Effect of Welding Orientation in Angular Distortion in Multipass GMAW

Round 1

Reviewer 1 Report

The review of the published work on GMAW is intensively summarized，but the novelty of the paper should be highlighted.

The result of this paper should be discussed in detail and the works related to this work should be cited.  

1. There too many paragraphs in Section 2 of Literature Review and section 2 should be rewritten.
2. The chemical compositions of the base metal (S235JR) and the weld metal (electrode wire M/SG 2) should provide.
3. In Page1, line 9-10, “Along the welding, structural and metallurgical changes occur in the vicinity of the joint.” The metallurgical changes occur in the vicinity of the joint should provide to better understanding the microstructure of the welding joint (Section A-A present in Fig. 7).
4. In Fig. 9, 10 and 11, how many replicates for each condition in different tests? Please include in the manuscript.
5. In this work, the author reported that the orientation factor has been shown to significantly influence the final distortions and that the alternated orientation sequence has resulted in less distortions. The detailed analysis of the difference between the Single orientation and Alternated orientation on the final distortions should be addressed.

Author Response

Firstly, we would like to acknowledge the reviewer for spending his/her valuable time reading our manuscript and for presenting important comments and suggestions. Please note that the changes made in this revised version of the manuscript are highlighted in yellow.

The review of the published work on GMAW is intensively summarized，but the novelty of the paper should be highlighted.

The result of this paper should be discussed in detail and the works related to this work should be cited.  

We would like to acknowledge the reviewer for this suggestion, as we understand that it is a very important aspect. After a wide search, it was not found studies that approached the effect of welding orientation in angular distortions. Previous studies have investigated the effect of welding parameters, such as voltage, current, welding velocity, feed rate, gas flow, torch tilt angle, length of the electrode, number of passes, the time gap between the passes, rise of the angle of V groove, plate length and electrode diameter, in distortions. As the present work had as objective to evaluate the effect of welding orientation, which is a novelty, it was considered that those comparisons would be between very distinct aspects.

1. There too many paragraphs in Section 2 of Literature Review and section 2 should be rewritten.

Thank you very much for your suggestion. We rewrote and summarized this section, selecting the information that would fit better with the main objectives of the work. Note, at the request of reviewer two, we joint the “introduction” with the “literature review” in a single section (introduction).

1. The chemical compositions of the base metal (S235JR) and the weld metal (electrode wire M/SG 2) should provide.

We would like to thank you for the orientation. This information is now provided in the paper.

1. On Page1, lines 9-10, “Along the welding, structural and metallurgical changes occur in the vicinity of the joint.” The metallurgical changes that occur in the vicinity of the joint should provide to a better understanding of the microstructure of the welding joint (Section A-A present in Fig. 7).

We are very thankful for your suggestion. Once the aim of this research was to study the distortions and does not contemplate the microstructural changes in the material caused by the welding, we preferred to remove this mentioning regarding metallurgical changes as it leads to a better understanding of the manuscript scope.

1. In Fig. 9, 10, and 11, how many replicates for each condition in different tests? Please include it in the manuscript.

We appreciate this question as we understand that it is very important information for the work. The welding was carried out in triplicates for each condition (multipass sequence with single orientation, M[s], and multipass sequence with alternated orientation). This information is provided in lines 184-186.

1. In this work, the author reported that the orientation factor has been shown to significantly influence the final distortions and that the alternated orientation sequence has resulted in fewer distortions. A detailed analysis of the difference between the Single orientation and Alternated orientation on the final distortions should be addressed.

We are glad to explain better how these conclusions were made. After the graphical analysis, the vertical displacements measured by C-Track were summed, in order to transform in one variable for each sample, as shown in Table 3. This approach made possible a statistical analysis through ANOVA, that obtained true null hypothesis for the welding orientation, concluding that it significantly influences the final result (sum of displacements for each sample). Besides, ANOVA has also shown that the specimens welded with alternated orientation had an average displacement lower (17.8%) than the ones with a single orientation. This information is presented in Table 4 and better described in lines 210 – 218.

Reviewer 2 Report

Dear Authors,

I hve read the paper "Effect of welding orientation in angular distortion in multipass GMAW".

It fulfills the aims and scope of the journal. However, I have some suggestions, which may be helpfull in improving your paper.

Intruduction:

• In my opinion the Introduction and "Literature review" should be joined in one parahraph named "Introduction". Following the reuirements of the journal:
  "Introduction: The introduction should briefly place the study in a broad context and highlight why it is important. It should define the purpose of the work and its significance, including specific hypotheses being tested. The current state of the research field should be reviewed carefully and key publications cited. Please highlight controversial and diverging hypotheses when necessary. Finally, briefly mention the main aim of the work and highlight the main conclusions. Keep the introduction comprehensible to scientists working outside the topic of the paper."
• Some important information are missing. You should mark the factors, which are responsible for angular distortion. It was proved, that tack weld distribution and welding sequence plays significant role in the angular distortion of welded joints (http://casopisi.junis.ni.ac.rs/index.php/FUMechEng/article/view/6362). These important information should be added in your paper.
• Fig. 1 and Fig. 2 - in you are not authors of these pictures, the source should be added

Materials and Methods:

• The chemical composition and mechanical properties of used materials should be listed. It will proved that you have chosen proper welding wire.
• Table 1 - You should desribe, why these parameters are used. Moreover, the most important welding parameter is heat input [kJ/mm], which should be presented.

Results:

• The biggest mislack in your paper is lack of scientific discussion. You have not compared your results with other scientiests. It will underline the novelty of your work.
• Fig. 9 and Fig. 10 - the values are unknown. You should present values in the pictures or in additional table.
• Please add the real photo of welded joints, which will show the effet of your investigations.

Conclusions:

• This section is clear.

Author Response

Firstly, we would like to acknowledge the reviewer for spending his/her valuable time reading our manuscript and for presenting important comments and suggestions. Please note that the changes made in this revised version of the manuscript are highlighted in yellow.

Introduction:

• In my opinion, the Introduction and "Literature review" should be joined in one paragraph named "Introduction". Following the requirements of the journal:
  "Introduction: The introduction should briefly place the study in a broad context and highlight why it is important. It should define the purpose of the work and its significance, including specific hypotheses being tested. The current state of the research field should be reviewed carefully and key publications cited. Please highlight controversial and diverging hypotheses when necessary. Finally, briefly mention the main aim of the work and highlight the main conclusions. Keep the introduction comprehensible to scientists working outside the topic of the paper."

We would like to thank you for your valuable suggestion. We rewrote and summarized the Introduction and Literature Review sections in order to present better the information and selected the parts that fit more with the objectives of the study

• Some important information is missing. You should mark the factors, which are responsible for angular distortion. It was proved, that tack weld distribution and welding sequence play a significant role in the angular distortion of welded joints (http://casopisi.junis.ni.ac.rs/index.php/FUMechEng/article/view/6362). This important information should be added to your paper.

Thank you very much for your contribution, we added the important conclusions of this work in our manuscript, it contributed a lot to its improvement.

• Fig. 1 and Fig. 2 - in you are not authors of these pictures, the source should be added

We really appreciate the orientation and reminder, these pictures were made by one of the authors of the paper, but adapted from another source, so we added them.

 

Materials and Methods:

• The chemical composition and mechanical properties of used materials should be listed. It will be proved that you have chosen the proper welding wire.

We would like to thank you for the orientation. This information is now provided in the paper.

• Table 1 - You should describe, why these parameters are used. Moreover, the most important welding parameter is heat input [kJ/mm], which should be presented.

We are grateful for this orientation. The parameters were selected following the range recommended by the electrode’s manufacturer and in order to provide the arc stability. This information is now included in the manuscript.

 

Results:

• The biggest mislack in your paper is the lack of scientific discussion. You have not compared your results with other scientists. It will underline the novelty of your work.

We would like to acknowledge the reviewer for this suggestion, as we understand that it is a very important aspect. After a wide search, it was not found studies that approached the effect of welding orientation in angular distortions. Previous studies have investigated the effect of welding parameters, such as voltage, current, welding velocity, feed rate, gas flow, torch tilt angle, length of the electrode, number of passes, the time gap between the passes, rise of the angle of V groove, plate length and electrode diameter, in distortions. As the present work had as objective to evaluate the effect of welding orientation, it was considered that those comparisons would be between very distinct aspects.

• Fig. 9 and Fig. 10 - the values are unknown. You should present values in the pictures or in an additional table.

Thank you for your valuable question, it helped to clarify the information given in those figures. The values of the graphs of Figure 9 are shown and explained in Figures 10 and 11. For a better understanding, the positioning of the sections was added in Figure 9.

• Please add the real photo of welded joints, which will show the effect of your investigations.

We appreciate your suggestion. Unfortunately, the distortions cannot be clearly seen without the help of precision measurement equipment, such as the one used in the present work (Metrolog). Figure 9 (b) shows one example of one welded sheet, that illustrates the magnitude of the distortions.

Conclusions:

• This section is clear.

 

Round 2

Reviewer 2 Report

Dear Authors,

Thank you for your response. Your efforts are appripiate. The manuscript has been improved a lot. Youhave ansewered all my comments and suggestions. I propose to publish this work. During proofreading, please improve the brackets, e.g., it is "[1],[2]" should be [1,2].

Best regards,
Reviewer