Effect of Ni-Based Buttering on the Microstructure and Mechanical Properties of a Bimetallic API 5L X-52/AISI 316L-Si Welded Joint

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

Reviewer’s comments

The authors studied “Effect of the Ni-based buttering on the microstructure and mechanical properties of bimetallic API 5L X-52/AISI 316L-Si welded joint”. The research is well-executed, with clearly presented findings that provide valuable insights. This work is novel and can be accepted after major revisions. 

 

1. In Fig. 1, two tensile test figures were given. Please mention the sample details of the figure in the figure caption.
2. In Fig. 4, the terminology of C1 to C8 must be given in the text.
3. “The equiaxed grains have an average 187 size of ~13.75 ± 5 μm (see Figure 5b)”. Is this for ferrite grains?
4. In 1 (a), the dimensions of the unit must be mentioned.
5. “The line scan passing through the interface ER70S-6 / 233 ERNiCrMo-3 filler metal showed an abrupt drop in intensity at 225 μm of distance in Fe content, while the composition chemical of elements Ni, Cr, and Mo increased gradually until ~300 μm”. Why does the Fe intensity drop here? What is the effect of temperature on the diffusion of Ni, Cr, and Mo elements here?
6. “In the middle region of the weld, a significant effect on microhardness can be observed due to the precipitation of Ti and Nb carbides on the WM of the mixture between ERNiCrMo-3 and ER70S-6”. What is the effect of Ti and Nb that needs to be mentioned here?
7. What is the effect of cladding on microhardness and tensile test?
8. “The increase in hardness is also due to the presence of titanium and niobium precipitates within the austenite by the application of the ERNiCrMo-3 electrode on the hot pass”. The authors need to mention the austenite matrix here.
9. Why does the MB sample show higher ductility compared to other samples?

Author Response

Good day,

Reply answered as a file.

Thanks for your comments and recommendations.

Author Response File: Author Response.pdf

Reviewer 2 Report

Comments and Suggestions for Authors

The authors have written an article that clearly describes the phenomenon under study. The drawings and photos in the article are legible and understandable. Below are some comments on the article:

1. While the introduction provides a general overview, it could be improved by including a more comprehensive literature review that contextualizes the study within recent advancements. A clearer discussion of the gaps in the current literature and the innovative aspects of this work would strengthen its impact.
2. Please, emphasize more precisely in Introduction novelty as well as potential industrial and practical contribution of your paper in comparison with other papers in this area.
3. Please explain the entry: “Plates of API 5L-X52 measuring 200 x 100 x 15.36 mm³”
4. What change did the microstructure of API 5L-X52 steel undergo after cladding with an ER316L-Si stainless steel?
5. The article lacks research on the impact strength of the material. I suggest conducting such research. The article will gain value.
6. How the authors assessed the quality of the obtained joint using NDT testing.
7. Please explain the phenomenon of increasing microstructure hardness.
8. Please, add in Conclusions potential constraints of your investigation and possible measures to avoid them in the future. Consequently, provide few potential points for future research in this area.

Author Response

Good day,

Reply answered as a file.

Thanks for your comments and recommendations.

Author Response File: Author Response.pdf

Reviewer 3 Report

Comments and Suggestions for Authors

Manuscript: Effect of the Ni-based buttering on the microstructure and mechanical properties of bimetallic API 5L X-52/AISI 316L-Si welded joint  - covers an important issue. It is both practical and scientific in nature.
The manuscript consists of 16 pages, and the authors used 41 references. The manuscript is 16 pages long, and the authors used 41 references.
There are seven authors in the manuscript, and the area of contribution for each of them is specified (in the Author Contributions section).
The topic of the paper is written correctly. 
The abstract contains the most important information, but does not include numerical results (the most important ones), which should be corrected.
Already in the first sentence: The bimetallic pipelines (BPs) are pieces normally composed of carbon steel or low alloy steel as backing material and an inner layer of corrosion-resistant alloy steel (CRAs) [1-4] - the authors refer to four sources. This is unnecessary. The knowledge presented is common knowledge, so it is sufficient to cite one source. There can be four, but this should be justified on substantive grounds.
I believe that item (number referens) 15 is important and it is worth providing more information about it.
The experiment is well described, the properties of the tested materials are presented, and drawings are shown. I believe that they could be described better, e.g., Fig. 1. I believe that Figure 2b is valuable; the authors have presented the measured values in an interesting way.
The results are also well presented, but I believe it would be better to use mm instead of cm (e.g., in Fig. 3, instead of 1 cm, you could write 10 mm).
The authors have compared their results with others and discussed what is valuable. The use of items 25 to 29 is not very well justified. Either leave one or justify it substantively.
The authors have presented important conclusions. They are both cognitive and practical in nature.
I believe that the research conducted is important, the results are valuable, and they fit in with the work carried out by the largest research centers.
In the future, I believe it would be worthwhile to expand the research to include non-destructive evaluation of connections.
The authors have done a good job, and the manuscript requires only minor corrections.

Author Response

Good day,

Reply answered as a file.

Thanks for your comments and recommendations.

Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

Comments and Suggestions for Authors

The manuscript has been modified by the authors based on the comments provided by the reviewers. As a result, it can be approved for publication.

Reviewer 3 Report

Comments and Suggestions for Authors

Most of the comments have been taken into account. There are approx.