Sökning: "Chromium oxides"

Visar resultat 1 - 5 av 39 avhandlingar innehållade orden Chromium oxides.

  1. 1. Studies of transport in some oxides by gas phase analysis

    Författare :Qian Dong; KTH; []
    Nyckelord :LANTBRUKSVETENSKAPER; AGRICULTURAL SCIENCES; gas phase analysis GPA ; secondary ion mass spectrometry SIMS ; chromium; platinum; quartz; porous oxides; Soil science; Markvetenskap;

    Sammanfattning : .... LÄS MER

  3. 2. Key Aspects of Sintering Powder Metallurgy Steel Prealloyed with Chromium and Manganese

    Författare :Ola Bergman; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Manganese; Prealloyed; Sintering; Mechanical properties; Chromium; Spinel oxide; Powder metallurgy; PM steel; Oxide reduction; Residual oxides; Atmosphere;

    Sammanfattning : The powder metallurgy (PM) process is a cost efficient near net-shape technology suitable for sustainable manufacturing of structural steel components. A drawback with the PM technology is the difficulty to use oxidation sensitive alloying elements, such as Cr and Mn. LÄS MER

  4. 3. Studies of oxide reduction and nitrogen uptake in sintering of chromium-alloyed steel powder

    Författare :Ola Bergman; John Ågren; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; powder metallurgy; chromium; pre-alloying; surface oxides; sintering; Materials science; Teknisk materialvetenskap;

    Sammanfattning : The powder metallurgy (PM) process route is very competitive for mass production of structural steel components with complex shape, due to efficient material utilisation, low energy consumption, and short overall production time. The most commonly used alloying elements are the processing friendly metals Cu, Ni and Mo. LÄS MER

  5. 4. The rule of hydrogen and rare earth metals in the formation of protective metal-oxides

    Författare :Bent N. Tveten; KTH; []
    Nyckelord :chromium; high-temperature corrosion; oxide growth; scale adherence; hydrogen; yttria; REM; reactive element effect; gas phase analysis;

    Sammanfattning : The effects of hydrogen and rare earth metal (REM) additionson the oxidation behavior of metals and alloys that formchromia, alumina and zirconia in 20 mbar O2and/or H2O have been investigated at elevated temperatures.The metal-gas reactions were studied by the use of isotopicallylabeled gas in combination with mass spectrometry and bymeasuring changes in the total pressure in a closed reactionchamber. LÄS MER

  7. 5. ROLE OF SURFACE OXIDES IN SINTERING OF CHROMIUM-ALLOYED STEEL POWDER

    Författare :Henrik Karlsson; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; water atomisation; surface analysis; sintering; chromium-alloyed steel.; Powder metallurgy; surface reactions; surface; surface oxide; SEM; XRD; AES; XPS;

    Sammanfattning : During water-atomisation and handling of steel powder the surface inevitably oxidises. The surface bound oxide is an important factor in the processing of powder metallurgical (PM) steels, especially in case the powder contains elements forming stable oxides, such as Cr, Mn, and Si. LÄS MER