Sökning: "repair welding"

Visar resultat 1 - 5 av 14 avhandlingar innehållade orden repair welding.

  1. 1. 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

  3. 2. Weld Cracking of Precipitation Hardening Ni-based Superalloys - Investigation of repair welding characteristics and susceptibility towards strain age cracking

    Författare :Fabian Hanning; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Gleeble; Haynes 282; Waspaloy; welding; ATI 718Plus®; weldability; post-weld heat treatment; weld cracking; strain age cracking; hot cracking; Nickel-based superalloys;

    Sammanfattning : High temperature resistance and strength requirements make nickel-based superalloys the material of choice for the hot section of aero engines. Fabrication in terms of combining wrought and cast parts in the manufacturing of hot structural components enables component optimisation via the use of wrought high-strength parts, where geometrical constraints allow, and cast parts to produce complex geometries. LÄS MER

  4. 3. Weldability of Precipitation Hardening Superalloys – Influence of Microstructure

    Författare :Joel Håkan Andersson; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Hot cracking; GTAW; Transvarestraint testing; Varestraint testing; Gleeble testing; Solidification cracking; HAZ liquation cracking; Repair welding; Strain age cracking; EBW; DSC thermal analysis;

    Sammanfattning : Superalloys and in particular the precipitation hardened Ni-based superalloys havealways been used extensively in the hot sections of jet engines. Large hot structuralengine components with complex geometry have preferably been cast as single piececomponents since the large scale vacuum investment casting process becameavailable about fifty years ago. LÄS MER

  5. 4. Railway wheel steel behaviour upon thermo-mechanical loadings

    Författare :Erika Steyn; 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; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; residual stress; thermo-mechanical fatigue; railway wheel steel; pearlitic microstructure; severe block braking; repair welding;

    Sammanfattning : Optimised railway maintenance techniques such as rail grinding and milling, or rail repair welding, are vital to more sustainable rail networks. As demands on the railway increases, the need to better understand the material behaviour during local heating events occurring during maintenance is amplified. LÄS MER

  7. 5. Modelling of induction heat treatment in a manufacturing chain

    Författare :Martin Fisk; Jesper Hattel; Luleå tekniska universitet; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Material Mechanics; Materialmekanik;

    Sammanfattning : Due to increased competitiveness in the aerospace industry, deeper knowledge of the manufacturing process is needed. It is, for example, known that the microstructure is important for the performance of the components. LÄS MER