Advertisement

Journal of Failure Analysis and Prevention

, Volume 13, Issue 6, pp 658–665 | Cite as

Failure Analysis of Welded Radiant Tubes Made of Cast Heat-Resisting Steel

  • Ali Reihani
  • Seyyed Ali Razavi
  • Ehsan Abbasi
  • Ahmad-Reza Etemadi
Case History---Peer-Reviewed

Abstract

Radiant tubes made of cast heat-resisting steels were cracked after 4 years of operation at 1020 °C temperature in hydrocarbon cracking furnace. Optical microscopy of the tubes showed that there was extensive precipitation and intermetallic compound formation especially as brittle networks with progressive reduction in toughness and resistance to thermal and mechanical stresses. SEM and EDS analysis proved both decarburization and oxidation on interior and exterior surfaces. Apart from cracking due to long-term heating, the tubes experienced high temperature creep. HAZ cracking after welding of cracked and/or creeped tubes due to formation of brittle carbide networks was overcome by localized solution heat treatment followed by fast dry air cooling. Localized dissolution of carbide networks and intermetallic compounds resulted in lower strain microstructures and enhanced resistance of parts to thermal and mechanical stresses during repair welding. It is evident that localized solution heat treating other than lowering strains can cause the precipitates to be more uniformly and finely distributed. Fast dry air cooling rate after solution heat treating and similar cooling after welding can help to control precipitation of carbides. Detailed non-destructive testing after welding along with tensile testing proved that post-weld cracking was controlled.

Keywords

Embrittlement Cracks Decarburization Heat-affected zone Welding 

Notes

Acknowledgments

The authors would like to thank all staffs in the Welding/NDT section, Assessment and Integrity Division of Arya-Sasol Polymer Company, Southern Pars of Special Zone.

References

  1. 1.
    A.M. Gujarathi, S.P. Dipesh, A. Pravar, L.K. Ashwin, and B.V. Babu, Simulation and Analysis of Ethane Cracking Process. Proceedings of International Symposium & 62nd Annual Session of IIChE in association with International Partners (CHEMCON-2009), Andhra University, Visakhapatnam, Dec 27–30, 2009Google Scholar
  2. 2.
    A. Tarafder, B.C.S. Lee, A.K. Ray, G.P. Rangaiah, Multi-objective optimization of an industrial ethylene reactor using a nondominated sorting genetic algorithm. Ind. Eng. Chem. Res. 44(1), 124–141 (2005)CrossRefGoogle Scholar
  3. 3.
    F.W. Tsai, S.C. Che, R.G. Minet, Fixed bed catalytic reactors—analysis and design. Hydrocarb. Process. 64, 41–47 (1985)Google Scholar
  4. 4.
    J.R. Davis, High Alloy Cast Steels, ASM Specialty Handbook Heat-Resistant Material, 200–202, 1997Google Scholar
  5. 5.
    C.M. Schillmoller, HP-Modified Furnace Tubes for Steam Reformers and Steam Crackers. NIDI Technical Series No. 10058, Nickel Development Institute, 1992Google Scholar
  6. 6.
    G.Y. Lai, Heat Resistant Materials for Furnace Parts, Trays and Fixtures, Heat Treating, vol. 4. ASM Handbook, ASM International, 1991, pp. 510–518Google Scholar
  7. 7.
    M. Blair, T.L. Stevens, Heat Resistant High Alloy Steels, Steel Castings Handbook, 6th edn. Steel Founder’s Society of America and ASM International, 1995, pp. 22-1–22-13Google Scholar
  8. 8.
    Alloy Casing Institute, Investigation of Strengthening Mechanisms and Surface Protection of Cast Alloy Above 2000°F. Project No. 49, 1996Google Scholar
  9. 9.
    Steel Founder’s Society of America, High Alloy Data-sheet, Heat Series, Steel Casting Handbook Supplement 9Google Scholar
  10. 10.
    J. Huber, D. Jakobi, Centricast Materials for High-Temperature Service, Nitrogen + Syngas, No. 37. Schmidt + Clemens GmbH & Co. KG, Nov–Dec 2010, LindlarGoogle Scholar
  11. 11.
    L.T. Shinoda, M.B. Zhaghloul, Y. Kondo, The effect of single and combined addition of Ti and Nb on the structure and strength of the centrifugally cast HK40 steel. Trans. ISIJ 18, 139 (1978)Google Scholar
  12. 12.
    D.E. Hendrix, Hendrix Group, Comparative Performance of Six Cast Tube Alloys in an Ethylene Pyrolysis Test Heater. NACE International-Corrosion, March 22–27, San Diego, 1998Google Scholar
  13. 13.
    A. Ul-Hamid, H.M. Tawancy, A.I. Mohammad, N.M. Abbas, Failure analysis of furnace radiant tubes exposed to excessive temperature. Eng. Fail. Anal. 13, 1005–1021 (2006)CrossRefGoogle Scholar
  14. 14.
    Gh Dini et al., Computational and experimental failure analysis of continuous-annealing furnace radiant tubes exposed to excessive temperature. Eng. Fail. Anal. 15(5), 445–457 (2008)CrossRefGoogle Scholar
  15. 15.
    M.A. Irfan, W. Chapman, Thermal stresses in radiant tubes due to axial, circumferential and radial temperature distributions. Appl. Therm. Eng. 29(10), 1913–1920 (2009)CrossRefGoogle Scholar
  16. 16.
    B. Piekarski, Damage of heat-resistant castings in a carburizing furnace. Eng. Fail. Anal. 17(1), 143–149 (2010)CrossRefGoogle Scholar
  17. 17.
    A.K. Ray et al., Health assessment of 22 years service-exposed radiant tube from an oil refinery. Eng. Fail. Anal. 18(3), 1067–1075 (2011)CrossRefGoogle Scholar
  18. 18.
    J. Swaminathan et al., Failure analysis and remaining life assessment of service exposed primary reformer heater tubes. Eng. Fail. Anal. 15(4), 311–331 (2008)CrossRefGoogle Scholar
  19. 19.
    K. Guan, Analysis of failed ethylene cracking tubes. Eng. Fail. Anal. 12(3), 420–431 (2005)CrossRefGoogle Scholar
  20. 20.
    K. Guan et al., Analysis of failed electron beam welds in ethylene cracking tubes. Eng. Fail. Anal. 18(5), 1366–1374 (2011)CrossRefGoogle Scholar
  21. 21.
    UTP 2535 Nb, Material No.: 1.4853, EN 1600: EZ 25 35 Nb B 6 2, www.utp-welding.com
  22. 22.
    UTP 3545 Nb, EN 1600: EZ 35 45 Nb B 6 2, EN ISO 14172: E Ni Z, www.utp-welding.com
  23. 23.
    Herda W., Nickel Containing Materials for High Temperature Applications in Petrochemical Processes and Refinery Furnaces. International Nickel LtdGoogle Scholar
  24. 24.
    S.R. Keown, F.R. Pickering, Effect of Niobium Carbide on the Creep-Rupture Properties of Austenitic Stainless Steels Creep Strength in Steel and High Temperature Alloys (Metals Society, London, 1974)Google Scholar
  25. 25.
    H. Wen-Tai, R.W.K. Honeycombe, Structure of centrifugally cast austenitic stainless steels Part 1: HK 40 as cast and after creep between 750 and 1000 °C. Mater. Sci. Technol. 1(5), 385–389 (1985)CrossRefGoogle Scholar
  26. 26.
    J. DuPont, J.C. Lippold, S.D. Kiser, Welding Metallurgy and Weldability of Nickel-Base Alloys (Wiley, Hoboken, 2009)CrossRefGoogle Scholar
  27. 27.
    R.G. Baker, R.P. Newman, Cracking in welds metal construction and Br. Weld. J. 1, 1–4 (1969)Google Scholar
  28. 28.
    J.G. Franklin, W.F. Savage, Stress relaxation and strain—age cracking in Ren é 41 weldments. Weld. J. 53, 380 (1974)Google Scholar
  29. 29.
    D. McKeown, Re-heat cracking in high nickel alloy heat—affected zone. Weld. J. 50, 201–206 (1971)Google Scholar
  30. 30.
    Y. Nakao, Study on reheat cracking on Ni—base superalloy Waspaloy. Trans. Jpn. Weld. Soc. 19(1), 66–74 (1988)Google Scholar
  31. 31.
    M. Prager, C.S. Shira, Welding of precipitation—hardening nickel—base alloys. Weld. Res. Counc. Bull. 128, 18–21 (1968)Google Scholar
  32. 32.
    R.N. Younger, R.G. Barker, Heat—affected zone cracking in welded austenitic steels during heat treatment. Br. Weld. J. 8(12), 579–587 (1961)Google Scholar

Copyright information

© ASM International 2013

Authors and Affiliations

  • Ali Reihani
    • 1
  • Seyyed Ali Razavi
    • 1
  • Ehsan Abbasi
    • 1
  • Ahmad-Reza Etemadi
    • 2
  1. 1.Welding & NDT Section, Assessment, Integrity DepartmentArya-Sasol Company, Southern Pars of Special ZoneAsaluyehIran
  2. 2.Department of Materials & Metallurgical EngineeringNew Mexico TechSocorroUSA

Personalised recommendations