**5. Conclusions**

The microstructural changes in Cr-V ledeburitic steel Vanadis 6 with different subzero treatments and tempering were investigated using SEM, TEM, and X-ray diffraction. The corresponding changes in corrosion resistance in a 3.5% water solution of NaCl were studied by potentiodynamic polarisation tests, calculation of the corrosion rate, and by analysis of attacked surfaces by SEM.

The following conclusions can be expressed from the present study:

1. The austenitizing at 1050 ◦C for 30 min followed by nitrogen gas quenching produced the microstructure composed of needle-like martensite, retained austenite, and undissolved carbides.


**Author Contributions:** Conceptualization, P.J.; methodology, P.J., M.D., A.B., M.C., software, A.B., ˇ D.B.; validation, P.J., A.B.; formal analysis, P.J.; investigation, P.J., M.D., A.B., M.C.; resources, M.H.; ˇ data curation, P.J., D.B.; writing—original draft preparation, P.J.; writing—review and editing, P.J., A.B.; visualization, P.J., M.H., M.D., D.B.; supervision, P.J.; project administration, M.H.; funding acquisition, P.J. All authors have read and agreed to the published version of the manuscript.

**Funding:** The authors would like to acknowledge that the article is an outcome implementation of the following two projects: scientific project VEGA 1/0112/20 and APRODIMET, ITMS: 26220120048, supported by the Research & Development Operational Programme funded by the European Regional Development Fund.

**Institutional Review Board Statement:** Not applicable.

**Informed Consent Statement:** Not applicable.

**Data Availability Statement:** The data presented in this study are available on request from the corresponding author. The data are not publicly available due to the fact the this is an ongoing research.

**Acknowledgments:** The authors would like to acknowledge that the article is an outcome implementation of the following two projects: scientific project VEGA 1/0112/20 and APRODIMET, ITMS: 26220120048, supported by the Research & Development Operational Programme funded by the European Regional Development Fund. Special thanks are expressed to Suzanne Morsch from The University of Manchester, for realizing the Kelvin probe force microscopy.

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

#### **References**


*Article*
