Properties of a Plasma-Nitrided Coating and a CrNx Coating on the Stainless Steel Bipolar Plate of PEMFC
Round 1
Reviewer 1 Report
Congratulations on the work.
Please see attachment.
Comments for author File: 
Comments.pdf
Author Response
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Author Response File: Author Response.pdf
Reviewer 2 Report
The manuscript coatings-705144 deals with the preparation of coated 316L stainless steel. A plasma-enhanced balanced magnetron sputtering process is used to provide plasma nitrided coating and CrNx coating. Some aspects of this manuscript chock the reviewer that why he decided to reject it for publication in the Coatings journal.
And he hopes that its comments will help the authors to improve the quality of their manuscript.
Comments:
- Within the results and discussion part, there is only one cited-reference! Hence it sounds more like a results part, so where is the discussion one?
- Where is the comparison with the scientific literature of the obtained-results? Without discussions of the results, from time to time, the authors give some truths which appear speculative to the reader.
- The analysis and interpretations of the results should be improved. For instance, the authors could perform a Rietveld analysis of the powder XRD patterns, describe more finely SEM images, etc. ...
Author Response
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Author Response File: Author Response.pdf
Reviewer 3 Report
- This paper reports investigation of 316 L stainless steel with surface modification by coatings, specifically plasma-nitride and CrNx coatings, aiming to improve the corrosion resistance of the mentioned material. In particular, the corrosion resistance is evaluated under corrosive conditions closely to the convential use of the PEM bipolar plates. This technical paper contains interesting results, the accuracy of the measurements is high. The manuscript is well structured, abstract is coincise and enougly informative, the state-of the art is properly introduced, the results are well described.
I just have only several remarks, namely: Although the PEM bipolar plates be known for most readers, I would recommend deciphering PEM at the beginning of the paper to less knowledgeable Readers. The surface finishing is one of the key steps in preparing the material for a coating process. The coating technique succeeds if the surface is properly treated/prepared before. For this reason I suggest the authors to add more details into the "materials and speciments preparation" section related to the polishing. The table 1 should be revised. What does it means “others”? Fe content should be included. If “others” means Fe-content, I suggest to replace Fe and bal. instead of “others” and to "---”, respectively. Page 2, line 68: What does it mean “Ar gas nitrogen flow”? Please clarify. Page 2, Line 77: H2SO4 and HF are used in a solution? Are use them in separately? It is not clear…. Page 3, Line 84: If the SEM acronym is extended, for EDS should be the same. Page 3, Line 96: The authors refer to a Fig. 3, is it Figure 1? Page 3, Line 102: Please replace “increased” instead of “stregthened”. Page 4, line 150: I suggest to replace “corrosive substances/agents” instead of”corrosive particles". Page 5, Line 163, I suggest to remove the subtitle “Potentiodynamic polarization…”. The same for pages 6, 7 and 8. The paper also contains some other grammatical errors and misprints (unnecessary or missing commas, hyphenations etc.), which should be corrected by a careful check of the manuscript before the submission. As examples: - Page 1, Line 46: Please replace “are” instead of “is”
- Page 4, Line 132: Please remove hyphenations to “striations”
- Page 4, line 152, 153: Please check the sentence.
- Page 7, Line 229, the sub-subtitle is repeated.
The paper may be published after a minor revision, in accordance with the comments and suggestions made to the authors.
Author Response
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Author Response File: Author Response.pdf
Round 2
Reviewer 2 Report
The manuscript could be improved by adding a discussion in the conclusion part (1-3 sentences) of the obtained results versus the reported one in literature.
