Effect of Heating Rate on Microstructure and Corrosion Resistance of Quenched and Tempered 8620 Low Carbon Alloy Steel
Round 1
Reviewer 1 Report
Comments and Suggestions for AuthorsThe manuscript under review aims to correlate the Heating Rate on Microstructure and Corrosion Resistance of Q+T 8620 Low Carbon Alloy Steel. There are several shortcomings within the text:
1. The authors must quantify the microstructural features of Martensite and ferrite.
2. Figure 2f and 2h: The authors state that the ferrite phase is detected. However, this is not clear from the provided micrographs. Optical metallography would be more suitable, and I highly recommend using it instead of the SEM/SEI images currently used.
3. Page 4, Paragraph 2.4: It is not clear which method was used. Hardness measurements (as it is suggested by the HRC method and the load used) or microhardness measurements as it is stated in the text?
4. Page 10, lines 332-334 "It is reported that tempering around 500°C (considered a moderate tempering) provides reduction in misorientation, grain coarsening, less acicularity, and higher spheroidization (see Fig. 2 f and h). None of the features given in Fig. 2f and 2h are consistent with those characteristics. The authors must explain grain coarsening, acicularity, and spheroidization in relation to the referred Figures.
The reviewer strongly recommends that the shortcomings be addressed and the paper be reconsidered
Author Response
Please see the attachment.
Author Response File: 
Author Response.pdf
Reviewer 2 Report
Comments and Suggestions for AuthorsThank you for your hard work on writing the paper. Please make the following revisions:
1. abstract, “Mechanical testing indicated that SR samples had higher hardness than FR, although hardness decreased for both after tempering.” How many decreased? Please present the value in a format that is easy for the readers to understand.
2. abstract, “Electrochemical tests demonstrated superior corrosion resistance in as-quenched SR specimens compared to FR.” Which test results showed an improvement in corrosion resistance? How much did the values change? Please specify the values.
3. Label Figure 1 as "DI Water Quenching."
4. Please enhance the caption.
5. In ASTM G 61, a scan rate of 0.167 mV is used. A scan rate of 1 mV is considered very fast. Provide an appropriate explanation for choosing these conditions.
6. In Figure 2, distinguishing between martensite and pearlite is challenging. Please include EBSD or TEM results.
7. Didn't you measure the volume fraction? If you want to discuss phase growth, include the volume fraction results.
8. The microstructural changes due to heat treatment condition are critically important. However, the analysis results only include FE-SEM images. Please add XRD or similar data.
9. Please correct experimental method. “the potential was swept between -0.5 V and +1.5 V” （images see attached PDF file）
10. You mentioned that the formation of martensite changes the mechanical properties. This is a well-known fact. Include hardness results in the conclusion. Presenting them along with the phase fraction will make it easier to explain the results.
11. “The quenching heat treatment increased hardness factor by 2.6 and 3.2 folds, respectively, for FR and SR and then dropped after tempering by approximately 6 and 11 HRC for Temp FR and Temp SR, respectively.” This is result. Please explain what this means.
12. All conclusions need to be revised as they currently only state the results.
Comments for author File: Comments.pdf
English needs to be revised overall.
Author Response
Please see the attachment.
Author Response File: Author Response.pdf
Round 2
Reviewer 1 Report
Comments and Suggestions for AuthorsThe manuscript in the revised version has been considerably improved.
Reviewer 2 Report
Comments and Suggestions for AuthorsThe content of the paper is acceptable.
