Sökning: "sigma-phase"

Visar resultat 6 - 10 av 11 avhandlingar innehållade ordet sigma-phase.

1. 6. Relativenobility of precipitated phases in stainless steels : Evaluation with a combination of local probing techniques

   Författare :Namurata Sathirachinda; Jinshan Pan; Thomas Ladwein; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Materials science; Teknisk materialvetenskap;

   Sammanfattning : Stainless steels often exhibit complex transformation and precipitation behaviour due to a high content of alloying elements. Secondary phases can be formed in the temperature range of 300-1000°C and are generally undesirable due to their detrimental effect on mechanical properties and corrosion resistance of stainless steels. LÄS MER

3. 7. Super duplex stainless steels : Microstructure and propertiesof physically simulated base and weld metal

   Författare :Vahid Hosseini; Leif Karlsson; Högskolan Väst; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Super duplex stainless steel; weld metal; physical simulation; phase balance; precipitation; secondary phases; corrosion; nitrogen loss; arc heat treatment; production technology; Production Technology; Produktionsteknik; Manufacturing and materials engineering; Produktions- och materialteknik;

   Sammanfattning : High-temperature processing and application of super duplex stainless steel(SDSS) are associated with the risk of changes in the ferrite/austenite balance and precipitation of secondary phases. This study was therefore aimed at improving knowledge about effects of thermal cycles on the microstructure and properties of SDSS base and weld metal. LÄS MER

4. 8. Computer simulations of condensed phases with icosahedral local order

   Författare :Sergei Simdyankin; Paul Madden; Stockholms universitet; []
   Nyckelord :SAMHÄLLSVETENSKAP; SOCIAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; simple liquids; glasses; liquid-glass transition; Frank-Kasper phase; molecular dynamics; phonon dispersion; normal-mode analysis; wavelet analysis; numerisk analys; Numerical Analysis;

   Sammanfattning : Understanding the fundamental aspects, and the formation mechanisms of glasses remains an outstanding unsolved problem of condensed-matter physics.Glass-formation in simple atomic systems is generally associated with the icosahedral local order. LÄS MER

5. 9. Use of localised techniques to elucidate the influence of process variables on the corrosion of stainless steels

   Författare :Nuria Fuertes; Rachel Pettersson; Inger Odnevall; Stuart Lyon; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Stainless steel; corrosion; passive film; thermal oxides; Volta potential; pickling; deformation; cold rolling; AM; SKPFM; SVET; Kemi; Chemistry;

   Sammanfattning : Several factors during steel manufacture and fabrication can alter the passivity and corrosion behaviour of stainless steels. These include alloying, deformation, welding and heat treatments. LÄS MER

7. 10. Weldability and Testing Methodology in Precipitation Hardening Superalloys

   Författare :Jonny Jacobsson; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Weldability; Alloy 718; ATI® 718Plus™ and Haynes® 282®; Superalloys; Varestraint; Waspaloy®;

   Sammanfattning : Usable weldability data is desired in the manufacturing industry, especially within the aerospace industry where fabrication of structural jet engine components are realized. Welding of precipitation hardening superalloys such as Waspaloy®, Alloy 718, ATI® 718Plus™ and Haynes® 282® in particular can lead to solidification cracking in the fusion zone, liquation cracking in the heat affected zone and/or to solid state cracking. LÄS MER