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Article
Failure analysis of superheater tube supports of the primary reformer in a fertilizer factory
Journal of Failure Analysis and Prevention (2005)
Abstract

A failure analysis of superheater tube supports of the primary reformer in a local fertilizer factor is presented. A number of tube supports failed at approximately half of their designed service life. Following the failure, the factory was visited, and relevant information and samples were collected. The samples were investigated in the laboratory by chemical analysis, macro- and microhardness measurements, macro-and micrometallographic examinations, and X-ray diffractometry. The analysis showed the supports were fabricated from HH-type heat-resisting alloy and that the failure mode was high-temperature creep. The microstructure of the alloy showed the presence of massive intergranular as well as intragranular σ-phase and intragranular needle-shaped M 23C 6 carbides. It was also concluded from the formation of massive σ-phase in the tube that the failure was hastened because the supports were operating at approximately 800 °C. The alloy composition led to the formation of σ-phase under the operating conditions of the reformer, and the use of an alloy with a higher concentration of austenite-stabilizing element(s) could have avoided the failure. © ASM International.

Keywords
  • σ-phase,
  • Creep,
  • Failure analysis,
  • Reformer tube support,
  • Chemical analysis,
  • Failure (mechanical),
  • Metallography,
  • Microanalysis,
  • Microhardness,
  • Microstructure,
  • Phase composition,
  • Service life,
  • Superalloys,
  • Superheater tubes,
  • X ray diffraction analysis,
  • Macrohardness measurements,
  • Microhardness measurements,
  • Primary reformer,
  • Superheater tube supports
Publication Date
2005
Citation Information
"Failure analysis of superheater tube supports of the primary reformer in a fertilizer factory" Journal of Failure Analysis and Prevention Vol. 5 Iss. 3 (2005)
Available at: http://works.bepress.com/asmd_haseeb/43/