Abstract: Accurately measuring the liquid fraction and the solidification end of the slab is of great significance to reduce internal defects such as central segregation and shrinkage porosity of the slab, and it is also great significance to improve the quality of slabs and productivity. In this paper, a new method is proposed to detect the liquid core thickness and the solidification end of the casting, which is achieved by controlling the low amplitude and low frequency vibration of the arc in the fan section, and at the same time extracting the fluctuation amplitude of the liquid level under the corresponding vibration frequency. According to the coupling relationship between the reduction efficiency and the thickness of the liquid core, as well as the rheological behavior of the slab in the solid-liquid coexistence zone under the periodic vibration of the inner arc of the segment, the mathematical relationship between the liquid core thickness and the liquid level fluctuation in the mold is deduced theoretically. The liquid core thickness and solidification end of the slab with different amplitude and different casting speed were tested in a steel plant, and the feasibility of the method was verified by comparison with the theoretical values. The results provide guidance and reference for the on-line detection of the liquid core thickness and the solidification end of the slab in the solidification process of continuous casting.

Key words: continuous casting slab, liquid core, online detection, reduction efficiency, mold level