Sökning: "Widmanstätten ferrite"

Hittade 5 avhandlingar innehållade orden Widmanstätten ferrite.

1. 1. Does Bainite form with or without diffusion? : The experimental and theoretical evidence

   Författare :Peter Kolmskog; Annika Borgenstam; John Ågren; Bevis Hutchinson; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Carbon steels; Bainite; Bainitic ferrite; Widmanstätten ferrite; Microstructure; Microscopy; Thermodynamic modeling;

   Sammanfattning : With the increased interest in bainitic steels, fundamental understanding of the bainite transformationis of major importance. Unfortunately, the research on bainite has been hampered by an oldcontroversy on its formation mechanism. Over the years two quite different theories have developedclaiming to describe the bainite transformation i.e. LÄS MER

3. 2. Formation of Bainite in Steels

   Författare :Jiaqing Yin; Annika Borgenstam; Bevis Hutchinson; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Fe-C alloys; Bainitic transformation; Proeutectoid ferrite; Upper bainite; Lower bainite; Morphology; Steels.; Teknisk materialvetenskap; Materials Science and Engineering;

   Sammanfattning : A systematic survey of morphology of bainite and proeutectoid ferrite was carried out in order to validate some old thoughts of bainite transformation mechanism. It is confirmed that there is no morphological evidence supporting a sharp change neither between Widmanstätten ferrite and the ferritic component of upper bainite, nor between upper and lower bainite. LÄS MER

4. 3. Formation of Bainite Studied by In-situ High-energy X-ray Diffraction

   Författare :Sen Lin; Peter Hedström; Annika Borgenstam; Sébastien Allain; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Steel; Bainitic transformation; High-energy X-ray diffraction; Electron microscopy; Carbon diffusion; Thermodynamics and kinetics; Microstructure evolution; 高强钢; 贝氏体转变; 原位高能X射线衍射; 扫描与透射电子显微镜; 碳扩散; 热力学与动力学; 微观结构表征; Stål; Bainitiska fasomvandlingen; Högenergi-röntgendiffraktion; Elektronmikroskopi; Koldiffusion; Termodynamik och kinetik; Mikrostrukturutveckling; Materials Science and Engineering; Teknisk materialvetenskap;

   Sammanfattning :       Bainitic steels have attracted great attentions in recent years due to their excellent combination of properties to accommodate a wide range of applications. A deep and comprehensive understanding of how bainite forms is required to better design the production process and optimize the properties of bainitic steels. LÄS MER

5. 4. Modeling Bainite Formation in Steels

   Författare :Lindsay Leach; Annika Borgenstam; John Ågren; Lars Höglund; Hatem Zurob; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY;

   Sammanfattning : This study examines the fundamental aspects of bainite formation in a guided effort to lay a foundation for development of a model capable of predicting bainite formation. In the first part of this study, the tenets of an existing model for growth, developed by Zener and later modified by Hillert are examined. LÄS MER

7. 5. Cracking during Continuous Casting of Steels : Analysis tools and procedures to identify their causes on microalloyed steel slabs

   Författare :Rosa Maria Pineda Huitron; Esa Vuorinen; Pavel Ernesto Ramí­rez López; Maria Begoña Santillana; Luleå tekniska universitet; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Transverse corner cracks; Continuous Casting; Microalloyes steels; Secondary cooling; Cooling curves; Crack susceptibility; Materialteknik; Engineering Materials;

   Sammanfattning : Transverse corner cracks are one of the most common but complex defects formed in microalloyed steels during continuous casting (CC). Such cracks are detrimental because it leads to a loss in productivity with a great impact on environment, energy and economics for several steel making companies all over the world. LÄS MER