Search for dissertations about: "Pär Jönsson"

Showing result 6 - 10 of 111 swedish dissertations containing the words Pär Jönsson.

  2. 6. A Study of the Swirling Flow Pattern when Using TurboSwirl in the Casting Process

    Author : Haitong Bai; Mikael Ersson; Pär Jönsson; Yogeshwar Sahai; KTH; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; flow pattern; swirling flow; TurboSwirl; CFD; turbulence models; water model; flödesmönster; roterandeflöde; TurboSwirl; CFD; turbulensmodeller; vattenmodell; Metallurgical process science; Metallurgisk processvetenskap;

    Abstract : The use of a swirling flow can provide a more uniform velocity distribution and a calmer filling condition according to previous studies of both ingot and continuous casting processes of steel. However, the existing swirling flow generation methods developed in last decades all have some limitations. READ MORE

  4. 7. Microstructural Evolution In As-cast Alloys during Plastic Deformation

    Author : Mitra Basirat; Pär Jönsson; Hasse Fredriksson; Jacques Lacaze; KTH; []
    Keywords : plastic deformation; compression test; recrystallization; deformation band; As-cast; microsegregation; carbide dissolution; disordered structure; order disorder transformation; twining; steel; β brass; copper; SRA - E-Science SeRC ; SRA - E-vetenskap SeRC ;

    Abstract : The effect of deformation on microstructural changes in metals and alloys is the subject of considerable practical interest. The ultimate goal is to control, improve and optimize the microstructure and texture of the finished products produced by metal forming operations. READ MORE

  5. 8. A study of slag-steel-inclusion interaction during Ladle treatment

    Author : Johan Björklund; Pär Jönsson; Voicu Brabie; KTH; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Ladle treatment; steel; slag; inclusions; ladle; refining; vacuum; tool steel; oxide activity; slag models; oxygen; equilibrium; Metallurgical process and manufacturing engineering; Metallurgisk process- och produktionsteknik;

    Abstract : The thesis is based on two supplements with two major objectives. In the first supplement equilibrium top slag-steel bulk and inclusions-steel bulk were investigated by comparison between calculated and measured oxygen activity values. This was done by applying different oxide activity models for slags combined with thermodynamic calculations. READ MORE

  6. 9. Thermodynamic Aspects on Inclusion Composition and Oxygen Activity during Ladle Treatment

    Author : Johan Björklund; Pär Jönsson; Margareta Andersson; Leiv Kolbeinsen; KTH; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Ladle treatment; thermodynamics; inclusions; steel; slag; equilibrium; ladle treatment; vacuum; oxide activity; oxygen activity.; Metallurgical process and manufacturing engineering; Metallurgisk process- och produktionsteknik;

    Abstract : Two industrial studies and one set of lab scale trials have been done. In addition, a theoretical study has been done. The main focus has been on non metallic inclusion composition during the ladle refining operation in industrial steel production. Sampling has been done together with careful inclusion determination. READ MORE

  7. 10. Advanced BaZrO3-BaCeO3 Based Proton Conductors Used for Intermediate Temperature Solid Oxide Fuel Cells (ITSOFCs)

    Author : Junfu Bu; Pär Jönsson; Zhe Zhao; Mogens Mogensen; KTH; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Solid oxide fuel cells SOFCs ; Intermediate temperature solid oxide fuel cells ITSOFCs ; Electrolyte; Electrochemical impedance spectroscopy EIS ; Barium zirconate BaZrO3 ; Barium cerate BaCeO3 ; Solid-state reaction SSR ; Sintering; Conventional sintering CS ; Solid-state reactive sintering SSRS ; Spark plasma sintering SPS ; Ionic conductivity; Oxygen ion conductivity; Proton conductivity; Electronic conductivity; Oxygen ion conductor; Proton conductor; Oxygen partial pressure OPP ; Composite electrolyte; Materials Science and Engineering; Teknisk materialvetenskap;

    Abstract : In this thesis, the focus is on studying BaZrO3-BaCeO3 based proton conductors due to that they represent very promising proton conductors to be used for Intermediate Temperature Solid Oxide Fuel Cells (ITSOFCs). Here, dense BaZr0.5Ce0.3Y0. READ MORE