Влияние длительных высокотемпературных выдержек на механические свойства и структуру сплава 42ХНМ после нейтронного облучения в составе ВВЭР-1000. Часть 2. Структурные исследования

Представлены результаты структурных исследований образцов из сплава 42ХНМ после облучения в составе СУЗ ВВЭР-1000 до повреждающей дозы ~12 сна при температуре ~350°С и последующих изотермических отжигов в интервале температур ~400–1150°С при продолжительности нагрева и выдержки ~2 ч. Показано, что в процессе длительных изотермических отжигов наблюдается изменение фазового состава сплава, происходит отжиг дислокационных структур и зернограничных сегрегаций, а также эволюция пористости. Подтверждено, что причинами снижения пластических свойств сплава 42ХНМ после облучения и последующих изотермических отжигов в интервале температур 400–1000°С являются образование выделений вторых фаз (зон прерывистого распада твердого раствора с выделением частиц α-Cr по границам зерен) и пор на границах зерен.

1. Mukherji D., Rösler J., Strunz P., Gilles R., Schumacher G., Piegert S. Beyond Nibased superalloys: Development of CoRe-based alloys for gas turbine applications at very high temperatures // Int. J. Mater. Res. – 2011. – V. 102, N 9. –P. 1125–1132.

2. Backman D. G., Williams J. C. Advanced Materials for Aircraft Engine Applications // Science. – 1992. – V. 255, N 5048. – P. 1082–1087.

3. Kear B. H., Thompson E. R. Aircraft Gas Turbine Materials and Processes // Science. – 1980. – V. 208, N 4446. – P. 847–856.

4. Pollock T. M., Tin S. Nickel-Based Superalloys for Advanced Turbine Engines: Chemistry, Microstructure and Properties // J. Propuls. Power. – 2006. – V. 22, N 2. – P. 361–374.

5. Rowcliffe A. F., Mansur L. K., Hoelzer D. T., Nanstad R. K. Perspectives on radiation effects in nickel-base alloys for applications in advanced reactors // J. Nucl. Mater. – 2009. – V. 392, N 2. – P. 341–352.

6. Stopher M. A. The effects of neutron radiation on nickel-based alloys // Mater. Sci. Technol. (United Kingdom). – 2017. – V. 33, N 5. – P. 518–536.

7. Solonin M., et al. Cr–Ni alloys for fusion reactors // J. Nucl. Mater. – 1998. – V. 258–263. – P. 1762–1766.

8. Solonin M. I., Alekseev A. B., Kazennov Y. I., Khramtsov V. F., Kondrat ev V. P., Krasina T. A., Rechitsky V. N., Stepankov V. N., Votinov S. N. XHM-1 alloy as a promising structural material for water-cooled fusion reactor components // J. Nucl. Mater. – 1996. – V. 233–237, Part 1. – P. 586–591.

9. Solonin M. I. Radiation-Resistant Alloys of the Nickel-Chromium System // Met. Sci. Heat Treat. – 2005. – V. 47, N 7–8. – P. 328–332.

10. Vatulin A. V., Kondrat ev V. P., Rechitskii V. N., Solonin M. I. Corrosion and radiation resistance of “Bochvaloy” nickel-chromium alloy // Met. Sci. Heat Treat. – 2004. – V. 46, N 11–12. – P. 469–473.

11. De los Reyes M., Edwards L., Kirk M. A., Bhattacharyya D., Lu K. T., Lumpkin G. R. Microstructural Evolution of an Ion Irradiated Ni–Mo–Cr–Fe Alloy at Elevated Temperatures // Mater. Trans. – 2014. – V. 55, N 3. – P. 428–433.

12. Le Brun C. Molten salts and nuclear energy production // J. Nucl. Mater. – 2007. – V. 360, N 1. – P. 1–5.

13. Delpech S., Cabet C., Slim C., Picard G. S. Molten fluorides for nuclear applications // Mater. Today. – 2010. – V. 13, N 12. – P. 34–41.

14. Angeliu T., Ward J., Witter J. Assessing the Effects of Radiation Damage on Ni-base Alloys for the Prometheus Space Reactor System. – Niskayuna, NY, 2006.

15. Gurovich B. A., Frolov A. S., Kuleshova E. A., Maltsev D. A., Safonov D. V., Fedotova S. V., Kochkin V. N., Panferov P. P. Structural evolution features of the 42XNM alloy during neutron irradiation under VVER conditions // J. Nucl. Mater. – 2021. – V. 543. – P. 152557.

16. Gurovich B. A., Frolov A. S., Kuleshova E. A., Maltsev D. A., Safonov D. V. Microstructural evolution of the 42XNM alloy during a severe accident (LOCA) // J. Nucl. Mater. – 2022. – V. 561. – P. 153535.

17. Kuleshova E. A., Fedotova S. V., Gurovich B. A., Frolov A. S., Maltsev D. A., Stepanov N. V., Margolin B. Z., Minkin A. J., Sorokin A. A. Microstructure degradation of austenitic stainless steels after 45 years of operation as VVER-440 reactor internals // J. Nucl. Mater. – 2020. – V. 533. – P. 152124.

18. Gurovich B. A., Frolov A. S., Fedotov I. V. Improved evaluation of ring tensile test ductility applied to neutron irradiated 42XNM tubes in the temperature range of 500–1100°C // Nucl. Eng. Technol. – 2020. – V. 52, N 6. – P. 1213–1221.

19. Салтыков С. А. Стереометрическая металлография. – М.: Металлургия, 1976. – 273 с.

20. Deutsche Gesellschaft für Metallkunde. Zeitschrift für Metallkunde. – Riederer-Verlag, 1948.

21. Maziasz P. J. Overview of microstructural evolution in neutron-irradiated austenitic stainless steels // J. Nucl. Mater. – 1993. – V. 205. – P. 118–145.

22. Ayanoglu M., Motta A. T. Microstructural evolution of the 21Cr32Ni model alloy under irradiation // J. Nucl. Mater. Elsevier B.V. – 2018. – V. 510. – P. 297–311.

23. Yang Y., Yiren C., Yina H., Todd A., Appajosula R. Irradiation Microstructure of Austenitic Steels and Cast Steels Irradiated in the BOR-60 Reactor at 320°C // 15th Int. Conf. Environ. Degrad. Mater. Nucl. Power Syst. React. John Wiley & Sons, Inc., 2012. – P. 2447–2450.

24. Ken H., Yao Z., Morin G., Griffiths M. TEM characterization of in-reactor neutron irradiated CANDU spacer material Inconel X-750 // J. Nucl. Mater. Elsevier B.V. – 2014. – V. 451, N 1–3. – P. 88–96.

25. Allen T. R., Cole J. I., Kenik E. A., Was G. S. Analyzing the effect of displacement rate on radiation-induced segregation in 304 and 316 stainless steels by examining irradiated EBR-II components and samples irradiated with protons // J. Nucl. Mater. – 2008. – V. 376, N 2. – P. 169–173.

26. Kato T., Takahashi H., Izumiya M. Grain boundary segregation under electron irradiation in austenitic stainless steels modified with oversized elements // J. Nucl. Mater. – 1992. – V. 189, N 2. – P. 167– 174.

27. Was G. S., Bruemmer S. M. Effects of irradiation on intergranular stress corrosion cracking // J. Nucl. Mater. – 1994. – V. 216. – P. 326–347.

28. Kenik E. A., Inazumi T., Bell G. E. C. Radiation-induced grain boundary segregation and sensitization of a neutron-irradiated austenitic stainless steel // J. Nucl. Mater. – 1991. – V. 183, N 3. – P. 145–153.

29. Duh T., Kai J., Chen F. Effects of grain boundary misorientation on solute segregation in thermally sensitized and proton-irradiated 304 stainless steel // J. Nucl. Mater. – 2000. – V. 283–287. – P. 198–204.

30. Renault A.-E., Pokor C., Garnier J., Malaplate J. Microstructure and Grain Boundary Chemistry Evolution in Austenitic Stainless Steels Irradiated in the BOR-60 Reactor up to 120 Dpa // 14th, Int. Conf. Environ. Degrad. Mater. Nucl. power Syst. water React. Virginia Beach, VA. – 2009. – P. 1324–1334.

31. Jensen R. R., Tien J. K. Temperature and strain rate dependence of stress-strain behavior in a nickel-base superalloy // Metall. Trans. A. – 1985. – V. 16, N 6. – P. 1049–1068.

32. Kim I. S., Choi B. G., Seo S. M., Kim D. H., Jo C. Y. Influence of heat treatment on microstructure and tensile properties of conventionally cast and directionally solidified superalloy CM247LC // Mater. Lett. – 2008. – V. 62, N 6–7. – P. 1110–1113.

33. Kim I. S., Choi B. G., Seo S. M., Jo C. Y. Mechanical Behavior of As-Cast and High Temperature Exposed Ni-Base Superalloy B1900 // Mater. Sci. Forum. – 2004. – V. 449–452. – P. 541–544.

34. Zheng L., Schmitz G., Meng Y., Chellali R., Schlesiger R. Mechanism of Intermediate Temperature Embrittlement of Ni and Ni-based Superalloys // Crit. Rev. Solid State Mater. Sci. – 2012. – V. 37, N 3. – P. 181–214.

35. Лякишев Н. П. Диаграммы состояния двойных металлических систем. – М.: Машиностроение, 1996–2000.

36. Gurovich B. A., Frolov A. S., Maltsev D. A., Kuleshova E. A., Fedotova S. V. Phase transformations in irradiated 42CrNiMo alloy after annealing at elevated temperatures, and also after rapid annealing, simulating the maximum design basis accident [in Russian] // Proc. 11-th Conf. React. Mater. Sci. Russ. Dimitrovgrad. – 2019.