Evaluation of residual stresses in isothermal friction stir welded 304L stainless steel plates

Journal Article · 24 August 2021 · Materials Science and Engineering. A, Structural Materials: Properties, Microstructure and Processing

DOI: https://doi.org/10.1016/j.msea.2021.141982 · OSTI ID:1817344

Bhattacharyya, Madhumanti ^[1]; Gnaupel-Herold, Thomas ^[2]; Raja, Krishnan S. ^[3]; Darsell, Jens ^[4]; Jana, Saumyadeep ^[4]; Charit, Indrajit ^[5]

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1. Univ. of Idaho, Moscow, ID (United States); University of Idaho
2. NIST Center for Neutron Research, Gaithersburg, MD (United States)
3. Univ. of Idaho, Moscow, ID (United States)
4. Pacific Northwest National Lab. (PNNL), Richland, WA (United States)
5. Univ. of Idaho, Moscow, ID (United States); Dept. of Nuclear Engineering and Industrial Management, Idaho Falls, ID (United States); Center for Advanced Energy Studies, Idaho Falls, ID (United States)

Friction stir welding was performed on 304L SS plates in order to heal simulated cracks created by electrical discharge machining. Two different tool temperatures (825 and 725°C) were chosen for this study. Both neutron diffraction and X-ray diffraction techniques were employed to evaluate the residual stresses along two orthogonal reference directions, longitudinal (σ_yy) and transverse (σ_xx). The former technique was also used to measure residual stresses at various depths. It was found that, at 1 mm depth from the top surface inside the stir zone (SZ), the longitudinal component was tensile in nature while the transverse component was compressive. Furthermore, the nature and magnitude of the residual stress fields, and the position of the peak residual stresses were found to vary with the weld depth. The SZ of the 725°C weld exhibited higher peak stress than 825°C weld mainly due to a lack of stress relief at the lower temperature.

• Research Organization: Univ. of Idaho, Moscow, ID (United States)
• Sponsoring Organization: USDOE Office of Nuclear Energy (NE)
• Grant/Contract Number: NE0008776
• OSTI ID: 1817344
• Journal Information: Materials Science and Engineering. A, Structural Materials: Properties, Microstructure and Processing, Journal Name: Materials Science and Engineering. A, Structural Materials: Properties, Microstructure and Processing Vol. 826; ISSN 0921-5093
• Publisher: ElsevierCopyright Statement
• Country of Publication: United States
• Language: English