Characterization and Corrosion Resistance Behavior of Shape Memory Stainless Steel Developed by Alternate Routes

Round 1

Reviewer 1 Report

The manuscripts describe the Fe-Mn-Si-Cr-Ni alloy with shape memory effect under different mechanical processing conditions and heat treatments. Discuss more about the importance and also more references in the introduction section. Also minor english correction need to be done.The manuscript is good to publish with this correction.

Author Response

Response to Reviewer 1 Comments

Comments and Suggestions for Authors

The manuscripts describe the Fe-Mn-Si-Cr-Ni alloy with shape memory effect under different mechanical processing conditions and heat treatments. Discuss more about the importance and also more references in the introduction section. Also minor english correction need to be done.The manuscript is good to publish with this correction.

RESPONSE:

Now it is more discussed about the importance of such alloy, respective applications and a way to reduce its production costs.

More importante references were introduced and better discussion with the alredy presented ones.

Minor English corrections done.

Author Response File: Author Response.pdf

Reviewer 2 Report

The present study conducted microstructural characterization and corrosion resistance behavior of Fe-Mn-Si-Cr-Ni alloy with SME, under different mechanical processing conditions and heat treatments. Some results are valuable but need to more evidences.

Please give a clearer explanation of the Fig.1, It is very difficult to find what is the differences under different mechanical processing. Fig.1(a,d,g) are a SEM image? Why Fig.1 (c) have a different scale. It is better to give a clearly EDS element analysis in Fig.2. In line 204, mass grains should be mass gains. Please explain why there are two mass grains in two stages, before and after 600 °C, under the heat-treated condition. In your conclusions: 1.the cast condition exhibited a dendritic structure and the presence of the secondary phases: ferrite-δ and Chi-X phase. 2.The heat treatment eliminated phases, reincorporated elements in the matrix, and increased the austenitic grain. 3. After the hot rolling process, a refined microstructure with recrystallized austenitic grains was observed. 4. The heat-treated condition presented better resistance to oxidation than the others. Everyone need more clear image and more evidences for better understanding.

Author Response

Author's Reply to the Review2 Report (Reviewer 2)

Comments and Suggestions for Authors

The present study conducted microstructural characterization and corrosion resistance behavior of Fe-Mn-Si-Cr-Ni alloy with SME, under different mechanical processing conditions and heat treatments. Some results are valuable but need to more evidences.

Please give a clearer explanation of the Fig.1, It is very difficult to find what is the differences under different mechanical processing.

Now it is better discussed and ilustrated what are the the containing phases and what the heat treatment caused and also the mechanical processing. The cast condition exhibited a dendritic structure and the presence of the secondary phases: ferrite-δ and Chi-X phase. The heat treatment eliminated phases, reincorporated elements in the matrix, and increased the austenitic grain. After the hot rolling process, a refined microstructure with recrystallized austenitic grains was observed

Fig.1(a,d,g) are a SEM image? Why Fig.1 (c) have a different scale.

Yes, Figures 1 (a, d, g) are SEM IMAGES. Different scales removed.

It is better to give a clearly EDS element analysis in Fig.2.

Figure 2 was removed because it was not good presentation. The same values obtained are presented in table 2. The description of where does the elements came from and what they represent are weel defined

The sulfide inclusions are mostly of manganese sulfide (MnS) due to the high Mn content of the alloy. Sulfur, which has low solubility in steel, has a high affinity for Mn and forms sufficiently high melting point inclusions and stability to prevent network precipitation in the form of films between interdendritic spacings, as occurs with iron sulfide inclusions (FeS). These inclusions have a low melting point and can cause hot cracking in the material during the next steps of thermomechanical processing. The oxide inclusions come from the oxidation reactions of the metallic bath during the induction furnace casting process without a protective atmosphere. Also, exogenous inclusions rich in aluminum and silicon occurs due to dragging erosion products of the refractory material of the furnace wall and sand mold during the alloy casting process. Normally, non-metallic inclusions are undesirable for the mechanical performance of metallic materials, as they can significantly affect material properties such as ductility, toughness, corrosion resistance, and fatigue life.

In line 204, mass grains should be mass gains. Please explain why there are two mass grains in two stages, before and after 600 °C, under the heat-treated condition.

Now its corrected. MASS GAINS and better explanation for its behaviors.

In your conclusions: 1.the cast condition exhibited a dendritic structure and the presence of the secondary phases: ferrite-δ and Chi-X phase. 2.The heat treatment eliminated phases, reincorporated elements in the matrix, and increased the austenitic grain. 3. After the hot rolling process, a refined microstructure with recrystallized austenitic grains was observed. 4. The heat-treated condition presented better resistance to oxidation than the others. Everyone need more clear image and more evidences for better understanding. 

Everything now have better evidences for understanding.

 Author Response File: Author Response.pdf

Reviewer 3 Report

Different phases migh be clearly named and pointed out with arrows in figure 1

In several tables some words are not written in english.

More occurate explainations on the physico-chemical phenomena that make the corrosion resistance after heat treatment will be very interesting to improve this paper. The same remark can be made for all very interresting results observed.

Author Response

Comments and Suggestions for Authors

 Different phases migh be clearly named and pointed out with arrows in figure 1

Now they are better presented and indicated with arrows

In several tables some words are not written in english.

Corrected

More occurate explainations on the physico-chemical phenomena that make the corrosion resistance after heat treatment will be very interesting to improve this paper. The same remark can be made for all very interresting results observed.

According to the literature , the corrosion resistance of stainless steel strongly depends on the properties of the passive film formed on the surface, including thickness, chemical composition, compaction, and stability. Pitting corrosion resistance is noble with the refined microstructure, which can be attributed to the formation of a more stable and compact passive film. Improved corrosion resistance has already been attributed to grain refinement, because surfaces with high grain boundary density has the ability in faster passivation.

 Author Response File: Author Response.pdf

Round 2

Reviewer 2 Report

The authors gave the appropriate answer to reviewer, and the paper is indeed easier to understand than before, I am not further comments on that.

Author Response

PERFECT

Author Response File: Author Response.pdf