TY - JOUR

T1 - Solidification Principle in Large Vertical Steel Casting Under the EMS Effect

AU - Zhang, Zhao

AU - Wu, Menghuai

AU - Zhang, Haijie

AU - Hahn, Susanne

AU - Wimmer, Franz

AU - Ludwig, Andreas

AU - Kharicha, Abdellah

N1 - The authors acknowledge the financial support from the Austria Research Promotion Agency (FFG) through the Bridge 1 project (No. 868070) as well as the technical support of the industrial partner Primet-als Technologies Austria GmbH. On behalf of all authors, the corresponding author states that there is no conflict of interest. Open access funding provided by Montanuniversitat Leoben.

PY - 2023/5/19

Y1 - 2023/5/19

N2 - The surging demand for large high-quality rotor shafts or similar steel components in heavy industries (energy sector) poses new challenges to steelmakers. Based on the experience of conventional ingot and continuous casting, several new process concepts have been proposed, e.g., vertical continuous casting (VCC), semi-continuous casting (SCC), and segment casting (SC), but none of them are optimally put in operation. The main problems include the control of the as-cast structure and macrosegregation. Electromagnetic stirring (EMS) is necessary to obtain the center equiaxed zone, but EMS-induced multiphase flow can cause severe macrosegregation and uneven distribution of the as-cast structure between equiaxed and columnar. In this study, an advanced mixed columnar-equiaxed solidification model was used to investigate the formation of the as-cast structure and macrosegregation in an example of SCC with a large format (diameter 1 m). The main role of EMS is to create crystal fragments by fragmentation, which is regarded in this work as the only origin of equiaxed grains. The created equiaxed grains are brought by the EMS-induced (primary and secondary) flow and gravity-induced sedimentation to the central/lower part of the casting. The main goal of this study was to understand the solidification principle of SCC. In addition, a numerical parameter study by varying the EMS parameters was also performed to demonstrate the model capability towards the process optimization of SCC.

AB - The surging demand for large high-quality rotor shafts or similar steel components in heavy industries (energy sector) poses new challenges to steelmakers. Based on the experience of conventional ingot and continuous casting, several new process concepts have been proposed, e.g., vertical continuous casting (VCC), semi-continuous casting (SCC), and segment casting (SC), but none of them are optimally put in operation. The main problems include the control of the as-cast structure and macrosegregation. Electromagnetic stirring (EMS) is necessary to obtain the center equiaxed zone, but EMS-induced multiphase flow can cause severe macrosegregation and uneven distribution of the as-cast structure between equiaxed and columnar. In this study, an advanced mixed columnar-equiaxed solidification model was used to investigate the formation of the as-cast structure and macrosegregation in an example of SCC with a large format (diameter 1 m). The main role of EMS is to create crystal fragments by fragmentation, which is regarded in this work as the only origin of equiaxed grains. The created equiaxed grains are brought by the EMS-induced (primary and secondary) flow and gravity-induced sedimentation to the central/lower part of the casting. The main goal of this study was to understand the solidification principle of SCC. In addition, a numerical parameter study by varying the EMS parameters was also performed to demonstrate the model capability towards the process optimization of SCC.

KW - Vertical Steel Casting

KW - Solidification Principle

KW - EMS

KW - EMS Effect

U2 - 10.1007/s11663-023-02801-9

DO - 10.1007/s11663-023-02801-9

M3 - Article

VL - 54.2023

SP - 1078

EP - 1085

JO - Metallurgical and materials transactions. B, Process metallurgy and materials processing science

JF - Metallurgical and materials transactions. B, Process metallurgy and materials processing science

SN - 1073-5615

IS - August

ER -