Abstract
An HK40 steam-reforming tube that ruptured after 35,000 h of operation was analyzed to identify the causes of failure. Analysis of the fracture surface and cross sections indicated extensive and localized corrosion associated with the primary crack site. The fracture surface showed three distinct types of propagation morphology at the inner, middle, and outer portions of the pipe. Severe localized corrosion at interdendritic grain boundaries was detected at the inner pipe, while at the middle, cracks propagated transgranularly along primary carbides. Elemental mapping and line profiles showed a correlation between rupture behavior and the elemental segregation of chromium, manganese, carbon, and silicon at the inner and middle regions. Sulfur, encountered as a contaminant in natural gas, was also detected at these regions. Based on the characteristics exhibited by the fracture surface, failure was attributed to oxidation and fracture enhanced by the elemental redistribution of chromium, carbon, manganese, nickel, and silicon.
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References
M.B. Zaghloul, T. Shimoda, and R. Tanaka: “On the Strengthening of the Centrifugally Cast HK40 Tube,” Trans. ISIJ, 1977, 17, pp. 28–36.
A.A. Kaya: “Microstructure of HK40 Alloy after High-Temperature Service in Oxidizing/Carburizing Environment, Part II: Carburization and Carbide Transformations,” Mater. Charact., 2002, 49(1), pp. 23–34.
Steel Casting Handbook—Supplement 9, High Alloy Data Sheets, Heat Series, Steel Founders’ Society of America, Barrington, IL, 2004.
G.D. Barbadela et al.: “Phase Characterization in Two Centrifugally Cast HK Stainless Steel Tubes,” Mater. Charact., 1991, 26, pp. 1–7.
F. Wang and D.O. Northwood: “The Effect of Carbon Content on the Microstructure of an Experimental Heat-Resistant Steel,” Mater. Charact., 1993, 31, pp. 3–10.
D. McLean: Vacancies and Other Point Defects in Materials and Alloys, Institute of Metals, London, 1958, pp. 188–99.
Y. Saito, B. Önay, and T. Maruyama, ed.: High Temperature Corrosion of Advanced Materials, Elsevier Publishers, North Holland, 1992, pp. 123–35.
T.C. Chou, W. Huang, and R. Paciej: “Stress Corrosion Cracking of Pyrotherm Reformer Tube for Steam-Reforming Hydrogen Production,” J. Mater. Sci., 1997, 32(1), pp. 67–72.
R.C. Lobb and H.E. Evans: “The Oxidation of Chromium-Depleted Stainless Steels in a CO2-Based Gas of Low Sulphur Activity,” Corros. Sci., 1985, 25, pp. 503–18.
R.K. Wild: Surface Analysis Techniques and Applications, W. Neagle and D.R. Randell, ed., Royal Society of Chemistry, U.K., 1990, pp. 73–95.
D.P. Whittle et al.: “Concentration Profiles in the Underlying Alloy during the Oxidation of Iron-Chromium Alloys,” Acta Metall., 1967, 15, pp. 1747–55.
A.A. Kaya, P. Krauklis, and D.J. Young: “Microstructure of HK40 Alloy after High Temperature Service in Oxidizing/Carburizing Environment, Part I: Oxidation Phenomena and Propagation of a Crack,” Mater. Charact., 2002, 49(1), pp. 11–21.
“Standard Specification for Centrifugally Cast Iron-Chromium-Nickel High-Alloy Tubing for Pressure Application at High Temperatures,” A 608/A 608M-02, ASTM International, W. Conshohocken, PA.
“Standard Specification for Castings, Austenitic, Austenitic-Ferritic (Duplex), for Pressure-Containing Parts,” A 351, ASTM International, W. Conshohocken, PA.
Properties and Selection: Irons, Steels, and High-Performance Alloys, vol. 1, Metals Handbook, 10th ed., ASM International, Materials Park, OH, 1990.
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Caceres-Valencia, P.G., Baiges, I.J. Effect of elemental redistribution on the failure of centrifugally cast HK40 alloy. J Fail. Anal. and Preven. 6, 67–72 (2006). https://doi.org/10.1361/154770206X99334
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DOI: https://doi.org/10.1361/154770206X99334