DOI QR코드

DOI QR Code

보수용접부 폭에 따른 용접잔류응력의 변화 및 재분배 거동 평가

Investigation into Variations of Welding Residual Stresses and Redistribution Behaviors for Different Repair Welding Widths

  • 박치용 (한국수력원자력(주) 중앙연구원) ;
  • 이휘승 (서울과학기술대학교 기계시스템디자인공학과) ;
  • 허남수 (서울과학기술대학교 기계시스템디자인공학과)
  • Park, Chi-Yong (Central Research Institute, Korea Hydro & Nuclear Power Corporation) ;
  • 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)
  • 투고 : 2013.09.22
  • 심사 : 2013.12.18
  • 발행 : 2014.02.01

초록

본 논문에서는 보수용접부 폭 변화에 따른 이종금속 맞대기 용접부(Dissimilar metal butt weld) 용접잔류응력의 분포 및 동종금속용접/기계적 하중에 의한 재분배 거동을 평가하였다. 이를 위해 5가지 다른 보수용접부 폭을 고려한 상세 2차원 유한요소 열해석 및 응력해석을 수행하였다. 유한요소해석 결과를 바탕으로 보수용접에 의한 용접잔류응력 분포를 평가하였으며, 동종금속용접 및 기계적 하중에 의한 응력 재분배 특성을 평가하였다. 보수용접에 의해 배관 내면에서는 큰 인장 용접잔류응력이 축방향과 원주방향에 대해 발생하는 것으로 나타났으며 보수용접부 폭이 특정값 이상이 되면 용접잔류응력 분포가 변하는 것으로 나타났다. 그러나 동종금속용접과 기계적 하중을 고려하면 인장잔류응력값이 크게 감소하였으며 그 경향은 보수용접부 폭에 무관한 것으로 나타났다.

In this study, we investigated the variations in welding residual stresses in dissimilar metal butt weld due to width of repair welding and re-distribution behaviors resulting from similar metal welding (SMW) and mechanical loading. To this end, detailed two-dimensional axi-symmetric finite element (FE) analyses were performed considering five different repair welding widths. Based on the FE results, we first evaluated the welding residual stress distributions in repair welding. We then investigated the re-distribution behaviors of the residual stresses due to SMW and mechanical loads. It is revealed that large tensile welding residual stresses take place in the inner surface and that its distribution is affected, provided repair welding width is larger than certain value. The welding residual stresses resulting from repair welding are remarkably reduced due to SMW and mechanical loading, regardless of the width of the repair welding.

키워드

참고문헌

  1. EPRI, Materials Reliability Program, 2004, "Welding Residual and Operating Stresses in PWR Alloy 182 Butt Welds (MRP-106)," EPRI report.
  2. Kim, J.S., Lee, S.G., Park, H.B., Jin, T.E. and Kang, S.S., 2009, "Investigation of the Effect of Internal Repair Welding Variables on PWSCC of Dissimilar Welds on Pressurizer Safety/Relief Nozzle," Trans. Korean Soc. Mech. Eng. A, Vol. 58, pp. 270-275.
  3. Lee, S.G., Jin, T.E., Kang, S.S. and Kwon, D.I., 2009, "Residual Stress Analysis for Repair Welding in Dissimilar Metal Weld," Journal of KWJS, Vol. 27, pp. 376-381.
  4. Dong, P., Hong, J.K. and Bouchard, P.J., 2005, "Analysis of Residual Stresses at Weld Repairs," International Journal of Pressure Vessels and Piping, Vol. 82, pp. 258-269. https://doi.org/10.1016/j.ijpvp.2004.08.004
  5. 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
  6. 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.
  7. Soh, N.H., Oh, G.J., Huh, N.S., Lee, S.H., Park, H.B., Lee, S.G., Kim, J.S. and Kim, Y.J., 2012, "Effects of Finite Element Analysis Parameters on Weld Residual Stress of Dissimilar Metal Weld in Nuclear Reactor Piping Nozzles," Trans. of the KPVP, Vol. 8, pp. 8-18.
  8. "ABAQUS/Standard User's Manual," Version 6.11-1, Dassault Systemes Corp., 2011.
  9. 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. https://doi.org/10.3795/KSME-A.2012.36.2.137
  10. 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
  11. Song, T.K., Bae, H.Y., Chun, Y.B., Oh, C.Y., Kim, Y.J., Lee, K.S. and Park, C.Y., 2008, "Effect of Preemptive Weld Overlay on Residual Stress Mitigation for Dissimilar Metal Weld of Nuclear Power Plant Pressurizer," Trans. Korean Soc. Mech. Eng. A, Vol. 32, pp. 873-881. https://doi.org/10.3795/KSME-A.2008.32.10.873
  12. Song, T.K., Bae, H.Y., Chun, Y.B., Oh, C.Y., Kim, Y.J., Lee, K.S. and Park, C.Y., 2008, "Estimation of Residual Stress Distribution for Pressurizer Nozzle of Kori Nuclear Power Plant Considering Safe End," Trans. Korean Soc. Mech. Eng. A, Vol. 32, pp. 668-677. https://doi.org/10.3795/KSME-A.2008.32.8.668
  13. 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
  14. Limpus, C.R., Dijamco, D.G., Bax, R. and Cofie, N.G., 2007, "Effect of Size of Butt Weld Repairs on Weld Overlay Residual Stresses," ASME Pressure Vessels and Piping Conference, PVP2007-26636.

피인용 문헌

  1. 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