Effects of Tempering Temperature on Mechanical and Tribological Behavior of Ductile Iron
Round 1
Reviewer 1 Report
The paper reports an investigation of mechanical properties and tribological behavior of ductile iron tempered at different temperatures: 420 oC, 500 oC and 580 oC. First, the materials and methods are presented and, second, the experiments with the effects of tempering temperature on material microstructure, on mechanical properties and wear properties are discussed.
This is an interesting investigation but maybe can be improved.
The introduction can be improved regarding the necessity of this new study. The paper is well written and presented while its theoretical foundation has moderate novelty. The present work’ connection with the open literature background is well presented but need more explanation.
Please explain how and why you chosen these 3 tempered temperature study at such high values? Why only these 3 temperature were used? Maybe a better understand of the behavior would be for 5 values if possible. And how you choose the interval of these values?
Also please add a discussion and explanation for the practical applicability of such materials! For what is used this paper study?
My specific comments are as follows:
-Please check all the paper regarding the spaces and font in the text:
for example:
at page 1, row 44, there is an added space before “heat”: “…Therefore, even the heat treatment processes similar to steels are adopted to ductile…”;
at page 2, row 59 there is a need a space before [23]: “…quenching[23]. Therefore, the martensite…”;
at page 3, rows 99-103, please correct the font: “…Wear tests were performed on a ball-on-plate machine under dry condition, as shown in Fig. 1. A GCr15 steel ball with a diameter of 9.5 mm and hardness higher than 62 HRC was set as the ball, and the tempered ductile iron with a diameter of 30 mm and thickness of 4 mm was set as the plate. The normal loads of 10 N, 15 N and 20 N were applied, the reciprocating….”;
at page 3, row 108 please correct the word: ” …profile-meter,..”;
at page 4, Figure 3, there is needed a correction of the spaces before 420, and, and (c)…
at page 9, row 246, the space before “the sample”: “…was obtained for the sample tempered…”
-Figures from Figure 3 should have an improved view of the text inside the images;
-All figures from Figure 7 need to be correct for an improved view of the black text in the images! The text is not visible.
- Regarding the experiments, at Figures 9 and 11 why you used only 3 loads? Maybe is better at least 5 values to be used here to improve the graphics.
Author Response
Please see the attachment.
Author Response File: 
Author Response.docx
Reviewer 2 Report
The manuscript reports on the study of tempering temperature effect on the mechanical and tribological behavior of ductile iron. The presented results would be interesting to materials communities. Thus, the manuscript can be recommended to be published in Lubricants after the authors addressing the following comments/concerns.
Introduction
Lines 44, 53, 55, 145, 181, 243, 246, … – odd spaces.
Line 58 – missing word after “martensitic” or should be “martensite”?
Lines 59, 140, 138, 255 – missing space?
Materials and Methods
Line 79 – missing word after “cylindrical”?
Results and Discussions
Line 138 – white captions in the figure are not very well distinguishable.
Line 153 – Figs. 3 and 4 - Were the sizes of plates and carbide particles determined?
Line 160 – From Fig. 5 it is not obvious that “the diffraction peak of (200)α shifted toward a higher angle with the increasing tempering temperature”. Perhaps it is worth showing a section of the diffraction pattern with 2 theta in the range of 60-70 degrees?
Line 204 – black captions in the figure 7 are not very well distinguishable.
Lines 216, 218, 221 – “Fiction coefficient” – typo “Friction”.
Line 224 – typo, missed preposition “at 500°C”.
Lines 238-239 – Is the sentence “Consequently, the sample tempered at 420 ℃ showed the lowest friction coefficient when the load was 10 N” wrong? The load should be equal to 15 N?
Line 265 – Wrong reference to figure (Fig. 11e and h)?
Line 273 – double referenced to figure 12.
Line 285 – Wrong reference to figure (Fig. 13f)?
Line 286 – the word “sample” is repeated twice.
Line 293 – dot twice.
Line 314 – the word “tempered” is repeated twice.
Lines 319-320 - "friction coefficient of the sample" or "the sample increased"?
However, these comments do not reduce the relevance and importance of the results. The article is sufficiently novel and interesting to warrant publication. Results and discussion are reliable. References reflect the main publications on which the work is based.
Author Response
Please see the attachment.
Author Response File: Author Response.docx
Reviewer 3 Report
This manuscript discribed the effects of annealing/tempering temperature on the wear properties of the DCIs. It is quite interesting that the friction coefficient is quite and almost does not vary with annealing temperature, which may result from the granular graphite phase. It is revealed that the wear lost of the DCIs is mainly controlled by the applied load. The results are useful to the application of DCIs and the explantion is reasonable. Thus I would like to recommend this manuscript to be published in this journal after a minor adding of the information about comparison of the friction coeffecients of this DICs with others that published in literature.
Author Response
Please see the attachment.
Author Response File: Author Response.docx
