Study of Quenched Crankshaft High-Cycle Bending Fatigue Based on a Local Sub Model and the Theory of Multi-Axial Fatigue

Round 1

Reviewer 1 Report

This work studied the quenched crankshaft high cycle bending fatigue based on a local sub model. The simulation was made for the magnetic-thermal coupling process and experimental results are compared with simulated results. A new fatigue limit load prediction is proposed. However, there is few points tp be clarified as below: 

(1). Please correctly use "Figure/Fig." and "Table" in the text and there is no "Tab. X" as a short of "Table x". 

(2). Numbers for the figures are mixed starting from Fig. 3 that "Fig. 1-Fg.4" should be "Fig. 3- Fig. 6", which results in the difficulties on the reading. 

(3).  Something seems missed between L85-86 to introduce the following 3 steps. 

(4). In Table 8, it shows the current prediction is much more precise than other four though it is too good to be true. Then the authors should explain why the current prediction can have so high preciseness, for instance, which parameter has been modified/improved or is there any limitation for the other four models. 

Author Response

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Reviewer 2 Report

I think this is a good paper, overall. I could not really find anything that requires a great deal of attention. The study is based on FEA and experimental validation. It is about an important topic now that Ultrasonic Fatigue Testing techniques are developing and that there is an interest of extending the lifetime of Engineered systems into the Very High Cycle Fatigue.

The authors use the electromagnetic induction quenching method, but I am now thinking what would be the results if different treatments would have been used, such as the novel alternate magnetic field treatments proposed by Akram et al. (2021): Improvement of the wear resistance of EN8 steel by application of alternating magnetic field treatment, Wear, doi: 10.1016/j.wear.2021.203926. Not sure if it is worth mentioning anything about this technique in the paper. I am genuinely intrigued to learn what the authors think about it.

English is generally ok-ish. On one hand, the grammar could be improved significantly. On the other hand, I could generally understand the meaning of the sentences. However, one sentence I could not understand was one in line 194/195: "According to our previous study, the solid engine parts such as crankshaft always have the property of multi-axial fatigue." Does this not apply to everything, really? What exactly are you trying to say? If you could perhaps rephrase/clarify that might be helfpul.

There is some inconsistency in the way figures are numbered too, e.g. line 144 (Figure. 3 to Fig.6). Also, why do "Figure." and "Table." have a full stop if they are not abbreviations? A space between Figure/Table and the number should also be used.

I am wondering if table 7 should not be better represented as a figure? Why is this a table? Maybe plotting it will show too much scatter hence the option for presenting the data as a table? Happy to leave it as is if the authors think a plot would not be helpful.

Author Response

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Reviewer 3 Report

After reading and studying the proposed paper, it is with regret that in the opinion of this reviewer the paper suffers from a number of serious defficiencies and flaws.

It would be difficult to recommend individual measures to improve the paper as they would be too numerous  so that, regretfully, the recommendation is that paper is not acceptable for publication. 

Among other things most pronounced defficiencies of the paper include:

• rather poor quality of English language throughout the manuscript, various grammar mistakes and typographical errors
• title of the paper is related to high cycle (multiaxial) fatigue of automotive component due to bending loading yet majority of paper deals with heat treatment
• methodology is poorly described and a lot of important information is missing
• selection of multiaxial criterion is not sufficiently justified (McDiarmid)
• images are unclear and text on them is too small to read
• how is von Mises stress related to selected multiaxial fatigue criterion?
• experimental setup and relevant conditions and parameters are barely described
• discussion is weak
• conclusion section is missing from the paper
• ...

There are other shortcomings and deficiencies, but at this point reviewer does not want to go into further detail and paper needs to be thoroughly rewritten before it can be considered for publication.

Author Response

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Round 2

Reviewer 1 Report

The paper is improved after modification but it is still needed for futher verification: 

(1). Please refine the paper with professionals. Some of them is listed as below: 

A: L 54, "in ." 

B: L103: "high strenght alloy steel" should be "high-strength alloy steel" 

C: L121: " bulleted list looks like this", what does this mean? 

D: L212 and L262, refs should be added after "...previous study". 

E: Please use either "Figure X" or " Fig. x", "Table X". 

(2). Calculations are made according to some other models in 3.3.3, but at least the author should introduce which equation is used in each model. 

(3). Is this model applicable to other materials since the thermal conductity will be different? 

(4). The explanation on the much lower error of current model is not sufficient. Is there any other model which can be applied in multi-axis load? 

(5). "4 Dissusion" should be "4 Conclusions". 

Author Response

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Reviewer 3 Report

Dear Authors,

Thank you for your responses to my earlier remarks.

Please note that I do not lightly recommend against publication of the paper. I give a serious amount of consideration before I submit such recommendation to the Journal. 

It is my sincere opinion that serious flaws such as those that I indicated previously can not be ammended in 3-4 days. Was it otherwise, I would have made some other recommendation.

Regarding to some of your responses to my previous review:

1) Response: Thanks for the comments. In fact, the whole manuscript has already been edited by the professional editor company AJE (American journal experts) before submission. And further modification can be conducted again if necessary. And we have checked and made some modifications."

Well, the language, style and grammar are very bad. Thank you for pointing the service provider (AJE) you used so that I can avoid them. I would consider asking them for a refund.

2) The data in (old?) Table 7 and in current Diagram in Figure 16 are not identical. Considering that high-cycle fatigue is the subject of this research, I would expect significantly more tests to be performed before any reasonable conclusions can be drawn. Especially considering that quenched component is tested where significant scatter can be expected.There is group of datapoints in the range below 1 million cycles. This does not correspond to the data in Table 7 which is still visible in the article. This is worrisome. Which data is true? Also, there is single point in the 7-8 million cycles range. 

3) You mention that more discussion is added to the end of the Results section. Exactly two (2) sentences were added.

4) The remark that there is no Conclusion section was solved in a way that the old "Discussion" section is just renamed to "Conclusion". Well, you can not just convert discussion to conclusion!
Even so, you provide 3 individual "conclusions". However, "conclusion 1) and "conclusion" 2) are actually not conclusions at all - these sentences just state obvious facts from the analysis. Conclusion Nr. 3 is very vague and general and based on questionable and insufficient data provided earlier in the paper.

Regretfuly, due to these and others serious deficiencies, I remain at my previous decision that the article is not suitable for publication.

Author Response

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Round 3

Reviewer 1 Report

In Fig. 16, it seems the liner regression relationship is not so "obvious", especially at lower fatigue strength. Please consider to modify that. 

Author Response

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