Assessment of the Structural Integrity of a Laser Weld Joint of Inconel 718 and ASS 304L
Round 1
Reviewer 1 Report
The present paper investigates the dissimilar welding between IN 718 and SS 304l using laser beam welding (LBW) process. The study explains the detailed study on microstructural and mechanical behavior of the LBW dissimilar joint. The LBW dissimilar weld between Inconel 718 and SS 304L is qualified for safely use in high temperature end applications, which provides great reference value for engineering application. However, some major revisions are necessary before it can be accepted. The detailed comments and suggestions are listed as follows.
1. The abstract needs to be simplified and should reflect some important data and specific conclusions, such as hardness value, tensile strength, etc.
2. In the manuscript, the abbreviation of Austenitic stainless-steel 304l needs to be unified and changed to SS304L or ASS304L.
3. Page 6, line 110, “the Nb and Mo elements promoting the formation of the laves phases” , please check whether they promote or inhibit.
4. Electron beam welding and plasma arc welding are both connection processes that provide the advantages of low heat input and high solidification rate. It is suggested to quote some references.
5. Page 4, figure 1. (b) Tensile specimen, (c) impact specimen, (d) metallographic specimen, Whether the schematic diagram of “(a) LBW setup” is the cross section along the vertical weld direction, if yes, please indicate. If (b) and (c) are cross sections of (a) in the direction perpendicular to the weld, the height of (b) and (c) specimens is 8 mm.
6. Page 5, figure 2. Page 6, figure 3. Page 10, figure 10 and figure 11. The scale bar mark is confusing.
7. Page 6, figure 3. Please unify the marks of a and c in fig 3. Such as fig 3 (a) “HAZ IN 718 grains” and fig 3 (c) “ASS 304L HAZ” , fig. 3 (a) “Fine grains in weld zone” and fig 3 (c) “Weld zone fine grains”.
8. Page 9, figure 8. The scale length of the second line and the third line is inconsistent.
9. Page 11, line 354. In addition to the possible existence of laves phase in the weld zone, whether there are other factors for the fracture reason of the weld can be explained by referring to relevant documents.
10. Page 11, line 358-360. From the obtained tensile strength conclusion, whether it can be concluded “the dissimilar laser beam welded joint between IN 718 and ASS 304L is certified for the high temperature end applications.” Please reconsider it.
11. Page 13, line 380. “The highest value of hardness along the length is 220.5 HV”, this is wrong. From the fig13(a), the maximum hardness along the length is 220.2 HV.
12. The conclusion part should be supported by detailed data.
Author Response
Dear Editor-in-chief,
We are glad for providing us the great opportunity to revise our manuscript. Also, we would like to thank the reviewers for their time spent on reviewing our manuscript and their comments helping us in improving the quality. The inputs and suggestion of he reviewers has been taken into the consideration and have been updated in the manuscript. Below, the authors have tried to answer the questions and reply to the reviewer’s comments, point by point.
Answers to Reviewer 1
- The abstract needs to be simplified and should reflect some important data and specific conclusions, such as hardness value, tensile strength, etc.
Response 1: we agreed to the reviewer observation and with the reviewer suggestion the abstract has been updated with important data and specific conclusions.
- In the manuscript, the abbreviation of Austenitic stainless-steel 304l needs to be unified and changed to SS304L or ASS304L.
Response 2: The abbreviation for austenitic stainless steel 304l has been updated with ASS 304L throughout the manuscript.
- Page 6, line 110, “the Nb and Mo elements promoting the formation of the laves phases” please check whether they promote or inhibit.
Response 3: In line 110, author agrees with the statement “the Nb and Mo elements promoting the formation of the laves phases”.
- Electron beam welding and plasma arc welding are both connection processes that provide the advantages of low heat input and high solidification rate. It is suggested to quote some references.
Response 4: Author finds this comment very obvious and author added reference 16 relating electron beam welding with this study.
- Page 4, figure 1. (b) Tensile specimen, (c) impact specimen, (d) metallographic specimen, Whether the schematic diagram of “(a) LBW setup” is the cross section along the vertical weld direction, if yes, please indicate. If (b) and (c) are cross sections of (a) in the direction perpendicular to the weld, the height of (b) and (c) specimens is 8 mm.
Response 5: Author finds this comment very useful and the schematic diagram showing the testing coupons have been updated with detailed information for (b) Tensile specimen, (c) impact specimen, (d) metallographic specimen.
- Page 6, figure 3. Please unify the marks of a and c in fig 3. Such as fig 3 (a) “HAZ IN 718 grains” and fig 3 (c) “ASS 304L HAZ”, fig. 3 (a) “Fine grains in weld zone” and fig 3 (c) “Weld zone fine grains”.
Response 7: As suggested by reviewer author finds the mistake and corrected as suggested by reviewer in figure 3.
- Page 9, figure 8. The scale length of the second line and the third line is inconsistent.
Response 8: Authors are agreed with the reviewer suggestion and scale length of the second and third line of figure 8 have been properly updated.
- Page 11, line 354. In addition to the possible existence of laves phase in the weld zone, whether there are other factors for the fracture reason of the weld can be explained by referring to relevant documents.
Response 9: A reference have been added supporting the fracture behavior of the tensile sample. Regarding tensile fracture of weld zone there are several existing factors are solidification cracks, presence of porosity, and presence of highly brittle phases in weld zone. Specific to this study author did not found any weld defect in the weld zone. Through the EDS result it has been found that the presence of Nb and Mo might result in formation of lave phase supporting the tensile fracture.
- Page 11, line 358-360. From the obtained tensile strength conclusion, whether it can be concluded “the dissimilar laser beam welded joint between IN 718 and ASS 304L is certified for the high temperature end applications.” Please reconsider it.
Response 10: Observation of the reviewer is much correct on page 11, line 358-360, author have corrected and updated the part.
- Page 13, line 380. “The highest value of hardness along the length is 220.5 HV”, this is wrong. From the fig13(a), the maximum hardness along the length is 220.2 HV.
Response 11: Authors are agreed with the reviewer observations and corrected the mistake observed by reviewer on page 13 line 380.
- The conclusion part should be supported by detailed data.
Response 12: As suggested by reviewer, author have added detailed data in the conclusion section.
Author Response File: 
Author Response.docx
Reviewer 2 Report
I appreciate the work done by the authors, both the microstructures and properties of welding joints were investigated, and the relationship between them was built scientifically. In my opinion, some images should be provided or changed, Fig.8 is not clear and should be changed, also the fracture images of joints (SEM) should be provided which can show the failure mechanism
Author Response
Dear Editor-in-chief,
We are glad for providing us the great opportunity to revise our manuscript. Also, we would like to thank the reviewers for their time spent on reviewing our manuscript and their comments helping us in improving the quality. The inputs and suggestion of the reviewers has been taken into the consideration and have been updated in the manuscript.
Answers to Reviewer 2
Author is very thankful to the reviewer’s thoughtful view on this paper. As suggested by reviewer the figure 8 has been changed with clear visibility.
Figure 8. SEM/EDS color mapping showing presence of distributed elements in the center of weld zone.
Author Response File: Author Response.docx
Reviewer 3 Report
The current study experimentally investigates the dissimilar autogenous laser beam welding (LBW) between Inconel 718 and ASS 304L. The study explored in detail the microstructural and mechanical behavior of the LBW dissimilar joint. The topic is interesting. However, there are several concerns about this manuscript which needs to be addressed before its acceptance.
1. Abstract sounds unclear. Rewriting/rephrasing of the abstract is recommended.
2. Introduction section lack critical review of the previous literature.
3. It is recommended to briefly explain some of the terminologies (e.g. laves phase, columnar morphology etc.) before in discussing them.
4. Motivation of the current study in terms of the shortcoming in the literature is missing.
5. At the end of introduction, add a brief para describing the paper organization.
6. It is recommended to add actual figure of the setup along with the schematic diagram (Figure 1).
7. Description of the schematic diagram given in the early part of section 2 needs to be revised to provide more clarity and understanding.
8. The methodology section may be enhanced to facilitate understanding of wide audience.
9. Authors needs to provide the reasons for selecting the parameters used in the Vickers microhardness tester.
10. Porosity in welding zone is one of the causes of defects. Did the authors observe any kind of porosity in the tested specimen?
11. Which type of etchant was used in the metallography?
12. It is recommended to add the microstructural images of the specimen after the impact and tensile tests.
13. Conclusions should be curtailed summarizing only key points. Further study limitations should be added.
14. The linguistic quality of the paper also warrant improvement.
Author Response
Dear Editor-in-chief,
We are glad for providing us the great opportunity to revise our manuscript. Also, we would like to thank the reviewers for their time spent on reviewing our manuscript and their comments helping us in improving the quality. The inputs and suggestion of the reviewers has been taken into the consideration and have been updated in the manuscript. Below, the authors have tried to answer the questions and reply to the reviewer’s comments, point by point.
Answers to Reviewer 3
- Abstract sounds unclear. Rewriting/rephrasing of the abstract is recommended.
Response 1: we agreed to the reviewer observation and with the reviewer suggestion the abstract has been updated with important data and specific conclusions.
- Introduction section lack critical review of the previous literature.
Response 2: Some important references have been included in the introduction part. Introduction part of the literature includes the motivation behind the selection of the dissimilar weld and selection of the laser weld for this work.
- It is recommended to briefly explain some of the terminologies (e.g. laves phase, columnar morphology etc.) before in discussing them.
Response 3: In introduction section lave phase explanation is well updated in line 77-79. Suitable reference is added for better explanation.
- Motivation of the current study in terms of the shortcoming in the literature is missing.
Response 4: Authors are very thankful to the reviewer for this valuable comment, author have explained and well connected about the material included in this literature their applications in the high temperature industries, along with the limitations of the conventional welding processes. Author explains the advantages of the laser beam welding over conventional welding, line 135 to 139.
- At the end of introduction, add a brief para describing the paper organization.
Response 5: Author finds this comment very useful and author updated the introduction section including the article organization
- It is recommended to add actual figure of the setup along with the schematic diagram (Figure 1).
Response 6: As per suggestion, the experimental setup is given below. However, author don’t have permission to use this setup for publication.
Fig. 1. Evobeam Cube200 electron beam welding setup.
- Description of the schematic diagram given in the early part of section 2 needs to be revised to provide more clarity and understanding.
Response 7: As suggested by reviewer author finds the same and added a clear view on schematic diagram shown in figure 1 in lines 187 to 189.
- The methodology section may be enhanced to facilitate understanding of wide audience.
Response 8: Authors are agreed with the reviewer suggestions, through methodology author have connected the microstructural properties of the laser beam welded IN 718 and ASS 304L with the mechanical properties of the weld. Hence the relative explanations provide useful information to the readers. As suggested by reviewer some more study on this combination will add some advantageous information in future.
- Authors needs to provide the reasons for selecting the parameters used in the Vickers microhardness tester.
Response 9: The parameters were selected on the basis of previous study. Also the range of microhardness tester was 100g-1000g.
- Porosity in welding zone is one of the causes of defects. Did the authors observe any kind of porosity in the tested specimen?
Response 10: Observation of the reviewer is much correct because porosity is primary defect during the welding process. In this study there is no porosity observed during the microstructural study of the weld and HAZ zone.
- Which type of etchant was used in the metallography?
Response 11: In section 2 line 196-199, author explains about the etchant used in this study. “The microstructure of Inconel 718 base and fusion zone is revealed through electrolytic etching for 10 sec in 10% oxalic acid solution at 8V DC supply. Whereas for ASS 304L side HAZ and base material aqua regia (3HCl + 1HNO3) etchant was used”.
- It is recommended to add the microstructural images of the specimen after the impact and tensile tests.
Response 12: I agree with learned reviewer(s) suggestion that fracture surface study could enhance the overall quality of the work. However, for SEM facility, author have to wait for three months as it is slot basis system. Hence, author is more relied on the macrograph of the fracture surface for study.
- Conclusions should be curtailed summarizing only key points. Further study limitations should be added.
Response 13: As per the reviewer comment, correction has been made in the revised manuscript and limitation of the study has been updated in the conclusion.
- The linguistic quality of the paper also warrant improvement.
Response 14: Author is thankful to reviewer for this comment. Author agree that the linguistic quality of the paper needs to be improved. I will work on making the paper more concise and clearer by using simpler language for further studies.
Author Response File: Author Response.docx
Round 2
Reviewer 1 Report
1. The caption of Fig. 2 (a) “image” should be followed by “of”.
2. The caption of Fig. 2 (b) “Sem” needs to be changed to “SEM”.
Author Response
Dear Editor-in-chief,
We are glad for providing us the great opportunity to revise our manuscript. Also, we would like to thank the reviewers for their time spent on reviewing our manuscript and their comments helping us in improving the quality. The inputs and suggestion of he reviewers has been taken into the consideration and have been updated in the manuscript. Below, the authors have tried to answer the questions and reply to the reviewer’s comments, point by point.
Answers to Reviewer 1
- The caption of Fig. 2 (a) “image” should be followed by “of”.
Response 1: A correction has been made as per learned reviewer(s) suggestion.
- The caption of Fig. 2 (b) “Sem” needs to be changed to “SEM”.
Response 2: A correction has been made as per learned reviewer(s) suggestion.
Author Response File: Author Response.docx
Reviewer 3 Report
Authors have accommodated all of my suggestions/recommendations. Therefore, I would like to recommend the article for publication in its current form.
Author Response
Dear Editor-in-chief,
We are glad for providing us the great opportunity to revise our manuscript. Also, we would like to thank the reviewers for their time spent on reviewing our manuscript and their comments helping us in improving the quality. The inputs and suggestion of the reviewers has been taken into the consideration and have been updated in the manuscript. Below, the authors have tried to answer the questions and reply to the reviewer’s comments, point by point.
Answers to Reviewer 3
- Authors have accommodated all of my suggestions/recommendations. Therefore, I would like to recommend the article for publication in its current form.
Response 1: Thank you for kind consideration.
Author Response File: Author Response.docx
