Tundish metallurgical technology of advanced automotive sheet
MA Wen-jun1, LI Hai-bo1, LIU Guo-liang1, ZHU Ke-ran2
1. Research Institute of Technology, Shougang Group Co., Ltd., Beijing 100043, China; 2. Qian'an Iron and Steel Company,Shougang Co., Ltd., Tangshan 064400,Hebei, China
Abstract:High-grade automobile sheet has a higher proportion of inclusion defects during the subsequent rolling or stamping process. In order to further improve the metallurgical effect of the tundish, the influence of the perforated dam of the tundish on the removal of inclusions during the normal casting process was studied. In order to ensure the consistency of the cleanliness of molten steel, a dam without holes is used on one side, and a perforated dam is used on the other side of the same tundish. Tundish molten steel samples and slab samples are taken, and analyzed by Aspex inclusion automatic scanning electron microscope. The results show that the dam without holes is beneficial to removal of inclusions in the tundish. There is a short-circuit flow in the molten steel flow field in the tundish of the perforated dam. This leads to a short residence time in the tundish, and inclusions don't have enough time to float up. It floats up and enters the crystallizer and slab with the molten steel. Therefore, the cleanliness of the molten steel cast by the dam without holes tundish is better than that of the perforated dam tundish.
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