Research on Microstructure and Mechanical Properties of Laser Welding of BR1500HS Joints
Round 1
Reviewer 1 Report
The article entitled "Investigation of the microstructure and mechanical properties of laser welding of BR1500HS joints" includes some interesting empirical developments, but significant improvement is needed before publication.
Authors should make the following remarks to improve the article:
- The abstract must be more precise and contain the principal findings of the work. Please complete the information contained in the abstract
- Throughout the text, there are power markings with non-SI notation; please check the correctness of the units used.
- Please explain on what basis the Authors adopted the material data regarding the strength properties of the base material.
- Please improve the quality of the photos in figures 13 and 14.
- Please correct the conclusions to show the research's novelty, and the findings must be more precise and detailed.
Please check the detailed comments in the attached file.
Comments for author File: 
Comments.pdf
Author Response
Dear Reviewer,
Thank you for your comments concerning our manuscript entitled “Research on microstructure and mechanical properties of laser welding of BR1500HS Joints” (1740834). Those comments are all valuable and very helpful for revising and improving our paper. We have studied comments carefully and have made correction which we hope meet with approval. The main corrections in the paper and the respond to your comments are as flowing.
Point 1: The abstract must be more precise and contain the principal findings of the work. Please complete the information contained in the abstract.
Response 1: Thank you for your nice suggestion. We have revised the abstract.
Point 2: Throughout the text, there are power markings with non-SI notation; please check the correctness of the units used.
Response 2: We are very sorry for making such a mistake. We have corrected the unit.
Point 3: Please explain on what basis Authors adopted these values.
Response 3: We adopted those values according to the conferences. We are very sorry that we forgot to mark the references. Now, we list the references [24] to [26].
Point 4: Please indicate how the strain was measured.
Response 4: The strain rate is the ratio of strain to time. We are very sorry for making a mistake that “1mm/min” should be the loading speed not the strain rate. We have corrected it in the manuscript.
Point 5: Please explain how the weld was positioned on the sample.
Response 5: We have correted the picture and marked the welding joint in the picture.
Point 6: The authors discussed their results with only two literature items; please extend the discussion.
Response 6: We gratefully appreciate for your valuable suggestion. There are really too few references. And we additionally combine several references to discuss the results.
Point 7: Please present the relationship that allows you to calculate heat input.
Response 7: Thank you for your nice suggestion. We have presented the relationship in the manuscript.
Point 8: Please explain the validity of introducing a linear correlation of the test results and why a different heat input unit was used.
Response 8: We consult the literature and find that such a law of tensile strength does exist, so we used linear fitting to discuss the law.The heat input unit is incorrect here. We have changed the unit from “J/mm” to “J/cm” and changed the picture.
Point 9: I cannot find this type of observation in Figure 7a. Please explain.
Response 9: We are very sorry that the description here is really inappropriate. We have removed it.
Point 10: Please improve the quality of the photos in figures 13 and 14.
Response 10: Thank you for your nice suggestion. We have changed figures 13 and 14.
Point 11: This statement is inconsistent with the data contained in Table 3. Please verify this conclusion.
Response 11: We gratefully appreciate for your valuable suggestion. We have revised this conclusion.
Point 12: Please correct the conclusions to show the research's novelty, and the findings must be more precise and detailed.
Response 12: Thank you for your nice suggestion. We have revised the conclusions.
We tried our best to improve the manuscript and made some changes in the manuscript.
We appreciate for your warm work earnestly, and hope that the correction will meet with approval. Once again thank you very much for your comments and suggestion.
Yours sincerely,
Authors
Reviewer 2 Report
The topic of the work is relevant for modern industry because it touches upon the issue of high-performance welding of steels. Increasing production efficiency is an important task and the presented work is directly related to this.
1. The review uses modern literature. The problems of research in this area are clearly traced from the description of the works.
2. Research methods are modern and adequately selected. The description of the material and research methods is made in sufficient detail.
3. Results and discussion. The results of experimental studies are presented in sufficient quantity and are illustrative due to well-prepared illustrations. An exception is the pictures obtained by the EBSD method.
The results are discussed together with the results.
4. Conclusions are based on the results obtained.
Notes:
1. The specific purpose of the work has not been formulated. Why did the authors conduct research? Examine the impact of welding and post-processing on the steel in question?
2. line 212 missing dot at the end of the sentence
3. subsection 3.6. EBSD test - EBSD is more of a method for examining the state of a structure than a test - it's better to rename the section
4. I recommend increasing the image sizes to 15, 17, 19-21 so that changes in the structure are more clearly visible.
5. When discussing the results, the authors make too few comparisons with the literature data on laser welding of low-alloy steels. There are only two references [24-25]. I believe this is not enough and the discussion should be supplemented by comparing the results obtained with modern literature data.
Author Response
Dear Reviewer,
Thank you for your comments concerning our manuscript entitled “Research on microstructure and mechanical properties of laser welding of BR1500HS Joints” (1740834). Those comments are all valuable and very helpful for revising and improving our paper. We have studied comments carefully and have made correction which we hope meet with approval. The main corrections in the paper and the respond to your comments are as flowing.
Point 1: The specific purpose of the work has not been formulated. Why did the authors conduct research? Examine the impact of welding and post-processing on the steel in question?
Response 1: Thank you for your nice suggestion. The specific purpose of the work is to investigate the effects of process parameters and quenching process on mechanical properties and microstructure of the joints to provide valuable guidance for BR1500HS steel welding. We have revised the “Introduction” to embody the purpose.
Point 2: line 212 missing dot at the end of the sentence.
Response 2: We are very sorry for making such a mistake. And we have added the dot.
Point 3: subsection 3.6. EBSD test - EBSD is more of a method for examining the state of a structure than a test - it's better to rename the section.
Response 3: We gratefully appreciate for your valuable suggestion. And we have renamed the section to “EBSD Analysis”.
Point 4: I recommend increasing the image sizes to 15, 17, 19-21 so that changes in the structure are more clearly visible.
Response 4: Thank you for your nice suggestion. We have increased the image sizes to 15, 17, 19-21.
Point 5: When discussing the results, the authors make too few comparisons with the literature data on laser welding of low-alloy steels. There are only two references [24-25]. I believe this is not enough and the discussion should be supplemented by comparing the results obtained with modern literature data.
Response 5: We gratefully appreciate for your valuable suggestion. There are really too few references. And we additionally combine several references to discuss the results.
We tried our best to improve the manuscript and made some changes in the manuscript.
We appreciate for your warm work earnestly, and hope that the correction will meet with approval. Once again thank you very much for your comments and suggestion.
Yours sincerely,
Authors
Reviewer 3 Report
The manuscript is well organised, however the following technical aspects need to be clarified.
1. Why 9 samples only. What is the basis to select 9 experiments in Table 3.?
It looks DoE is not considered here. How the combinations of parameters selected/set in table 9.
2. Line 152,153 the cooling rate decreases with increase in heat input. Why/how? usually when more heat, cooling rate to be high
3. section 3.1, 3.3 & 3.4, to study the effect of process parameters, some statistical analysis is advised. In the present form, the effects are concluded without proper justification or citation. suggested to justify/cite.
4. Ref line 281-285, what is the basis of the statement. discuss with some references if any
5. Ref Section 3.6 , how is it useful for this study. No useful conclusion from this section.
6. some of the conclusions are drawn, just based results from 1 sample . usually multiple samples are suggested to take care experimental errors. include justification.
Author Response
Dear Reviewer,
Thank you for your comments concerning our manuscript entitled “Research on microstructure and mechanical properties of laser welding of BR1500HS Joints” (1740834). Those comments are all valuable and very helpful for revising and improving our paper. We have studied comments carefully and have made correction which we hope meet with approval. The main corrections in the paper and the respond to your comments are as flowing.
Point 1: Why 9 samples only. What is the basis to select 9 experiments in Table 3.? It looks DoE is not considered here. How the combinations of parameters selected/set in table 9.
Response 1: We gratefully appreciate for your valuable comment.We selet 9 experiments in Table 3 because only two welding process parameters were considered, namely laser power and welding speed. When the laser power is constant at 2600W, the welding speed of sample No.9#, No.2#, No.6#, No.5# and No.4# is 65cm/min, 75 cm/min , 100 cm/min ,125 cm/min and 150cm/min respectively. When the welding speed is constant at 75cm/min, the laser power of sample No.7#, No.1#, No.3#, No.2# and No.8# is 1800W, 2200W, 2600W, 3000W and 3400W respectively. We think that 9 samples are divided into two groups of 5 samples, which is sufficient to discuss the influence of welding process parameters. For the effect of welding process parameters on the tensile strength, we considered the combined effect of laser power and welding speed, that is, heat input.
Point 2: Line 152,153 the cooling rate decreases with increase in heat input. Why/how? usually when more heat, cooling rate to be high
Response 2: We are very sorry for making such a mistake. By consulting the literature, we found that the cooling rate is not necessarily related to the heat input, but related to the thermal conductivity of the material.We have deleted the wrong conclusion in the manuscript. Thank you for your helpful question.
Point 3: section 3.1, 3.3 & 3.4, to study the effect of process parameters, some statistical analysis is advised. In the present form, the effects are concluded without proper justification or citation. suggested to justify/cite.
Response 3: Thank you for your nice suggestion. we additionally combine several references to discuss the results.
Point 4: Ref line 281-285, what is the basis of the statement. discuss with some references if any.
Response 4: We gratefully appreciate for your valuable suggestion. We discuss the statement with references [30-31] in the manuscript.
Point 5: Ref Section 3.6 , how is it useful for this study. No useful conclusion from this section.
Response 5: The EBSD test investigates the effect of the quenching process on the grain diameter, grain orientation, grain boundary, phase and kernel average misorientation. We have revised the conclusions.
Point 6: some of the conclusions are drawn, just based results from 1 sample . usually multiple samples are suggested to take care experimental errors. include justification.
Response 6: In deed, it will be more convincing if we draw the conclusions based results from multiple samples. We find that only one sample was discussed in the fracture morphology and EBSD analysis. Therefore, for the analysis of the fracture morphology, we add the analysis of the sample No.5#, as shown in Figure 7. But for the EBSD analysis, We understand that add samples may better reveal the conclusions. However, the cost of EBSD test is too high, and we do not have enough funding to support it. Therefore, we seek for your tolerance and understanding. Many thanks for your kind help!
We tried our best to improve the manuscript and made some changes in the manuscript.
We appreciate for your warm work earnestly, and hope that the correction will meet with approval. Once again thank you very much for your comments and suggestion.
Yours sincerely,
Authors
Round 2
Reviewer 1 Report
Dear Authors,
the changes made and clarifications sent allow the article to be accepted in its current form.
Sincerely
Reviewer 3 Report
Response 6 not convincing
