**5. Conclusions**

Different surface mechanical attrition treatments (SMAT) were used in order to investigate their effects on the fatigue behavior of a 304L austenitic stainless steel. The metastable nature of this stainless steel makes it a good candidate for cryogenic treatment. The focus was put on (i) the potential of cryogenic SMAT treatment, and (ii) the nature of the cyclic loading condition during fatigue tests.


**Author Contributions:** Conceptualization, M.A. and T.G.; methodology, M.A., P.B., Y.N. and T.G.; validation, C.D. and M.N.; formal analysis, M.A., P.B., Y.N. and T.G.; investigation, C.D. and M.N.; resources, M.A., P.B., Y.N. and T.G.; data curation, C.D. and M.N.; writing—original draft preparation, C.D. and M.N.; writing—review and editing, M.A., R.M., P.B., Y.N. and T.G.; supervision, M.A. and T.G.; funding acquisition, M.A., P.B., Y.N. and T.G. All authors have read and agreed to the published version of the manuscript.

**Funding:** This study was supported by the French State through the program "Investment in the future" operated by the National Research Agency (ANR), referenced by ANR-11-LABX-0008-01 (Labex DAMAS). M.N. was supported by a Canadian–French Frontenac scholarship during his stay in ETS-Montréal.

**Conflicts of Interest:** The authors declare no conflict of interest.
