**4. Conclusions**

In our research, we have investigated the effects of LSP treatment on the surface properties of the maraging steel X2NiCoMo18-9-5 in a precipitation-hardened state. We have used different combinations of PD and spot size on the surface. The LSP was performed in a confined mode without a protective coating using constant laser pulse energy and duration. The conclusions could be summarized as following:


value at the surface after the LSP is around 750 HV0.2 and was registered on the specimen treated with a 2.0 mm-diameter laser spot and laser PDs of 1600 and of 2500 cm<sup>−</sup>2.


**Author Contributions:** J.G. and J.L.O. conceived, designed and performed the experiments; J.A.P. performed LSP experiments, R.Š. and L.P. performed the microstructural, roughness, fatigue, and RS characterizations; L.P. and J.G. analyzed and evaluated the data; L.P. and R.Š. wrote the manuscript. J.G. supervised the study. All the authors reviewed the final paper.

**Funding:** This research received no external funding.

**Acknowledgments:** This paper is part of the research work within the National Research Program (Nr. P2-0270) financed by the Slovene Ministry of Education, Science and Sport. The authors are very grateful for the financial support.

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