Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
7963170 | Journal of Nuclear Materials | 2018 | 31 Pages |
Abstract
To clarify the influence of long-term Ï phase embrittlement on repair weldability for type 316FR stainless steel weld metals (316FR-AF and 316FR-FA), the prediction of Ï-phase embrittlement and a spot-Varestraint test were performed. The precipitation of Ï and Ï phases were characterized during accelerated aging treatments for both weld metals, and the precipitation behavior (Ï+Ï phases) could be expressed by a JohnsonâMehl-type kinetic equation. By using the variation of mechanical properties upon precipitation (Ï+Ï phases) and the determined kinetic equation, Ï-phase embrittlement for 316FR-AF and 316FR-FA weld metals during service exposure in FBR plants could be successfully predicted. Specifically, a 30.7% decrement of the absorbed impact energy as compared with the as-welded specimens could be anticipated just after one year of service for 316FRâFA weld metal at 823Â K. By using the simulated weld metal with Ï-phase embrittlement, the possibility of weld cracking caused by Ï-phase embrittlement during repair welding was confirmed, showing micro-crack formation within the Ï phase after the spot-Varestraint test.
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Physical Sciences and Engineering
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Nuclear Energy and Engineering
Authors
EunâJoon Chun, Kazuyoshi Saida,