Search for dissertations about: "Hot cracking"

Showing result 1 - 5 of 39 swedish dissertations containing the words Hot cracking.

2. 1. On the hot crack formation during solidification of iron-base alloys

   Author : Karin Hansson; KTH; []
   Keywords : hot cracking; hot tearing; cracking fracturing ; tearing; ductility; brittleness; embrittlement; fractures; ductile brittle transition; solidification; iron; copper; nickel; Invar; steels; free machining steels; stainless steels; penetration; crack;

   Abstract : Hot cracking during solidification is a severe problem inmany casting processes, for example in continuous casting.Combinations of low strength and low ductility of the materialat high temperatures and applied tensile stress can cause hotcracking. READ MORE

4. 2. Weld Cracking of Precipitation Hardening Ni-based Superalloys - Investigation of repair welding characteristics and susceptibility towards strain age cracking

   Author : Fabian Hanning; Chalmers tekniska högskola; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Gleeble; Haynes 282; Waspaloy; welding; ATI 718Plus®; weldability; post-weld heat treatment; weld cracking; strain age cracking; hot cracking; Nickel-based superalloys;

   Abstract : High temperature resistance and strength requirements make nickel-based superalloys the material of choice for the hot section of aero engines. Fabrication in terms of combining wrought and cast parts in the manufacturing of hot structural components enables component optimisation via the use of wrought high-strength parts, where geometrical constraints allow, and cast parts to produce complex geometries. READ MORE

5. 3. Weldability of Cast Superalloys - Effect of homogenization heat treatments on hot cracking susceptibility of cast Alloy 718, ATI® 718Plus®, and Haynes® 282®

   Author : Sukhdeep Singh; Chalmers tekniska högskola; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Hot ductility; Segregation; Homogenization; Boron; Gleeble; Welding; Nickel-based superalloys; Varestraint; Hot cracking; Hot isostatic pressing; Niobium;

   Abstract : Precipitation hardened Ni- and Ni–Fe-based superalloys are used in high-temperature sections of aero engines owing to their superior mechanical properties compared to those of the other alloys. However, their better mechanical performance is accompanied by its own challenges during the manufacturing process. READ MORE

6. 4. Weldability of Precipitation Hardening Superalloys – Influence of Microstructure

   Author : Joel Håkan Andersson; Chalmers tekniska högskola; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Hot cracking; GTAW; Transvarestraint testing; Varestraint testing; Gleeble testing; Solidification cracking; HAZ liquation cracking; Repair welding; Strain age cracking; EBW; DSC thermal analysis;

   Abstract : Superalloys and in particular the precipitation hardened Ni-based superalloys havealways been used extensively in the hot sections of jet engines. Large hot structuralengine components with complex geometry have preferably been cast as single piececomponents since the large scale vacuum investment casting process becameavailable about fifty years ago. READ MORE

7. 5. Hot Cracking and Grain Boundary Weaknesses of Nickel - Based Superalloys

   Author : Joel Håkan Andersson; Chalmers tekniska högskola; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Hot cracks; Notch rupture testing; Eutectic; Weldability; Varestraint testing; Grain boundary weaknesses; Superalloys;

   Abstract : Abstract Grain boundary weaknesses of nickel-based superalloys not only materialize during service in the hot turbine engine sections but also during the weld manufacturing. The performance, in this respect, of the most commonly used alloys at Volvo Aero Corporation (VAC), 718 and the higher temperature capacity Waspaloy, are therefore the main subjects for this thesis. READ MORE