Effect of Extensive and Limited Plastic Deformation on Recrystallized Microstructure of Oxide Dispersion Strengthened Fe-Cr-Al Alloy

Round  1

Reviewer 1 Report

The manuscript deals with the question, why recrystallization temperature is so high in ferritic ODS steels, and why slight changes in their processing can produce enormous changes in the subsequent recrystallization behaviour. Slight and extensive deformations with different directions have been applied and the grain and especially the texture structures observed after annealing in ODS PM2000.

The authors have published related papers earlier, so they have strong experience and deep knowledge in the topic (several own references are given). The novelty and originality are good. The presentation is reader-friendly explaining also some background for a reader. 

The work is worth of publishing, but there are minor deficiencies which might be revised before:

Few sentences have somewhat complex structure, examples such as: P. 2, line 64:  ”Specifically, this paper deals with the influence that different levels of plastic deformation on consolidated ODS material, and the applied direction, has on the microstructure of ferritic ODS alloys.” 

Could this be: … different levels of plastic deformation and its direction in the consolidated state have on the microstructure of ferritic ODS alloys ?

Similarly line 69: ”…achieve which allows…”  ??

A few grammatic mistakes:

Line 72: ”manufactures…”, manufactured

P. 3, line 125: ”… be describe”, be described

P. 7, line 239: “However, the causes of the decrease in recrystallization temperature and the refinement of the microstructure deserves some paragraphs in this paper to be discussed.”  Deserve.

The whole text could be rechecked.

The text with numerous references over the lines 75 – 90 deals obviously with results, not the experimental procedure ! Initial microstructure ?

Line 83: ”…primarily in the form of grain surfaces,…”  If the number of LAGBs is particularly high, do you mean in the form of subgrain surfaces by grain surfaces ?  LAGBs consists of dislocations, hence the dislocation density is high, so we might conclude as well that the energy is in dislocations, which have arranged, not randomly distributed.

Line 130: “…recrystallization is normally accelerated as the stored energy increases.” Also for ODS alloys, increase in the cold rolling reduction accelerates recrystallization (e.g. M. Dade et al., Journal of Nuclear Materials 472 (2016) 143–152). Although, as discussed in the paper, the stored energy can even decrease with increasing reduction due to the change of the texture.

Line 248: “Chou [32] measured.”  Chou and Bhadeshia [32] measured…

Figure 4 caption: (b) L-Sample for 80% compression ratio, and (c) N-300 sample for 80% compression ratio. Obviously a mistake, N-Sample in (b) and L in (c), the codes inside the figures.

The section of 4. Conclusions. According to the title of the paper, the target was to investigate the effect of slight heterogeneous plastic strains and, otherwise, that of directional strong deformation, on recrystallization. However, the conclusions have not been structured to explain the difference obtained from these different deformation modes, but they describe the two fold effects of “cold deformation“ only.  Further, the extended recovery is pointed out in the first paragraph, although it was only shortly mentioned in the text, not particularly investigated.  Could this be considered ?

Line 328: complex:  “…consisting to a geometrical change in grain morphology, no nucleation stage, increase in percentage of LAGBs, and no significant change in material texture.” 

…consisting of geometrical change in grain morphology without a nucleation stage, but with increasing fraction of LAGBs and without significant change in the texture.

Line 334: “…with grains that are so fine their junctions are...“  …so fine that their junctions are ...?

References have been written in a varying (vague) style: journal titles in full or abbreviated (with or without dots), articles titles sometimes in capital letters, sometimes with lower case.

Author Response

Response to the comments are in the report attached

Author Response File: Author Response.pdf

Reviewer 2 Report

  The manuscript clarifies the recrystallization mechanism of ODS alloy and the effect of additional plastic strain on the texture after recrystallization.  The authors successfully explain obtained data by "orientation pinning" and grain rotation.  The scheme to control recrystallization temperature and texture would be of great interest to the readers.  I have minor comments and suggestions to further improve the manuscript.

1. Line 91 to 95, I guess 80% of compression cannot be uniformly applied.  Which position of the compressed specimen was observed? 

2. In Fig. 3, which position in indented area was observed?

3. Line 249 to 251, in the authors' case, was the decrease in deformation stored energy detected?

4. Line 265 to 273, it would be of interest to the readers if the authors can provide the temporal development of microstructure in deformed region and its comparison with as-extruded one.

5. In Fig. 4(b) and (c), the captions in the figure are "N80" and "L80" in (b) and (c), respectively.  These should be swapped.

Author Response

Response to comments are in the report attached

Author Response File: Author Response.pdf