On the Short-Term Creep Response at 482 °C (900 °F) of the 17-4PH Steel Produced by Bound Metal Deposition

Round 1

Reviewer 1 Report

Abstract - missing key numerical results

Minor English language issues - please check carefully.

Very well written and balanced introduction

Some issues with table formatting (line numbers) in table 1.

Undefined acronym LVDT

Experimental detail lacking in some places. There should be sufficient information for an independent reviewer to repeat the study. Please add in further detail. 

Generally the results seem realistic, the discussion is balanced and effective.

The data is likely to be useful, but the experimentation is routine. The key novelty is the new production approach.

Author Response

Please, find enclosed our replies to the reviewer 1 suggestions.

 

Abstract - missing key numerical results

R: We included the most important numerical details (range of applied stress, reduction of the creep strength)

 

Minor English language issues - please check carefully.

R: the language of the second draft was thoroughly revised.

 

Very well written and balanced introduction

R: We thank the reviewer for his/her comment.

 

Some issues with table formatting (line numbers) in table 1.

R: We are not sure on the nature of the problem, but in any case, we reformatted the table.

 

Undefined acronym LVDT

R: The meaning of the acronym was provided in the revised draft.

 

Experimental detail lacking in some places. There should be sufficient information for an independent reviewer to repeat the study. Please add in further detail.

R: We tried to include as many experimental details as possible. We are confident that enough information is available to repeat the experiments.

 

Generally the results seem realistic, the discussion is balanced and effective. The data is likely to be useful, but the experimentation is routine. The key novelty is the new production approach.

R: We thank the reviewer for his/her comment. We fully agree with his/her opinion.

Reviewer 2 Report

This work is devoted to interesting studies of creep of samples obtained by bound metal deposition on the example of 17-4PH martensitic aging steel. The paper is well-written, results and discussion are described in logical manner. I can recommend this paper for publication, however some moments should be considered by authors:

• The aim of the study is not clearly described. Therefore, it is not clear, why D1 state was studied after H1150 and H900 treatment, whereas D2 state was studied only after H1150 treatment.
• Fig. 4, figure capture: As I understand, in the figure capture “for D2 H900” should be changed by “for D1 H900”.
• Fig. 9, figure capture: Please, add information about this crept sample: treatment (H900 or H1150), creep stress.
• Paragraph 3.2. It seems that creep behavior of D1 and D2 (in H1150 state) differs not only by the steeper tertiary stage of D2, but also by the shorter “steady-state” (or minimum creep ) stage of D2.
• Unfortunately, authors do not present the microstructure of the studied steel samples. Discussion of the effect of H1150 and H900 treatment on the creep behavior is not confirmed experimentally. These results could strengthen the paper.

Author Response

Please, find enclosed our replies to Reviewer 2 comments

 

This work is devoted to interesting studies of creep of samples obtained by bound metal deposition on the example of 17-4PH martensitic aging steel. The paper is well-written, results and discussion are described in logical manner. I can recommend this paper for publication, however some moments should be considered by authors:

 

The aim of the study is not clearly described. Therefore, it is not clear, why D1 state was studied after H1150 and H900 treatment, whereas D2 state was studied only after H1150 treatment.

R: We tried to clarify the aim and rationale of the study (see the new paragraph at the end of Introduction)

 

Fig. 4, figure capture: As I understand, in the figure capture “for D2 H900” should be changed by “for D1 H900”.

R: the reviewer is correct, we modified the caption

 

Fig. 9, figure capture: Please, add information about this crept sample: treatment (H900 or H1150), creep stress.

R: we included the experimental stress in the caption.

 

Paragraph 3.2. It seems that creep behavior of D1 and D2 (in H1150 state) differs not only by the steeper tertiary stage of D2, but also by the shorter “steady-state” (or minimum creep ) stage of D2.

R: This comment is fully correct. We thus included a new paragraph in section 3.2

 

Unfortunately, authors do not present the microstructure of the studied steel samples. Discussion of the effect of H1150 and H900 treatment on the creep behavior is not confirmed experimentally. These results could strengthen the paper.

R: We in principle agree with this comment. On the other hand, during the study we realized that the creep response was heavily influenced by pre-existing defects. Thus, any attempts to correlate the microstructure (phases, dislocation substructures)  and the present data creep was devoid of any significance. A deep study of the microstructure would only result in a further analysis of the aged microstructure of 17-4PH, which is meaningless, since very detailed studies are already available in the literature. Thus, we included a new sub-section to properly outline this problem. Since we are well aware of the limitations of the present work, a further study on the creep response of the “bulk” steel, processed by traditional technology, is presently running in our lab. In that case, a detailed microstructural analysis will be carried out, and the results will be discussed in a further paper.

Round 2

Reviewer 2 Report

The authors revised their paper in accordance with the reviewer's suggestions.