Sökning: "austenite formation"

Visar resultat 1 - 5 av 52 avhandlingar innehållade orden austenite formation.

  1. 1. Modelling and Characterisation of the Martensite Formation in Low Alloyed Carbon Steels

    Författare :Jessica Gyhlesten Back; Lars-Erik Lindgren; Göran Engberg; Bevis Hutchinson; Luleå tekniska universitet; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Dilatometry; Hardness; EBSD; Martensite; Austenite; Kurdjumov-Sachs; Phase transformation; Modelling; Material Mechanics; Materialmekanik; Steel Forming and Surface Engineering;

    Sammanfattning : The current work contains experimental and theoretical work about the formation of martensite from the austenitic state of the steel Hardox 450. Simulation of rolling and subsequent quenching of martensitic steel plates requires a model that can account for previous deformation, current stresses and the temperature history, therefore dilatometry experiments were performed, with and without deformation. LÄS MER

  3. 2. Morphological characterization of primary austenite in cast iron

    Författare :Juan Carlos Hernando; Attila Diószegi; Jönköping University; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Lamellar Graphite Iron; Solidification; Primary Austenite; Microstructure Evolution; Dendritic coarsening; Compacted Graphite Iron; Magnesium Fading; Nodularity;

    Sammanfattning : Automotive industry products portfolio includes a wide variety of complex‐shaped cast iron products, such as truck engine components, that need to withstand a constant trend of higher demands, especially urged by stricter environmental regulations on emissions. Combined with this continued demand on properties improvement, cast iron industry faces a process problem related to the lack of understanding of solidification and mechanisms behind defect formation. LÄS MER

  4. 3. Defect Formation during Solidification in Grey Iron Castings

    Författare :Lennart Elmquist; Ingvar Svensson; Attila Diószegi; Doru Stefanescu; Jönköping University; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Shrinkage Porosity; Grey Iron; Solidification; Nucleation; Primary Austenite; DAAS; Eutectic Cells; Microstructure; Macrostructure; Hot Spot; Oxygen; Hydrogen; Materials science; Teknisk materialvetenskap;

    Sammanfattning : The presence of defects is of major concern in the production of grey iron castings. Some defects are merely an aesthetic problem while others can be detrimental for the performance of the component. Among the several possible defects, shrinkage porosity is one of the more challenging to understand and avoid. LÄS MER

  5. 4. Welds in the lean duplex stainless steel LDX 2101 : effect of microstructure and weld oxides on corrosion properties

    Författare :Elin M. Westin; John Ågren; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Duplex stainless steel; welding; weld metal; HAZ; nitrogen; manganese; austenite formation; phase balance; precipitates; pitting resistance; heat input; solidification; element loss; evaporation; deposition; weld oxides; discoloration; mechanical properties; thermo-mechanical simulation; Geeble; GTA; laser; LOM; SEM; EDS; TEM; Leco; EPMA; ferroxyl test; XPS; post weld cleaning; pickling; Materials science; Teknisk materialvetenskap;

    Sammanfattning : Duplex stainless steels are a very attractive alternative to austenitic grades due to their higher strength and good corrosion performance. The austenitic grades can often be welded autogenously, while the duplex grades normally require addition of filler metal. LÄS MER

  7. 5. Microstructure and properties of welds in the lean duplex stainless steel LDX 2101

    Författare :Elin M. Westin; John Ågren; Hannu Hänninen; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Duplex stainless steel; welding; HAZ; nitrogen; manganese; microstructure; austenite formation; phase balance; precipitates; element distribution; segregation; depletion; solidification; pitting corrosion resistance; solidification; element loss; evaporation; deposition; weld oxide; thermo-mechanical simulation; thermodynamic modelling; EPMA; XPS; post-weld cleaning; pickling; Metallurgical process and manufacturing engineering; Metallurgisk process- och produktionsteknik;

    Sammanfattning : Duplex stainless steels can be very attractive alternatives to austenitic grades due to their almost double strength at equal pitting corrosion resistance. When welding, the duplex alloys normally require addition of filler metal, while the commodity austenitic grades can often be welded autogenously. LÄS MER