Effect of Tungsten Carbide Morphology, Quantity, and Microstructure on Wear of a Hardfacing Layer Manufactured by Plasma Transferred Arc Welding

Round 1

Reviewer 1 Report

The Effect of tungsten carbide morphology, quantity and microstructure on wear properties of tungsten carbide hardfacing layer were investigated in this manuscript. Three morphological types of tungsten carbide powder were used during the plasma transferred arc welding process. However, the poorly preparation and lack of good understanding of the results makes this manuscript inadequate for publication.

Here are the points to consider for revision of the manuscript:

 

1. The author described the decomposed area of WC particle was intermetallic compounds based on EDS data. What kind of intermetallic compounds? No XRD, TEM data and other references to support this statement.
2. In section 4.2, the author used length fraction of WC to show the IMCs effect on the wear properties. It is not accurate. Volume fraction is more accurate than length fraction.
3. In this study, the purpose of using Fe-V-based material as binder should be clear.
4. Line 82, how much welding layers of WC deposited for the 4 mm thick overlay? What is the substrate temperature?
5. Line 97, to my knowledge, the voltage should be 26V, the current should be 150A.
6. Line 115, What is ‘Sound hardfacing samples’?
7. The results were not well discussed, no references were cited in the discussion part.
8. Line 165, how to distinguish the BM and WC just by surface optical microscope image?
9. Line 194, I have not seen the results of SWC45 and SWC 55.
10. HRC test in the manuscript make no sense to show the difference of samples. Microhardness is more useful.
11. A lot of typo were found in the (1) Line 36, ‘are’ should be ‘arc‘.; (2) Line 96 ‘Table 3’ should be ‘Table 4’. (3) Line 163, ‘Fig.7’ should be ‘Fig.6’. (4) Line 214，Position 4 of the binder metal should be ‘Position3’. (5) Line 217，isolated ridges(Position3) should be ‘(Position4)’.

Author Response

The author would like to great thank to your kind and helpful advice. Please check the answer and the modified manuscript.

Author Response File: Author Response.pdf

Reviewer 2 Report

The manuscript is prepared properly and clearly. Some good results are obtained. However, there are also some errors in the article. 
The following comments are for the author's reference when revising. 

1. The surfaces after abrasion test (Figure 7) are suggested to be observed by SEM for a scientific research paper.
2. The interfacial phases formed after PTAW should be characterized in detail. Just providing their EDS results is not enough.
3.  The discussion section should be rewriten to include the scientific mechanisms concerning the phase evolution of the hardfacing layer, the abrasive wear mechanism and the stress concertration around particles.

Author Response

The author would like to great thank to your kind and helpful advice. Please check the answer and the modified manuscript.

Author Response File: Author Response.pdf

Reviewer 3 Report

The results presentation should be improved to lead a better understanding:

1) in page 3, between line 77 and 91, it is necessary to precise the thickness of the coatings used for wear tests and for hardness tests, all samples have the same thickness ? all samples have the same machining conditions ? For wear test, it is extremely important to indicate the measurement precision; for hardness test, it is absolutely necessary to precise the associated errors and discuss the corresponding validity of indentation mark size with 150g comparing to WC particle size;

2) in figure 3, it is necessary to add a scale;

3) in figure 5 and figure 9, it is important to add error bars;

4) in figure 6 and figure 10, it is necessary to put error bars;

5) in caption of figure 7, it is neceessary to precise explicitely what are the BM, SWC and FWC;

6) in caption of figure 11 and figure 12, it is necessary to precise the sample coating condtions (or corresponding sample name); in figure 12, it is important to give quantitative information about the bottom and top zone in total thickness of coating;

7) in caption of table 5 and 6, it is important to precise the corresponding unit (wt% or vol%); it is also necessary to  precise the mresutement precision;

8) in figure 13, it is important to put error bars, in caption of figure 13, it is necessary to precise the sample name and the corresponding test conditions;

9) in discussion part it is extremely important to cite previous works with bibliographic references. 

 

Author Response

The author would like to great thank to your kind and helpful advice. Please check the answer and the modified manuscript.

Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

The author just changed ‘IMC’ to ‘Intermediate phases (IPs), EDS data could not support the statement of IMC or IP formation. XRD and TEM works and other references  are needed for this statement.

Author Response

Thank you for your comments. Several literatures reported that Cr- [14, 17] and V- [18] containing particles are identified after PTAW. Further analysis is required to clearly identify the IPs using XRD or TEM.

Reviewer 2 Report

Despite the numerous laguage errors, I suggest to reject this paper for its lack of scientific contribution.  

Author Response

Thank you for your effort and time to review the manuscript. This manuscript has been quite improved with reviewers' comments.

Reviewer 3 Report

in the revised version of the manuscript, author has made necessary corrections including all remarks from reviewers. 

Author Response

Thank you for your comments. This manuscript has been quite improved with reviewers' comments.