Sökning: "Phase transformations"

Visar resultat 16 - 20 av 129 avhandlingar innehållade orden Phase transformations.

  1. 16. Thermodynamic and Kinetic Investigation of the Fe-Cr-Ni System Driven by Engineering Applications

    Författare :Wei Xiong; Malin Selleby; John Ågren; Byeong-Joo Lee; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; phase transformation; magnetism; spinodal decomposition; stainless steel; low temperature CALPHAD; phase field; ab initio; atom probe tomography; calorimetry; SRA - E-vetenskap SeRC ; SRA - E-Science SeRC ; SRA - Energy; SRA - Energi;

    Sammanfattning : This work is a thermodynamic and kinetic study of the Fe-Cr-Ni system as the core of stainless steels. The Fe-Cr, Fe-Ni and Cr-Ni systems were studied intensively using both computational and experimental techniques, including CALPHAD (CALculation of PHAse Diagrams), phase field simulation, ab initio modeling, calorimetry, and atom probe tomography. LÄS MER

  3. 17. Railway Wheel Flats. Martensite Formation, Residual Stresses, and Crack Propagation

    Författare :Johan Jergeus; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; sliding contact; metallographic investigation; crack propagation; thermal shock; constitutive modelling; phase transformations; railway wheel flats; full-scale field experiments; transformation plasticity; tread damage; residual stresses; spalling; martensite formation;

    Sammanfattning : A railway wheel flat is a flat spot on the rolling surface of a wheel caused by its unintentional sliding on the rail. The reason for the sliding may be poorly adjusted, frozen or defect brakes, or too high braking forces in relation to the available wheel/rail adhesion. LÄS MER

  4. 18. Simulation of diffusional processes in alloys : techniques and applications

    Författare :Henrik Strandlund; John Ågren; John Morral; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Diffusion; Kirkendall effect; Phase transformations; Random walk; Solute drag; Interfacial mobility; Other materials science; Övrig teknisk materialvetenskap;

    Sammanfattning : This thesis concerns computer simulation of diffusional processes in alloys. The main focus is on the development of simulation techniques for diffusion in single-phase domains, but also diffusion controlled phase-transformations and interfacial processes are discussed. LÄS MER

  5. 19. Thermal and mechanical behaviour of railway wheel steel

    Författare :Johan Ahlström; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; phase transformations; plastic deformation; sliding contact; heat conduction modelling; low cycle fatigue; railway wheel steel Fe-0.5C-0.3Si-0.75Mn-0.05V ; austenitisation; transformation kinetics; heat treatment; friction;

    Sammanfattning : The wish to increase loads and speeds of trains puts higher demand on construc¬tion, engineering and material than ever before. Therefore it is necessary to con¬tinuously develop technology to meet these increasing requirements. LÄS MER

  7. 20. Thermo-Mechanical-Metallurgical Modelling of Pearlitic Steels and Railhead Repair Welding

    Författare :Björn Andersson; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Pearlitic steels; Railhead repair; Welding simulations; Phase transformations; Cyclic plasticity; Finite element analysis; Homogenisation;

    Sammanfattning : The efficiency of rail transport is attributed to low rolling resistance, which comes at the cost of high contact pressures between rail and wheel. Consequently, both the rail and wheel can be susceptible to fatigue crack initiation and propagation due to the resulting high stresses and large number of load cycles in service. LÄS MER