Sökning: "Jens Bergström"

Visar resultat 1 - 5 av 22 avhandlingar innehållade orden Jens Bergström.

  1. 1. Estimating inclusion content in high performance steels

    Författare :Jens Ekengren; Jens Bergström; Christer Burman; Hans Nordberg; Karlstads universitet; []
    Nyckelord :ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; Materials Engineering; Materialteknik;

    Sammanfattning : Non-metallic inclusions in steel pose a major problem for the fatigue resistance, especially regarding fatigue at very long lives corresponding to low cyclic stress levels, as well as being detrimental to material toughness and polishability.The largest inclusions are quite rare, which makes conventional detection methods timeconsuming if reliable results are to be obtained. LÄS MER

  2. 2. Large and rare : An extreme values approach to estimating the distribution of large defects in high-performance steels

    Författare :Jens Ekengren; Jens Bergström; Christer Burman; Thomas Svensson; Karlstads universitet; []
    Nyckelord :ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Non-metallic inclusions; Tool steel; Extreme value statistics; Distribution of defects; Generalized extreme values; Materialteknik; Materials Engineering;

    Sammanfattning : The presence of different types of defects is an important reality for manufacturers and users of engineering materials. Generally, the defects are either considered to be the unwanted products of impurities in the raw materials or to have been introduced during the manufacturing process. LÄS MER

  3. 3. A study on wear characteristics of high strength steels under sliding contact

    Författare :Abdulbaset Mussa; Pavel Krakhmalev; Jens Bergström; Jens Hardell; Karlstads universitet; []
    Nyckelord :ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; High strength steels; thread joint wear; punch wear; sliding wear; surface cracking; reciprocal sliding; fatigue; surface delamination; white etching layer; nano-structured layer; friction; Materialteknik; Materials Engineering;

    Sammanfattning : In the last decades, significant improvements regarding the design, materials and technology of rock drills have been made. Likewise, in sheet metal forming, forming tools experience very high contact pressures when processing high strength steel sheets. LÄS MER

  4. 4. Palaeosurfaces and palaeovalleys on North Atlantic previously glaciated passive margins : reference forms for conclusions on uplift and erosion

    Författare :Johan M. Bonow; Karna Lidmar-Bergström; Clas Hättestrand; Jens-Ove Näslund; Mats Olvmo; Adrian Hall; Stockholms universitet; []
    Nyckelord :NATURAL SCIENCES; NATURVETENSKAP; palaeosurface; palaeovalley; uplift; valley; incision; glacial erosion; weathering; Neogene; southern Norway; West Greenland; Earth sciences; Geovetenskap;

    Sammanfattning : Palaeosurfaces and palaeovalleys are landforms under destruction in the present climate and/or tectonic regime, and thus mainly reflect processes not active today. Uplifted palaeosurfaces exist along the formerly glaciated passive continental margins around the North Atlantic. LÄS MER

  5. 5. Wear in sheet metal forming

    Författare :Anders Gåård; Pavel Krakhmalev; Jens Bergström; Åsa Kassman; Karlstads universitet; []
    Nyckelord :ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; Friction; Sheet metal forming; Galling; Materials science; Teknisk materialvetenskap; Materialteknik; Materials Engineering;

    Sammanfattning : The general trend in the car body manufacturing industry is towards low-series production and reduction of press lubricants and car weight. The limited use of press lubricants, in combination with the introduction of high and ultra-high strength sheet materials, continuously increases the demands of the forming tools. LÄS MER