Microstructural characterization of alloy 52 narrow-gap dissimilar metal weld after aging
- Resource Type
- Authors
- Sarikka, Teemu; Mouginot, Roman; Ahonen, Matias; Lindqvist, Sebastian; Ehrnstén, Ulla; Nevasmaa, Pekka; Hänninen, Hannu
- Source
- Sarikka, T, Mouginot, R, Ahonen, M, Lindqvist, S, Ehrnstén, U, Nevasmaa, P & Hänninen, H 2018, Microstructural characterization of alloy 52 narrow-gap dissimilar metal weld after aging . in J H Jackson, D Paraventi & M Wright (eds), Proceedings of the 18th International Conference on Environmental Degradation of Materials in Nuclear Power Systems – Water Reactors . vol. 2, Springer, Minerals, Metals and Materials Series, no. Part F11, pp. 763-777, 18th International Conference on Environmental Degradation of Materials in Nuclear Power Systems-Water Reactors, 2017, Portland, United States, 13/08/17 . https://doi.org/10.1007/978-3-319-68454-3_58
- Subject
- Aging
Dissimilar metal weld
Ni-base alloy
Microstructural characterization
- Language
- English
The safe-end dissimilar metal weld (DMW) joining the reactor pressure vessel to the main coolant piping is one of the most critical DMWs in a nuclear power plant (NPP). DMWs have varying microstructures at a short distance across the ferritic-austenitic fusion boundary (FB) region. This microstructural variation affects the mechanical properties and fracture behavior and may evolve as a result of thermal aging during long-term operation of an NPP. This paper presents microstructural characterization performed for as-manufactured and 5000 h and 10,000 h thermally aged narrow-gap DMW representing a safe-end DMW of a modern pressurized water reactor (PWR) NPP. The most significant result of the study is that the thermal aging leads to a significant decrease in a hardness gradient observed across the ferritic-austenitic FB of the as-manufactured DMW.