Sökning: "pearlite"

Visar resultat 21 - 25 av 25 avhandlingar innehållade ordet pearlite.

1. 21. Cavitation Erosion Mechanisms in Cast Irons

   Författare :Marcio Freitas de Abreu; Stefan Jonsson; Jessica Elfsberg; Matevz Dular; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Teknisk materialvetenskap; Materials Science and Engineering;

   Sammanfattning : The research presented in this thesis investigated the mechanisms by which cavitation erosion damage develops in lamellar graphite iron (LGI) and austempered ductile irons (ADIs). This has been achieved by image sequences of surface erosion on test samples in tandem with weight change measurements. LÄS MER

3. 22. Modeling of phase transformations and cyclic plasticity in pearlitic steels

   Författare :Björn Andersson; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Phase transformations; TRIP; Pearlitic steel; FEM; Cyclic plasticity; Homogenization;

   Sammanfattning : The low rolling resistance in railway transportation is a key factor for its high efficiency, but it comes at the price of very high contact pressure between the rail and wheel. Due to the high stresses and the large number of load cycles during railway operation, both the rail and the wheel can be susceptible to fatigue crack initiation and propagation. LÄS MER

4. 23. 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

5. 24. Modelling and simulation of hot stamping

   Författare :Paul Åkerström; Luleå tekniska universitet; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Hållfasthetslära; Solid Mechanics;

   Sammanfattning : The growing effort to reduce vehicle weight and improve passive safety in the automotive industry has drastically increased the demand for ultra high strength steel components. There are several production technologies for such components. LÄS MER

7. 25. Formation of Bainite Studied by In-situ High-energy X-ray Diffraction

   Författare :Sen Lin; Peter Hedström; Annika Borgenstam; Sébastien Allain; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Steel; Bainitic transformation; High-energy X-ray diffraction; Electron microscopy; Carbon diffusion; Thermodynamics and kinetics; Microstructure evolution; 高强钢; 贝氏体转变; 原位高能X射线衍射; 扫描与透射电子显微镜; 碳扩散; 热力学与动力学; 微观结构表征; Stål; Bainitiska fasomvandlingen; Högenergi-röntgendiffraktion; Elektronmikroskopi; Koldiffusion; Termodynamik och kinetik; Mikrostrukturutveckling; Materials Science and Engineering; Teknisk materialvetenskap;

   Sammanfattning :       Bainitic steels have attracted great attentions in recent years due to their excellent combination of properties to accommodate a wide range of applications. A deep and comprehensive understanding of how bainite forms is required to better design the production process and optimize the properties of bainitic steels. LÄS MER