Sökning: "Keiji Nakajima"

Hittade 5 avhandlingar innehållade orden Keiji Nakajima.

  1. 1. Inclusions and/or Particles Engineering for Grain Refining Purposes in Ferritic Fe-20mass%Cr alloys

    Författare :Jesper Janis; Pär Jönsson; Keiji Nakajima; Lauri Holappa; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Inclusions; Particles; Grain size; High Cr; Ferritic; Grain refining; Solidification; Pinning effect; Stainless steel; Oxides; Nitrides; Metallurgical process engineering; Metallurgisk processteknik;

    Sammanfattning : Compared to more common used austenitic stainless steels, ferritic stainless steels contain very low amounts of the expensive alloying element Ni. In addition, they have good corrosion properties, but are sometimes suffering from poor weldability and bad mechanical properties. LÄS MER

  3. 2. Control of Wear-Resistance Properties in Ti-added Hypereutectic High Chromium Cast Iron

    Författare :Qiang Liu; Pär Jönsson; Keiji Nakajima; José Tinoco; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; High Chromium Cast Iron; cooling rate; Ti addition; M7C3; TiC; carbides size distributions; volume fraction; heat treatment; microstructure; mechanical properties; wear resistance;

    Sammanfattning : High chromium cast iron (HCCI) is considered as one of the most useful wear resistance materials and their usage are widely spread in industry. The wear resistance and mechanical properties of HCCI mainly depend on type, size, number, morphology of hard carbides and the matrix structure (γ or α). LÄS MER

  4. 3. Microstructure Evaluation and Wear-Resistant Properties of Ti-alloyed Hypereutectic High Chromium Cast Iron

    Författare :Qiang Liu; Pär Jönsson; Keiji Nakajima; Niels Skat Tiedje; KTH; []
    Nyckelord :High Chromium Cast Iron; cooling rate; Ti addition; M7C3; TiC; carbides size distributions; volume fraction; heat treatment; microstructure; mechanical properties; wear resistance; statistics of extreme values SEV ; maximum carbides size.;

    Sammanfattning : High chromium cast iron (HCCI) is considered as one of the most useful wear resistance materials and their usage are widely spread in industry. The mechanical properties of HCCI mainly depend on type, size, number, morphology of hard carbides and the matrix structure (γ or α). LÄS MER

  5. 4. Microstructure and Inclusion Characteristics in Steels with Ti-oxide and TiN Additions

    Författare :Wangzhong Mu; Pär Jönsson; Keiji Nakajima; Casper Van der Eijk; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; intragranular ferrite; oxide metallurgy; inclusion engineering; titanium nitride; titanium oxide; inclusion size; heterogeneous nucleation; critical diameter; confocal laser scanning microscopy CLSM ; differential scanning calorimetry DSC ; continuous cooling transformation CCT diagram.; Materials Science and Engineering; Teknisk materialvetenskap;

    Sammanfattning : Non-metallic inclusions in steels are generally considered to be detrimental for mechanical properties. However, it has been recognized that certain inclusions, such as Ti-oxide and TiN, can serve as potent nucleation sites for the formation of intragranular ferrite (IGF) in low-alloy steels. LÄS MER

  7. 5. A study of solid and liquid inclusion separation at the steel-slag interface

    Författare :Jenny Strandh; Pär Jönsson; Robert Eriksson; Keiji Nakajima; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Materials science; mathematical modeling; inclusion separation; tundish; ladle; slag; steel-slag interface; physical properties; Materialvetenskap; Materials science; Teknisk materialvetenskap;

    Sammanfattning : This thesis work aimed to provide a better knowledge of inclusion behavior at the steel-slag interface. All results are based on mathematical modeling of liquid and solid inclusion separation to the slag. The model descriptions of the inclusion transfer are based on the equation of motion at the system. LÄS MER