Vacuum Hot Pressing of Oxide Dispersion Strengthened Ferritic Stainless Steels: Effect of Al Addition on the Microstructure and Properties
Round 1
Reviewer 1 Report
The content of the manuscript is interesting, reporting the effect of Al in ODS ferritic stainless steel.
However, there are some issues needed to clarify: Several words are repeated constantly along the manuscript as well as grammar mistakes. Figures are simple, with no good resolution and, in case of microscopy images, not easy to observe what it is described in the main text.
Research is not well defined, and some questions would be adequate to be solved.
Conclusions should be written according to what it is said in Results and Discussion section.
Some References should be updated.
According to these arguments, major revisions of this manuscript is proposed.
Resume of the main issues corresponding to each section of the paper:
- Materials and Method
The selection of the composition of the three alloys must be justified and explained as well as why 430L and a combination of ZrO2, Y2O3, W, Ti were selected as main steel and other components, respectively. What implications do you expect for each component in the final properties?
Please provide the morphology and mean particle size of the starting materials.
- Results and discussion
Figure 1 does not have the quality for a manuscript.
Could you please explained if you observe amorphization?
Figure 5 and 7 are not needed since the information is provided in the main text. Instead, you should add more figures about SEM or optical microscopy of the consolidated samples with the corresponding explanations.
Almost nothing of what it is said in the main text about powders after milling are observed in figure 3. Please, divide this figure and add some insets to corroborate what it is said in the text (“The fine size oxides (Y2O3 and ZrO2) are found to disperse unevenly in the matrix. The less number of flaky particles of Al are also observed in Alloys B, and C (Fig. 3(f and k)). As expected, during the MA process, the powder particles have undergone repeated welding and fracture events [34]. The particle size decreases for all three alloys after 10 h of MA due to repeated welding sequences.”)
Which is the role of W?
Proper discussion is missing in the whole manuscript as well as the final propose of the material.
-Conclusions
Conclusions don’t agree the main text; specially this one: “The results demonstrate that the compositions and nano complex oxides is crucial for achieving good properties in the oxide dispersion strengthening based ferritic stainless steels. Based on the observations in the current study best suited alloy for nuclear cladding material is alloy C.”
Author Response
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Author Response File: 
Author Response.pdf
Reviewer 2 Report
This article deals with ODS ferritic stainless steel (430L) fabricated by powder metallurgy. There were selected three chemical composition of powder mixture with different aluminum content – 0 wt.%, 2 wt. % and 4 wt.% for Alloy A, B and C respectively. The prepared powder mixtures were mechanically alloyed and sintered by VHP method. The fabricated samples were characterized by TEM observation, chemical analysis, density and hardness measurements. The obtained results have low science soundness and citation impact as well as low novelty. It is clear that increasing of aluminum content decreasing samples hardness (samples hardness must be compared with hardness of reference sample (SS 430L)) at the statistically comparable density for all alloys. It can be explain if detailed microstructure observation were conducted. Moreover the mechanical properties (e.g. compression strength) of fabricated samples should be designated and compared with reference material.
Author Response
Please find the word file with a detailed response to the questions raised.
Author Response File: Author Response.pdf
Reviewer 3 Report
The paper „Effect of Al in oxide dispersion strengthened ferritic stainless steel” by Dharmalingam et al. is an article on the fabrication of oxide dispersion strengthened ferritic stainless steel. The paper is well written and highlights important issues. In general, I recommend the article for publication in Journal of Manufacturing and Materials Processing with the following, minor comments:
- there is no justification for using a blue background for all figures,
- conclusions are too general. It is necessary to compare the results obtained with the results from references,
- old references should be replaced by more recent journal paper references.
Author Response
Please find the word file with a detailed response to the questions raised.
Author Response File: Author Response.pdf
Reviewer 4 Report
This work was aimed to study the effect of the aluminium composition on the microstructure and mechanical properties of oxide dispersion strengthened ferritic stainless steel. The research field is relevant, presenting technical and scientific interest. A deep experimental characterisation was conducted by the authors. Important experimental techniques were used to characterise the samples/alloys. However, the authors should consider the following comments so that the paper can be accepted for publication:
TITLE
1) The title of the paper is vague. The title should detail in which aspects/characteristics/properties of the strengthened ferritic stainless steel the influence of the Al composition is being studied.
INTRODUCTION
2) The authors should explicitly refer what is the innovation of the research presented in this paper.
3) Lines 62-63, Why is not the W (composition) referred?
RESULTS AND DISCUSSION
4) The figures should be carefully located in the manuscript. Most of the figures are not in a proper location. For example, Figs. 1, 4, 5 and 6 are located at the beginning of the subsections, without any text before them; Fig. 3 is located in subsection 3.1, but it is only addressed in subsection 3.2.
5) The text is somewhat repetitive in lines 122-124 and 135-136. The authors refer the crystallite size before analysing Fig. 2, and then, they refer it again during the analysis of Fig. 2.
6) When the authors have different items in each figure (a, b, c, etc.), they should be individually referred in the figure caption (for example, Figs. 2, 3 and 6).
7) The authors refer (lines 144-145):
“The less number of flaky particles of Al are also observed in Alloys B, and C (Fig. 3(f and k)).”
This is very difficult to be understood by observing the present version of Fig. 3. Presenting text/arrows in these micrographs or presenting micrographs with a higher magnification are two strategies that may be adopted by the authors in order to better illustrate what they refer.
8) The authors refer (lines 146-147):
“The particle size decreases for all three alloys after 10 h of MA due to repeated welding sequences (Fig. 3 (c, h, and m)).”
This is very difficult to be understood by observing the present version of Fig. 3. Presenting text/arrows in these micrographs or presenting micrographs with a higher magnification are two strategies that may be adopted by the authors in order to better illustrate what they refer.
9) Figure 6
It is difficult to understand the meaning of zones I and II. This should be better explained in the text.
In which way are the spectra in Fig. 6 adding any information besides that displayed in Table 2? If they add some relevant information, it should be explained in the text.
10) The authors refer (lines 190-195):
“In addition, the TEM images show that the oxides (Y2O3 and ZrO2) are distributed uniformly in the Fe-matrix and the average size of the nano oxide particles (Y-Zr-Ti-O) observed in Alloy A is between 15-18 nm (Fig. 6(a)). However, it may be observed that the average size of the nano oxide particles (Y-Zr-Ti-Al-O) in Alloys B and C increases and are observed in the range of 20-25 nm (Fig. 6(c and e)), which is relatively bigger than the particles observed in Alloy A.”
This is very difficult to be understood by observing the present version of Fig. 6. The authors should better highlight the particles they are referring to. The differences in particle size among the three alloys are not evident by observing the micrographs (Fig. 6a, 6b and 6c).
11) The authors refer (lines 204-205):
“More over importantly, the Zr content in Alloys B and C decreases as compared to Alloy A.”
An explanation for this result should be referred in the text.
CONCLUSIONS
12) Lines 239-240, “(…) Based on the observations in the current study best suited alloy for nuclear cladding material is alloy C.”
If the authors intend to take conclusions regarding the practical/industrial application of the alloys based on its chemical composition, this should be discussed in the manuscript (not only presented in the Conclusions). The authors should present a discussion that establishes a relationship between the practical application of the alloys, their chemical composition and properties. They should also refer in which way the properties of the alloy C make it more suitable to be used for nuclear cladding.
Author Response
Please find the word file with a detailed response to the questions raised.
Author Response File: Author Response.pdf
Round 2
Reviewer 1 Report
Thank you for the improved version.
I still think Figure 5 and 8 should be removed because the information is already in the main text.
Author Response
Response to Reviewer 1#
I still think Figure 5 and 8 should be removed because the information is already in the main text.
As suggested by the reviewer, Figures 5 and 8 were removed from the manuscript.
Reviewer 2 Report
The article has been significantly improved. However for evaluation of obtained results the reference material (“pure” 430L steel) is strongly needed. The lack of it makes impossible to determine usefulness and science soundness of this work.
Author Response
Response to Reviewer 2#
The article has been significantly improved. However for evaluation of obtained results the reference material (“pure” 430L steel) is strongly needed. The lack of it makes impossible to determine usefulness and science soundness of this work.
We thank the reviewer for the comments. As suggested by the reviewer the results (density, hardness and compression property) of the ‘pure’ 430L steel sample (matrix) has been introduced in the revised version of the manuscript to improve its quality.
Reviewer 4 Report
The authors refer:
"The zones I and II marked in the TEM images show the positions at which the I – the EDS spectrum was made (see Fig. 7 (b, d, and e) and II – corresponds to the oxide particle, where EDS spectrum was measured and tabulated in Table 4."
Is it Fig. 7 (b, d, and e) or Fig. 7 (b, d, and f)?
Author Response
Response to Reviewer 4#
The authors refer:
"The zones I and II marked in the TEM images show the positions at which the I – the EDS spectrum was made (see Fig. 7 (b, d, and e) and II – corresponds to the oxide particle, where EDS spectrum was measured and tabulated in Table 4."
Is it Fig. 7 (b, d, and e) or Fig. 7 (b, d, and f)?
Thanks for pointing out the error. It has to be Fig 7 (b, d, and f) and in the revised version of the manuscript it should be Fig. 6 (b, d, and f) and it has been modified accordingly.
Round 3
Reviewer 2 Report
I have no more comments.
