Search for dissertations about: "John Ågren"

Showing result 11 - 15 of 24 swedish dissertations containing the words John Ågren.

2. 11. Modeling Bainite Formation in Steels

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

   Abstract : 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. READ MORE

4. 12. Towards computational materials design and upscaling of alternative binder cemented carbides

   Author : David Linder; Annika Borgenstam; John Ågren; Jonas Östby; KTH; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Teknisk materialvetenskap; Materials Science and Engineering;

   Abstract : Increasing demands on economic, social and environmental sustainability throughout society is putting pressure on the development of new and improved materials for resource efficiency, improved component life-time and substitution of toxic or rare elements. For the cemented carbide industry, as a major provider of tools for e.g. READ MORE

5. 13. Multicomponent diffusional reactions in tool steels : Experiment and Theory

   Author : Greta Lindwall; Malin Selleby; Karin Frisk; John Ågren; Carelyn Campbell; KTH; []
   Keywords : hot-work tool steel; precipitation hardening; DICTRA; coarsening; mobilities; CALPHAD; cobalt; PM tool stees; nitrogen; compound materials;

   Abstract : Many phenomena determining the microstructure of a tool steel and consequently the properties of the material, are governed by multicomponent diffusion. The diffusion driven reactions that take place during, for example, tempering of a hot-work tool steel or when the microstructure develops during hot isostatic pressing of cold-work tool steel, are dependent on the types and amounts of alloying elements. READ MORE

6. 14. WC grain growth during sintering of cemented carbides : Experiments and simulations

   Author : Karin Mannesson; John Ågren; Annika Borgenstam; Håkan Engqvist; KTH; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Cemented carbide; Grain growth; Abnormal grain growth; Image analysis; Modeling; 3-D grain size distribution; Inverse Saltykov; Materials science; Teknisk materialvetenskap;

   Abstract : Cemented carbides are composite materials consisting of a hard carbide and a ductile binder. They are powdermetallurgically manufactured, where liquid-phase sintering is one of the main steps. The most common cemented carbide consists of WC and Co and it is widely used for cutting tools. READ MORE

7. 15. Modeling the Microstructure Evolution During and After Hot Working in Martensitic Steel

   Author : Nima Safara Nosar; John Ågren; Göran Engberg; Hans-Olof Andrén; KTH; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Modeling; Martensitic steel; Carbides; Carbide size distribution; Carbide volume fraction; Carbide shape factor; Modellering; Martensitiskt stål; karbider; karbidstorleksfördelning; karbidvolymfraktion; karbidformfaktor; Teknisk materialvetenskap; Materials Science and Engineering;

   Abstract : In this study, the goal is to predict the microstructure evolution during and after the hot working of a martensitic stainless steel with 13% chromium using a physically-based model in the form of a MATLAB toolbox. This model is based on dislocation density theory and consists of coupled sets of evolution equations for dislocation, vacancies, recovery, recrystallization, and grain growth. READ MORE