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On the origin of extraordinary cyclic strengthening of the austenitic stainless steel Sanicro 25 during fatigue at 700 °C

  • Milan Heczko (a1), Bryan D. Esser (a2), Timothy M. Smith (a3), Přemysl Beran (a4), Veronika Mazánová (a5), Tomáš Kruml (a5), Jaroslav Polák (a5) and Michael J. Mills (a2)...

The origin of the extraordinary strengthening of the highly alloyed austenitic stainless steel Sanicro 25 during cyclic loading at 700 °C was investigated by the use of advanced scanning transmission electron microscopy (STEM). Along with substantial change of the dislocation structure, nucleation of two distinct populations of nanoparticles was revealed. Fully coherent Cu-rich nanoparticles were observed to be homogeneously dispersed with high number density along with nanometer-sized incoherent NbC carbides precipitating on dislocations during cyclic loading. Probe-corrected high-angle annular dark-field STEM imaging was used to characterize the atomic structure of nanoparticles. Compositional analysis was conducted using both electron energy loss spectroscopy and high spatial resolution energy dispersive X-ray spectroscopy. High-temperature exposure-induced precipitation of spatially dense coherent Cu-rich nanoparticles and strain-induced nucleation of incoherent NbC nanoparticles leads to retardation of dislocation movement. The pinning effects and associated obstacles to the dislocation motion prevent recovery and formation of the localized low-energy cellular structures. As a consequence, the alloy exhibits remarkable cyclic hardening at elevated temperatures.

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1. Mughrabi, H.: Dislocations in Fatigue, in Dislocations and Properties of Real Materials (The Institute of Metals, London, 1985); p. 244.
2. Mughrabi, H. and Christ, H-J.: Cyclic deformation and fatigue of selected ferritic and austenitic steels: Specific aspects. ISIJ Int. 37, 1154 (1997).
3. Laird, C., Charsley, P., and Mughrabi, H.: Low energy dislocation structures produced by cyclic deformation. Mater. Sci. Eng., A 81, 433 (1986).
4. Mughrabi, H.: Dislocation wall and cell structures and long-range internal stresses in deformed metal crystals. Acta Metall. 31, 1367 (1983).
5. Marshall, P.: Austenitic Stainless Steels—Microstructure and Mechanical Properties, 1st ed. (Springer, London, England, 1984); p. 432.
6. Maziasz, P.J. and Busby, J.T.: Properties of austenitic steels for nuclear reactor applications. In Comprehensive Nuclear Materials, Vol. 2, Konings, R.J.M., ed. (Elsevier, Amsterdam, the Netherlands, 2012); p. 267.
7. Chai, G. and Forsberg, U.: Sanicro 25: An advanced high-strength, heat-resistant austenitic stainless steel. In Materials for Ultra-Supercritical and Advanced Ultra-Supercritical Power Plants, Di Gianfrancesco, A., ed. (Elsevier, Amsterdam, the Netherlands, 2017); p. 391.
8. Polák, J., Petráš, R., Heczko, M., Kuběna, I., Kruml, T., and Chai, G.: Low cycle fatigue behavior of Sanicro 25 steel at room and at elevated temperature. Mater. Sci. Eng., A 615, 175 (2014).
9. Polák, J., Petráš, R., Heczko, M., Kruml, T., and Chai, G.: Evolution of the cyclic plastic response of Sanicro 25 steel cycled at ambient and elevated temperatures. Int. J. Fatigue 83, 75 (2016).
10. Polák, J., Mazánová, V., Kuběna, I., Heczko, M., and Man, J.: Surface relief and internal structure in fatigued stainless Sanicro 25 steel. Metall. Mater. Trans. A 47, 1907 (2016).
11. Polák, J., Mazánová, V., Heczko, M., Kuběna, I., and Man, J.: Profiles of persistent slip markings and internal structure of underlying persistent slip bands. Fatigue Fract. Eng. Mater. Struct. 40, 1101 (2017).
12. Chai, G., Boström, M., Olaison, M., and Forsberg, U.: Creep and LCF behaviors of newly developed advanced heat resistant austenitic stainless steel for A-USC. Procedia Eng. 55, 232 (2013).
13. Zurek, J., Yang, S-M., Lin, D-Y., Huttel, T., Singheiser, L., and Quadakkers, W.J.: Microstructural stability and oxidation behavior of Sanicro 25 during long-term steam exposure in the temperature range 600–750 °C. Mater. Corros. 66, 315 (2015).
14. Heczko, M., Polák, J., and Kruml, T.: Microstructure and dislocation arrangements in Sanicro 25 steel fatigued at ambient and elevated temperatures. Mater. Sci. Eng., A 680, 168 (2017).
15. Petráš, R., Škorík, V., and Polák, J.: Thermomechanical fatigue and damage mechanisms in Sanicro 25 steel. Mater. Sci. Eng., A 650, 52 (2016).
16. Sourmail, T.: Precipitation in creep resistant austenitic stainless steels. Mater. Sci. Technol. 17, 1 (2001).
17. Danielsen, H.K., Hald, J., Grumsen, F.B., and Somers, M.A.J.: On the crystal structure of Z-phase Cr(V,Nb)N. Metall. Mater. Trans. A 37, 2633 (2006).
18. Obrtlík, K., Kruml, T., and Polák, J.: Dislocation structures in 316L stainless steel cycled with plastic strain amplitudes over a wide interval. Mater. Sci. Eng., A 187, 1 (1994).
19. Hong, S.I. and Laird, C.: Mechanisms of slip mode modification in F.C.C. solid solutions. Acta Metall. Mater. 38, 1581 (1990).
20. Lu, J., Hultman, L., Holström, E., Antonsson, K.H., Grehk, M., Li, W., Vitos, L., and Golpayegani, A.: Stacking fault energies in austenitic stainless steels. Acta Mater. 111, 39 (2016).
21. Caillard, D. and Martin, J-L.: Thermally Activated Mechanisms in Crystal Plasticity, 1st ed., Pergamon Materials Series (Elsevier Science, Amsterdam, the Netherlands, 2003); p. 452.
22. Gerland, M., Alain, R., Ait Saadi, B., and Mendez, J.: Low cycle fatigue behaviour in vacuum of a 316L-type austenitic stainless steel between 20 and 600 °C—Part II: Dislocation structure evolution and correlation with cyclic behaviour. Mater. Sci. Eng., A 229, 68 (1997).
23. Pham, M.S., Solenthaler, C., Janssens, K.G.F., and Holdsworth, S.R.: Dislocation structure evolution and its effects on cyclic deformation response of AISI 316L stainless steel. Mater. Sci. Eng., A 528, 3261 (2011).
24. Bowman, A.L., Arnold, G.P., Storms, E.K., and Nereson, N.G.: The crystal structure of Cr23C6 . Acta Crystallogr., Sect. B: Struct. Crystallogr. Cryst. Chem. 28, 3102 (1972).
25. Tohyama, A. and Minami, Y.: Development of the high temperature materials for ultra super critical boilers. In Advanced Heat Resistant Steel for Power Generation, Viswanathan, R. and Nutting, J., eds. (The Institute of Materials, London, U.K., 1999); p. 494.
26. Jiang, J. and Zhu, L.: Strengthening mechanisms of precipitates in S30432 heat-resistant steel during short-term aging. Mater. Sci. Eng., A 539, 170 (2012).
27. Chi, C., Yu, H., Dong, J., Liu, W., Cheng, S., Liu, Z., and Xie, X.: The precipitation strengthening behavior of Cu-rich phase in Nb contained advanced Fe–Cr–Ni type austenitic heat resistant steel for USC power plant application. Prog. Nat. Sci.: Mater. Int. 22, 175 (2012).
28. Poddar, D., Cizek, P., Beladi, H., and Hodgson, P.D.: Evolution of strain-induced precipitates in a model austenitic Fe–30Ni–Nb steel and their effect on the flow behavior. Acta Mater. 80, 1 (2014).
29. Williams, D.B. and Carter, C.B.: Transmission Electron Microscopy—A Textbook for Materials Science, 2nd ed. (Springer, USA, 2009); p. 775.
30. Carroll, M.C. and Carroll, L.J.: Fatigue and creep-fatigue deformation of an ultra-fine precipitate strengthened advanced austenitic alloy. Mater. Sci. Eng., A 556, 864 (2012).
31. Thomas, G.: Kikuchi electron diffraction and applications. In Modern Diffraction and Imaging Techniques in Material Science, Amelinckx, S., Gevers, R., Remant, G., and Van Landuyt, L., eds. (North-Holland Publishing Co., Amsterdam, Holland, 1970); p. 746.
32. Edington, J.W.: Electron Diffraction in the Electron Microscope (MacMillan Press, London, England, 1975); p. 136.
33. Haddrill, D.M., Youngerand, R.N., and Baker, R.G.: Precipitation of niobium carbide on dislocations in austenite. Acta Metall. 9, 982 (1961).
34. Zhang, Z., Hu, Z., Tu, H., Schmauder, S., and Wu, G.: Microstructure evolution in HR3C austenitic steel during long-term creep at 650 °C. Mater. Sci. Eng., A 681, 74 (2017).
35. Solenthaler, C., Ramesh, M., Uggowitzer, P.J., and Spolenak, R.: Precipitation strengthening of Nb-stabilized TP347 austenitic steel by a dispersion of secondary Nb(C,N) formed upon a short-term hardening heat treatment. Mater. Sci. Eng., A 647, 294 (2015).
36. Pham, M.S. and Holdsworth, S.R.: Dynamic strain ageing of AISI 316L during cyclic loading at 300 °C: Mechanism, evolution, and its effects. Mater. Sci. Eng., A 556, 122 (2012).
37. Rösler, J. and Arzt, E.: A new model-based equation for dispersion strengthened materials. Acta Metall. Mater. 38, 671 (1990).
38. Kesternich, W.: Dislocation-controlled precipitation of TiC particles and their resistance to coarsening. Philos. Mag. A 52, 533 (1985).
39. Challenger, K.D. and Moteff, J.: Characterization of the deformation substructure of AISI 316 stainless steel after high strain fatigue at elevated temperatures. Metall. Trans. 3, 1675 (1972).
40. Bressers, J. and Steen, M.: Fatigue and microstructure in austenitic high temperature alloys. Int. J. Pressure Vessels Piping 47, 217 (1991).
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Journal of Materials Research
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