Finite Element Analysis of Dynamic Recrystallization of Casting Slabs during Hot-Core Heavy Reduction Rolling Process
Round 1
Reviewer 1 Report
This study aims to optimize the parameters of the hot-core heavy reduction rolling process considering the effect of the dynamic recrystallization (DRX) on microstructure homogeneity. The calculations included two stages of continuous casting and rolling, using ABAQUS and DEFORM-3D respectively to obtain the temperature evolution of the slab and the deformation and the dynamic recrystallization behavior of the hot-core heavy reduction rolling process for different reduction ratios. The influence of the reduction amount on DRX and microstructure homogeneity in terms of thickness was investigated. The manuscript worth publication since it meets all the standards of the Journal. The structure of paper is clear while the English language is used proficiently. The results presented are reasonable achieving the objectives.
Author Response
Dear Reviewer:
On behalf of my co-authors, we thank you very much for giving us an opportunity to revise our manuscript, we appreciate you very much for the positive and constructive comments and suggestions on our manuscript entitled “Finite Element Analysis of Dynamic Recrystallization of Casting Slabs during Hot-core Heavy Reduction Rolling Process”. (Manuscript ID: metals-698345). we would like to express our great appreciation to your warm work earnestly.
Sincerely,
Tianxiang Li
Reviewer 2 Report
Very interesting subject, detailed literature survey and conclusions adequate to yhe presented results. Although a few remarks are as follows:
Line 46: A HR technology named "Forging" [11] ...
The name "forging" is related with particular technology. Precisely speaking, one can say that "HR technology was CLASSIFIED AS FORGING [11] ..." or CLASSIFIED AMONG FORGING TECHNOLOGY.
Fig.1
At least the main components of the production line - mill, caster machine, ... - should be pointed out in the figure.
Line 110: A tetrahedral mesh was used, and the number of elements is 15320.
In the FEM analysis, the good practice is to perform model optimization first, ie. check sensitivity of the model to the the mesh density, which is known to be crucial for further results quality. There is no information in the article if any model optimization was carried out. If not, on what basis the number of elements was assumed? Earlier experiments/experience?
line 112: The temperature-dependent material properties ...
Not precise. Other authors studies or authors' own ones?
Line 125 (the whole paragraph)
How many experiments/specimens described in this paragraph have been made for further analysis? And following question is, if next results are individual examples or average values taken from experiments carried out? eg. in Fig 6?
Line 216: Figure 11 shows the distribution of the DRX volume fraction.
Better/mode precise seems to be : Figure 11 shows CALCULATED distribution of the DRX volume fraction.
A few grammar/language/edition remarks:
Abstract, line 16: The secondary development ...
Sentence needs to be corrected.
Line 126: According to a previous work [19]...
Superscript for [19] not needed.
Figure 6
Description is on another page than the tifure itself.
Author Response
Dear Reviewer:
On behalf of my co-authors, we thank you very much for giving us an opportunity to revise our manuscript, we appreciate you very much for the positive and constructive comments and suggestions on our manuscript entitled “Finite Element Analysis of Dynamic Recrystallization of Casting Slabs during Hot-core Heavy Reduction Rolling Process”. (Manuscript ID: metals-698345). Those comments are all valuable and very helpful for revising and improving our paper, as well as the important guiding significance to our researches. We have studied comments carefully and have made correction which we hope meet with approval. Revised portion are marked in red in the paper.
The main corrections in the paper and the responds to the comments are as flowing:
Line 46: A HR technology named "Forging" [11]
The name "forging" is related with particular technology. Precisely speaking, one can say that "HR technology was CLASSIFIED AS FORGING [11] ..." or CLASSIFIED AMONG FORGING TECHNOLOGY.
Response: Thank you for the suggestion. We have modified the sentence “A HR technology named "Forging" [11] was used in continuous casting bloom...” into “A HR technology classified among forging technology [11] was used in continuous casting bloom”.
Fig.1 ----At least the main components of the production line - mill, caster machine, ... - should be pointed out in the figure.
Response: Thank you for the suggestion. We have modified this figure according to the previous comment.
Line 110: A tetrahedral mesh was used, and the number of elements is 15320.
In the FEM analysis, the good practice is to perform model optimization first, ie. check sensitivity of the model to the the mesh density, which is known to be crucial for further results quality. There is no information in the article if any model optimization was carried out. If not, on what basis the number of elements was assumed? Earlier experiments/experience?
Response: Thank you for underlining this deficiency. The number of elements are according to the calculation experience of rolling process of medium plate, whose mesh density can ensure the accuracy of the calculation.
Line 112: The temperature-dependent material properties ...
Not precise. Other authors studies or authors' own ones?
Response: Thank you for underlining this deficiency. We have added the missing information, and it was modified as “The temperature-dependent material properties such as Poisson's ratio, Young modulus, thermal conductivity, and specific heat were obtained from authors' own studies [18], which covered the temperature range of the HHR2 process.”
Line 125 (the whole paragraph)
How many experiments/specimens described in this paragraph have been made for further analysis? And following question is, if next results are individual examples or average values taken from experiments carried out? eg. in Fig 6?
Response: Thank you for the suggestion. The whole paragraph has been changed as follows:
“According to a previous work [19], for the Nb–Ti microalloyed steel selected in this study, hot compressive deformation tests were conducted using a Gleeble-3800 thermo-mechanical simulator. The specimens were reheated to 1400 °C and held for 180 s to ensure that the austenite grain size was close to the coarse grain size of the original continuously cast slab. Next, they were cooled at the deformation temperature and held for 15 s. The tested temperatures were 850–1350 °C, and the strain rates ranged from 0.01s-1 to 1s-1. After deformation, the specimens were water quenched to room temperature to retain austenite morphology at high temperatures. The quenched samples were polished to mirror finish and etched in saturated picric acid by adding a wetting agent and hydrofluoric acid in a water bath heated at 70 °C for approximately 145 s. Based on the above experimental method, three paralleled tests were carried out, and the average values were used in modeling to reduce the experimental error.”
Line 216: Figure 11 shows the distribution of the DRX volume fraction.
Better/mode precise seems to be: Figure 11 shows CALCULATED distribution of the DRX volume fraction.
Response: We are grateful for your suggestion. We have made modifications according to your previous comment.
A few grammar/language/edition remarks:
Abstract, line 16: The secondary development ...
Sentence needs to be corrected.
Response: We are very sorry for our mistake, and we have modified this sentence as follows “The secondary development of commercial software DEFORM-3D is conducted to calculate the deformation and DRX behavior of HHR2 for different reduction ratios.”
Line 126: According to a previous work [19]...
Superscript for [19] not needed.
Response: We are very sorry for our negligence, and we have modified it according to your suggestion.
Figure 6
Description is on another page than the tifure itself.
Response: We are grateful for the suggestion, and we have made some adjustments to ensure that the description and figure are located in the same page.
At last, we would like to express our great appreciation to you for comments on our paper. Looking forward to hearing from you.
Thank you and best regards.
Sincerely,
Tianxiang Li
