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Visar resultat 1 - 5 av 18 avhandlingar som matchar ovanstående sökkriterier.

1. 1. Slag inclusion formation during solidification of steel alloys and in cast iron

   Författare :Sofia Adolfi; Hasse Fredriksson; Karin Hansson; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; solidification; segregation; precipitation; inclusions; inoculation; EMPA; Other materials science; Övrig teknisk materialvetenskap;

   Sammanfattning : This thesis explores the formation of segregation and inclusions during solidification of steel and cast iron. A better understanding of the formation mechanism should result in decreasing fraction of defects during solidification of ingot and strand material. LÄS MER

3. 2. Microstructural Evolution In As-cast Alloys during Plastic Deformation

   Författare :Mitra Basirat; Pär Jönsson; Hasse Fredriksson; Jacques Lacaze; KTH; []
   Nyckelord :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 ;

   Sammanfattning : 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. LÄS MER

4. 3. Liquid phase sintering of W-Ni-Fe composites : liquid penetration, agglomerate separation and tungsten particle growth

   Författare :Anders Eliasson; Hasse Fredriksson; Thomas Gomez-Acebo; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Liquid phase sintering; heavy metal; particle composites; tungsten; penetration; agglomerate separation; particle interaction; parabolic flight; sounding rockets; microgravity; Kirkendall effect; Metallurgical process engineering; Metallurgisk processteknik;

   Sammanfattning : The initial stage of liquid phase sintering, involving liquid penetration, agglomerate separation, particle spreading and growth has been investigated in experiments using tungsten heavy alloys. The particle composites used were produced by hot isostatic pressing (HIP) of pure powder mixtures of W-Ni-Fe-(Co). LÄS MER

5. 4. Solidification of iron and nickel base alloys and its relation to hot crack and air gap formation

   Författare :Futsum Hailom Yosef; Hasse Fredriksson; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Metallurgical process engineering; Metallurgisk processteknik;

   Sammanfattning : .... LÄS MER

7. 5. 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