Distinctive Oxide Films Develop on the Surface of FeCrAl as the Environment Changes for Nuclear Fuel Cladding

Round 1

Reviewer 1 Report

Interesting work. In the reviewer's opinion, valuable. The reviewer appreciates the attempt to prepare a study that is a literature review of phenomena occurring on the surface of FeCrAl alloys under the conditions of potential interactions occurring in LWR and a presentation of surface oxide structures obtained experimentally in laboratory conditions.

With regard to the work, the reviewer has two groups of comments: methodological in nature and those related to editorial requirements.

The following substantive aspects will be added to the discussion:

-Was the description of the methodology for producing samples for observation, the types of devices used, detectors and the conditions of the observations themselves treated too briefly? The information in the photos is often illegible and incomplete.

-Wouldn't it be worth more highlighting the data (somewhat hidden in the text) regarding the thickness of oxides formed in various conditions?

-It may be worth considering whether it would be useful to have a summary diagram or a compilation of carefully selected photos (in the form of thumbnails, with the same magnification) for the distribution of Al and/or Cr, presenting the fundamental differences between oxides formed in different conditions. It would be a kind of map of the relationship between the operating conditions and the emerging structure. Extremely important for designers.

From the editorial side (editing of work):

-The format of references is completely inconsistent with the recommendations, as is the format of references to subsequent references in the text (should be [1], [2] etc.). Have the authors read Instructions for Authors?

- Most figures and tables are aligned to the left margin of the page, even though there is a lot of space on the right side and should be aligned to the right margin.

-Captions should be on the same page as the drawings (see Figure 7).

-Why is it that in the case of divided drawings (e.g. Figure 2a, Figure 2b, etc.) there is no information in the caption about what is visible in each drawing, but there is only a description for the entire series? Placing explanations only in the text makes reading difficult.

-The position of the word "Matrix" in Figures 6a and 6b changes. It would be better if the position was fixed in this case.

-Drawings of structures are sometimes difficult to read - the colors of the background and descriptions are too close to each other and therefore illegible. At the same time, I would like to point out that the font size of the description identifying the signal from individual elements changes randomly, which looks bad.

-The font used in the table was too large - after all, it is not a graphic and you could have used a font corresponding to the main text.

-The spaces between the preceding text and the figures are too small.

I strongly suggest that you carefully read the instructions in Instructions for Authors in the section on recommended text formatting.

The English used in the work is generally correct. It seems that we should consider whether punctuation (commas) are used sufficiently. In some cases, they seem to be missing. On page 7 (2nd line from the bottom), the wrong type of bracket was used

Author Response

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Author Response File: Author Response.pdf

Reviewer 2 Report

 The manuscript “Distinctive oxide films develop on the surface of FeCrAl as the environment changes.” presents an important subject related to alloys exposed to different steam and environmental conditions; however, the theme would be more enjoyable for the readers if it was more comprehensive, including other alloys or materials used for this application. The authors present many auto-citations and too few references (24) for a review-type article. The reviewer does not recommend publishing in the journal at this stage because there are no arguments, criticism, and discussions enough to support a review-type article.

Some punctual comments:

In Table 1, the authors have to reference each material specification since they are not developed in this manuscript but are other authors’ works.

On pg.4, the author must reference this affirmation: “The first and more complete sets of tests were conducted at (a) General Electric Corrosion and Electrochemistry Laboratory (now GE Vernova Advanced Research or GEVAR), (b) at the Oak Ridge National Laboratory, and (c) at the Nippon Fuel Development or NFD laboratories”.

If the Figures were not produced for this manuscript and are reproductions of other papers, they must be referred to the original authors and documents.

The references do not follow the MDPI standards. The authors have to review the reference links in the manuscript.

10 of 24 references are auto-citations, limiting the review to the subjects studied by the authors of this manuscript. The authors must increase the number of research documents. 24 is too few references for a review-type article.

The authors should present future perspectives for FeCrAl for steam application in the Conclusions section, such as new alloying elements or corrosion protection. A development or application trend would signify novel solutions to industry demands.

Author Response

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Reviewer 3 Report

This review paper is about investigating the distinctive oxide films on the surface of FeCrAl. The topic is interesting and relevant; however, the manuscript needs to be revised thoroughly before publication.

My comments on this paper as follows

The Title should be changed. In my opinion, it does not reflect properly the message of this review.

The Introduction is too short, generalized, and there is no cited references at all. The manuscript can be improved by highlighting and elaborating on the plus information or recent research data that is collected and presented in this review paper in the Introduction part. In the present form, it does not contain sufficient explanation of its novelty compared to similar review paper on this topic.

What is the exact methodology used to elaborate this review?

The structure of the paper is not clear, there is no connection and message transition between the consecutive sub-sections.

This article seems more like a thesis that was transformed into an article. I would recommend to work on it to improve the quality and reproducibility of the study.

Are the Figures the Authors' own work or they cited? There is no indication of it in the text, please make it clear and cite them accordingly.

As a review paper, it would be advisable to mention the future perspectives, challenges and application possibilities of the investigated alloy material and the oxide layers in a separated section.

The Conclusion is way too concise, the Authors should highlight and summarize the results and their novelty in a more detailed way.

The reference list is up-to-date, however way too short for a review paper (only 24 paper). Much more and relevant citations are needed to reflect properly the development and current state of research works in this particular field.

The listing style of reference is not in accordance their citation style in the text. They should be numbered accordingly in the text also and not present in [Name,Year] format.

The quality of English is good, there are only a few misspelled words and unnecessary repetitions.

Author Response

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Round 2

Reviewer 2 Report

Dear authors,

A review-type article needs to present the state-of-art including different and divergent points of view, i.e., other researchers, research centers, groups, etc. It is not contemplated in this manuscript. 27 references with many of them from the same research centre is too few for a good scientific review article. Maybe this technique really does not have enough development or research, as the authors commented. This argument supports the reviewer's recommendation to reject this publication because the technique/materials/results are too young and premature for a robust review-type article.

Author Response

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Reviewer 3 Report

In my opinion, the Authors did their best to answer the comments and made sufficient corrections. The answers to the comments are relatively correct and I found them enough. The understandability and structure of the paper improved.

Author Response

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