Abstract
Structural evolution of the tempered lath martensite of the 10% Cr–3% Co steel microalloyed with rhenium and copper with a low nitrogen content and a high boron content during creep at 923 K was investigated for the purpose of establishment of the rison of decrease in creep resistance of this steel under the low applied stress. The tempered martensite lath structure of 10% Cr–3% Co steel with an average lath size of 370 nm and a high dislocation number density of 2 × 1014 m–2 was observed after normalizing at 1323 K with the following tempering at 1043 K for 3 h. The structure was stabilized by M23C6 carbides, M6C carbides, and NbX carbonitrides. During long-term creep, the lath structure strongly experienced an evolution: the width of the martensitic laths increased significantly, dislocation density decreased, the Laves phase and Cu-enriched particles remarkably coarsen. Such structural evolution correlates with an appearance of creep strength breakdown on curves “Applied stress vs. Time to failure” and “Minimum creep rate vs. Applied stress”. Significant coarsening of the Laves phase particles and Cu-enriched particles via formation of the large particles with sizes more than 250 nm along high-angle boundaries and full dissolution of the fine particles with sizes less than 50 nm along low-angle boundaries of martensite laths is considered to be the main cause of degradation of the creep resistance of the steel studied.
REFERENCES
F. Abe, T.-U. Kern, and R. Viswanathan, Creep-Resistant Steels (Woodhead, Cambridge, 2008). https://doi.org/10.1533/9781845694012
R. O. Kaybyshev, V. N. Skorobogatykh, and I. A. Shchenkova, “New martensitic steels for fossil power plant: Creep resistance,” Phys. Met. Metallogr. 109, 186–200 (2010). https://doi.org/10.1134/s0031918x10020110
R. L. Klueh, “Elevated-temperature ferritic and martensitic steels and their application to future nuclear reactors,” Int. Mater. Rev. 50, 287–310 (2005). https://doi.org/10.1179/174328005X41140
F. Abe, “Precipitate design for creep strengthening of 9% Cr tempered martensitic steel for ultra-supercritical power plants,” Sci. Technol. Adv. Mater. 9, 013002 (2008). https://doi.org/10.1088/1468-6996/9/1/013002
A. E. Fedoseeva, P. A. Kozlov, V. A. Dudko, V. N. Skorobogatykh, I. A. Shchenkova, and R. O. Kaibyshev, “Microstructural changes in steel 10Kh9V2MFBR during creep for 40000 hours at 600°C,” Phys. Met. Metallogr. 116, 1047–1056 (2015). https://doi.org/10.1134/s0031918x15080049
V. V. Sagaradze, T. N. Kochetkova, N. V. Kataeva, K. A. Kozlov, V. A. Zavalishin, N. F. Vil’danova, V. S. Ageev, M. V. Leont’eva-Smirnova, and A. A. Nikitina, “Structure and creep of Russian reactor steels with a BCC structure,” Phys. Met. Metallogr. 118, 494–506 (2017). https://doi.org/10.1134/s0031918x17050131
A. Fedoseeva, I. Nikitin, E. Tkachev, R. Mishnev, N. Dudova, and R. Kaibyshev, “Effect of alloying on the nucleation and growth of laves phase in the 9–10% Cr–3% Co martensitic steels during creep,” Metals 11, 60 (2021). https://doi.org/10.3390/met11010060
A. E. Fedoseeva and S. I. Degtyareva, “The effect of prolonged annealing on the structural stability of nanoparticle-hardened low-carbon 9% Cr–3% Co steel,” Phys. Met. Metallogr. 123, 1041–1047 (2022). https://doi.org/10.1134/S0031918X22600889
S. Morito, H. Tanaka, R. Konishi, T. Furuhara, and T. Maki, “The morphology and crystallography of lath martensite in Fe–C alloys,” Acta Mater. 51, 1789–1799 (2003). https://doi.org/10.1016/s1359-6454(02)00577-3
S. Morito, Y. Adachi, and T. Ohba, “Morphology and crystallography of sub-blocks in ultra-low carbon lath martensite steel,” Mater. Trans. 50, 1919–1923 (2009). https://doi.org/10.2320/matertrans.mra2008409
V. M. Gundyrev, V. I. Zeldovich, and V. M. Schastlivtsev, “Crystallographic analysis and mechanism of martensitic transformation in Fe alloys,” Phys. Met. Metallogr. 121, 1045–1063 (2020). https://doi.org/10.1134/S0031918X20110046
V. A. Dudko, A. E. Fedoseeva, A. N. Belyakov, and R. O. Kaibyshev, “Influence of the carbon content on the phase composition and mechanical properties of P92-type steel,” Phys. Met. Metallogr. 116, 1165–1174 (2015). https://doi.org/10.1134/s0031918x15110058
A. Fedoseeva, I. Nikitin, N. Dudova, and R. Kaibyshev, “On effect of rhenium on mechanical properties of a high-Cr creep-resistant steel,” Mater. Lett. 236, 81–84 (2019). https://doi.org/10.1016/j.matlet.2018.10.081
Y. Li and T. G. Langdon, “A simple procedure for estimating threshold stresses in the creep of metal matrix composites,” Scr. Mater. 36, 1457–1460 (1997). https://doi.org/10.1016/s1359-6462(97)00041-9
F. A. Mohamed, K.-T. Park, and E. J. Lavernia, “Creep behavior of discontinuous SiC-Al composites,” Mater. Sci. Eng., A 150, 21–35 (1992). https://doi.org/10.1016/0921-5093(90)90004-m
I. Lifshitz and V. Slyozov, “The kinetics of precipitation from supersaturated solid solutions,” J. Phys. Chem. Solids 19, 35–50 (1961). https://doi.org/10.1016/0022-3697(61)90054-3
R. Wagner, R. Kampmann, and P. W. Voorhees, in Homogeneous Second-Phase Precipitation (Wiley, New York, 1991), pp. 213–303. https://doi.org/10.1002/9783527603978.mst0388
F. J. Humphreys and M. Hatherly, “Recrystallization of two-phase alloys,” in Recrystallization and Related Annealing Phenomena, 2nd ed. (Pergamon, Oxford, 2004), pp. 285–319. https://doi.org/10.1016/B978-008044164-1/50013-X
A. E. Fedoseeva, I. S. Nikitin, and R. O. Kaibyshev, “Effect of the quenching temperature on the creep resistance of 9% Cr–1% W–1% Mo–V–Nb martensite steel,” Phys. Met. Metallogr. 123, 92–98 (2022). https://doi.org/10.1134/s0031918x22010033
ACKNOWLEDGMENTS
Author thanks the Joint Research Center of Belgorod State National Research University “Technology and Materials”, the activity of which was supported from the Ministry of Science and Higher Education of the Russian Federation within the framework of agreement no. 075-15-2021-690, for using the equipment.
Funding
The work was financially supported by Russian Science Foundation (no. 19-73-10089-П, https://rscf.ru/en/project/19-73-10089/).
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Fedoseeva, A.E. Structural Evolution of 10% Cr–3% Co Steel Microalloyed with Re and Cu during Creep at 923 К. Phys. Metals Metallogr. 124, 734–741 (2023). https://doi.org/10.1134/S0031918X23601038
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DOI: https://doi.org/10.1134/S0031918X23601038