Sökning: "TIG-remelting"

Hittade 4 avhandlingar innehållade ordet TIG-remelting.

  1. 1. Fatigue life extension in existing steel bridges. High-Frequency Mechanical Impact treatment and Tungsten Inert Gas remelting in life extension and fatigue crack repair of welded steel structures

    Författare :Hassan al-Karawi; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; HFMI; TIG-dressing; Life extension; Post weld treatment; Gain factor; Linear elastic fracture mechanics; Crack retrofiting; Peening; fatigue crack; Crack detection; Microhardness; Concentration factor; LEFM; TIG-remelting; Strain gauge;

    Sammanfattning : This thesis investigates the performance of improved welds with two post-weld treatment methods for application on existing structures. High-Frequency Mechanical Impact (HFMI) treatment and Tungsten Inert Gas (TIG) remelting were used for fatigue life extension of welded structures. LÄS MER

  3. 2. Super duplex stainless steels : Microstructure and propertiesof physically simulated base and weld metal

    Författare :Vahid Hosseini; Leif Karlsson; Högskolan Väst; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Super duplex stainless steel; weld metal; physical simulation; phase balance; precipitation; secondary phases; corrosion; nitrogen loss; arc heat treatment; production technology; Production Technology; Produktionsteknik; Manufacturing and materials engineering; Produktions- och materialteknik;

    Sammanfattning : High-temperature processing and application of super duplex stainless steel(SDSS) are associated with the risk of changes in the ferrite/austenite balance and precipitation of secondary phases. This study was therefore aimed at improving knowledge about effects of thermal cycles on the microstructure and properties of SDSS base and weld metal. LÄS MER

  4. 3. Influence of multiple welding cycles on microstructure and corrosion resistance of a super duplex stainless steel

    Författare :Vahid Hosseini; Leif Karlsson; Högskolan Väst; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Super duplex stainless steel; autogenous TIG welding; multiple welding thermal cycles; sensitization; nitrogen loss; sigma phase; ferrite content; production technology; Production Technology; Produktionsteknik; Manufacturing and materials engineering; Produktions- och materialteknik;

    Sammanfattning : Super duplex stainless steel (SDSS) has found a wide use in demanding applications such as offshore, chemical and petrochemical industries thanks to its excellent combination of mechanical properties and corrosion resistance. Welding of SDSS, however, is associated with the risk of precipitation of secondary phases and formation of excessive amounts of ferrite in the weld metal and heat affected zone. LÄS MER

  5. 4. Application of high-frequency mechanical impact treatment for fatigue strength improvement of new and existing bridges

    Författare :Hassan al-Karawi; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Corrosion; Bridges; Fatigue; Crackdetection; HFMI; Finiteelement; Steel; Lifeextension; Post-weldtreatment; Variableampli- tude;

    Sammanfattning : This thesis investigates the application of High-Frequency Mechanical Impact (HFMI) treatment for fatigue strength improvement of weldments in existing and new bridges. In the former case, the welds have already been subjected to fatigue loading and accumulated damage before treatment. LÄS MER