## 4 Conclusions  
In this study, the Fe-13 Cr-4 Al alloy intended for ATF cladding was carefully prepared by vacuum induction melting and hot-working processes, with the aim of investigating its high-temperature mechanical properties and serration behaviors. To this end, uniaxial tension tests were conducted across a wide temperature range of 200-800 \({}^{\circ}\)C at a strain rate of 10\({}^{-3}\) s\({}^{-1}\). Furthermore, a detailed examination of fracture morphologies was carried out to elucidate the underlying fracture mechanisms at each deformation temperature. Based on these investigations, the following conclusions were drawn:  
1. In the engineering stress-strain responses of the Fe-13 Cr-4 Al alloy, serrated flow behaviors were evident at 300 and 400 \({}^{\circ}\)C. At these temperatures, the alloy exhibited distinct plateaus in yield strength, ultimate tensile strength, and strain-hardening exponent, coupled with minima in ductility, indicating the occurrence of DSA.
2. The fracture modes of the Fe-13 Cr-4 Al alloy specimens tested within the temperature range of 200 to 400 \({}^{\circ}\)C exhibited a combination of ductile and cleavage fracture features. As the temperature increased beyond 500 \({}^{\circ}\)C, the fracture mode transitioned completely to ductile fracture.
3. Upon increasing the temperature from 300 to 400 \({}^{\circ}\)C, the serration type transitioned from type-A + B to type-B + C. This shift was accompanied by a change in the distribution curve of stress drop amplitude, which peaked at a higher amplitude.  
Considering the limitation imposed on the formability of the FeCrAl alloy due to the DSA effect-induced ductility reduction, the DSA phenomenon necessitates rigorous attention and should be carefully avoided in practical applications. In the future, it is imperative to conduct a comprehensive investigation into the impacts of the DSA phenomenon on both the low-cycle fatigue life and creep characteristics of the FeCrAl alloy. Such an investigation will facilitate a more thorough evaluation of the FeCrAl alloy's potential as a viable ATF cladding material, as well as its long-term service reliability.  
Conceptualization, M.C.; data curation, H.S.; formal analysis, H.L.; funding acquisition, Y.S.; investigation, M.C. and Z.H.; methodology, M.C. and H.S.; project administration, H.S. and Y.S.; resources, H.S.; software, Z.H. and P.L.; supervision, H.S. and Y.S.; validation, Z.H.; visualization, M.C. and P.L.; writing--original draft, M.C.; writing--review and editing, M.C., H.L. and Y.S. All authors have read and agreed to the published version of the manuscript.  
The study was supported by the Innovative Scientific Program of CNNC, the National Natural Science Foundation of China (No. 12072249), and the National Science and Technology Major Project (2019-VII-0007-0147).  
Not applicable.  
The original contributions presented in the study are included in the article, further inquiries can be directed to the corresponding authors.  
Author [PERSON] was employed by the company China Nuclear Power Engineering Co., Ltd. The remaining authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.