Sökning: "Experimental evolution"

Visar resultat 26 - 30 av 450 avhandlingar innehållade orden Experimental evolution.

1. 26. Phase equilibria and thermodynamic properties of high-alloy tool steels : theoretical and experimental approach

   Författare :Johan Bratberg; John Ågren; Bengt Hallstedt; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; thermodynamic modelling; thermodynamic calculations; tool steels; high-speed steels; CALPHAD; Other materials science; Övrig teknisk materialvetenskap;

   Sammanfattning : The recent development of tool steels and high-speed steels has led to a significant increase in alloy additions, such as Co, Cr, Mo, N, V, and W. Knowledge about the phase relations in these multicomponent alloys, that is, the relative stability between different carbides or the solubility of different elements in the carbides and in the matrix phase, is essential for understanding the behaviour of these alloys in heat treatments. LÄS MER

3. 27. Temperature dependent mechanical properties of as-cast steels : Experimental and theoretical studies

   Författare :Zhihua Dong; Levente Vitos; Imre Bakonyi; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY;

   Sammanfattning : The temperature-dependent mechanical properties of steels are important to avoid processing defects, to understand and to improve the high-temperature performance. At the same time, having access to thermal properties gives us opportunity to assess the first-principles theoretical predictions at elevated temperatures. LÄS MER

4. 28. Modeling the microstructural evolution during hot working of C-Mn and of Nb microalloyed steels using a physically based model

   Författare :Linda Lissel; []
   Nyckelord :austenite; modeling; hot deformation; microstructure; evolution; static recrystallization; dynamic recrystallization; metadynamic recrystallization; Modellering av mikrostrukturutvecklingen hos mikrolegerade stål under varmdeformation;

   Sammanfattning : Recrystallization kinetics, during and after hot deformation, has been investigated for decades. From these investigations several equations have been derived for describing it. The equations are often empirical or semi-empirical, i.e. LÄS MER

5. 29. Evolution of artificial defects during shape rolling

   Författare :Mirjana Filipovic; Stefan Jonsson; Per-Olov Perä; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; shape rolling; wire rod rolling; artificial defects; defect evolution; surface cracks; porosity; FEM; high speed steel; stainless steel; Other materials science; Övrig teknisk materialvetenskap; Initiering och utveckling av defekter under spårvalsning;

   Sammanfattning : Very often defects are present in rolled products. For wire rods, defects are very deleterious since the wire rods are generally used directly in various applications. For this reason, the market nowadays requires wire rods to be completely defect-free. Any wire with defects must be rejected as scrap which is very costly for the production mill. LÄS MER

7. 30. Processes of Magma-crust Interaction : Insights from Geochemistry and Experimental Petrology

   Författare :Frances M Deegan; Valentin R Troll; Luigi Dallai; Uppsala universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Canary Island magmatism; HP-HT experimental petrology; magma-crust interaction; Merapi volcano; radiogenic isotopes Sr; Nd; Pb ; stable isotopes O; B .; Solid earth geology and petrology; Berggrundsgeologi och petrologi; Geovetenskap med inriktning mot mineralogi; petrologi och tektonik; Earth Science with specialization in Mineral Chemistry; Petrology and Tectonics;

   Sammanfattning : This work focuses on crustal interaction in magmatic systems, drawing on experimental petrology and elemental and isotope geochemistry. Various magma-chamber processes such as magma-mixing, fractional crystallisation and magma-crust interaction are explored throughout the papers comprising the thesis. LÄS MER