Improvement of the Mechanical Properties of 30CrNi2MoVA through Ultrasonic-Milling in Certain Key Components

Round 1

Reviewer 1 Report

The peer-reviewed article "Improving the mechanical properties of 30CrNi2MoVA by ultrasonic grinding of some key components" contains a complete study on the problem under consideration! the literature review covers information sources 2013-2022, it would be nice to consider 3-4 more sources 2022-2023, to get more relevant information on the issue under consideration. The described studies were carried out with the financial support of the National Foundation of Natural Sciences Foundation of China (No. 52001261), which confirms the importance of the issue under consideration!

Author Response

Dear reviewer

Thank you for your valuable comments. We have added several new references 2022-2023 to the direction of the paper and marked them with blue font.See References 24,25,27,28 for details.New references are as follows:

 

[24] Qian H , Han Y , Zhang K ,et al.The dependence of microstructure and mechanical properties on substrate heat treatment in AlN ceramics/AgCuTi/316 stainless steel brazed joints[J].Vacuum, vol .213,2023 .

 

[25] Takeda S , Ueki K , Ueda K ,et al.Improvement of mechanical properties of Co–Cr–W–Ni alloy tube suitable for balloon-expandable stent applications through heat treatment[J].Materials Science & Engineering, A. Structural Materials: Properties, Misrostructure and Processing, vol .862, 2023.

 

[27] Likhtman V I , Krishtal M A , Golovin S ,et al.Strengthening of Metals by Decorating Dislocations with Surface-Active Impurities[J].2022,

 

[28] Yuan L , Wang F , Chen H ,et al.Improvement of  the Mechanical Properties and Corrosion Resistance of CSS-42L Steel with a Novel TiAlMoNbW Nitrid Film Deposition[J].Coatings, 2022.

 

 

 

 

 

 

Author Response File: Author Response.docx

Reviewer 2 Report

Review comments attached

Comments for author File: Comments.pdf

Author Response

Dear reviewer

 It is grateful for your valuable opinions on the paper. The author has carefully understood and responded to each opinion. The corresponding part has been marked in blue font in the paper. The specific questions and replies are as follows.

 

 

• It is noted that fewer latest article cited in the article. Most are discussed with a decades ago. It is essential to show the current technology comparison with recent citations.

Reply : Four references have been added to the relevant literature from 2022 to 2023.

 

• The novelty is questionable. Why the surface modification introduced? There is no literature discussed on surface modification in this article for the selected field of 30CrNi2MoVA.

Reply : At present, there are few reports on the surface modification of 30CrNi2MoVA steel at home and abroad.Due to the double action of cyclic fatigue load and corrosive medium in the process of oil mining, 30CrNi2MoVA steel will crack and fail after dozens of hours in using.Therefore, the surface of this steel needs to be strengthened.

 

• Author chose number of performance test. On what basis it was selected as no comparison shown in the literature for other techniques discussion on field of 30CrNi2MoVA.

Reply : According to the experimental research literature on other similar high strength structural steel, such as 40 Cr and other materials, select the approximate number of performance tests, and change the experimental parameters for multiple sets of performance test analysis.

 

• Section 2.2. need to be supported with citations as author supports like “surface of the parts to achieve the mirror effect and be modified”.

Reply : Modified in the text, see reference 17.

 

• What is the standard that the fatigue test followed? Article should show the specimen for testing with standards as it has to follow the results for the reproducibility.

Reply : The experimental parameters and methods of fatigue testing are described in 2.3.Fatigue Test Conditions of Experiment 2.

 

• Abbreviate UNSM and AUMSM in the first ever specified place.

Reply : It has been marked in the text, see Line 91 and 127.

 

• The discussion were not made enough with citations.

Reply : Four references have been added to the relevant literature from 2022 to 2023.

 

• The structure should be reconsider for the journal preferences for the preparation of article.

Reply : The paper format has been modified according to the journal preference.

 

• Testing standards are to be justify with proper standards and justification

 

Reply : It has been modified in the text. The environmental tests such as rain, salt spray, damp heat, high and low temperature on the samples according to the test requirements of the corresponding environmental test standards ( GB/T 2423-2012).

Author Response File: Author Response.docx

Reviewer 3 Report

The paper discusses the effect of ultrasonic treatment on the properties of 30CrNi2MoVA steel. The authors have performed a detailed investigation of surface properties, microhardness, wear and fatigue.

The investigation is adequate and logical, the conclusions in general are justified. However the paper is lacking a huge number of details concerning both the treatment procedure and experimental investigations. Also the authors are focussing on comparing treated and untreated samples omitting the appropriated discussion of experimental results. 

1) Line 41: the discussion of paper [8] sounds very unclear, the authors discuss a "certain nanometer layer", without discussing the properties or at least content of this layer the relation of ref.8 with the presented paper in unclear.

2) The technological procedure is not discussed properly. What kind of equipment has been used for the treatment? What is the duration of the treatment? What is the heat strength? etc.

3) Line 95-96. Some more information is needed on the parameter called "the activation energy". What kind of activation process is is discuss? 

4) Figure 3b. The difference in microhardness dependence on the distance in X-Y and Z directions should be discussed somehow. Why doesn't the microharndess decrease with the distance in Z direction?

5) Figure 4. What was the equipment for residual stress measurements?

6) Figure 6. The origin of the oscillations of the wear with the sampling length should be discussed at least briefly. 

7) Line 228: While discussing the Figure 7 the authors say that the distance between the wear curves and 1:1 curve is 400 nm at Fig.7a and 400 nm at Fig.7b. It cannot be seen from the figures since 1:1 curve is not visualized.

8) LIne 246: Discussing the Fig.8 the authors say that the friction after treatment was significantly reduced. However the friction scale in unchanged moreover in some points the friction of the untreated sample is even lower than that of the treated one.

9) The conditions of environmental experiments at Fig.3.7 are poorly discussed.

The entire text is to be proofreaded. I can mention some of the inconsistent text i noticed.

Line 21: "Low alloy high strength alloy" the sentence should be checked.

Line 22: "The steel often widely" - often cannot be combined with widely. Also "is" is missing (The steal is used);

Line 25-27 please check the sentence ("is used in this alloy"). Maybe on the contrary the alloy is used in pump head connection shaft ?

Line 35 "of, low" should be probably corrected

Line 50: Is the future tense appropriate here? Please check

Line 243 "Figure 16" - probably Figure 8, please check.

 

Author Response

Dear reviewer

     It is grateful for your valuable opinions on the paper. The author has carefully understood and responded to each opinion. The corresponding part has been marked in blue font in the paper. The specific questions and replies are as follows.

• Line 41: the discussion of paper [8] sounds very unclear, the authors discuss a "certain nanometer layer", without discussing the properties or at least content of this layer the relation of ref.8 with the presented paper in unclear.

Reply：Paper [8] is to enumerate a method of self-nanocrystallization of steel surface, that is, through a thermal diffusion technology, but the process is complex and time-consuming. Then, in order to lead to the high efficiency of ultrasonic technology, another metal surface self-nanocrystallization method used in this paper, and the current research progress of this technology at home and abroad.

• The technological procedure is not discussed properly. What kind of equipment has been used for the treatment? What is the duration of the treatment? What is the heat strength? Etc.

Reply : In the second part of Experiment 2.1. Experimental materials and Testing system, the experimental equipment is CK6150 numerical control lathe. Ultrasonic static pressure is the key parameter. By changing the pressure. The static pressure exerted by the ultrasonic device on the work piece surface is set to be 779N. Under the same static pressure, the work-piece is continuously excited by ultrasonic compound processing for three times..

• Line 95-96. Some more information is needed on the parameter called "the activation energy". What kind of activation process is is discuss? 

Reply : ' the activation energy ' has been changed to the’ ultrasonic vibration energy and the static pressure’.

• Figure 3b. The difference in microhardness dependence on the distance in X-Y and Z directions should be discussed somehow. Why doesn't the microharndess decrease with the distance in Z direction?

Reply:In Line 158-161, the hardness changes in the X, Y, and Z directions have been discussed. The Z direction is the surface hardness of the hardness test specimen. Since the surface is treated with AUMSM, the surface hardness is maintained at about 660 HV, and will not decrease with the change of the distance in the Z direction.

• Figure 4. What was the equipment for residual stress measurements?

Reply :The residual stress was measured by HS 1010 ultrasonic residual stress detector. It has been supplemented in the 2.1.Experimental materials and Testing system in the second part of Experiment.

• Figure 6. The origin of the oscillations of the wear with the sampling length should be discussed at least briefly. 

Reply : Modified in the text. However, the meaning of the symbol of each test curve is still introduced in detail, in order to avoid the reader 's lack of understanding.

• Line 228: While discussing the Figure 7 the authors say that the distance between the wear curves and 1:1 curve is 400 nm at Fig.7a and 400 nm at Fig.7b. It cannot be seen from the figures since 1:1 curve is not visualized.

Reply : Modified in the text.In line 218-220, In addition，the distance between the wear curves and the 1:1 curve in Figure 6(a) is close to 400nm. But that in Figure 6b is about 100nm, which is smaller than that shown in Figure6(a).

• Line 246: Discussing the Fig.8 the authors say that the friction after treatment was significantly reduced. However the friction scale in unchanged moreover in some points the friction of the untreated sample is even lower than that of the treated one.

Reply：In the scratch distance of 240μm, it can be seen from Figure 8 that the friction coefficient of the original sample fluctuates greatly with the wear distance curve, and changes in a broken line. The maximum friction coefficient is 0.31. However, the friction coefficient of the sample after AUMSM treatment is significantly reduced and the fluctuation range is relatively small. The maximum friction coefficient is 0.19. In some points the friction of the untreated sample is even lower than that of the treated one, which may because that the measured points of the untreated sample was carbides.

• The conditions of environmental experiments at Fig.3.7 are poorly discussed.

It has been supplemented in Section 2.1:Experimental materials and Testing system.The conditions of environmental experiments are according to the  the test requirements of the corresponding environmental test standards( GB/T 2423-2012).

 

Comments on the Quality of English Language

The entire text is to be proof readed. I can mention some of the inconsistent text i noticed.

Line 21: "Low alloy high strength alloy" the sentence should be checked.

Reply : has been changed to’ low alloy high strength structural steel’.

Line 22: "The steel often widely" - often cannot be combined with widely. Also "is" is missing (The steal is used);

Reply : Modified in the text.

Line 25-27 please check the sentence ("is used in this alloy"). Maybe on the contrary the alloy is used in pump head connection shaft ?

Reply : Modified in the text.

Line 35 "of, low" should be probably corrected

Reply : Modified in the text.

Line 50: Is the future tense appropriate here? Please check

Reply : Modified in the text.

Line 243 "Figure 16" - probably Figure 8, please check.

Reply : Modified in the text.

 

 

Author Response File: Author Response.docx

Round 2

Reviewer 2 Report

Test specimen standards could specify with ASTM standards with specimen sizes.

Author Response

Dear reviewer

 It is grateful for your valuable opinions on the paper. The author has carefully understood and responded to your opinion. The specific question and reply are as follows:

Test specimen standards could specify with ASTM standards with specimen sizes.

 

Reply : The size of the test specimen in this paper is processed and tested by the relevant material performance experimental standards of China, which meets the requirements of the sample size of the experimental equipment.

Author Response File: Author Response.docx

Reviewer 3 Report

The authors have made great effort to improve the paper. However few issues are still to be improved.

1. Line 41: the discussion of paper [8] sounds very unclear, the authors discuss a "certain nanometer layer", without discussing the properties or at least content of this layer the relation of ref.8 with the presented paper in unclear.

Reply：Paper [8] is to enumerate a method of self-nanocrystallization of steel surface, that is, through a thermal diffusion technology, but the process is complex and time-consuming. Then, in order to lead to the high efficiency of ultrasonic technology, another metal surface self-nanocrystallization method used in this paper, and the current research progress of this technology at home and abroad.

Comment: Although the authors have clarified the issue in the revised version, the expression like "certain nanometer layer" still sounds unclear. I would recommend the authors to check this part.

2) Line 246: Discussing the Fig.8 the authors say that the friction after treatment was significantly reduced. However the friction scale in unchanged moreover in some points the friction of the untreated sample is even lower than that of the treated one.

Reply：In the scratch distance of 240μm, it can be seen from Figure 8 that the friction coefficient of the original sample fluctuates greatly with the wear distance curve, and changes in a broken line. The maximum friction coefficient is 0.31. However, the friction coefficient of the sample after AUMSM treatment is significantly reduced and the fluctuation range is relatively small. The maximum friction coefficient is 0.19. In some points the friction of the untreated sample is even lower than that of the treated one, which may because that the measured points of the untreated sample was carbides.

Comment: The issue is still lacking appropriate discussion. The decrease of scatter of friction coefficient is still to be discussed. In addition the carbides-related greater friction coefficient should be at least mentioned in the paper.

Author Response

Dear reviewer

 It is grateful for your valuable opinions on the paper. The author has carefully understood and responded to each opinion. The corresponding part has been marked in blue font in the paper. The specific questions and replies are as follows.

1. Line 41: the discussion of paper [8] sounds very unclear, the authors discuss a "certain nanometer layer", without discussing the properties or at least content of this layer the relation of ref.8 with the presented paper in unclear.

Reply：Paper [8] is to enumerate a method of self-nanocrystallization of steel surface, that is, through a thermal diffusion technology, but the process is complex and time-consuming. Then, in order to lead to the high efficiency of ultrasonic technology, another metal surface self-nanocrystallization method used in this paper, and the current research progress of this technology at home and abroad.

Comment: Although the authors have clarified the issue in the revised version, the expression like "certain nanometer layer" still sounds unclear. I would recommend the authors to check this part.

Reply :The expression of 'certain nanometer layer ' has been removed in this paper, because the reference in this paper is only to illustrate that the thermal diffusion technology is a method of self-nanocrystallization of steel surface. But the process is complex and time-consuming. Then, in order to lead to the high efficiency of ultrasonic technology, another metal surface self-nanocrystallization method used in this paper, and the current research progress of this technology at home and abroad.

2) Line 246: Discussing the Fig.8 the authors say that the friction after treatment was significantly reduced. However the friction scale in unchanged moreover in some points the friction of the untreated sample is even lower than that of the treated one.

Reply：In the scratch distance of 240μm, it can be seen from Figure 8 that the friction coefficient of the original sample fluctuates greatly with the wear distance curve, and changes in a broken line. The maximum friction coefficient is 0.31. However, the friction coefficient of the sample after AUMSM treatment is significantly reduced and the fluctuation range is relatively small. The maximum friction coefficient is 0.19. In some points the friction of the untreated sample is even lower than that of the treated one, which may because that the measured points of the untreated sample was carbides.

Comment: The issue is still lacking appropriate discussion. The decrease of scatter of friction coefficient is still to be discussed. In addition the carbides-related greater friction coefficient should be at least mentioned in the paper.

Reply： The following is added in line 255-258:“The decrease of scatter of friction coefficient is due to two factors. One is the hardening effect on the surface of the material after AUMSM treatment and the other is the low roughness and good lubrication of the surface after AUMSM treatment."

The following is added in line 258-260:“In some points the friction of the untreated sample is even lower than that of the treated one, which may because that the measured points of the untreated sample was carbides.”

 

Author Response File: Author Response.pdf