Search for dissertations about: "karbider"

Showing result 1 - 5 of 9 swedish dissertations containing the word karbider.

  2. 1. Some aspects of convection as well as graphite and carbide formations during casting

    Author : Fareed Ashraf Khan; Michael Vynnycky; Pär Jönsson; Bo Rogberg; Hasse Fredriksson; Jessica Elfsberg; KTH; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; carbides; heat treatment; cast iron; ball bearing steel; casting; cooling rate; structure analysis; nodule distribution; melt stirring; nuclei; karbider; värmebehanding; gjutjärn; kullagerstål; gjutning; kylningshastighet; strukturanalys; nodulefördelning; smältrörelse; kärnor.; Metallurgical process science; Metallurgisk processvetenskap;

    Abstract : It is an established fact that segregation during casting affects the physical properties of carbon-based ferro alloys; this motivates the study of the segregation behaviour of carbon and carbide-forming solute elements. In this context, this thesis investigates two different situations: the effects of cooling rate and turbulence on the precipitation behaviour of the graphite nodules in nodular cast iron; the nature of carbide precipitation in a bearing steel grade and the effects of subsequent soaking on these carbides. READ MORE

  4. 2. Modeling the Microstructure Evolution During and After Hot Working in Martensitic Steel

    Author : Nima Safara Nosar; John Ågren; Göran Engberg; Hans-Olof Andrén; KTH; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Modeling; Martensitic steel; Carbides; Carbide size distribution; Carbide volume fraction; Carbide shape factor; Modellering; Martensitiskt stål; karbider; karbidstorleksfördelning; karbidvolymfraktion; karbidformfaktor; Teknisk materialvetenskap; Materials Science and Engineering;

    Abstract : In this study, the goal is to predict the microstructure evolution during and after the hot working of a martensitic stainless steel with 13% chromium using a physically-based model in the form of a MATLAB toolbox. This model is based on dislocation density theory and consists of coupled sets of evolution equations for dislocation, vacancies, recovery, recrystallization, and grain growth. READ MORE

  5. 3. On deoxidation practice and grain size of austenitic manganese steel

    Author : Dimitrios Siafakas; Anders Jarfors; Taishi Matsushita; Johan Nils Ahlström; Jönköping University; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Hadfield steel; deoxidation; grain size; inoculation; particles; carbides; oxides; Hadfield stål; desoxidering; kornstorlek; ympning; partiklar; karbider; oxider;

    Abstract : The exceptional wear resistance and work hardenability, place Hadfield steel as one of themost important materials for manufacturing cast components used in the mining, crashing,drilling, and excavation industries. In all metallic alloys used for component casting, themechanical properties are highly influenced by the microstructure of the material. READ MORE

  6. 4. Carbides in martensitic medium carbon low alloyed tool steels studied with small angle scattering techniques, electron microscopy and atom probe tomography

    Author : Erik Claesson; Peter Hedström; Hans Magnusson; Erik Offerman; KTH; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Low alloyed tool steel; Martensite; Small angle scattering; Scanning transmission electron microscopy; Energy dispersive x-ray spectroscopy; atom probe tomography; Scanning precession electron diffraction; Precipitation; carbides; Tempering.; Materials Science and Engineering; Teknisk materialvetenskap;

    Abstract : Medium carbon low alloyed tool steels are used today in various areas to shape plastics, nonferrous metals, and steels, and they are crucial in the manufacturing industry. To be effective, tool steels must be strong and tough, and have high wear resistance and temperature stability. READ MORE

  7. 5. Microstructural Decay in High-Strength Bearing Steels under Rolling Contact Fatigue

    Author : Tania Loaiza; Peter Hedström; Mårten Olsson; Steve Ooi; Prasath Babu; Harry Bhadeshia; KTH; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Microstructural decay; microscopy; rolling contact fatigue; Hybrid 60 steel; Bearing steel; 52100; dislocations; ferrite microbands; Mikrostrukturell nedbrytning; mikroskopi; rullande kontaktfatigue; Hybrid 60-stål; dislokationer; Materials Science and Engineering; Teknisk materialvetenskap;

    Abstract : The work presented in this thesis aims to enhance our understanding of material decay in high-strength steels used for bearing applications. The primary objective is to investigate the microstructural changes in two high-strength steels: 52100 steels, a popular bearing steel, and Hybrid 60, a relatively new bearing steel designed for long fatigue life and use at elevated temperatures. READ MORE