Duplex Stainless Steels for Thermal Energy Storage: Characterization of Oxide Scales Formed in Carbonate Salts at 500 °C

Round 1

Reviewer 1 Report

The manuscript, "Duplex stainless steels as potential materials for thermal Energy Storage: Characterization of Oxide Scales Formed in Molten Carbonate Salts at 500⁰C", is analysis with the oxide scales with two duplex stainless steels (DS2205 and DS2507) for thermal energy storage application. The molten salts with mixture carbonate salts at 500⁰C were immersion with above-mentioned duplex stainless steels in the alumia crucibles. The oxide scales on these two duplex stainless steels were characterization with surface analysis methods for morphology, crystalline, mechanical properties, such as, SEM, XRD, Raman and tribology and so on.  

In my point of view, this manuscript is fitting the publication standard. However, there are few points should be corrected as following: 

1. The title should be changed as following: Duplex stainless steels as potential materials for thermal Energy Storage: Characterization of Oxide Scales Formed in Molten Carbonate Salts at 500⁰C. The capital characters should be used. 

2. In Figure 7., the indication of the layers should be exactly showed.

 After minor revision, this manuscript could be publication in this journal. 

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Reviewer 2 Report

The manuscript is quite interesting, however it has some serious drawbacks as follows:

1.      The presence of the Sigma phase in duplex steel in as delivered condition is questionable.

2.      The quality of metallographic specimens is very poor (there are numerous pieces of debris and scratches), which translated into poor quality of the SEM results presented in Figures 4-7.

3.      SEM studies can be supplemented with images of backscattered electrons, mapping of elements. EBSD results can be an advantage.

Author Response

Please see the attachment.

Author Response File: Author Response.pdf