Microstructural Characterization and Mechanical Properties of Direct Quenched and Partitioned High-Aluminum and High-Silicon Steels
Round 1
Reviewer 1 Report
Line 11: steel instead of steels
Line 12: has been instead of have been
Line 34: add a reference (A. Di Schino, L. Alleva, M. Guagnelli: Microstructure evolution during quenching and tempering of martensite in a medium C steel, Materials Science Forum, 715-716, 860-865, 2012)
Line 36: add a reference
Line 38: add a reference
Line 57: Rewrite: Si is the most commonly used element to prevent.....
Line 69: please add: Also if lower C content are considered (down to 0.15%), Si showed to be more efficient than Al in retarding transition carbides formation (reference: A. Di Schino, C. Braccesi, F. Cianetti, P.E. Di Nunzio, S. Mengaroni, P. Calvillo, J.M. Cabrera, Manganese effect of Q and P CMnSi steels, Materials Science Forum, 879, 430-435, 2017.
Line 119: retained austenite instead of austenite retained
Line 135: size instead of dimension
Author Response
Paper No: Metals-450316
Technical Paper: Microstructural Characterization and Mechanical Properties of Direct Quenched and Partitioned High-Aluminum and High-Silicon Steels
We sincerely thank all the reviewers for their relevant comments / suggestions, which will definitely improve the quality of the manuscript. Replies to the questions/comments are given below:
Reviewer 1:
Line 11: steelinstead of steels -> Done.
Line 12: has been instead of have been -> Corrected.
Line 34: add a reference (A. Di Schino, L. Alleva, M. Guagnelli: Microstructure evolution during quenching and tempering of martensite in a medium C steel, Materials Science Forum, 715-716, 860-865, 2012) -> The reference has been added.
Line 36: add a reference -> A new reference has been added in support of the statement (Comparison on mechanical properties and microstructure of a C–Mn–Si steel treated by quenching and partitioning (Q&P) and quenching and tempering (Q&T) processes, Shu Yan, Xianghua Liu, Wayne J. Liu, Huifang Lan, Hongyan Wu; Mater. Sci. Eng. A 2014, 620, 58–66.
Line 38: add a reference -> The new reference added at line 36 [2]is relevant for this sentence, too, as it is related to the preceding sentence.
Line 57: Rewrite: Si is the most commonly used element to prevent..... -> Done.
Line 69: please add: Also if lower C content are considered (down to 0.15%), Si showed to be more efficient than Al in retarding transition carbides formation (reference: A. Di Schino, C. Braccesi, F. Cianetti, P.E. Di Nunzio, S. Mengaroni, P. Calvillo, J.M. Cabrera, Manganese effect of Q and P CMnSi steels, Materials Science Forum, 879, 430-435, 2017. -> The sentence has been added and reference included in the text.
Line 119: retained austenite instead of austenite retained ->Done.
Line 135: size instead of dimension -> Done.
Reviewer 2 Report
This is a good paper acceptable for publication.
A few changes should be made:
The country is not identified.
Axes are not shown in Fig.1.
Fig. 10 title J/cm2 - "2" should be in superscript.
As the paper contains a large number of data the discussion part should be extended, if possible.
Author Response
Paper No: Metals-450316
Technical Paper: Microstructural Characterization and Mechanical Properties of Direct Quenched and Partitioned High-Aluminum and High-Silicon Steels
We sincerely thank all the reviewers for their relevant comments / suggestions, which will definitely improve the quality of the manuscript. Replies to the questions/comments are given below:
Reviewer 2:
This is a good paper acceptable for publication.
A few changes should be made:
1. The country is not identified. -> Finland has been added in the affiliation at Line 8.
2. Axes are not shown in Fig.1. -> Axes have now been shown.
3. Fig. 10 title J/cm2 - "2" should be in superscript. -> Done.
4. As the paper contains a large number of data the discussion part should be extended, if possible. -> In section 3. Results and Discussion, a detailed discussion has been combined together with the results, starting (now) at line 170 until line 466. However, the last section i.e. 4. Summary and Conclusionspresents only a summary of the results and conclusions. Previously, section 4 was wrongly mentioned as Summary and Discussion due to typo error and this has now been corrected. This has also been pointed out by another reviewer.
Reviewer 3 Report
The article gives a experimental investigations of mechanical properties of direct quenched and partitioned high-Aluminum and high-Silicon steels. Suggested treatment is strict and elegant and brings understanding of hot strip production field at new level. The article is well written. Minor errors of style may need to be corrected at the proof-reading stage. Perhaps it would be better to rename the section 4 "Summary" instead of "Summary and Discussion" but this should be left to the authors' judgement. Recommendation: Accept after minor revision.
Author Response
Paper No: Metals-450316
Technical Paper: Microstructural Characterization and Mechanical Properties of Direct Quenched and Partitioned High-Aluminum and High-Silicon Steels
We sincerely thank all the reviewers for their relevant comments / suggestions, which will definitely improve the quality of the manuscript. Replies to the questions/comments are given below:
Reviewer 3:
The article gives a experimental investigations of mechanical properties of direct quenched and partitioned high-Aluminum and high-Silicon steels. Suggested treatment is strict and elegant and brings understanding of hot strip production field at new level. The article is well written. Minor errors of style may need to be corrected at the proof-reading stage. Perhaps it would be better to rename the section 4 "Summary" instead of "Summary and Discussion" but this should be left to the authors' judgement. Recommendation: Accept after minor revision. -> Corrected. There was a typo error in section 4. It should have been typed as 4.Summary and Conclusionsinstead of 4.Summary and Discussion.
Reviewer 4 Report
The paper titled "Microstructural Characterization and Mechanical Properties of Direct Quenched and Partitioned High Aluminum and High-Silicon Steels" studies the mechanical properties of steels containing in weight percent 0.3C-2.0Mn-0.5Si-1.0Al-2.2Cr and 12 0.3C-1.9Mn-1.0Si-1.0Cr that are subjected to a specifid heat treatment method as explained in the manuscript.
The paper delivers the aimed information in a good way and can be accepted as publication after answering the following questions below.
1- It is a known fact that retained austenite transforms into martensite through stress and strained induced phase transformations. using the experimental methods used is it possible to identify the morphology of the martensite ? is it needle type or lathe type ?
2- Not only the initial RA content but also the temperature effects the phase transformation start stress and in some cases it has been shown that martensite can form before yielding ( stress induced). Is it possible to find any evidence related to this mechanism in your study ?
3- It is difficult to understand figure 1 can you define a y axis ?
4- It has been noted that the change of volume fractions can be estimed using Koistinen and Marburger relation whereas in the case of stress and strain induced phase transformation behavior other phenomenological models has to be implemented.
5- line 281 change sligthly to slightly.
Author Response
Paper No: Metals-450316
Technical Paper: Microstructural Characterization and Mechanical Properties of Direct Quenched and Partitioned High-Aluminum and High-Silicon Steels
We sincerely thank all the reviewers for their relevant comments / suggestions, which will definitely improve the quality of the manuscript. Replies to the questions/comments are given below:
Reviewer 4:
The paper titled "Microstructural Characterization and Mechanical Properties of Direct Quenched and Partitioned High Aluminum and High-Silicon Steels" studies the mechanical properties of steels containing in weight percent 0.3C-2.0Mn-0.5Si-1.0Al-2.2Cr and 12 0.3C-1.9Mn-1.0Si-1.0Cr that are subjected to a specified heat treatment method as explained in the manuscript.
The paper delivers the aimed information in a good way and can be accepted as publication after answering the following questions below.
1- It is a known fact that retained austenite transforms into martensite through stress and strained induced phase transformations. Using the experimental methods used is it possible to identify the morphology of the martensite? is it needle type or lathe type?
èAs also mentioned in the manuscript, the microstructure is essentially lath martensite and is also expected for the investigated steels with the carbon content of about 0.3 wt. %. We did not find any needle type martensite.
2- Not only the initial RA content but also the temperature effects the phase transformation start stress and in some cases it has been shown that martensite can form before yielding (stress induced). Is it possible to find any evidence related to this mechanism in your study?
èIndeed, a very good point. Yes, we know that stress-induced martensite can form during tensile testing, but we did not study this aspect in our interrupted tension tests at room temperature. Also, in principle, it is not simple to note the change in martensite formation just before the start of the yielding with the variation in carbon content of the austenite. We do not have any data on retained austenite fraction just prior to the point of yielding.
3- It is difficult to understand figure 1 can you define a y axis?
èCorrected.
4- It has been noted that the change of volume fractions can be estimated using Koistinen and Marburger relation whereas in the case of stress and strain induced phase transformation behavior other phenomenological models have to be implemented.
èKoistinen and Marburger relation is normally used to estimate the martensite phase fractions with certain quenching stop temperatures and is relevant for carbon steels with specified carbon contents. In our study, we just qualitatively ascertained the decrease in retained austenite fraction due to strain induced transformation through interrupted tensile tests and no efforts were made in this work for modelling the stress-/ strain-induced phase transformation behaviour using the available phenomenological models in literature. This can be included in future studies. However, we clearly see that the carbon content of the remaining retained austenite increases as the austenite content decreases during straining, obviously due to the inhomogeneous distribution of carbon in the austenite films / pools and the higher stability of the austenite with the highest carbon contents.
5- line 281 change sligthlyto slightly.
-> Corrected.
