Analysis of Corrosion-Mechanical Properties of Electroplated and Hot-Dip Zinc Coatings on Mechanically Pre-Treated Steel Substrate
Round 1
Reviewer 1 Report
Comments and Suggestions for AuthorsIn this article, the authors evaluated the effects of three mechanical pretreatment methods of S235JRG2 steel sheets (synthetic corundum blasting, steel shot blasting, and synthetic corundum grinding) on the corrosion-mechanical properties of electroplated and hot-dip zinc coatings applied to these sheets.
The topic is interesting. I would like to appreciate this paper since practical and useful results. I consider the topic important because All over the world, methods of pretreating steel substrates are being developed to eliminate the use of chemicals from the technological process. These alternative methods are mainly based on mechanical pretreatment techniques. For this reason, the article may be of interest to the scientific community.
The research methodology was adequate to the stated purpose of the paper. The authors described in detail the methodology of sample preparation, mechanical pretreatment methods used, electrolytic galvanization carried out, and hot-dip galvanization. The methods are clearly described. The methodology for mechanical testing of zinc coatings, and corrosion testing of zinc coatings were appropriate.
The manuscript is presented in a well-organized manner. The text is written in a way that the reader can understand. The work is scientifically documented, sufficiently detailed and conclusive. Graphs and tables correctly represent the results obtained. Microscopic images are of good quality. Data are interpreted correctly and consistently. The results are adequately discussed and explained to the reader. The conclusions summarize the research results obtained.
The references contain 56 items. 12 items were published within the last 5 years, so the manuscript is related to the latest research in the field. There are no inappropriate self-citations by the authors.
Considering the above-mentioned merits of the manuscript, I believe that the article is worth publishing. However some changes are required. Below my specific comments, in the order in which the weaknesses appear in the manuscript:
1) It is generally accepted that at the end of the Introduction section the authors state the purpose of the work and its scientific novelty compared to articles on the subject. Introduction requires additions in this regard so that the reader can understand the novelty and originality of the research presented.
2) section 2.5
The manuscript lacks a description of what the Ra and Rz parameters are, what they characterize, how they differ from each other, and the rules for interpreting their values.
3) Figure 9
Error bars should be drawn on the graphs next to each measurement point, according to the data of standard deviation given in Table 6.
4) Figure 12
Error bars should be drawn on the graphs next to each measurement point.
5) References, item No.5
The article from 2023 is "in press"?
Author Response
Comments 1: It is generally accepted that at the end of the Introduction section the authors state the purpose of the work and its scientific novelty compared to articles on the subject. Introduction requires additions in this regard so that the reader can understand the novelty and originality of the research presented.
Response 1: Chapter "1. Introduction" has been added (lines 92 to 98).
Comments 2: Section 2.5 – The manuscript lacks a description of what the Ra and Rz parameters are, what they characterize, how they differ from each other, and the rules for interpreting their values.
Response 2: Section 2.5 refers to Section 2.2, where the parameters Ra and Rz have already been characterized. In addition, the relevant text has been added in Section 2.2 for clarification (lines 168 to 176).
Comments 3: Figure 9 – Error bars should be drawn on the graphs next to each measurement point, according to the data of standard deviation given in Table 6.
Response 3: Figure 9 - error bars added, and graph replaced.
Comments 4: Figure 12 – Error bars should be drawn on the graphs next to each measurement point.
Response 4: Figure 12 - error bars added, and graph replaced.
Comments 5: References, item No.5 – The article from 2023 is "in press"?
Response 5: Yes, unfortunately, indeed this article has not yet been assigned a volume number or page number and is still marked "in press" (see https://doi.org/10.1016/j.matpr.2023.06.139), so I am leaving the citation as it is and without any changes.
Reviewer 2 Report
Comments and Suggestions for Authors1. It is necessary to distinguish the specific meaning of experiment and analysis, the second part of the paper should be the experiment, and the analysis method, such as for 2.5, 2.6 and 2.7 parts, should be simplified and incorporated into the description of the experiment part.
2. The paper lacks the scientific difference description of the three surface treatment methods, especially the specific parameters are directly used to quantify the difference of the three methods.
3. The chemical composition of steel should be represented completely in Table. 1.
4. The separate existence of Figure 2 does not make sense and should be incorporated into other figures. The metallographic picture in Figure 1 is not clear and duplicate the content in Figure 3, so it is recommended to delete it. You are advised to combine Figures 1-4 into one picture.
5. It is suggested that the four materials should be labeled and sorted. The current expression is not rigorous enough, especially the description of performance results is not clear.
6. The important point to judge the protection of the coating is the electrochemical performance test of the coating, and it is recommended to add this part of the test content and results as well as analysis.
7. The ruler in Figure 16 is too large, and similar problems occur in other figures.
8. Most images need to be formatted in a standardized way.
9. The ruler shown in Figure 19-20 is missing.
Comments on the Quality of English LanguageThe English could be improved to more clearly express the research.
Author Response
Comments 1: It is necessary to distinguish the specific meaning of experiment and analysis, the second part of the paper should be the experiment, and the analysis method, such as for 2.5, 2.6 and 2.7 parts, should be simplified and incorporated into the description of the experiment part.
Response 1: In section 2.5, the sentence “Increased surface roughness values are known to increase susceptibility to the adhesion of corrosive agents, as confirmed by studies [22,23]”, (lines 261 to 262), has been deleted. This sentence has been incorporated into Chapter 3.2.1 (lines 437 to 438). In Section 2.6, three consecutive sentences have been deleted (lines 269 to 274). These three sentences were copied unchanged into section 3.3 (lines 522 to 526). In section 2.7, a sentence was deleted (lines 287 to 290). This sentence has also been copied unchanged into Part 3.4 (lines 563 to 565).
Comments 2: The paper lacks the scientific difference description of the three surface treatment methods, especially the specific parameters are directly used to quantify the difference of the three methods.
Response 2: The end of Chapter 2.1 (lines 153 to 164) has been added.
Comments 3: The chemical composition of steel should be represented completely in Table. 1.
Response 3: Table 1 has been added.
Comments 4: The separate existence of Figure 2 does not make sense and should be incorporated into other figures. The metallographic picture in Figure 1 is not clear and duplicate the content in Figure 3, so it is recommended to delete it. You are advised to combine Figures 1-4 into one picture.
Response 4: For better clarity, a scale has been added to Figure 1 - the image has been reinserted as a single unit. Otherwise left without further modifications. To incorporate comment 2, an additional paragraph has been added after Figure 2, with the result that Figure 2 is no longer placed separately at the end of the text. As the figures in question are always directly related to the preceding text, the authors do not consider it appropriate to merge them.
Comments 5: It is suggested that the four materials should be labeled and sorted. The current expression is not rigorous enough, especially the description of performance results is not clear.
Response 5: As a result of the current description and division of the individual materials, which are chronological and interrelated in the publication, the author's team decided to maintain the current state of description and marking. The addition of sub-results and related text that better explains the subject matter has been incorporated into the text (line 623 to 628).
Comments 6: The important point to judge the protection of the coating is the electrochemical performance test of the coating, and it is recommended to add this part of the test content and results as well as analysis.
Response 6: The authors fully respect the view that electrochemical testing would provide valuable additional insights into the protective capabilities of coatings. However, time and especially budget constraints of the project do not currently allow the authors to perform these more detailed electrochemical analyses. However, we accept this point as an important area for future research that would complement our current knowledge.
Comments 7: The ruler in Figure 16 is too large, and similar problems occur in other figures.
Response 7:
Comments 8: Most images need to be formatted in a standardized way.
Response 8: Fig. 16 - bottom part always slightly cropped - to make the blue line disappear and new scale inserted. Images reinserted as a whole. Other images unchanged.
Comments 9: The ruler shown in Figure 19-20 is missing.
Response 9: Instead of scale, the title of both figures always states "Evaluated Surface Area: 143 × 55 mm" (line 613 and 619). It has therefore been left without a scale.
Reviewer 3 Report
Comments and Suggestions for AuthorsApplsci_3478019
Analysis of Corrosion-Mechanical Properties of Electroplated 2 and Hot-Dip Zinc Coatings on Mechanically Pre-Treated Steel 3 Substrate
This is a very interesting and high-quality written paper on the investigation of different methods of pre-treatment of S235JRG2 steel sheets on mechanical and corrosion properties of Zn coatings obtained electrochemically and by hot dip galvanising process. Specifically, it investigates how surface integrity, roughness, and hardness influence coating deposition, adhesion, and long-term performance.
The topic of investigation is very actual from practical point of view. The research in this manuscript is new and original. Compared to existing literature, this study provides a systematic comparison of pre-treatment methods and their effect on zinc coatings. The abstract accuratelly reflect the content of the article. The investigation was well planned and conducted. The focus on sustainability—by reducing chemical pre-treatments—adds further relevance to the field of materials engineering. The results of this study can be interesting for the industrial applications, where optimized pre-treatment is crucial for extending the duration of coated components. The research methodology is extensive, incorporating standardized testing methods (ISO 21920-2, ISO 6507-1, ISO 1520, ISO 9227) and advanced analytical techniques. Applied research methods are appropriate, and the obtained results of the research are explained in detail. The whole paper is written clearly and in understandable way. The tables and figures are well-structured and effectively support the data analysis. The visual appearance of the figures in the paper is of a high standard. The conclusions align well with the experimental results. The findings clearly demonstrate that grinding is the most effective mechanical pre-treatment, while synthetic corundum blasting leads to structural inhomogeneities that can accelerate corrosion. The study effectively correlates roughness, hardness, and coating behavior.
The references are appropriate and include relevant literature on corrosion science, surface engineering, and zinc coatings. However, adding more recent publications (from the last 3–5 years) on mechanical pre-treatments and sustainable coating technologies could strengthen the literature review even more.
A few suggestion for the further investigations in this topic well be:
Althoug mean values and standard deviations are reported in the paper, statistical significance testing (e.g., ANOVA, t-tests) would strengthen the results of investigations.
I suggest performing a long therm corrosion measurements in the field (real medium) to further enhance the applicability of the result.
My recomandation is acceptance of the article in the present form.
Author Response
Comments 1: However, adding more recent publications (from the last 3–5 years) on mechanical pre-treatments and sustainable coating technologies could strengthen the literature review even more.
Response 1: Two more recent publications have been added to the introduction [57,58], which are dated 2022 and 2024 (lines 778 to 782).
Round 2
Reviewer 1 Report
Comments and Suggestions for AuthorsIn the revised manuscript, the authors have addressed all my comments and recommendations and answered my questions.
I believe that the manuscript has been sufficiently revised and can be accepted in its present form.
Author Response
Comments 1: In the revised manuscript, the authors have addressed all my comments and recommendations and answered my questions. I believe that the manuscript has been sufficiently revised and can be accepted in its present form.
Response 1: Thank you.
Reviewer 2 Report
Comments and Suggestions for AuthorsNone
Comments on the Quality of English LanguageThe English could be improved to more clearly express the research.
Author Response
Comments 1: The English could be improved to more clearly express the research.
Response 1: The entire article has been very carefully proofread by a native English speaker who is knowledgeable in the field, and the text has been stylistically edited without changing its meaning.
