Sökning: "microalloyed steels"

Visar resultat 1 - 5 av 7 avhandlingar innehållade orden microalloyed steels.

  1. 1. Modeling the Microstructural Evolution during Hot Deformation of Microalloyed Steels

    Författare :Linda Bäcke; Stefan Jonsson; Eric J. Palmiere; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; modeling; austenite; microalloyed steels; hot deformation; microstructure evolution; static recrystallization; dynamic recrystallization; metadynamic recrystallization<; Materials science; Teknisk materialvetenskap;

    Sammanfattning :   This thesis contains the development of a physically-based model describing the microstructural evolution during hot deformation of microalloyed steels. The work is mainly focused on the recrystallization kinetics. During hot rolling, the repeated deformation and recrystallization provides progressively refined recrystallized grains. LÄS MER

  3. 2. Cracking during Continuous Casting of Steels : Analysis tools and procedures to identify their causes on microalloyed steel slabs

    Författare :Rosa Maria Pineda Huitron; Esa Vuorinen; Pavel Ernesto Ramí­rez López; Maria Begoña Santillana; Luleå tekniska universitet; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Transverse corner cracks; Continuous Casting; Microalloyes steels; Secondary cooling; Cooling curves; Crack susceptibility; Materialteknik; Engineering Materials;

    Sammanfattning : Transverse corner cracks are one of the most common but complex defects formed in microalloyed steels during continuous casting (CC). Such cracks are detrimental because it leads to a loss in productivity with a great impact on environment, energy and economics for several steel making companies all over the world. LÄS MER

  4. 3. Laser-induced phase transformations in microalloyed steels

    Författare :Handika Sandra Dewi; Alexander Kaplan; Joerg Volpp; William O´Neill; Luleå tekniska universitet; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Produktionsutveckling; Manufacturing Systems Engineering;

    Sammanfattning : The application of thermal cycles below melting temperature can induce solid-to-solid phase transformation in steels, which is the transition between different crystalline structures of the same compound. There are many types of crystalline structures in steels produced, depending on the characteristics of the applied thermal cycle. LÄS MER

  5. 4. Very high cycle fatigue of automotive steels : Testing and computation at 20 kHz

    Författare :Mohamed Sadek; Jens Bergström; Nils Hallbäck; Ulrich Krupp; Karlstads universitet; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Very high cycle fatigue; ultrasonic fatigue testing; automotive steels; fatigue strength; stress intensity computation; crack growth; Materialteknik; Materials Engineering;

    Sammanfattning : Mechanical fatigue failure occurs in components subjected to cyclic loading. A crack initiates at critical regions in the component and propagates during repeated loading. The expected fatigue life depends on the level, type and frequency of the loading. LÄS MER

  7. 5. On the chemistry and stability of ternary precipitates in microalloyed steels

    Författare :Jan Strid; Luleå tekniska universitet; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Materialteknik; Engineering Materials;

    Sammanfattning : Light optical-, electron microscopy and Charpy-V-notch testing is used to characterize a number of different Ti-microalloyed steels, containing various alloying additions including high and low levels of nitrogen, and a Nb-steel is used as a comparison. The steels are studied in both the as-received and weld simulated conditions. LÄS MER