Corrosion Behaviour of Cu/Carbon Steel Gradient Material

Round 1

Reviewer 1 Report

Crystals

Electrochemical corrosion behaviour of Cu/carbon steel gradient material

General comments:

Short overview:

The paper focuses on investigation corrosion properties of differently prepared Cu/carbon steel in NaCl environment. The corrosion measurements included linear polarization measurement and electrochemical impedance spectroscopy.

 Paper is organized in subchapters in appropriate way. The support of the literature in the paper is ok.

There are 7 figures and 4 tables. There are 19 references, 2 of them are from 2020, all other are older.

Obstacles:

There are many technical limits to say that paper would be in good shape.

One is English (use of tenses is extremely poor), the second  is the systematic presentation of the samples that were studied ( steel sheet, Cu-Fe- gradient, Cu gradient and Cu plating).

 

 

Detailed comments:

 

Title:  Electrochemical corrosion behaviour

Either electrochemical or corrosion would be ok

 

Keywords: electrochemical corrosion not ok

Abstract

addition vs conditioning in the abstract are not well defined.

It is important to shortly state what is studied. The method (name) is not that important as the conditions and data received by particular study. Using measurement… is not ok. Using a method is ok… in order to obtain data by a measurements using a method, ok?

 

Introduction:

Introduction is informative, easy to follow.

 

The authors state that introducing Cu in steel is hot topic; however no evidence in the used references are present.

It is very important to define the novelty of your study and confirm it.

Experimental:

First, Table 1 (the composition of steel can be placed in the text), but it is very important to present the different samples (new table 1) in the for of the table

Name of the sample	process	Thickness of the layer	Additional info
Carbon steel	-
Cu-fe/carbon steel gradient material
Cu/carbon steel gradient material
Cu-plated	plating

 

Then, the whole text will be more easy to follow.

 

 

Results

PD

Table 2: 3 significant numbers is enough in electrochemistry

What was the scan rate of PD curves?

EIS

 

Nyguist and bode plots have to be presented. Nyquist x and X scale should be symetrical.

Table 3: 3 significant numbers

Present also the quality of fitting with chi square value.

 

 

Total R sum should be somehow introduced and results compared to PD results.

 

Conclusions

Conslusion 1: for which of your sample?

Conclusion 2: equiip with % or numbers.

Conclusion x: what is new finding in your research?

 

 

Author Response

1. Keywords: electrochemical corrosion not ok

Abstract

addition vs conditioning in the abstract are not well defined.

It is important to shortly state what is studied. The method (name) is not that important as the conditions and data received by particular study. Using measurement… is not ok. Using a method is ok… in order to obtain data by a measurements using a method, ok?

Response:The keywords and abstract have been modified as required

 

2.Introduction:

Introduction is informative, easy to follow. The authors state that introducing Cu in steel is hot topic; however no evidence in the used references are present. It is very important to define the novelty of your study and confirm it.

Response: The new references has been added as evidence that introducing Cu in steel is hot topic.

3.Experimental:

First, Table 1 (the composition of steel can be placed in the text), but it is very important to present the different samples (new table 1) in the for of the table

Name of the sample	process	Thickness of the layer	Additional info
Carbon steel	-
Cu-fe/carbon steel gradient material
Cu/carbon steel gradient material
Cu-plated	plating

 

Then, the whole text will be more easy to follow.

Response: Table 1 was presented as required

 

 

4.Results

PD

Table 2: 3 significant numbers is enough in electrochemistry 已经修改

Response: Has been modified.

What was the scan rate of PD curves?

Response: 5 mV/s

5. EIS 

Nyguist and bode plots have to be presented. Nyquist x and X scale should be symetrical.

Table 3: 3 significant numbers

Present also the quality of fitting with chi square value. 

Total R sum should be somehow introduced and results compared to PD results.

Response: Sorry, the bode plots cannot be rendered due to no experiments at that time.

           Has been modified.

           The polarization resistance Rp  has been introduced as the total R and the results has been compared to PD results.

 

6. Conclusions

Conslusion 1: for which of your sample?

Response:Cu/carbon steel gradient material

Conclusion 2: equiip with % or numbers.

Response: Has been modified.

 

Conclusion x: what is new finding in your research?

Response: Has been modified.that indicate that even if the copper layer on the gradient material surface is destroyed, the gradient material can sitll resist corrsion

Reviewer 2 Report

1. I recommend the disignation of the specimen as follows; 1) Fe, 2) Cu/Fe, 3) Cu-Fe, 4) 80%Cu-Fe. Every figures and tables can be plotted and summarized in this series(Fe, Cu/Fe, Cu-Fe, 80%Cu-Fe) for the reader's understanding.
2. Table 1; Fe-balance
3. line 122; the scan rate was very slow of 0.1mV/s. Is there any reason?
4. Figure 2&3; Why didn't you analyze the mapping on the cross section. The mapping can reveal the segregation of Cu in Fe matrix. Did you check the Cu-Fe phase diagram? Cu-Fe alloy system shows the miscibillity gap. Therefore, the manuscript must show the microstructure of 80%Cu-Fe specimen.
5. line 162; beta a, not alpha.
6. Figure 4; you have to use the diferent symbols for curves(almost dot-lines). Why didn't you plot over 0.2V(SCE)? Because Cu may be segreaged in Fe matrix, the selective dissolution of Fe may be occurred. Please show the results!
7. Table 2; Ecorr, mV(SCE)
8. Table 3; 10^-3, please check the superscript.
9. Figure 7 and Table 4; Whether the selective dissolution occur or not after the anodic polarization test over 0.2V(SCE)?
10. line 311&319; -600mV(SCE)
11. line 312; Icorr, check the subscript.

Author Response

Comments and Suggestions for Authors

1. I recommend the disignation of the specimen as follows; 1) Fe, 2) Cu/Fe, 3) Cu-Fe, 4) 80%Cu-Fe. Every figures and tables can be plotted and summarized in this series(Fe, Cu/Fe, Cu-Fe, 80%Cu-Fe) for the reader's understanding.

   Response：It has been modified as required

2. Table 1; Fe-balance

    Response：The composition of steel can be placed in the text

3. line 122; the scan rate was very slow of 0.1mV/s. Is there any reason?

    Response：Sorry, due to a typo, the result should be 5 mV/s, which has been modified

4. Figure 2&3; Why didn't you analyze the mapping on the cross section. The mapping can reveal the segregation of Cu in Fe matrix. Did you check the Cu-Fe phase diagram? Cu-Fe alloy system shows the miscibillity gap. Therefore, the manuscript must show the microstructure of 80%Cu-Fe specimen.

    Response：Sorry, the 80% Cu-Fe sample is polished and polished from Cu-Fe, and its microstructure was not observed at that time

5. line 162; beta a, not alpha.

    Response：It has been modified as required

 

6. Figure 4; you have to use the diferent symbols for curves(almost dot-lines). Why didn't you plot over 0.2V(SCE)? Because Cu may be segreaged in Fe matrix, the selective dissolution of Fe may be occurred. Please show the results!

    Response：Sorry, in order to compare the corrosion rate, data exceeding 0.2V (SCE) were not collected in the experiment. Others have been modified as required

7. Table 2; Ecorr, mV(SCE)

    Response：It has been modified as required

8. Table 3; 10^-3, please check the superscript.

Response：It has been modified as required

 

9. Figure 7 and Table 4; Whether the selective dissolution occur or not after the anodic polarization test over 0.2V(SCE)?

    Response：No active dissolution was observed in the test range, and data exceeding 0.2V (SCE) were not collected in the experiment.

10. line 311&319; -600mV(SCE)

Response：It has been modified as required

11. line 312; Icorr, check the subscript.

 Response：It has been modified as required

Reviewer 3 Report

Dear Authors:

Hi,  I checked the paper with great interest, because I had a similar research experience in the past.  I think that such a combination of surface finishing and heat treatment should have a more promising application. 

By the way, I think that the following points should be checked or revised before acceptance.

1. Fig.2

More focused figures should be needed.  And please add the explanation for each part in the figure. 

2. Fig.7 

The expression of scales should be adjusted to those in Fig.1 and 2.

3.  Electrochemical measurement systems. 

Please show schematic or block diagrams for experimental apparatuses.  You described them literally, but the figures will help readers to follow and understand your paper more precisely and easily.

4. Would you discuss the surface layers, comparing with the phase diagram between iron and copper.  And please fix the phases in the surface layers. 

5. Comparing the diffusion coefficients of iron and copper, please discuss which elements diffuse mainly.  Or mutually? 

6.  Didn't you observe the Kirkendall effect in your results. 

Author Response

Comments and Suggestions for Authors

Dear Authors:

Hi,  I checked the paper with great interest, because I had a similar research experience in the past.  I think that such a combination of surface finishing and heat treatment should have a more promising application. 

By the way, I think that the following points should be checked or revised before acceptance.

1. Fig.2

More focused figures should be needed.  And please add the explanation for each part in the figure. 

Response：It has been modified as required

2. Fig.7 

The expression of scales should be adjusted to those in Fig.1 and 2.

Response：It has been modified as required

3. Electrochemical measurement systems. 

Please show schematic or block diagrams for experimental apparatuses.  You described them literally, but the figures will help readers to follow and understand your paper more precisely and easily.

Response：It has been modified as required and block diagrams has been presented.

4. Would you discuss the surface layers, comparing with the phase diagram between iron and copper.  And please fix the phases in the surface layers. 

Response：Sorry, there is no experimental analysis for this part for the time being

 

5. Comparing the diffusion coefficients of iron and copper, please discuss which elements diffuse mainly.  Or mutually? 

Response：It has been explained that it is mutual diffusion

6. Didn't you observe the Kirkendall effect in your results. 

Response：sorry, I am not observe the Kirkendall effect in my results

Round 2

Reviewer 1 Report

Authors have changed some of the parts of the submitted manuscript. The overall rate on the work of authors would be: minimum changes for maximum output.

Unfortunately, as a reviewer, I am not satisfied with the quality of the paper:

Title is not ok, abstract could be improved, Novelty of the paper in 1 or two sentences are missing, changes have quite same flaws, mistakes,  they are attached as PDF.

Figure captions of Figure 2 and 3 and 4 have to be improved.

Nyquist plots in Figure 6 and 7 have to be presented with symmetrical axis. Have a look in other scientific journals.

In conclusions, all the samples have to be referred to.

Comments for author File: Comments.pdf

Author Response

1. The title was revised, and novelty was added to the abstract and the text
2. Figure captions of Figure 2 and 3 and 4 have been improved.
3. Nyquist plots in Figure 6 and 7 have been presented with symmetrical axis as required