RESEARCH ON WELD RESIDUAL STRESS OF DISSIMILAR STEEL WELD IN THICK-WALL PRESSURE PIPE OF NUCLEAR POWER PLANT BY THE FINITE ELEMENT SIMULATION METHOD

In pressurized-water reactor nuclear power plants, the vessel nozzles of large carbon steel equipment such as reactor pressure vessel (RPV), steam generator (SG), and main pumps are connected to austenitic steel pipes through dissimilar metal welds (DMWs). The thick-walled DMW has material inhomogen...

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Bibliographic Details
Main Authors: CHEN Mingya, YU Weiwei, HAN Yaolei, LIN Lei, PENG Qunjia, SHI Fangjie, ZHAO Wanxiang
Format: Article
Language:zho
Published: Editorial Office of Journal of Mechanical Strength 2025-08-01
Series:Jixie qiangdu
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Online Access:http://www.jxqd.net.cn/thesisDetails#10.16579/j.issn.1001.9669.2025.08.007
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Summary:In pressurized-water reactor nuclear power plants, the vessel nozzles of large carbon steel equipment such as reactor pressure vessel (RPV), steam generator (SG), and main pumps are connected to austenitic steel pipes through dissimilar metal welds (DMWs). The thick-walled DMW has material inhomogeneity and complex weld residual stress (WRS), which easily leads to the generation of fatigue or stress corrosion cracks.Firstly, the WRS of DMW in nuclear power plants obtained through international measurements and numerical analyses was investigated. Then, based on a rapid WRS simulation method for volume uniform heating of unit cells, the WRS of DMW in the hot leg of the primary loop (the connecting pipe section from RPV outlet to SG inlet, which is the pipe section with the highest operating parameters in the primary loop pressure boundary) was obtained.The numerical simulation results are consistent with the trend of the fitting envelope curve recommended by the United States, and the overall results can be enveloped by the fitting curve recommended by the United States, indicating that the described rapid WRS simulation method is feasible. The WRS of thick-walled DMW is relatively high, and the stress values at the inner and outer surfaces of the pipe are more conservative than the recommended values of the United States, suggesting that more safety margins can be obtained in actual structural analyses.
ISSN:1001-9669