Effect of Rare Earth Oxides on Microstructure and Corrosion Behavior of Laser-Cladding Coating on 316L Stainless Steel
, Junwei Zhang 1,3 and Yueming Huang 1Round 1
Reviewer 1 Report
In the linear polarization graphs, you should include the difference between the Ecorr and Epit (pitting potential). This is the best comparison with the pitting resistance of the alloy. Therefore the rare earths are improving uniform corrosion resistance (lower current densities), but decreasing the pitting/crevice corrosion.
Also the salt spray, it is not the most suitable test to extract conclusions, so it would be better just to state that the pitting size is different between the cladding types, than conclude that the corrosion resistance is better, as some conditions can create smaller but more numerous pits than other conditions, where pitting is more localized and bigger.
Author Response
Dear reviewer:
We appreciate your valuable comments.According to these comments, we have revised our manuscript and responded to them carefully. We hope this revision can meet with approval. The revised portions are marked in red in the revised manuscript and the response to the reviewers’ comments are below:
1.In the linear polarization graphs, you should include the difference between the Ecorr and Epit (pitting potential). This is the best comparison with the pitting resistance of the alloy. Therefore the rare earths are improving uniform corrosion resistance (lower current densities), but decreasing the pitting/crevice corrosion.
The reviewer has a good point. Although the laser cladding using rare earth oxides lowered the passive current densities, it decreased the pitting potentials, suggesting that 316L stainless steel has a higher probability to undergo pitting corrosion using laser cladding with the modification of rare earth oxides. The manuscript has been modified accordingly.
2.Also the salt spray, it is not the most suitable test to extract conclusions, so it would be better just to state that the pitting size is different between the cladding types, than conclude that the corrosion resistance is better, as some conditions can create smaller but more numerous pits than other conditions, where pitting is more localized and bigger.
We agree. Although the pitting event and size were different among these 4 cladding types, the penetration depth might vary as well.
Author Response File: 
Author Response.docx
Reviewer 2 Report
GENERAL COMMENTS: The manuscript entitled “Effect of Rare Earth Oxides on Microstructure and Corrosion Behavior of Laser Cladding Coating on 316L Stainless Steel” was carefully reviewed. In the manuscript, the authors characterized the corrosion behavior of laser cladding coating on stainless steel in the presence of rare earth oxides such as CeO2 and La2O3. I consider the manuscript an overall well written work and I consider the findings interesting. However, there are some important points I would like to highlight. In fact, the discussion lacks in going into the details and justifications and the literature overview should be deepened and integrated. Moreover, the innovation of the topic is not well highlighted and this, most of all, makes the manuscript weak. I do not have experience in the mechanical/metallurgical field, so my review will be addressed mostly to other aspects. In addition to my comments above, in the following I will highlight some points that need a further revision: Abstract: how is it possible that the addition odìf rare earth oxides have no effect on the composition? What do you mean? Lines 29-35: please deepen the issues related to the marine environment (and add references) and better explain the connection between this and the pipelines, which are introduced in the next sentence Line 53-54: please rewrite the sentence. It is not clear Line 81: Please specify the dimension of Pt compared to stainless steel Line 84: add info about the EIS setup and experimental conditions Fig. 1: How do you explain the presence of a double peak in xrd at about 45 °? Shouldn’t you detect peaks from CeO2 and La2O3? Fig 5: Please add standard deviations Tab 2: Please put “corr” as subscript Fig 8: provide a higher resolution image Final consideration: what is the advantage of using such laser technique instead of fabricating other types of layers? Please add some sentences to justify this point
Author Response
Dear Reviewer:
We appreciate yourvaluable comments. According to these comments, we have revised our manuscript and responded to them carefully. We hope this revision can meet with approval. The revised portions are marked in red in the revised manuscript and the response to the reviewers’ comments are below:
1.The manuscript entitled “Effect of Rare Earth Oxides on Microstructure and Corrosion Behavior of Laser Cladding Coating on 316L Stainless Steel” was carefully reviewed. In the manuscript, the authors characterized the corrosion behavior of laser cladding coating on stainless steel in the presence of rare earth oxides such as CeO2 and La2O3. I consider the manuscript an overall well written work and I consider the findings interesting. However, there are some important points I would like to highlight. In fact, the discussion lacks in going into the details and justifications and the literature overview should be deepened and integrated. Moreover, the innovation of the topic is not well highlighted and this, most of all, makes the manuscript weak. I do not have experience in the mechanical/metallurgical field, so my review will be addressed mostly to other aspects.
We appreciate these comments. We have been trying our best to deepen our discussion and highlight our research innovation.
2.Abstract: how is it possible that the addition odìf rare earth oxides have no effect on the composition? What do you mean?
Here, we mean that the addition of rare earth had minor change on the composition. The manuscript has been modified.
3.Lines 29-35: please deepen the issues related to the marine environment (and add references) and better explain the connection between this and the pipelines, which are introduced in the next sentence
It has been rewritten in the revised manuscript.(add references 9-11)
4.Line 53-54: please rewrite the sentence. It is not clear
It has been rewritten in the revised manuscript.
5.Line 81: Please specify the dimension of Pt compared to stainless steel
The surface area of Pt electrode was 1 cm2, which was the same as the exposed surface of the stainless steel electrode.
6.Line 84: add info about the EIS setup and experimental conditions
This information has been added as the reviewer suggested.
7.Fig. 1: How do you explain the presence of a double peak in xrd at about 45 °? Shouldn’t you detect peaks from CeO2 and La2O3?
The reason for the presence of the double peak at 45 ° is uncertain. After carefully identification of the characteristic peaks of the potential phases, we did not detect the formation of either CeO2 or La2O3 since their content was quite low. As mentioned in the text, Ce or La should be present as a solid solution state, which might cause partial distortion of crystal lattice, leading to the presence of the double peak of Fe-Cr-Ni-C phase.
8.Fig 5: Please add standard deviations
It has been added in the revised manuscript.
9.Tab 2: Please put “corr” as subscript
It has been corrected as suggested.
10.Fig 8: provide a higher resolution image
A higher resolution image has been provided in the revised manuscript.
11.Final consideration: what is the advantage of using such laser technique instead of fabricating other types of layers? Please add some sentences to justify this point
It has been changed as the reviewer suggested.
Author Response File: Author Response.docx
Round 2
Reviewer 2 Report
Line 54: change "was" with "were"
Line 55: "were added to not only improve" change into "were added not only to improve ".."but also to increase"
