Hardness Prediction in Hot Stamping Process by Local Blank Heating Based on Quench Factor Analysis
Round 1
Reviewer 1 Report
The purpose of the study is to predict hardness for hot stamped parts by local blank heating based on quench factor analysis (QFA). Volume fraction of austenite was measured to consider phase transformation in heating stage. The dilatometry test was also performed to measure hardness according to cooling rates which was used to determine material constants for QFA. FE-simulation was carried out to predict temperature histories during hot stamping process and its results were used to predict hardness based on QFA. Hot stamping experiment with local blank heating equipment was preformed to compare between predicted and experimental results for verification of suggested hardness prediction method.
However, I have some questions related which have to be addressed to improve the quality of the manuscript
1. Some references are very old. I recommend removed references: 7, 14, 15, 16, 17, 18 and 19.
2. I recommend changing “Hv” for “HV” in all paper (text) and table 3, Figures 15 and 16, since it is more used in the literature (Vickers Hardness).
3. In the equation (4), line 124, it is necessary to indicate the units of the temperature “T”.
4. In line 153 y 155, it is necessary to change “ºC” for “°C”.
5. In line 166, there is a mistake, it is necessary to change “harness” for “hardness”. I recommend checking the English grammar.
6. In line 193, it is necessary to indicate the dimensions of the punch in order to other authors can reproduce the simulation.
7. In paragraph 3.3, can the authors explain what is the reason of the three ranges of values (900-720°C, 900-770°C y 900-8200°C), and the lowest value of 720°C?
8. In line 259, what is the measurement frequency of temperature?
9. In line 271, there is a mistake, it is necessary to change “Marensite” for “Martensite”.
10. In line 281, can the authors explain how the error rate of 4.52% is calculated?
11. I recommend making larger the graphs of figures 12 and 14. This is necessary to be able to appreciate the differences between the lines. It is also necessary to explain in the text that the temperatures T1, T2, T3 and T4 correspond with the points P1, P2, P3 and P4.
12. In the Figure 12 (a) the curve T2 shows a difference of more than 100°C between measurement and prediction. Is it accurate enough?
13. In line 242, paragraph 4.1, what is the pressure (in MPa) applied experimentally in the press?
14. Can the authors explain the advantages of the proposed procedure in the article (using QFA) in comparison with the results of the FE simulation (hardness distribution)? The proposed procedure is much more complicated and expensive.
Author Response
Thank you for your considerate review about the manuscript.
I attached response of your review as a word file.
Author Response File: 
Author Response.pdf
Reviewer 2 Report
Manuscript metals-402465, "Hardness prediction in hot stamping process by local blank heating based on quench factor analysis"
This paper presents an investigation on the prediction of hardness in a hot stamped sheet of boron steel. The work is well done, nevertheless remain some inaccuracies that can be easily clarified, so, and because the paper is well written and do not present critical errors, the manuscript is recommended for publication.
Various comments will be useful for the authors:
1. Page 1, and everywhere. The references [x] must be before the end of the sentence. E.g., at line 34, please write "...accuracy [3-4]."
2. Page 2. Line 71. Change "JMAK equation is empirical equation" by "JMAK is an empirical equation"
3. Page 3, and everywhere. Between the number and the unit there is one space (except on degrees). E.g., at line 85, is "0 min and 10 min", instead of "0min and 10min"
4. Page 5. Line 145. Vickers is a person name, so, at line 145 and everywhere, is HV instead of Hv
5. Page 7. Lines 187 and 189. “quasi-static” instead of “qusi-static”
6. Page 11. Figure 12. The graphs are too small. It is impossible to see well
7. Page 11. Figure 13.
- What means M1-M4? Do you mean P1-P4 of Figure 11? Please, change;
- The caption title is not good. What results?
8. Page 12. Figure 14. The graphs are too small. It is impossible to see well
9. Page 13. Conclusions. (1) and (2) are not conclusions. They refer what is done and it is fine. May be it is better to move these sentences to the beginning of the chapter
10. Page 13. Line 319. What is “high strange region”?
Author Response
Thank you for your considerate review about the manuscript.
I attached response of your review as a word file.
Author Response File: Author Response.pdf
Round 2
Reviewer 1 Report
The paper has improved with the changes.
