Change search
Refine search result
1 - 8 of 8
CiteExportLink to result list
Permanent link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Rows per page
  • 5
  • 10
  • 20
  • 50
  • 100
  • 250
Sort
  • Standard (Relevance)
  • Author A-Ö
  • Author Ö-A
  • Title A-Ö
  • Title Ö-A
  • Publication type A-Ö
  • Publication type Ö-A
  • Issued (Oldest first)
  • Issued (Newest first)
  • Created (Oldest first)
  • Created (Newest first)
  • Last updated (Oldest first)
  • Last updated (Newest first)
  • Disputation date (earliest first)
  • Disputation date (latest first)
  • Standard (Relevance)
  • Author A-Ö
  • Author Ö-A
  • Title A-Ö
  • Title Ö-A
  • Publication type A-Ö
  • Publication type Ö-A
  • Issued (Oldest first)
  • Issued (Newest first)
  • Created (Oldest first)
  • Created (Newest first)
  • Last updated (Oldest first)
  • Last updated (Newest first)
  • Disputation date (earliest first)
  • Disputation date (latest first)
Select
The maximal number of hits you can export is 250. When you want to export more records please use the Create feeds function.
  • 1.
    Gran, Jimmy
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Micro-Modelling.
    Thunman, Mikael
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Micro-Modelling.
    Sichen, Du
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Micro-Modelling.
    Effects of slag composition and cooling rate on formation of glaze on MgO refractory2010In: Ironmaking & steelmaking, ISSN 0301-9233, E-ISSN 1743-2812, Vol. 37, no 1, p. 27-34Article in journal (Refereed)
    Abstract [en]

    The formation of a slag glaze layer on dense and porous MgO rods was studied by dipping MgO rods into liquid slag at 1873 K and thereafter cooling the rods at a predetermined cooling rate. Three different slag compositions and three different cooling rates were employed. It was found that the phases formed upon cooling were mostly dependent on slag composition and to a minor extent on the cooling rate. The initially liquid slag was transformed into crystalline phases for all the samples except the ones terminated at 1573 K and one of the samples with high cooling rate. In addition, the three slags were equilibrated at 1773, 1673 and 1573 K in order to get an understanding of the equilibrium phases and their relationship during cooling. On the basis of the experimental results, the mechanism regarding entrainment of exogenous inclusions from the refractory lining was also discussed.

  • 2. Kang, Y.
    et al.
    Thunman, Mikael
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering.
    Sichen, Du
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Micro-Modelling.
    Morohoshi, Takashi
    Mizukami, Kazumi
    Morita, Kazuki
    Aluminum Deoxidation Equilibrium of Molten Iron-Aluminum Alloy with Wide Aluminum Composition Range at 1873 K2009In: ISIJ International, ISSN 0915-1559, E-ISSN 1347-5460, Vol. 49, no 10, p. 1483-1489Article in journal (Refereed)
    Abstract [en]

    Al-0 equilibria in molten Fe-Al alloys were experimentally investigated. Molten steel with varying Al content (0.01-10 mass%) was equilibrated with a pure Al2O3(S) crucible at 1873 K in an Ar atmosphere with 3 vol% H-2, The oxygen content of steel with Al content higher than 1.0 mass% was found to be much lower than that found in previous works, while the oxygen content for Al content less than I mass% was found to be slightly higher, resulting in a smaller equilibrium constant. The interaction parameters as well as the equilibrium constant of the Al-O equilibria in molten steel at 1 873 K were reevaluated in the present study. The equilibrium for the Al deoxidation of molten steel was well represented up to 10.0 mass% Al using the reevaluated parameters.

  • 3.
    Thunman, Mikael
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering.
    Formation of Inclusions and their Development during Secondary Steelmaking2009Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Al–O relations in iron were investigated. Pure iron with varying Al content was equilibrated at 1873 K. The oxygen content of iron with higher Al content than 1.0 mass % was found to be much lower than previous works, while the oxygen content for Al content less than 1 mass% was found to be slightly higher. Further, a classification procedure of inclusions was developed using the commercial software INCA Feature. Three classes were made, spinel, TP-(CaO-Al2O3), and (CaO-Al2O3) class, corresponding to the inclusions found during degassing at Uddeholm Tooling. The results showed that the spinel phase disappeared after degassing along with a reduction in numbers for the two phase inclusion (TP-(CaO-Al2O3)). Pure calcium aluminates however showed an increasing trend in a majority of the heats. The chemical development of inclusions at OVAKO Steel in Hofors, Sweden was also established. According to the morphologies and compositions, the inclusions were classified into 5 different types, namely, (1) alumina inclusions, (2) calcium aluminate, (3) spinel+calcium aluminate, (4) calcium aluminate surrounded by a CaS shell, and (5) spinel+calcium aluminate surrounded by a CaS shell. Thereafter refractory lining samples with attached slag layer were taken from used ladles at the two steel plants. The morphologies of the slag layers and the phases present were examined. The precipitated phases found in the refractory were 3CaO.Al2O3, MgO.Al2O3 and CaO in the case of Ovako Steel and 3CaO.Al2O3 and 2CaO.SiO2 in the case of Uddeholm Tooling. To help the understanding, model calculations using THERMOCALC were carried out. The model predictions differed somewhat from the experimental observation, the predicted major phases were in line with the EDS analysis on the refractory samples. Finally experiments were carried out to study the slag entrainment related to the open-eye during ladle treatment. Ga-In-Sn alloy was used to simulate the liquid steel, while MgCl2-Glycerol(87%) solution was used to simulate the ladle slag. No noticeable amount of top liquid was observed in any of the samples taken from the metal bulk during gas stirring. To confirm this aspect, slag-metal interface samples were taken from an industrial gas stirred steel ladle. No entrapment was found in the steel. The accordance of the laboratory and industrial results suggests that the entrainment of slag into the steel bulk around the open-eye cannot be considered as the major contribution to inclusion formation.

  • 4.
    Thunman, Mikael
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering.
    Identification of inclusions using the results of INCA feature analysis and its application on the inclusions found in ladle treatmentIn: Steel Grips - Journal of Steel and Related Materials, ISSN 1611-4442, E-ISSN 1866-8453Article in journal (Other academic)
  • 5.
    Thunman, Mikael
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering.
    Eckert, S.
    Hennig, O.
    Bjorkvall, J.
    Sichen, Du
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Micro-Modelling.
    Study on the formation of open-eye and slag entrainment in gas stirred ladle2007In: Steel Research International, ISSN 1611-3683, Vol. 78, no 12, p. 849-856Article in journal (Refereed)
    Abstract [en]

    Laboratory experiments were carried out to study the phenomena related to open-eye formation in ladle treatment. Ga-In-Sn alloy with a melting temperature of 283 K was used to simulate the liquid steel, while MgCl2-Glycerol(87%) solution as well as HCl solution were used to simulate the ladle slag. No open-eye was formed at lower gas flow rates, but, occurred when gas flow reached a critical rate. This critical gas flow rate was found to depend significantly on the height of the top liquid. No noticeable amount of top liquid was observed in any of the samples taken from the metal bulk during gas stirring. To confirm this aspect, samples of slag-metal interface were taken around the open-eye in an industrial gas stirred steel ladle. No entrapped slag droplet was found in the solidified steel within the region between the interface and 2 cm from the interface. The accordance of the laboratory and industrial results suggests that the entrainment of slag into the steel bulk around the open-eye cannot be considered as the major contribution to inclusion formation.

  • 6.
    Thunman, Mikael
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering.
    Gran, Jimmy
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering.
    Sichen, Du U.
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering.
    Impact of slag-refractory reaction on the formation of non-metallic inclusions2008In: Proc. ICS 2008: The 4th Int. Congress Sci. Technol. Steelmaking, 2008, p. 391-394Conference paper (Refereed)
  • 7.
    Thunman, Mikael
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering.
    Sichen, Du
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Micro-Modelling.
    Origins of non-metallic inclusions and their chemical development during ladle treatment2008In: STEEL RESEARCH INTERNATIONAL, ISSN 1611-3683, Vol. 79, no 2, p. 124-132Article in journal (Refereed)
    Abstract [en]

    In the present work, steel, slag and refractory samples were taken from the ladle at OVAKO Steel in Hofors, Sweden. The steel samples were analysed in LOM, SEM and OES PDA. The chemical compositions of the inclusions were determined by EDS. According to the morphologies and compositions, the inclusions were classified into 5 different types, namely, (1) type-1, alumina inclusions, (2) type-2, calcium aluminate, (3) type-3, spinel+calcium aluminate, (4) type-4, calcium aluminate surrounded by a CaS shell, and (5) spinel+calcium aluminate surrounded by a CaS shell. Ladle glaze was found to be a major supplier of the inclusions, while the inclusions brought over from EAF could be another important source. The results of OES PDA showed that removal of inclusions took place mostly during the vacuum degassing period.

  • 8.
    Thunman, Mikael
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Micro-Modelling.
    Sichen, Du
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Micro-Modelling.
    Gran, Jonas
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Micro-Modelling.
    Slag‐refractory reaction during ladle refining and teeming2009In: Steel Grips - Journal of Steel and Related Materials, ISSN 1611-4442, E-ISSN 1866-8453, Vol. 7, no 2, p. 129-135Article in journal (Other academic)
    Abstract [en]

    Refractory lining samples with slag layer were taken from used ladles at two steel plants, Ovako Steel and Uddeholm Tooling. The morphologies of the slag layers and the phases present were examined. The appearances and phases of the glaze layers were found to be somewhat different in the ladles from the two steel plants. The precipitated phases found in the refractory were 3CaO-Al2O3, MgO-Al2O3 and CaO in the case of Ovako Steel, and 3CaO-Al2O3 and 2CaO-SiO2 in the case of Uddeholm Tooling. To help the understanding, model calculations using commercial software Thermocalc were carried out. Although the model predictions differed somewhat from the experimental observation, the predicted major phases were in line with the EDS analysis on the refractory samples. Cold model study using both water and Ga-In-Sn alloy to simulate liquid steel were also performed. The results would be able to explain the thick slag line of the ladle and the serious erosion even far below the slag line. Both the slag line and the glaze layer below the slag line would be a potential source of non-metallic inclusions.

1 - 8 of 8
CiteExportLink to result list
Permanent link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf