Sökning: "kylningshastighet"

Hittade 4 avhandlingar innehållade ordet kylningshastighet.

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

    Författare :Fareed Ashraf Khan; Michael Vynnycky; Pär Jönsson; Bo Rogberg; Hasse Fredriksson; Jessica Elfsberg; KTH; []
    Nyckelord :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;

    Sammanfattning : 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. LÄS MER

  3. 2. Electron beam powder bed fusion of Nitinol : A development from production process window towards delicate structures

    Författare :Lin Zeyu; Amir Rashid; Carolin Körner; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Production Engineering; Industriell produktion;

    Sammanfattning : Electron beam powder bed fusion (PBF-EB) is increasingly attracting attention for manufacturing the near-net shape parts due to its incomparable merits, such as free residual stress and superior mechanical performance. Nickel Titanium (NiTi) as the most widely used functional alloy, has not been systematically explored for manufacturing using PBF-EB despite the perfect vacuum and high temperature manufacturing environment. LÄS MER

  4. 3. Experimental and Numerical Investigation of the Quenching Process on Rotary Hollow Cylinder by Multiple Impinging Jets

    Författare :Mohammad Jahedi; Bahram Moshfegh; Fredrik Berntsson; Joakim Wren; Rahmatollah Khodabandeh; Högskolan i Gävle; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Multiple jet arrays; Transient boiling; Moving surface; Rotating surface; Inverse heat conduction problem; Quenching; Water impinging jet; Experimental study; Matriser av jetstrålar; Direktverkande jetstrålar; Transient kokning; Roterande yta; Icke-stationär invers värmeledning; Släckning; Experimentell studie; Intelligent industri; Intelligent Industry;

    Sammanfattning : The worldwide competitive market on metal products with higher quality in industry has increased the need to implement more advanced and controllable quenching techniques in the hardening stage of the heat treatment process. Moreover, sustainability and energy efficiency are key factors to consider in the development of advanced quenching techniques. LÄS MER

  5. 4. Martensitic Transformation in High Carbon Steels - Martensite Tetragonality and Impact of Cooling Rate

    Författare :Thomas Kohne; Annika Borgenstam; Peter Hedström; Jilt Sietsma; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; High carbon steel; Martensitic transformation; Martensite tetragonality; Fatigue performance; Materials Science and Engineering; Teknisk materialvetenskap;

    Sammanfattning : Case-hardened gears are an essential part of our every day life in their role of power transmission in cars and heavy-duty trucks. The increasing use of low pressure carburizing (LPC) for case-hardening in combination with high pressure gas quenching (HPGQ) for cooling opens new possibilities in the design of heat treatments for improved fatigue performance. LÄS MER