Search for dissertations about: "Precipitates"

Showing result 21 - 25 of 144 swedish dissertations containing the word Precipitates.

2. 21. Evolution of Microstructure in Two Austenitic Alloys at High Temperatures

   Author : Jenny M Erneman; Chalmers tekniska högskola; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; N ; Thermo-Calc; Nb C; gamma prime; DICTRA; APFIM; quantitative metallography; AISI 347; Alloy 800; energy filtered TEM; sigma phase;

   Abstract : A niobium stabilised AISI 347 austenitic stainless steel was investigated after static ageing and creep deformation at temperatures between 500°C and 800°C for times up to 88 000 h. Coarse and fine NbX precipitates and also s-phase precipitates were formed in the temperature range 500-700°C. READ MORE

4. 22. High Resolution Microanalysis of Creep Resistant 9-12% Chromium Steels

   Author : Lars Lundin; Chalmers tekniska högskola; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; martensitic stainless steel; TEM; modified 12% chromium steel; creep resistant; atom-probe field-ion microscopy;

   Abstract : This thesis deals with detailed studies of the microstructure of 9-12% chromium steels. Three alloys with improved creep resistance have been studied in different stages of heat treatment and after creep testing. Two of them were manufactured using PM/HIP and were of the type 10. READ MORE

5. 23. Microstructure and Mechanical Properties of High Chromium Steel Weld Metals

   Author : Guang-Jun Cai; Chalmers tekniska högskola; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY;

   Abstract : The microstructure of three types of Cr steel weld metals, containing 5%, 9% and 12% chromium, was studied in different heat treated conditions using optical microscopy, analytical transmission electron microscopy and atom probe field-ion microscopy. The mechanical properties of the weld metals were investigated. READ MORE

6. 24. Microstructure and Fatigue Analysis of PM-HIPed Alloys : A Focus on Inconel 625 and High-Nitrogen Tool Steel

   Author : Faezeh Javadzadeh Kalahroudi; Mikael Grehk; Mattias Calmunger; Karlstads universitet; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; powder metallurgy; hot isostatic pressing; Inconel 625; high-nitrogen tool steel; microstructure; fatigue behavior; inclusions; Materialteknik; Materials Engineering;

   Abstract : Nickel-based superalloys and tool steels are well-known high-performance alloys due to their extensive use in many different industries. Nickel-based superalloys have found their way into aircraft, aerospace, marine, chemical, and petrochemical industries owing to their excellent high-temperature corrosion and oxidation resistance. READ MORE

7. 25. 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