Transactions of the Korean Society of Mechanical Engineers A (대한기계학회논문집A)

The Korean Society of Mechanical Engineers (대한기계학회)
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Crack Growth Analysis due to PWSCC in Dissimilar Metal Butt Weld for Reactor Piping Considering Hydrostatic and Normal Operating Conditions

수압시험 및 정상운전 하중을 고려한 원자로 배관 이종금속 맞대기 용접부 응력부식균열 성장 해석

  • Lee, Hwee-Sueng (Dept. of Mechanical System Design Engineering, Seoul Nat'l Univ. of Science and Technology) ;
  • Huh, Nam-Su (Dept. of Mechanical System Design Engineering, Seoul Nat'l Univ. of Science and Technology) ;
  • Lee, Seung-Gun (KEPCO Engineering & Construction Company) ;
  • Park, Heung-Bae (KEPCO Engineering & Construction Company) ;
  • Lee, Sung-Ho (KHNP Central Research Institute)
  • Received : 2012.08.02
  • Accepted : 2012.09.03
  • Published : 2013.01.01
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Abstract

This study investigates the crack growth behavior due to primary water stress corrosion cracking (PWSCC) in the dissimilar metal butt weld of a reactor piping using Alloy 82/182. First, detailed finite element stress analyses were performed to predict the stress distribution of the dissimilar metal butt weld in which the hydrostatic and the normal operating loads as well as the weld residual stresses were considered to evaluate the stress redistribution due to mechanical loadings. Based on the stress distributions along the wall thickness of the dissimilar metal butt weld, the crack growth behavior of the postulated axial and circumferential cracks were predicted, from which the crack growth diagram due to PWSCC was proposed. The present results can be applied to predict the crack growth rate in the dissimilar metal butt weld of reactor piping due to PWSCC.

본 논문에서는 Alloy 82/182를 용접재로 이용한 원자로 배관 이종금속 맞대기 용접부(Dissimilar Metal Butt Weld)에서의 PWSCC에 의한 균열성장 거동을 평가하였다. 이를 위해 먼저 유한요소 응력해석을 수행하여 이종금속용접부에서의 응력분포를 결정하였으며, 이때 이종금속용접 및 동종금속용접에 의한 용접잔류응력 외에 수압시험과 정상운전 조건도 고려하여 기계적 하중에 의한 응력 재분배를 고려하였다. 최종적으로 이와 같이 구한 응력 분포를 바탕으로 PWSCC에 의한 축방향 및 원주방향 가상 균열의 균열성장 거동을 평가하여 PWSCC 균열 성장량을 계산하였다. 본 논문의 결과는 향후 PWSCC에 의한 원자로 배관 이종금속 맞대기 용접부의 균열성장 거동 예측에 적용될 수 있다.

Keywords

References

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  2. Stress Distributions at the Dissimilar Metal Weld of Safety Injection Nozzles According to Safe-end Length and SMW Thickness vol.39, pp.10, 2015, https://doi.org/10.3795/KSME-A.2015.39.10.979