Characterization of macrosegregation and semi-macrosegregation in continuous casting bloom
JIANG Dong-bin1, ZHANG Li-feng2, CHEN Tian-ming3, LI Hong-guang3, LI Jian-quan4
1. School of Metallurgical and Ecological Engineering, University of Science and Technology Beijing, Beijing 100083, China; 2. Metastable Materials Science and Technology State Key Laboratory, Yanshan University, Qinhuangdao 066000, Hebei, China; 3. Panzhihua Iron and Steel Research Institute Co., Ltd., Panzhihua Iron and Steel Group, Panzhihua 617000,Sichuan, China; 4. Panzhihua Steel and Vanadium Co., Ltd.,Panzhihua Iron and Steel Group, Panzhihua 617000, Sichuan, China
Abstract:In order to obtain the distribution of macroscopic segregation and semi-macroscopic segregation in continuous casting bloom, the carbon-sulfur detection, chemical analysis, direct reading spectroscopy, and metal in-situ analysis were used to analyze the macrosegregation behavior of C and Mn elements in thickness direction of the bloom. The semi-macroscopic segregation distribution characteristics of continuous casting billet were investigated by low-power microstructure corrosion and image scanning processing. The result shows that the carbon-sulfur detection and direct reading spectroscopy detection are suitable for the macroscopic segregation detection of C. For the Mn segregation, the direct reading spectroscopy and metal in-situ analysis characterization methods are more appropriate. It also found the semi-macroscopic segregation degree can be quantitatively characterized by the semi-macroscopic segregation area ratio and the semi-macroscopic segregation degree. In the direction of the thickness of continuous casting bloom, the segregation of C and Mn elements fluctuates with the increase of the distance from the surface of the bloom, and the segregation is larger at the center of the bloom. The semi-macroscopic segregation mainly exists in the inner part of bloom, and the degree of semi-macroscopic segregation reaches the maximum in the dendrite transition zone and the center zone.
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