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Hittade 5 avhandlingar som matchar ovanstående sökkriterier.

1. 1. Modelling and Characterisation of the Martensite Formation in Low Alloyed Carbon Steels

   Författare :Jessica Gyhlesten Back; Lars-Erik Lindgren; Göran Engberg; Bevis Hutchinson; Luleå tekniska universitet; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Dilatometry; Hardness; EBSD; Martensite; Austenite; Kurdjumov-Sachs; Phase transformation; Modelling; Material Mechanics; Materialmekanik; Steel Forming and Surface Engineering;

   Sammanfattning : The current work contains experimental and theoretical work about the formation of martensite from the austenitic state of the steel Hardox 450. Simulation of rolling and subsequent quenching of martensitic steel plates requires a model that can account for previous deformation, current stresses and the temperature history, therefore dilatometry experiments were performed, with and without deformation. LÄS MER

3. 2. 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

4. 3. Dislocation density based material model applied in FE-simulation of metal cutting

   Författare :Dan Wedberg; Bevis Hutchinson; Luleå tekniska universitet; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Material Mechanics; Materialmekanik;

   Sammanfattning : Simulation based design enables rapid development of products with increased customer value in terms of accessibility, quality, productivity and profitability. However simulation of metal cutting is complex both in terms of numeric and physics. The work piece material undergoes severe deformations. LÄS MER

5. 4. 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

7. 5. Deformation Behaviour, Microstructure and Texture Evolution of CP Ti Deformed at Elevated Temperatures

   Författare :Zhipeng Zeng; Stefan Jonsson; Hans J. Roven; Bevis Hutchinson; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Commercially pure titanium; Zener–Hollomon parameter; Dynamic recovery; Dynamic recrystallization; Recrystallized volume fraction; Grain size; Flow stress; Constitutive equation; Texture; High angle grain boundary; Low angle grain boundary; Deformation twinning; Schmid factor; Misorientation; Hot compression; Slip system; Subgrain; EBSD; Construction materials; Konstruktionsmaterial;

   Sammanfattning : In the present work, deformation behavior, texture and microstructure evolution of commercially pure titanium (CP Ti) are investigated by electron backscattered diffraction (EBSD) after compression tests at elevated temperatures. By analysing work hardening rate vs. flow stress, the deformation behaviour can be divided into three groups, viz. LÄS MER