Search for dissertations about: "PM steels"

Showing result 1 - 5 of 24 swedish dissertations containing the words PM steels.

2. 1. Novel approaches for achieving full density powder metallurgy steels

   Author : Maheswaran Vattur Sundaram; Chalmers tekniska högskola; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Cr- and Mo-alloyed PM steels; vacuum sintering; high density; full density; hot isostatic pressing.; cold isostatic pressing; liquid phase sintering; master alloy; double pressing-double sintering; powder metallurgy steels; sintering; water atomised powder;

   Abstract : Powder metallurgy (PM) is one of the most resource-efficient methods for manufacturing structural components with complex shapes. The utilisation of the metal powder to shape the components allows to minimise material waste and increase energy efficiency. READ MORE

4. 2. 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

5. 3. Delubrication of Chromium Prealloyed Powder Metallurgy Steels

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

   Abstract : Consolidation of steel components produced by means of powder metallurgy (PM) is achieved typically through compaction and sintering. During consolidation, final dimensions of the part are already achieved after compaction, while sintering imparts strength to the components. READ MORE

6. 4. Contact fatigue and crack propagation studies of sintered PM steel

   Author : Anders Holmberg; Åsa Kassman Rudolphi; Urban Wiklund; Johan Ahlström; Uppsala universitet; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Tribology; PM steel; Fatigue; Crack Initiation; Crack Propagation; Material Analysis; Teknisk fysik med inriktning mot tribomaterial; Engineering Science with specialization in Tribo Materials;

   Abstract : Gears made of PM steel are of interest for the automotive industry because from the press/sinter route, complex geometries can be produced to near net shape with only a few processing steps while keeping the material and energy usage at a minimum. However, the PM steels of today have significant performance limitations caused by the inherent porosity which impairs the mechanical properties by acting as stress raisers in the material. READ MORE

7. 5. Surface Chemical Characteristics of Chromium-alloyed Steel Powder and the Role of Process Parameters during Sintering

   Author : Dimitris Chasoglou; Chalmers tekniska högskola; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; carbothermal reaction; sintering atmosphere; depth profiling; XPS AES; HR SEM EDX; water atomized powder; surface coverage; reduction oxidation; PM steels; sintering; Cr-Mn-spinel oxides; surface oxides;

   Abstract : Powder Metallurgy (PM) is a cost efficient method suitable for sustainable production of structural parts that have strict dimensional tolerances and complex geometries. It has been a common practice to utilize Ni and Cu as alloying elements in PM steels, but the high and fluctuating prices of Ni and the concerns around it associated with health hazards as well as the difficulty in recycling Cu lead the PM industry to search for effective alternatives such as Cr and Mn. READ MORE