Plate blank cooling and pressing method for improving quality of casting blank

Abstract

The invention belongs to the technical field of continuous casting, and particularly relates to a plate blank cooling and pressing method for improving the quality of a casting blank. According to the method, cooling water is adopted to control the surface temperature of the casting blank at a horizontal section of the casting blank, the internal and external temperature difference of the casting blank is increased, then the casting blank is pressed at an outlet of a casting machine, and therefore effective transfer of pressing deformation to the center of the casting blank is achieved, and the center porosity of the casting blank is improved. Meanwhile, the surface temperature of the casting blank is reduced to be below the phase change temperature, then the phase change occurs again through rolling heating, casting blank surface layer grains are refined through circulating phase changes of the casting blank surface layer structure, casting blank plasticity is improved, and the rolling crack occurrence rate is reduced. In order to prevent corner cracks from being generated in the pressing process due to low corner temperature of the casting blank, a heating device is arranged at the corner position of the casting blank after the casting blank is taken out of the casting machine, and the corner temperature of the casting blank is increased. The method is greatly helpful for improving the surface quality and the internal quality of products.

Description

technical field [0001] The invention belongs to the technical field of continuous casting, and in particular relates to a slab cooling and pressing method for improving the quality of the slab. The method can improve the rolling of the slab by cooling and pressing the slab according to the requirements of the steel type for the quality of the slab. Surface quality and internal quality, this method can not only improve the surface structure of the slab, but also improve its internal quality. Background technique [0002] In the production process of metallurgical continuous casting, the internal and external quality of the slab is a matter of great concern to metallurgical workers. The internal quality of the slab is mainly manifested in uniform composition, no looseness, no shrinkage cavity, no cracks, etc., and the external quality is no slag inclusions, no cracks, etc. These defects will be inherited to subsequent rolling products, so it is hoped to produce The internal s...

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Problems solved by technology

[0003] Patent CN106735026A mentions a single-point heavy reduction method, which uses a pair of support rollers in a sector to press the slab, and performs heavy reduction at one point in a short period of time. This method belongs to a high-pressure Deformation rate heavy reduction method, this method is better for solving the problem of central looseness of the slab, because the reduction distance is less effective for segregation problems

Patents CN106001476A and CN102921914B mention a two-stage continuous casting heavy reduction method. This method uses light reduction and heavy reduction for blooms and wide and thick slabs to solve the problem of segregation and loosening of the cast slab. The method uses multiple segments For the reduction in a longer distance range, the deformation rate of this method is low, and it is a low deformation rate deformation method. This method has certain limitations on product specifications and steel types, and is less effective in solving the problem of slab segregation. Good, not very efficient for thicker slab porosity problems

Lee CN104057049B and CN104858383A propose a continuous casting machine segment under heavy pressure at the end of continuous casting slab solidification and its heavy reduction method, which is characterized in that a large roll diameter drive roll is placed in the middle of the sector, which is equivalent to a large roll diameter rolling mill This is more conducive to improving the looseness of the central area of ​​the continuous casting slab, but this method has a certain distance from the inlet cylinder of the sector because the large roll is in the middle of the sector, which limits the play of the reduction

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