Effects of Rare Earth Elements on Microstructure and Mechanical Properties of H13 Die Steel
Round 1
Reviewer 1 Report
The paper describes the effect of the addition of a small amount of rare earth elements on the mechanical properties and carbide structure of a H13 die steel.
The results are interesting and clear, but there a few points that need further clarification.
One type of carbide is identified as Cr7C3 type, but more proof needs to be added. Cr7C3 carbides contain a large amount of stacking faults that lead to streaking in the diffraction pattern.
No such streaking can be observed in the diffraction pattern of Figure 3, neither can stacking faults be observed in the image. Can you comment on this issue? Do you have other arguments to be sure
that they are Cr7C3 type?
The diffraction pattern in figure 4 is wrongly indexed. No fcc crystal structure can have 232, 332 or 500 reflections. Do you have a better diffraction pattern to show the M23C6 crystal structure?
Does the observation that carbides are more likely formed at the grain boundaries after the addition of rare earth elements mean that fewer type 1 carbides are formed? Can you add a short discussion on that?
whereas it is mentioned that the rare elements are Y, La and Ce, their concentrations are not individually given in table 1. Can these data be provided?
Figure 2e and f shows EPMA data, but it is not explained what signal is used for these images. Are they C maps. A short description of the EPMA measurement needs to be added to the experimental.
Error bars need to be added to the mechanical properties to show that the differences that are measured are statistically relevant
The manuscript needs a revision about language, a few comments are added in the attachment.
Comments for author File: 
Comments.pdf
Author Response
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Author Response File: Author Response.pdf
Reviewer 2 Report
I have only editorial comments:
- In Table 1 - I propose to reduce the number font (chemical composition)
- on lines 132, 135 and 151 - Record the chemical formula of carbides in subscripts,
- Fig. 5 d- I suggest slightly increasing the font size of the chemical composition peaks,
- lines 238-249 - reduce the font size.
Author Response
Please see the attachment.
Author Response File: Author Response.pdf
Reviewer 3 Report
Paper is interested, but some corrections-additional informations are required:
- In Keywords term "thermodynamic calculation" is redundant. In text there is no such calculations...
- No full description of material production (mass of billet, type of furnace, mode of RE addition)
- O and N contents in chemical composition are required
- Hardness measurement conditions are doubtfull. Applied load was really 3 kG? Standard condition is 30 kG (294,3N)
- If melt contained N vanadium compound is complex carbonitride V(C,N), not VC (see Met. Trans A, 1987 (18A) 212 or Mat. Sc.&Tech., 1992 (8) 406). V shows higher chemical affinity to N in comparison with C
- References 8, 12 and 15 are exactly the same one publication...
- References 16 and 17 are incomplete (titles ?)
Author Response
Please see the attachment.
Author Response File: Author Response.pdf
