Austenite grain growth in tailored cooling rate experiment designed by numerical simulation for peritectic steel
Year: 2024
Type: article
Abstract: A heat transfer model for steel solidification in Al2O3 crucial and permanent mold by finite element method was developed, and validated by temperature measurement. The multi-gradient operation was newly designed, and the tailored cooling rate in range of 0.1~10°C/s can be obtained in the target location of the large-sized ingot. The experiment was carried out and the local cooling rate was verified by the result of secondary dendrite arm spacing. The size of austenite grain decreases slightly as cooling rate increases from 0.15°C/s to 0.31°C/s, and then increases dramatically in the range of 0.31~0.48°C/s, finally decreases with cooling rate increasing further. The relationship between austenite grain size and cooling rate was logarithmically regressed in the range of 0.48~9.76°C/s, in which the empirical equations on basis of cooling experiment and continuously cast slab can also predict the similar results. Based on the mechanism of peritectic transformation, it is concluded that the austenite grain growth is mainly controlled by diffusion at a low cooling rate smaller than 0.31°C/s, and the final grain size is less than 1.0mm. At a medium cooling rate between 0.48~3.60°C/s, austenite grain growth is accelerated by the energy stored during massive type peritectic transformation, and the grain size is between 1.7~2.9mm. At a high cooling rate larger than 9.76°C/s, the austenite grain grows to about 0.9mm in columnar shape. The time for grain growth not adequate, although addition energy storage by massive transformation can also occur. The austenite grain evolution is significantly affected by previous peritectic transformation.
Authors: Peng Lan, Huasong Liu, Jiaquan Zhang, Yifan Lu, Lirui Zhang
Institutions: University of Science and Technology Beijing, Ansteel (China)
Language: English
Subfield: Materials Chemistry
Field: Materials Science
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $1,430
OpenAlex ID: W4403264075