Sökning: "UHSS"

Visar resultat 1 - 5 av 7 avhandlingar innehållade ordet UHSS.

  1. 1. Challenges in Resistance Welding of Ultra High Strength Steels

    Författare :Erik Tolf; Arne Melander; Zuheir Barsoum; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Resistance welding; spot welding; surface cracks; nut welding; UHSS; projection welding; Teknisk materialvetenskap; Materials Science and Engineering;

    Sammanfattning : Increasing the use of Ultra High Strength Steels (UHSS) in vehicle bodystructures is important for reducing weight and cutting CO2 emissions. This thesis investigates challenges in resistance welding that can be a barrier to implementing UHSS as a replacement for low strength steels in vehicle structures. LÄS MER

  3. 2. A Study on Sandwich Structures : Development, Mechanical Characterization and Numerical Modeling

    Författare :Samuel Hammarberg; Pär Jonsén; Jörgen Kajberg; Simon Larsson; Dan Zenkert; Luleå tekniska universitet; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Ultra-High Strength Steel; UHSS; Sandwich; Micro-sandwich; Hybrix; Modeling; Composite; Hållfasthetslära; Solid Mechanics;

    Sammanfattning : Legislative demands force the automotive industry to reduce greenhouse gas (GHG) emissions. At the same time, crashworthiness must not be compromised. A ve-hicle’s GHG emissions, such as carbon dioxide, is dependent on its fuel consump-tion. Lowering the vehicle weight, reducing fuel consumption, will therefor reduce emissions. LÄS MER

  4. 3. Laser welding of ultra-high strength steel and a cast magnesium alloy for light-weight design

    Författare :Karl Fahlström; Lars-Erik Svensson; Leif Karlsson; Michael Rethmeier; Högskolan Väst; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Laser welding; ultra-high strength steel; cast magnesium alloy; light-weight design; automotive industry; distortion; porosity; Production Technology; Produktionsteknik; Manufacturing and materials engineering; Produktions- och materialteknik;

    Sammanfattning : There is a strong industrial need for developing robust and flexible manufacturing methods for future light-weight design. Better performing, environmental friendly vehicles will gain competitive strength from using light weight structures. LÄS MER

  5. 4. High temperature galling : influencing parameters and mechanisms

    Författare :Leonardo Pelcastre; Jens Bergström; Luleå tekniska universitet; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Maskinelement; Machine Elements; Centrumbildning - Centrum för högpresterande stål CHS ; Centre - Centre for High Performance Steel CHS ;

    Sammanfattning : Damage of forming tools at elevated temperatures is a major problem in metal forming processes such as hot stamping. Of special importance is the occurrence of adhesion and gross material transfer from the work-piece to the tool surface, a phenomenon known as galling. LÄS MER

  7. 5. Hot forming tribology : galling of tools and associated problems

    Författare :Leonardo Pelcastre; Ewald Badisch; Luleå tekniska universitet; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Maskinelement; Machine Elements; Centrumbildning - Centrum för högpresterande stål CHS ; Centre - Centre for High Performance Steel CHS ;

    Sammanfattning : In recent years, the use of ultra high-strength steels (UHSS) as structural reinforcements and in energy-absorbing systems in automobiles has increased rapidly; mainly in view of their favourable strength to weight ratios. However, due to their high strength, the formability of UHSS is poor, thus complex-shaped UHSS components are invariably produced through hot-metal forming processes. LÄS MER