Mechanistic Insights into Corrosion and Protective Coating Performance of X80 Pipeline Steel in Xinjiang’s Cyclic Freeze–Thaw Saline Soil Environments

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

The manuscript presents a potentially impactful study on corrosion mechanisms in freeze-thaw environments; however, a major revision is required to improve clarity, methodological detail, data interpretation, and the connection between multiscale findings and practical applications.

 

• Could the authors elaborate on the soil characterization process in Xinjiang and clarify how it was replicated or simulated in the laboratory corrosion systems?
• The abstract mentions "temporal-spatial corrosion behavior". Could the authors specify how spatial variation was captured and analyzed in the experiments in more details?
• What were the specific parameters (e.g., scan rate, frequency range) used in the electrochemical impedance spectroscopy and polarization tests, and how were they validated?
• How was the transition point between protective oxide layer formation and corrosion acceleration (around cycle 10) identified and statistically verified?
• Can the authors clarify the methodology and resolution of the synchrotron X-ray diffraction used to detect ion synergism, especially in heterogeneous soil matrices?
• Regarding the asphalt coating results, were the specimens subject to the same freeze-thaw cycles and corrosive media as uncoated ones? If so, how was coating degradation monitored?
• The molecular dynamics simulations are an important component. Can the authors justify the selected force fields, boundary conditions, and time scales used in simulating Cl⁻ permeation?
• The manuscript refers to a "mechanistic framework" for coating optimization. Could the authors detail how their findings could be generalized or applied to other pipeline materials or environmental conditions?

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Reviewer 2 Report

Comments and Suggestions for Authors

The protection of metal structures against corrosion and, in particular, the protection of steel pipelines, is a subject of interest for engineers. My observations regarding the article are the following:

- I ask the authors to analyze whether it is not more appropriate to use the expression “bitumen coated” instead of “asphalt-coated”. Asphalt (asphalt concrete) is a complex product that includes mineral aggregates along with bitumen

- I believe that, in the introduction, more examples of studies from the literature related to the subject of the article should be provided

- 2.1.1. – it is not specified whether the steel samples were in the form of pieces from the pipe, or were extracted from the pipe, or were from the X80 sheet

- I believe that real drawings and photographs of the tested samples (shape and dimensions) should be presented. These are important in the process of interpreting the results.

- the ”point” between the words “environments. kinetic” should be removed – lines 151-152

- were soil moisture measurements performed? Was the soil moisture level taken into account in the freeze-thaw cycles?

- figure 5 – the letter “j” appears, incorrectly, in the figure, instead of “g”. Also, the writing on the figures is unclear

- 366-376 – additional details are needed regarding the protective layers: thickness, composition, method of deposition. Was the deposition done on one side of the sample or on both sides?

There are no major problems with writing in English

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

Comments and Suggestions for Authors

The arcticle can be accepted for the publication in the present form.