Sökning: "isothermal martensite"

Visar resultat 1 - 5 av 9 avhandlingar innehållade orden isothermal martensite.

  1. 1. Nucleation and growth of martensite in steel

    Författare :Annika Borgenstam; KTH; []
    Nyckelord :martensite; Fe-alloys; α-martensite; athermal martensite; isothermal martensite; plate martensite; lath martensite; nucleation; growth; thermodynamics; plateau temperature; driving force; activation energy; bainite; Widmanstätten α; diffusive mechanism; displacive mechanism; ε-martensite; TECHNOLOGY; TEKNIKVETENSKAP;

    Sammanfattning : .... LÄS MER

  3. 2. Martensitic Transformation in High Carbon Steels - Martensite Tetragonality and Impact of Cooling Rate

    Författare :Thomas Kohne; Annika Borgenstam; Peter Hedström; Jilt Sietsma; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; High carbon steel; Martensitic transformation; Martensite tetragonality; Fatigue performance; Materials Science and Engineering; Teknisk materialvetenskap;

    Sammanfattning : Case-hardened gears are an essential part of our every day life in their role of power transmission in cars and heavy-duty trucks. The increasing use of low pressure carburizing (LPC) for case-hardening in combination with high pressure gas quenching (HPGQ) for cooling opens new possibilities in the design of heat treatments for improved fatigue performance. LÄS MER

  4. 3. Effect of heat treatment on microstructure and mechanical properties of a 5 wt.% Cr cold work tool steel

    Författare :Arbab Rehan; Lars-Erik Svensson; Leif Karlsson; Anna Medvedeva; Per Erik Skogholm; Berne Högman; Reinhold Schneider; Högskolan Väst; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Cold work tool steel; Hardening; Tempering; Microstructural characterisation; Retained austenite; Martensite; Bainite; Hardness; Impact toughness; Production Technology; Produktionsteknik; Manufacturing and materials engineering; Produktions- och materialteknik;

    Sammanfattning : This work presents investigations related to phase transformations occurring inthe 5 wt.% Cr cold work tool steel Caldie during hardening and tempering treatments. LÄS MER

  5. 4. Modeling Phase Transformations and Volume Changes during Cooling of Case Hardening Steels

    Författare :Matilda Tehler; Stefan Jonsson; Åsa Gustafson; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Phase transformation; volume changes; Other materials science; Övrig teknisk materialvetenskap;

    Sammanfattning : Case hardening distortions are a major problem for gear manufacturers. The aim of the current work is to create a simulation model, able to predict how and when case hardening distortions arise. The results presented in this thesis form a basis for such a model. Two case hardening steels, with base carbon contents of 0. LÄS MER

  7. 5. Structure and properties of advanced fine grained steels produced using novel thermal treatments

    Författare :Esa Vuorinen; David Porter; Luleå tekniska universitet; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Materialteknik; Engineering Materials;

    Sammanfattning : Fine grained advanced steels exhibit favourable mechanical properties for applications requiring high strength, ductility and impact toughness. These properties result from a microstructure containing a fine distribution of several phases including ferrite, austenite, martensite and bainite. LÄS MER