## 5 Conclusions  
The short-term mechanical properties of commercial corrosion-resistant alloys based on Ni-Cr (Hastelloy(r) G-35(r)), Ni-Mo (Hastelloy(r) B-3(r)), and Ni-Cr-Mo (VDM(r) Alloy C-4, VDM(r) Alloy 59, KhN62M-VI) systems were analyzed in both the as-received state and after long-term (up to 5000 h) aging at 500-700 \({}^{\circ}\)C. The obtained data showed that the content of the alloy's main components had a pronounced influence on the type of secondary phases released during long-term high-temperature aging, and the nature of these phases predetermined the deformation behavior of Ni-Cr-Mo alloys during tension.  
The analysis of the deformation behavior of Hastelloy(r) G-35(r) indicates that nickel-chromium-based materials are the most reliable in terms of mechanical property stability for structural applications within the temperature range of 550-700 \({}^{\circ}\)C. Hastelloy(r) G-35(r), in similar temperature conditions, exhibits the least sensitivity to aging due to the precipitation of particles identified as \(\sigma\)-phase and \(\alpha\)-Cr, which has no significant effect on the material's ductile properties while slightly increasing its strength.  
The high molybdenum content in B-family alloys reduces matrix stability under high-temperature aging, leading to complete embrittlement at 600-700 \({}^{\circ}\)C. This is attributed to the plate-like morphology of Ni\({}_{4}\)Mo precipitates, which are highly harmful to ductile properties, as these excess phases act as internal stress concentrators and crack initiation sites.  
C-family alloys have the greatest potential as structural materials for high-temperature applications at 500-700 \({}^{\circ}\)C. Their more balanced chemical composition results in the best combination of strength and ductility, making them highly processable. However, it hasbeen demonstrated that intragranular precipitates in the C-type nickel-based alloys slightly embrittle the metal, limiting its applicability within the specified temperature range.  
Therefore, it has been demonstrated that grain boundary precipitates have a negligible effect on the strength properties of the investigated alloys, while intragranular precipitates embrittle nickel-based alloys, reducing their possible application at high temperatures.  
The obtained results can be useful for the preliminary selection of candidate construction materials for MSRs. The final choice of the construction material requires performing prolonged resource testing in the molten salt medium with a forecast of mechanical properties on the entire service life of the MSR.  
Conceptualization, I.B.P.; Formal analysis, A.F.G. and V.A.K.; Investigation, A.F.G., V.A.K. and M.S.K.; Data curation, V.A.K. and I.B.P.; Writing--original draft, A.F.G.; Writing--review & editing, V.A.K. and I.B.P.; Visualization, A.F.G.; Project administration, I.B.P.; Funding acquisition, I.B.P. All authors have read and agreed to the published version of the manuscript.  
This research was funded by Ministry of Science and Higher Education of the Russian Federation (Ural Federal University Program of Development within the Priority-2030 Program).  
Not applicable.  
The original contributions presented in this study are included in the article. Further inquiries can be directed to the corresponding author.  
The authors declare no conflicts of interest.