Novel Approach to Grain Boundary Modification in Stainless and Duplex Steel L-PBF Components through In Situ Heat Treatment
Round 1
Reviewer 1 Report
The results of the two EBSD images （Figures 3 and 4） in the article are difficult for readers to see any differences, and the author did not provide any information on which ones are grain boundaries. Suggest providing SEM microstructure and EBSD treatment results with grain boundaries.
Author Response
Firstly, we would like to express our appreciation to the reviewer for their careful reading and valuable feedback on our manuscript.
With respect to Figures 3 and 4:
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Figure 3 pertains to the 2507 duplex steel, while Figure 4 is dedicated to the 316L stainless steel sample. Through these compositions, our intent was to elucidate the control of high-angle grain boundaries using reheating scan strategies.
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Grain boundaries are identifiable as the interfaces between grains in the EBSD images. Each grain is distinguished by a unique color. However, we recognize the reviewer's concern regarding the high-angle grain boundaries. Their distribution does appear random in the EBSD maps, which is why we have dedicated a section to their probability distribution. This is illustrated in Figure (e) for each composition. Here, one can discern the distinct differences between each case, highlighting how reheating scan strategies influence grain boundary distributions.
In light of the reviewer's feedback, we have revised the captions of the figures to elucidate these points further and to enhance clarity. We hope this addresses the concerns raised and we are grateful for the opportunity to improve our manuscript based on your insightful suggestions.
Reviewer 2 Report
The manuscript titled "Reduction in high-angle grain boundaries in L-PBF stainless steels using in situ heat treatment" explores an intriguing aspect of additive manufacturing (AM) related to improving grain boundary properties in metallic components produced through laser powder bed fusion (L-PBF). The study addresses the challenge of effectively modifying microstructure, particularly grain boundary properties, in L-PBF components. The authors propose an innovative approach of in-situ heat treatment to control grain boundary properties and present experimental validation on 2507 super duplex steel and 316L stainless steel samples.
The introduction sets the stage by emphasizing the significance of AM and L-PBF in engineering, allowing for the production of customized parts with unique shapes and properties. The discussion on the challenges associated with controlling grain boundary properties in L-PBF components is well-presented and helps contextualize the importance of the research.
The concept of grain boundary engineering (GBE) as a promising method to enhance material properties in L-PBF components is introduced effectively. The authors rightly point out the current limited understanding of how process parameters influence grain boundary properties in L-PBF components. This highlights the novelty and importance of the proposed in-situ heat treatment approach to modify grain boundary properties layer-by-layer.
However, to enhance the manuscript, there are some areas that need improvement.
1. The introduction section lacks sufficient background information on the significance of grain boundary properties in metallic components and their impact on material performance. Adding relevant references and expanding this section will provide a broader context for readers, especially those less familiar with the topic.
2. Furthermore, it is essential to address the reproducibility of the proposed in-situ heat treatment method.
3. Could the authors add information about the areas of grain boundaries? they could calculate the areas using a specific software.
4. The conclusion section should be improved to help a reader not familair wih the topic. The conclusion should be improved adding a specific section about the outlook for future research.
Author Response
We thank the reviewer for carefully reading and giving valuable comments. We found that all the suggestions were extremely useful to improve our work. We considered all the comments as follows and revised the manuscript accordingly.
1- We appreciate the suggestion. We have expanded the introduction section to provide a comprehensive background on the significance of grain boundary properties in metallic components. This now includes discussions on their impact on material performance. We believe this provides a broader context for readers, especially for those less acquainted with the subject. Relevant references have also been incorporated to support our discussions. Please refer to the revised manuscript for the expanded section.
2- Thank you for your feedback. We recognize the emphasis on demonstrating reproducibility. Our method was indeed tested on two different alloy compositions to exhibit that the reproducibility of our results is not confined to a singular run. Our experiments on various alloys have consistently shown promising results, suggesting that the method can be applied on different alloy systems. Although we currently lack additional datasets for each of the present alloy system within this manuscript, we have mentioned the significance of this aspect in our conclusion. Currently, we are working on this topic , and we should have another related work soon.
3- We appreciate your recommendation regarding the calculation of grain boundary areas. However, we currently do not have access to software that can effectively compute the grain boundary areas. Moreover, even with such software, there is a concern that the grain boundary area calculation could be highly correlated with the step size used to capture EBSD data, which might not give an accurate representation. We acknowledge the potential value of this analysis and will certainly consider this approach in our forthcoming works.
4- We understand the importance of a concise and insightful conclusion, especially for readers who might be new to the topic. As suggested, we have enhanced the conclusion section to be more comprehensive, summarizing our main findings and their implications more clearly. Furthermore, an additional section discussing potential outlooks and future research avenues has been incorporated. We believe these changes offer a clearer wrap-up of our study and guide readers on the subsequent steps in this research area.
We sincerely appreciate the constructive feedback provided. It has been instrumental in enhancing the quality and clarity of our manuscript. We hope the revisions meet the expectations and look forward to further suggestions.
Author Response File: 
Author Response.docx
Reviewer 3 Report
The authors investigated the high-angle grain boundaries in the duplex and 316L stainless steels, the results of this original work can be important for industries, however for improve this manuscript I have some comments/suggestions:
1-check the title again, remove the word TITLE: , also try to use another tentative and special title for your manuscript instead of this general title.
2- Your manuscript needs to be homogenous in all parts, for example its better to write your manuscript as passive form, check this : In this study, we propose an innovative in-situ heat treatment to control the grain boundary properties of L-PBF components. We propose a model to predict the thermal cycle at a single point and validate it through experiments on 2507 super duplex steel and 316L stainless steel samples. I don't like this change whole your manuscript in passive verbs.
3- add some numerical results to the abstract, it can help you to make your manuscript more attractive.
4-you need to extend the introduction by add some more definition and state of art , rich it using some new articles and explain the importance of your research, one of the articles which you can use to make your introduction is : https://doi.org/10.3390/met13071268, in your references and explain the AM by laser and why your research in novel.
5-the last paragraph of the introduction must to re-write again, for example : we verify the effectiveness of our proposed method. be careful with the sentences. also, I recognized that maybe you used AI in this research paper if yes, you must acknowledge this in the last part of your paper, look at these sentences: These findings contribute to the advancement of grain boundary engineering in L-PBF and offer insights for optimizing the manufacturing process of high-performance components. it seems a little machining makes it unique for your manuscript. In the last paragraph of the manuscript you must write about the novelty of your study.
6-316L???? Metastable austenitic stainless steel (MASS) or austenitic stainless steel (ASS) which one is your material, make it correct in the whole of your manuscript.
7-there are a lot of typography errors, for example: Reheat Scan Technique?? why do you write each word with the first capital letter?
8-in figure1, you need to define the a,b,c,d in the caption.
9-bring the equation of the relationship between power, scanning speed of your laser.
10-make it homogenous: LPBF?? L-PBF??
11-you must explain the laser equipment which you used, the characteristics of it.
12-what is the spot size of the laser?? maximum power? standoff distance?? focal plan position?? the laser nozzle degree?? etc.......
13-figure 2, make the numbers bigger.
14-explain and describe why and how you design your experiments such as this study? for example why you decided to select hatch space 80 or 65 um??
15-conclusion must be supported by the abstract and the last paragraph of the introduction.
Best wishes,
Author Response
We thank the reviewer for carefully reading and giving valuable comments. We found that all the suggestions were extremely useful to improve our work. We considered all the comments as follows and revised the manuscript accordingly.
1- Thank you for the comments. You are right. We removed the "TITLE" and updated the title to be more specific.
2- Thank you for your comment. The language is changed to passive now.
3- Thank you for your comment. Although we agreed with the reviewer, we don't have any specific numbers we could present it in the abstract. We revised the abstract to make it stronger.
4- The introduction is revised and more information and references are added. We added the provided references as well. Thank you again for your feedback.
5- The last paragraph of the introduction is revised as suggested. Thank you!
6-Sorry for the confusion. It is Austenitic steel. We applied the changes. Thank you for the comment.
7-We apologize for the oversight and have corrected the typographical errors, including the inconsistent capitalization.
8- Thank you for pointing that out. We have now defined a, b, c, and d in the caption of Figure 1.
9- We have now included the equation depicting the relationship between power and scanning speed of the laser in the results secitons.
10- We apologize for the inconsistency. We have standardized the term throughout the manuscript to 'L-PBF
11- Thank you for bringing this to our attention. We have added a section detailing the laser equipment and its characteristics.
12- We have now included the details such as the spot size, maximum power into the respective section.
13- We have revised Figure 2 to provide a higher resolutions image.
14- We've added some information that explains the rationale behind our experimental design, including our decision for selecting specific hatch spaces.
15- We have revised the conclusion to ensure that it aligns with the abstract and the introduction's last paragraph. We appreciate your guidance on this.
Thank you for your thorough feedback and suggestions. We believe these changes have strengthened our manuscript and made our findings clearer to the readers. We are grateful for your time and expertise
Author Response File: Author Response.docx
Round 2
Reviewer 2 Report
I recommend the publication of this article.
moderate revision
Reviewer 3 Report
The authors addressed all of my comments. It can consider for publishing.
spelling and typography errors need to be correct, like 316L or 316 L, there is some unnecessary spaces.
