Journal of Failure Analysis and Prevention

, Volume 13, Issue 4, pp 496–501 | Cite as

Failure Analysis for the Welded Elbow at the Bottom of the Rectifying Tower in the Alcohol Evaporation System

  • X. M. Bay
  • J. Q. Tang
  • J. M. Gong
Technical Article---Peer-Reviewed


Cracking was found on the welded elbow at the bottom of rectifying tower in an alcohol evaporation system. In order to determine the cause of failure, a detailed analysis was conducted. The analysis included macroscopic observation for the failed tube and optical microscopy for the morphology of cracks. The characterization of fracture was analyzed by scanning electron microscopy, and the components subjected to the cracks were analyzed using energy-dispersive x-ray spectroscopy. Results revealed that the welded elbow had suffered damage from external chloride stress corrosion cracking (ECSCC). The environmental factor responsible for ECSCC is the chloride present in the dampish insulation. The stress factor is the result of the welding residual stress induced in the material which was used to fabricate the elbow.


Failure analysis Welded elbow ESCC Chloride Stainless steel Insulation 



The authors gratefully acknowledge the financial support provided by Ministry of Education of Jiangsu (08KJB430007) and Innovation Project for College Graduates of Jiangsu Province in China (CXLX12_0434).


  1. 1.
    Vogelaere, F.D.: Corrosion under insulation. Process. Saf. Prog. 28, 30–35 (2009)CrossRefGoogle Scholar
  2. 2.
    Bovard, T.: The problem of corrosion under thermal insulation. Mater. Perform. 41, 34–38 (2002)Google Scholar
  3. 3.
    ASM: Corrosion Under Thermal Insulation. Corrosion, ASM Handbook, vol. 13, 9th edn, pp. 1144–1148. ASM, Metals Park (1987)Google Scholar
  4. 4.
    Babakr, A., Al-Subai, S.: Under insulation stress corrosion cracking of process piping. In: Corrosion 2006, pp. 065001–065009. NACE, Orlando (2006)Google Scholar
  5. 5.
    Okubo, M.: External stress corrosion cracking of stainless steels caused by used by thermal insulation. Corros. Eng. 30(12), 705–715 (1981)Google Scholar
  6. 6.
    Shonohara, T., Shirai, M., Shinogaya, T.: External stress corrosion cracking (ESCC) of austenitic stainless steel. Mater. Perform. 24(6), 26–32 (1985)Google Scholar
  7. 7.
    Elshawesh, F., El Houd, A., El Raghai, O.: Technical note corrosion and cracking under insulation of type 304 stainless steel at ambient temperature. Corros. Eng. Sci. Technol. 38(3), 239–240 (2003)CrossRefGoogle Scholar
  8. 8.
    Nakahara, M., Takahashi, M.: Case history of external stress corrosion cracking of stainless steel. Corros. Eng. 35(8), 467–470 (1986)Google Scholar
  9. 9.
    Handbook, Meta: Metallography and microstructures, vol. 9. ASM International, Materials Park (1986)Google Scholar
  10. 10.
    Kadry, S.: Corrosion analysis of stainless steel. Eur. J. Sci. Res. 22(4), 508–516 (2008)Google Scholar
  11. 11.
    Wu, M.D.: Corrosion and Tribology. Handbook of Materials Testing for Mechanical Engineering. China 2002, p. 233. (in Chinese)Google Scholar
  12. 12.
    Suresh, K.M., Sujata, M., Venkataswamy, M.A., et al.: Failure analysis of a stainless steel pipeline. Eng. Fail. Anal. 15(5), 497–504 (2008)CrossRefGoogle Scholar
  13. 13.
    Sedriks, A.J.: Corrosion Monograph: Corrosion of Stainless Steels, vol. 15. A Wiley Interscience Publication, New York (1996)Google Scholar
  14. 14.
    Torchio, S.: Stress corrosion cracking of type AISI 304 stainless steel at room temperature; influence of chloride content and acidity. Corros. Sci. 20, 555–561 (1980)CrossRefGoogle Scholar
  15. 15.
    Fontana, M.G.: Corrosion Engineering. McGraw-Hill, New York (1986)Google Scholar
  16. 16.
    Oberndorfer, M., Thayer, K., Kastenbauer, M.: Application limits of stainless steels in the petroleum industry. Mater. Corros. 55(3), 174–180 (2004)CrossRefGoogle Scholar
  17. 17.
    Miller, J., Dupont, M.: Labels, gaskets, and chloride cracking of austenitic stainless steels. J. Fail. Anal. Prev. 11, 26–28 (2011)CrossRefGoogle Scholar
  18. 18.
    Krishnan, K.N., Prasad, R.K.: Effect of microstructure on stress corrosion cracking behaviour of austenitic stainless steel weld metals. Mater. Sci. Eng. A 142(1), 79–85 (1991)CrossRefGoogle Scholar
  19. 19.
    Williams, J., Evans, O.: The influence of insulation material on corrosion under insulation. In: NACE Northern Area Western Conference (2010)Google Scholar
  20. 20.
    Winnik, S.: Corrosion Under Insulation (CUI) Guidelines, 1st edn, pp. 92–94. Woodhead Publishing and Maney Publishing, Cambridge (2008)CrossRefGoogle Scholar

Copyright information

© ASM International 2013

Authors and Affiliations

  1. 1.College of Mechanical and Power EngineeringNanjing University of TechnologyNanjingPeople’s Republic of China

Personalised recommendations