Distortion and residual stresses in electron beam-welded hydroelectric turbine materials |
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| Authors: | S Sarafan J-B Lévesque P Wanjara J Gholipour H Champliaud |
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| Affiliation: | 1. école de technologie supérieure, Montréal, QC, Canada H3C 1K3;2. National Research Council Canada, Aerospace, Ottawa, ON, Canada K1A 0R6sheida.sarafan.1@ens.etsmtl.ca;4. Institut de recherched'Hydro-Québec (IREQ), Varennes, QC, Canada J3X 1S1;5. National Research Council Canada, Aerospace, Ottawa, ON, Canada K1A 0R6 |
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| Abstract: | Heavy-section assembly of hydroelectric turbine runner materials using single-pass, autogenous EBW was demonstrated to penetrate a 90-mm-thick butt joint. The welding-induced distortions and residual stresses were characterised to understand the impact of the materials and process conditions (e.g. preheating and/or PWHT). Using 3D optical measurements, the angular distortions of EB-welded UNS S41500 and CA6NM steels were determined to be 0.13° and 0.38°, respectively. The longitudinal residual stresses, measured through the contour method, had a M-shaped distribution throughout the thickness with minimum (～?500?MPa) compressive stresses in the FZ and maximum (～600?MPa) tensile stresses in the HAZ. After PWHT, the tensile and compressive stresses reduced to ～100?MPa. |
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| Keywords: | Residual stress Distortion Electron beam welding Martensitic stainless steel Contour method 3-Dimensional optical measurement system |
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