Thermal relaxation of residual stresses in nickel-based superalloy inertia friction welds

M. Karadge, B. Grant, P. J. Withers, G. Baxter, M. Preuss

    Research output: Contribution to journalArticlepeer-review

    Abstract

    This article describes an experimental study aimed at characterizing the extent of residual stress relaxation during thermal treatment of inertia friction-welded alloy 720Li nickel-based superalloy welded tubular rings. In the as-welded condition, yield level tensile hoop stresses were found by neutron diffraction in the weld region along with axial bending stresses (tensile toward the inner diameter (ID)/compressive toward the outer). The evolution of these residual stress levels during postweld heat treatment (PWHT) was mapped experimentally over the weld cross section. After 8 hours of PWHT, the axial stresses relaxed by 70 pct, whereas the hoop stresses reduced by only 50 pct. Some scatter of residual stress evolution was found between samples, particularly for the axial stress direction. This was attributed to substandard tooling to grip the rings. The results on subscale samples were transferred to a full-scale aeroengine (650-mm diameter) compressor drum assembly that was postweld heat treated for 8 hours. It was found that the residual stresses, particularly in the axial direction, were noticeably lower in this full-scale weld component compared to the subscale weld heat treated for the same time. The differences seem to be best rationalized by the different standards of jigging used during joining these two types of welds. © 2011 The Minerals, Metals & Materials Society and ASM International.
    Original languageEnglish
    Pages (from-to)2301-2311
    Number of pages10
    JournalMetallurgical and Materials Transactions A: Physical Metallurgy and Materials Science
    Volume42A
    Issue number8
    DOIs
    Publication statusPublished - Aug 2011

    Fingerprint

    Dive into the research topics of 'Thermal relaxation of residual stresses in nickel-based superalloy inertia friction welds'. Together they form a unique fingerprint.

    Cite this