Sökning: "cast steel"

Visar resultat 16 - 20 av 66 avhandlingar innehållade orden cast steel.

1. 16. High-Temperature Corrosion-Fatigue of Cast Alloys for Exhaust Manifolds

   Författare :Shengmei Xiang; Joakim Odqvist; Baohua Zhu; Johan Ahlström; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; High temperature; corrosion fatigue; low-cycle fatigue; cast alloys; high-temperature oxidation; intermetallic phase; Teknisk materialvetenskap; Materials Science and Engineering;

   Sammanfattning : The introduction of gas-driven Otto engine and the corresponding usage of bio-fuels in heavy-duty engines will render the exhaust atmosphere more corrosive and bring a higher working temperature to exhaust manifolds. The current service material, a ferritic ductile cast iron called SiMo51, will soon meet its upper temperature limit set by the ferrite-austenite transformation at 860ºC. LÄS MER

3. 17. Depth Profiling of the Passive Layer on Stainless Steel using Photoelectron Spectroscopy

   Författare :Wendy Fredriksson; Kristina Edström; Fredrik Björefors; Sannakaisa Virtanen; Uppsala universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; depth profile; stainless steel; passive film; XPS; HAXPES; corrosion; powder metallurgical; Kemi med inriktning mot materialkemi; Chemistry with specialization in Materials Chemistry;

   Sammanfattning : The physical properties of the protective passive films formed on the surface of stainless steels under electrochemical polarization in different electrolytes were studied. The structure of these films was analyzed as a function of depth using photoelectron spectroscopy (PES). LÄS MER

4. 18. 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. 19. 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

7. 20. As-cast AZ91D magnesium alloy properties : Effects of microstructure and temperature

   Författare :Hoda Dini; Anders E.W. Jarfors; Nils-Eric Andersson; Jönköping University; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Magnesium; Magnesium Alloy; AZ91D; High-Pressure Die-Casting; Mechanical Property; Microstructural Characterisation; Physical Modelling; Dislocations; Distortion; Residual Stress; Magnesium; Magnesiumlegering; AZ91D; Pressgjutna; Mekanisk Egenskap; Mikrostrukturkarakterisering; Fysikalisk Modellering; Flytspänning; Dislokationer; Geometrisk Tolerans; Restspänning;

   Sammanfattning : Today, there is an essential need for lightweight, energy-efficient, environmentally benign engineering systems, and this is the driving force behind the development of a wide range of structural and functional materials for energy generation, energy storage, propulsion, and transportation. These challenges have motivated the use of magnesium alloys for lightweight structural systems. LÄS MER