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

The Korean Society of Mechanical Engineers (대한기계학회)
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Stress Distributions at the Dissimilar Metal Weld of Safety Injection Nozzles According to Safe-end Length and SMW Thickness

안전단 길이 및 동종금속용접부 두께 변화에 따른 안전주입노즐 이종금속용접부의 응력분포

  • Kim, Tae-Jin (Dept. of Mechanical System Design Engineering, Seoul Nat'l Univ. of Science and Technology) ;
  • Jeong, Woo-Chul (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)
  • 김태진 (서울과학기술대학교 기계시스템디자인공학과) ;
  • 정우철 (서울과학기술대학교 기계시스템디자인공학과) ;
  • 허남수 (서울과학기술대학교 기계시스템디자인공학과)
  • Received : 2015.04.08
  • Accepted : 2015.04.28
  • Published : 2015.10.01
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Abstract

In the present paper, we evaluate the effects of the safe-end length and thickness of the similar metal weld (SMW) of safety injection nozzles on stress distributions at the dissimilar metal weld (DMW). For this evaluation, we carry out detailed 2-D axisymmetric finite element analyses by considering four different values of the safe-end length and four different values of the thickness of SMW. Based on the results obtained, we found that the SMW thickness affects the axial stresses at the center of the DMW for the shorter safe-end length; on the other hand, it does not affect the hoop stresses. In terms of the safe-end length, the values of the axial and hoop stresses at the inner surface of the DMW center increase as the safe-end length increases. In particular, for the cases considered in the present study, the stress distributions at the DMW center can be categorized according to certain values of safe-end length.

본 논문에서는 국내 가동 중인 원자력발전소의 안전주입노즐을 대상으로 안전단의 길이와 동종금속용접부의 두께가 이종금속용접부의 응력분포에 미치는 영향을 평가하였다. 이를 위해 4가지의 서로 다른 안전단 길이와 4가지의 서로 다른 동종금속용접부 두께를 고려한 상세 2차원 유한요소 열해석 및 응력해석을 수행하였다. 유한요소해석 결과 동종금속용접부의 두께는 안전단의 길이가 짧은 경우 축방향 응력에 어느 정도 영향을 미쳤으나 원주방향 응력에는 거의 영향을 미치지 않았다. 안전단의 길이는 길이가 증가함에 따라 내면에서의 축방향 및 원주방향 응력값이 증가하는 것으로 나타났으나 특정 안전단 길이를 기준으로 응력분포가 구분되는 경향을 나타냈다.

Keywords

References

  1. Kim, J.W, Lee, K.S. and Park, C.Y., 2010, "Evaluation of Mechanical Properties of Alloy 82/182 Weld Joint Between SA508 Gr.3 Nozzle and F316L Safe-End," Trans. Korean Soc. Mech. Eng. A, Vol. 34, pp. 333-340.
  2. EPRI, Materials Reliability Program, 2004, "Welding Residual and Operating Stresses in PWR Alloy 182 Butt Welds (MRP-106)," EPRI report (This product is publicly available.).
  3. Rudland, D.L., Shim, D.J., Xu, H. and Wilkowski, G.W., 2007, "Evaluation of Circumferential Indications in Pressurizer Nozzle Dissimilar Metal Welds at the Wolf Creek Power Plant," NRC Summary Report No. ADAMS ML071560398.
  4. Zhang, J., Song, S. and Dong, P., 2011, "Important Residual Stress Features in Reactor Nozzle Dissimilar Metal Welds," ASME Pressure Vessels and Piping Conference, PVP2011-57824.
  5. Rudland, D.L., Csontos, A. and Shim, D.J., 2010, "Stress Corrosion Crack Shape Development Using AFEA," Journal of Pressure Vessel Technology, Vol. 132, pp. 011406-1-011406-7. https://doi.org/10.1115/1.4000349
  6. Lee, H.S., Huh, N.S., Lee, S.G., Park, H.B. and Lee, S.H., 2013, "Crack Growth Analysis due to PWSCC in Dissimilar Metal Butt Weld for Reactor Piping Considering Hydrostatic and Normal Operating Conditions," Trans. Korean Soc. Mech. Eng. A, Vol. 37, pp. 47-54. https://doi.org/10.3795/KSME-A.2013.37.1.047
  7. Lee, H.S., Huh, N.S., Kim, J.S. and Lee, J.H., 2013, "Stress Distribution in the Dissimilar Metal Butt Weld of Nuclear Reactor Piping due to the Simulation Technique for the Repair Welding," Trans. Korean Soc. Mech. Eng. A, Vol. 37, pp. 649-655. https://doi.org/10.3795/KSME-A.2013.37.5.649
  8. Park, C.Y., Lee, H.S. and Huh, N.S., 2014, "Investigation into Variations of Welding Residual Stresses and Redistribution Behaviors for Different Repair Welding Widths," Trans. Korean Soc. Mech. Eng. A, Vol. 38, pp. 177-184. https://doi.org/10.3795/KSME-A.2014.38.2.177
  9. Song, T.K., Chun, Y.B., Oh, C.Y., Bae, H.Y., Kim, Y.J., Lee, S.H., Lee, K.S. and Park, C.Y., 2009, "Effects of Similar Metal Weld on Residual Stress in Dissimilar Metal Weld According to Safe End Length," Trans. Korean Soc. Mech. Eng. A, Vol. 33, pp. 664-672. https://doi.org/10.3795/KSME-A.2009.33.7.664
  10. R6, "Assessment of the Integrity of Structures Containing Defects," Rev. 4, British Energy, 2000.
  11. Broussard, J., Private Communication, 2014-2015.
  12. "ABAQUS/Standard User's Manual," Version 6.11-1, Dassault Systemes Corp., 2011.
  13. Kim, J.S., Kim, J.H., Bae, H.Y., Oh, C.Y., Kim, Y.J., Lee, K.S. and Song, T.K., 2012, "Welding Residual Stress Distributions for Dissimilar Metal Nozzle Butt Welds in Pressurized Water Reactors," Trans. Korean Soc. Mech. Eng. A, Vol. 36, pp. 137-148.
  14. Brickstad, B. and Josefson, B.L., 1998, "A Parametric Study of Residual Stresses in Multi-Pass Butt-Welded Stainless Steel Pipes," International Journal of Pressure Vessels and Piping, Vol. 75, pp. 11-25. https://doi.org/10.1016/S0308-0161(97)00117-8
  15. Elcoate, C.D., Dennis, R.J., Bouchard, P.J. and Smith, M.C., 2005, "Three Dimensional Multi-Pass Repair Weld Simulations," International Journal of Pressure Vessels and Piping, Vol. 82, pp. 244-257. https://doi.org/10.1016/j.ijpvp.2004.08.003