fractions and well controlled conditions. Liquid-2CaO.SiO2 mixture behaved Newtonian even when the particle fraction reached 0.1. The results of both room temperature measurements and steelmaking temperature measurements were used to examine the applicability of the existing models. Einstein-Roscoe equation was found to be the only model applicably for the systems studied. No modification of the model parameter was found necessary, though the particles were not spherical.

  • 21. Zhu, M. Y.
    et al.
    Sichen, Du
    KTH, Tidigare Institutioner                               , Materialvetenskap.
    Modelling study of slag foaming phenomenon2000Inngår i: Steel research, ISSN 0177-4832, Vol. 71, nr 3, s. 76-82Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    A one-dimensional model based on mass and momentum conservations has been developed to predict the heights of foams caused by gas injection. In the development of the model, a dimensionless number, N-foam = u(s)[(3C(d))/(4d(b)g)](1/2) has been deduced to characterise the foaming behaviour. According to the model, an increase in this dimensionless number results in an increase In foaming height. The validity of the model has been experimentally examined using silicon oils. The experiments have also shown that foamings can be classified into two types, namely one-layer foaming and two-layer foaming. The former type results in much larger height than the latter.

1 - 21 of 21
RefereraExporteraLink til resultatlisten
Permanent link
Referera
Referensformat
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Annet format
Fler format
Språk
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Annet språk
Fler språk
Utmatningsformat
  • html
  • text
  • asciidoc
  • rtf