Diffraction strain measurements for the characterization of residual stresses in welds for gas turbine applications

Conference item

Neutron and synchrotron x-ray diffraction strain measurements around gas tungsten arc and electron beam welds are used to characterise the state of residual stress in an aeroengine component and testpieces in wrought nickel-based superalloys. Spatial resolution is typically found to be around 1 mm and typical counting times are around 15 minutes per orientation for neutron diffraction and 10 s for synchrotron x-rays. The effects of intergranular, orientation dependent strains are discussed and their avoidance in the determination of engineering strain illustrated. Grain size and beam divergence are found to limit the spatial resolution that can be achieved, and this illustrates why in-weld measurements made using these techniques can be unreliable. These effects are explored using case studies in gas tungsten arc, electron beam and low stress low distortion welds in IN718 and C263 and electron-beam welds in a Waspaloy plate and compressor disc assembly.

Authors: Dye, D; Conlon, K; Reed, R; James, K; Korsunsky, A

• Publication status: Published
• Peer review status: Peer reviewed
• Publisher: ASM International
• Host title: Trends in Welding Research: Proceedings of the 6th International Conference
• Pages: 878-885
• Publication date: 2003-01-01
• Event location: Pine Mountain, Georgia
• ISBN: 9780871707802
• Language: English
• Keywords: waspaloy; neutron-diffraction; intergranular strains; generation; steel
• Subjects: Engineering and allied sciences