Search for dissertations about: "low alloyed"

Showing result 6 - 10 of 75 swedish dissertations containing the words low alloyed.

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

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

   Abstract : 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. READ MORE

4. 7. ROLE OF SURFACE OXIDES IN SINTERING OF CHROMIUM-ALLOYED STEEL POWDER

   Author : Henrik Karlsson; Chalmers tekniska högskola; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; water atomisation; surface analysis; sintering; chromium-alloyed steel.; Powder metallurgy; surface reactions; surface; surface oxide; SEM; XRD; AES; XPS;

   Abstract : During water-atomisation and handling of steel powder the surface inevitably oxidises. The surface bound oxide is an important factor in the processing of powder metallurgical (PM) steels, especially in case the powder contains elements forming stable oxides, such as Cr, Mn, and Si. READ MORE

5. 8. Hydrogen embrittlement and corrosion behavior of low-temperature carburized austenitic stainless steel

   Author : Xiao Qin; Chalmers tekniska högskola; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; low-temperature carburising; hydrogen embrittlement; Austenitic stainless steel; microstructure; corrosion behavior; expanded austenite;

   Abstract : For metallic components used in hydrogen environments, hydrogen embrittlement and corrosion have always been important considering potential failure risks. Among many metallic materials, austenitic stainless steel has found broad application because of its excellent corrosion and hydrogen embrittlement resistance. READ MORE

6. 9. Critical Aspects of Delubrication and Sintering of Chromium-alloyed Powder Metallurgy Steels

   Author : Seshendra Karamchedu; Chalmers tekniska högskola; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; delubrication; oxide reduction; surface oxide; carbon control; sintering atmosphere; chromium-alloyed sintered steels;

   Abstract : The cost efficiency and performance of Powder Metallurgy (PM) steels can be improved by replacing conventionally used alloying elements such as copper and nickel with chromium. Utilizing chromium imposes a challenge in terms of processing due to its effect on powder compressibility and high oxygen affinity, the latter of which, to a certain extent, is dealt with by introducing chromium in prealloyed form that decreases its activity. READ MORE

7. 10. Thermal Stability and Mechanical Properties of Bainitic Steel

   Author : Adam Ståhlkrantz; Annika Borgenstam; Peter Hedström; Niklas Sarius; Joacim Hagström; KTH; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Bainite; Austempering; Low alloyed steel; Tempering; Variant pairing; Material characterization; Metallurgical process science; Metallurgisk processvetenskap; Materials Science and Engineering; Teknisk materialvetenskap;

   Abstract : For material design it is important to understand and establish the relations between the processing of the steel, the resulting microstructure and how that correlate to the properties of the steel. The main focus of this thesis has been to increase this knowledge for low alloy bainitic steels with medium to high carbon content. READ MORE