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| Abstract No.: |
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Scheduled at:
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Wednesday, March 10, 2021, Hall 1 2:50 PM
Special Materials
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| Title: |
Analysis of temperature field during electron beam welding of hot crack sensitive nickel base alloy
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| Authors: |
Torsten Jokisch* / Siemens Energy, Germany
Nikolay Doynov / Brandenburg University of Technology, Germany
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| Abstract: |
The use of temperature-resistant nickel-based superalloys in the field of industrial gas turbines is increasing due to constantly rising operating temperatures. Among different joining methods the Electron beam welding is commonly used for manufacturing of turbine components because it provides a reduced heat input. However, the highly localized beam impact causes high temperature gradients and leads to the formation of hot cracks. Welding of such material with a high brittle temperature range is challenging and needs an increasing effort of process adaption. Experiments indicate a significant improvement of hot crack susceptibility when welding outside the common welding parameter range. To understand these observations a study of the temperature field in the specimens using numerical simulations was carried out. For this purpose, a validated simulation model was used. Special attention was paid to the domain in close vicinity of the weld pool. The results illustrate the temperature gradients as well as the temperature rates when crossing the melting point. Finally, the relations between thermal fields, crack types and distributions in the different specimens are discussed.
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