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Visar resultat 1 - 5 av 6 avhandlingar som matchar ovanstående sökkriterier.

  1. 1. Delayed Hydride Cracking in Irradiated Zircaloy

    Författare :Pål Efsing; Kjell Pettersson; Christopher Coleman; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Hydrides; hydrogen; embrittlement; delayed cracking; fracture toughness; fracture resistance; Hållfasthetslära; Solid Mechanics;

    Sammanfattning : Under some circumstances nuclear fuel cladding tubes made from zirconium based alloys may develop long axial cracks. The formation of these cracks is mainly thought to be connected with the oxiditian and hydriding of the cladding which takes plage after the the formation of a small primary defect. LÄS MER

  3. 2. Modeling framework for ageing of low alloy steel

    Författare :Magnus Boåsen; Pål Efsing; Jonas Faleskog; Carl F. O. Dahlberg; Christian Niordson; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Low alloy steel; length scale effects; size effects; plasticity; cleavage fracture; brittle fracture; weakest link; ageing; weld metal; Hållfasthetslära; Solid Mechanics;

    Sammanfattning : Ageing of low alloy steel in nuclear applications commonly takes the form as a hardening and an embrittlement of the material. This is due to the evolution of the microstructure during irradiation and at purely thermal conditions, as a combination or separate. LÄS MER

  4. 3. Modeling of structural integrity of aged low alloy steels using non-local mechanics

    Författare :Magnus Boåsen; Pål Efsing; Jacques Besson; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Hållfasthetslära; Solid Mechanics;

    Sammanfattning : Ageing of low alloy steels affects the structural integrity assessment as it most commonly causes embrittlement and a hardening of the material. This is due to theevolution of the microstructure during operation in the specific application. LÄS MER

  5. 4. A Fracture Mechanics Approach to Study Hydrogen Embrittlement in High Strength Martensitic Steels

    Författare :Armin E. Halilović; Pål Efsing; Jonas Faleskog; Carl F.O. Dahlberg; Covadonga Betegon; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Solid Mechanics; Hållfasthetslära;

    Sammanfattning : High strength steels that are subjected to hydrogen experience embrittlement where the mechanical properties are reduced, and premature failure of components may occur. Although the phenomenon has been recognized for over 150 years, it is not clear what drives embrittlement. LÄS MER

  7. 5. Multiscale modeling of atomic transport phenomena in ferritic steels

    Författare :Luca Messina; Pär Olsson; Nils Sandberg; Pål Efsing; Pascal Bellon; KTH; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; diffusion; impurities; iron; metals; kinetic Monte Carlo; ab initio; mean field; defects; embrittlement; reactor pressure vessel; neural networks; Fysik; Physics;

    Sammanfattning : Defect-driven transport of impurities plays a key role in the microstructure evolution of alloys, and has a great impact on the mechanical properties at the macroscopic scale. This phenomenon is greatly enhanced in irradiated materials because of the large amount of radiation-induced crystal defects (vacancies and interstitials). LÄS MER