**5. Conclusions**

P675 carburizable martensitic stainless steel (UNS S42670) samples were processed using two different heat treatment methods (carburizing and carbo-nitriding (CN)) and two tempering temperatures (HTT and LTT). Following, the research conducted in this paper highlights the viability of SKPFM to effectively predict bulk corrosion behavior by measuring nanoscale surface differences in VPDs between carbides and the surrounding matrix, thereby providing insight into bulk observations by using information obtained at the nanoscale. More generally, SPM can be used to evaluate the potential efficacy of different steels and/or surface treatments for use in corrosive environments.


**Author Contributions:** All authors contributed to writing the manuscript. Conceptualization, A.K., C.M.E., K.A.H., P.H.D., M.F.H.; Investigation, A.K., C.M.E., K.A.H., O.O.M.; Project Administration, P.H.D., E.G.; M.F.H.; Visualization, A.K., C.M.E., K.A.H., O.O.M., P.H.D., M.F.H.; Resources, P.H.D., E.G., H.K.T., M.F.H.; Funding Acquisition, H.K.T., E.G., P.H.D., M.F.H.; Validation, H.K.T.; Supervision, M.F.H.

**Funding:** This research was funded by Micron School of Materials Science and Engineering, NSF MRI #1727026.

**Conflicts of Interest:** The authors declare no conflicts of interest. The funders had no role in the design of the study; in the collection, analyses, or interpretation of data; in the writing of the manuscript, or in the decision to publish the results.
