Investigation of Surface Oxidation of Cast Austenitic 304 Stainless Steel at High Temperatures

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

The article "Study of microstructural characteristics of cast 304 stainless 1 steel after annealing by Mössbauer spectroscopy and positron annihilation" by
Tatiana Ivanova, Michal Kořenek, Miroslav Mashlan  and Martin Fryšák devoted to the very interesting problem of 304 steel transformation under temperature action at normal air atmosphere. 

The author used a set of modern techniques but the result interpretation, for instance, the actual depth in microns of successful transformation of austenite to ferrite is not presented. The simplest method is layer-by-layer grinding and X-ray diffraction study

In the conclusion the authors wrote that " The formation of these oxides was demonstrated primarily by XRD, and 332 CEMS confirmed the presence of iron-bearing oxides in the 0.3 mm thick surface layer."  And furthermore " CXMS confirmed this phase transformation in the surface layer up to about 30 mm."

But in the text no  depth profiles were demonstrated. Is it possible to add such figures in the text?

Some minor recommendations

The information about Manufacture, City, Country for MS96 Mössbauer spectrometer must be added.

Figure 5. Depth dependency of elemental concentration of 304 stainless steel after 36 hours of annealing in air. But on the x-axis the authors show the accelerating voltage. There is no direct dependance between the accelerating voltage and  the yield of EDS electrons. Besides the effect of "deth etching" with collection the information from the elements on the surface must be discussed.

 

Author Response

We thank the reviewer for his questions and comments. Answers and comments are in the attached file.

 

Author Response File: Author Response.pdf

Reviewer 2 Report

Comments and Suggestions for Authors

The entitled paper:’ Study of microstructural characteristics of cast 304 stainless steel after annealing by Mössbauer spectroscopy and positron annihilation’ deal about the impact of annealing temperature on the 304 stainless steel. Various investigation methods were used to investigate subsurface and bulk of the specimen. The paper shows quite interesting results which were confirmed by various characterization methods. Nevertheless, some minor improvements are necessary:

1. Please detail more the state of art. It is very hard to visualize the novelty of this research
2. The references are very old, since 2000. It would be good to add recent research (5 years)
3. The authors have listed various measurement techniques: SEM, EDS, CXMR and XRD. I find interesting to state short summary about the principal and functioning of these methods. Also interesting to state the limits of each techniques.
4. For better interpretation of the curves, it would be to make one scale ( figure 8), for example normalize all the Emission, E (/) and just indicate (E×101 or E×114
5. In the conclusion, it is interesting to add quantitative values.

Author Response

We thank the reviewer for his questions and comments. Answers and comments are in the attached file.

Author Response File: Author Response.pdf

Reviewer 3 Report

Comments and Suggestions for Authors

The article is topical, because nowadays there is a very important development in the field of materials science and heat treatment, represented by the problem of studying the microstructural characteristics of cast 304 stainless steel after annealing by Mössbauer spectroscopy and positron annihilation. In their work, the authors have described in an interesting way the microstructure and surface behaviour of iron-based stainless steel after exposure to temperature. It is also necessary to add another direction for research to the article. After incorporating my comments, I recommend publishing an article in the journal Metals. My comments on the article are as follows:

1. The introductory chapter lacks an explanation of the abbreviation MS.
2. In line 88, the authors mention that they used the MS96 Mössbauer spectrometer software in the article. It would have been appropriate to add the version of the software in question.
3. The authors write in line 109 that "different slopes in the data sets correlate with different types of defects". What defects are we talking about here, or what errors do the authors have in mind?
4. The authors write in line 231 that "The formation of this oxide is correlated with the high diffusion rate of Mn under the temperature influence [51] and the octahedral particles observed on the surface by the SEM method". Is it a positive or negative correlation?
5. At the end of the article, it would be appropriate to add how the authors will continue their research, or what they will investigate next.

Author Response

We thank the reviewer for his questions and comments. Answers and comments are in the attached file.

Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

Comments and Suggestions for Authors

The subject are is very specific but could be interesting for peoples who deals with the steel usage in the manufacturing  of variable steel products. So, I believe that the article will be interesting for the readers of Metals. 

The authors made all the corrections according with the reviewer's remarks.