Evolution of Cementite Substructure of Rails from Hypereutectoid Steel during Operation

Round 1

Reviewer 1 Report

The manuscript analyzed the deformation-induced transformation of pearlite of hypereutectoid rail steel. Several revisions should be made to improve the quality of the manuscript.

1.     Lines 133-134, “The conducted studies showed that the steel structure is represented by three morphological components at a distance of 10 mm from the sample surface.”

The second and third morphological components should also be illustrated by figure.

2.     How were the volume fractions of three morphological components determined?

3.     Authors put forward three possible mechanisms of deformation transformation of lamellar pearlite during loading (operation). What is the main mechanism?

Minor English language editing is needed.

Author Response

We grateful to the reviewer for his work.
1. The volume fraction of lamellar perlite in the material is 65% that is why we provide the photo of this structure only. 
2. The volume fractions of morphological components were determined by traditional methods of planimetry.
3. It is difficult to establish the main mechanism of lamellar perlite transformation. All three possible mechanisms occur simultaneously.

Reviewer 2 Report

The authors have presented a very clear picture of microstructure changes to rails subject to cyclic loading over the course of many years.  While the results are clear, there is little in the way of measuring performance of the system and recommendations on lifetime based on such measurements.  Although not necessary to the publication of the results, such data and information would significantly strengthen the impact of the paper to the community.

N/A

Author Response

We grateful to the reviewer for his work. He states that Minor editing of English is required. The English language in the manuscript has been revised.

Author Response File: Author Response.pdf

Reviewer 3 Report

The present work is devoted to the study of the microstructural evolution of cementite during operation in railways. The works is very interesting and I suggest publication after the following major revisions

-Please improve the introduction section with recent works on other possible materials for railway applications such as high strength steels (https://doi.org/10.1016/j.triboint.2022.108071 and https://doi.org/10.1016/j.msea.2022.144553)

-Materials and methods section should be improved with detailed description of the procedure to prepare the TEM specimens

-In materials and methods should be better explained the conditions at witch the different samples were analysed. For this purpose I suggest to create a table that summarize the different specimens and after to call the samples with a name that after is used in the paper

-It is true that in this work more advanced characterization is presented however for a complete analysis I suggest to add at least some examples of Optical microscope observations

-The conclusion section is quite long. I suggest to move part of the text in a discussion section and after to write a very brief conclusion section in bullet points

Author Response

– We have analyzed the cementite evolution in noise with 0.92% “C” content. The behavior of cementite in a high strength steels is a separate complex problem and task.

– Fig. 1 shows the preparation shame of test object. We used the samples at 10 mm distance from the surface only.

– Optical microscopy does not give the advanced characterization of cementite substructure that is why we used TEM.

– In conclusion we have tried to summarize all the results in order to have clear image of paper content.

Author Response File: Author Response.pdf

Round 2

Reviewer 3 Report

The paper Is now acceptable