Soft reduction method of continuous casting slab

Abstract

The temperature difference (cooling water inlet and outlet temperature difference) between a cooling water inlet side temperature and a cooling water outlet side temperature for a cooling water pathway (11) provided for each roll disposition position in which an upper and lower pair of rolls (8) is disposed is found for each roll disposition position. A regression equation that expresses the cooling water inlet and outlet temperature difference in a range from a first roll disposition position to an nth roll disposition position is found from the cooling water inlet and outlet temperature differences for each roll disposition position. The cooling water inlet and outlet temperature difference for each roll is calculated from the regression equation and set as a corrected cooling water inlet and outlet temperature difference. A thermal expansion correction value is found at each roll disposition position from the corrected cooling water inlet and outlet temperature difference for each roll and the relationship, which is found in advance, between the cooling water inlet and outlet temperature difference and the total value for the amount of thermal expansion (combined value for thermal expansion for frame (9) and thermal expansion for continuous casting piece). The amount of reducing by each roll is corrected on the basis of the thermal expansion correction value at each roll disposition position.

Description

technical field [0001] The present invention relates to a soft reduction method of continuously cast slabs for preventing slab segregation at the end of solidification of continuously cast slabs. In addition, in this specification, a continuous casting slab is also called a slab. Background technique [0002] Such as Figure 14 As shown, the continuous casting equipment has a structure in which molten steel 1 is injected into a casting mold 2, and a slab 10 obtained by cooling and solidifying molten steel 1 in the casting mold 2 is bent and aligned through a slab supporting structure. Support is performed, and the cast strand 10 is sent out of the casting mold 2 . The casting strand support structure described above is constituted by a plurality of roller sections 5 formed by supporting a plurality of rollers 3 arranged at the lower part of the casting mold 2 on the frame 4 . [0003] Additionally, if Figure 14 as well as Figure 15 As shown, in the continuous casting eq...

AI Technical Summary

Problems solved by technology

[0007] However, after actually trying this soft reduction method on continuous casting equipment, it was concluded that, compared with the case where the thermal expansion amount of the frame is not corrected, although this method can perform appropriate soft reduction, It has a certain effect on improving segregation and preventing internal cracks, but the problems of segregation and internal cracks still occur

In other words, only by correcting the thermal expansion of the frame, it is impossible to achieve high-precision roller spacing control and correct reduction gradient when performing light reduction. From this point of view, this method needs to be improved.

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