Journal of Welding and Joining

The Korean Welding and Joining Society (대한용접접합학회)
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Fatigue Assessment of Reactor Vessel Outlet Nozzle Weld Considering the LBZ and Welding Residual Stress Effect

국부 취화부와 용접 잔류응력 효과를 고려한 원자로 출구노즐 용접부의 피로강도 평가

  • Published : 2006.04.01
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Abstract

The fatigue strength of the welds is affected by such factors as the weld geometry, microstructures, tensile properties and residual stresses caused by fabrication. It is very important to evaluate the structural integrity of the welds in nuclear power plant because the weldment undergoes the most of damage and failure mechanisms. In this study, the fatigue assessments for a reactor vessel outlet nozzle with the weldment to the piping system are performed considering the welding residual stresses as well as the effect of local brittle zone in the vicinity of the weld fusion line. The analytical approaches employed are the microstructure and mechanical properties prediction by semi-analytical method, the thermal and stress analysis including the welding residual stress analysis by finite element method, the fatigue life assessment by following the ASME Code rules. The calculated results of cumulative usage factors(CUF) are compared for cases of the elastic and elasto-plastic analysis, and with or without residual stress and local brittle zone effects, respectively. Finally, the fatigue life of reactor vessel outlet nozzle weld is slightly affected by the local brittle zone and welding residual stresses.

Keywords

References

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