한국신뢰성학회지:신뢰성응용연구 (Journal of Applied Reliability)

  • 제15권3호
  • /
  • Pages.197-206
  • /
  • 2015
  • /
  • 1738-9895(pISSN)
  • /
  • 2733-8320(eISSN)
한국신뢰성학회 (The Korean Reliability Society)
권호 표지

발전소용 이중보온용 강관의 홈부식(Grooving Corrosion)에 의한 파손 분석

The Failure Analysis of Double Pipe for Insulation Used Power Plant by Grooving Corrosion

  • 함종오 (한국화학융합시험연구원 금속엔지니어링팀) ;
  • 박기덕 (한국화학융합시험연구원 금속엔지니어링팀) ;
  • 박성진 (한국화학융합시험연구원 금속엔지니어링팀) ;
  • 선일식 (한국화학융합시험연구원 금속엔지니어링팀)
  • Ham, Jong-Oh (Metallic Materials and Mechanical Engineering Team, Korea Testing and Research Institute) ;
  • Park, Ki-Duck (Metallic Materials and Mechanical Engineering Team, Korea Testing and Research Institute) ;
  • Park, Sung-Jin (Metallic Materials and Mechanical Engineering Team, Korea Testing and Research Institute) ;
  • Sun, Il-Sik (Metallic Materials and Mechanical Engineering Team, Korea Testing and Research Institute)
  • 투고 : 2015.07.21
  • 심사 : 2015.08.30
  • 발행 : 2015.09.25
PDF 다운로드
⟨ 이전 논문 다음 논문 ⟩

초록

Failure analysis of pre-insulated pipe (SPPS 380, 400A) transporting high temperature water ($95{\sim}110^{\circ}C$) for a plant was carried out. The damaged area (${\Phi}5mm$) of pre-insulated pipe was found only on welds. The chemical composition of damaged pipe meets specification of carbon steel pipes for pressure service (KS D 3562). As results of microstructure analysis, crack propagated from outer to inside after pitting corrosion occurred on the outside surface. The non-metallic inclusion existed on the end of crack. And the non-metallic inclusion continuously and linearly formed along with the bond line of welds. Based on SEM-EDS analysis, the nonmetallic inclusions have higher Manganese (Mn) and Oxygen (O) content but sulfur (S) was not detected. As results of water quality analysis, hydrogen ion concentration and minerals like Fe, Mg, Si were in low level. But the content of dissolved oxygen (11.2 ppm) was slightly higher than that of standard. It seems that the cause of damaged pipe is grooving corrosion due to MnO inclusion formed on bond line and corrosion took place nearby welds.

키워드

참고문헌

  1. Kato, C., Otoguro, Y., Kado, S., and Hisaratsu, Y. (1978), Grooving Corrosion in Electric Resistance Welded Steel Pipe in Sea Water, Corrosipn Science, Vol. 18, pp. 61-74. https://doi.org/10.1016/S0010-938X(78)80076-6
  2. Kim, Y. and Lee, B. Y. (2004), A Study on Grooving Corrosion at the Weld of a Low Carbon Steel Pipe Made by Electrical Resistance Welding, Journal of KWS, Vol. 22, No. 5, pp. 58-64.
  3. KS B 0801, (2007), 금속재료 인장 시험편.
  4. KS B 0802, (2003), 금속재료 인장 시험방법.
  5. KS D 1652, (2007), 철 및 강의 스파크 방전 원자방출분광 분석 방법.
  6. KS D 3562, (2009), 압력 배관용 탄소강관.
  7. Kurisu, T., Kyuno, T., Harada, S., and Doi, T. (1979), Effects of Various Factors, Mechanisms and Preventive Method of Grooving Corrosion of ERW and CBW Carbon Steel Pipes, Kawasaki steel Tech Report, pp. 321-336.
  8. Lee, B. W. and Park, H. S. (2007), ERW 강관 용접부의 홈부식 거동에 미치는 입열량의 영향, 한국동력기계공학회지, 제11권, 제3호, pp. 41-46.
  9. Lee, H. D., Jeong, W. S., Park, J. H., Bea, C. H., and Kwak, P. J. (2001), Evaluation of Water Quality Characteristics Effects on the Internal Corrosion of Galvanized Steel Service Pipe in the Building, Korea Society of Water Quality, 17-5, pp. 627-635.
  10. Shinichi, Nejihashi (1988), KAWASAKI STEEL TECHNICAL REPORT, No. 19, pp. 17-22.
  11. Stichel, W. (1996), Corrosion of Welds in Galvanixes Steel Tubes of Drinking Waer Supplies, Materials and Corrosion, Vol. 47, pp. 452-456. https://doi.org/10.1002/maco.19960470806
  12. Sung, H. J., Kim, H. S., and Seo, D. S. (1998), Electrochemical Study on Grooving Corrosion in the Weld Metal of ERW Carbon Steel Pipe, Corrosion Seience Soc. of Korea, 27-2, pp. 122-136.