Method for preventing narrow surface of continuous casting sheet billet from bulging

Abstract

The invention discloses a method for preventing the narrow surface of a continuous casting sheet billet from bulging. The method comprises the following measures of: (a) figuring out the heat transfer flux of a narrow-surface copper plate of a crystallizer through the following formula: the heat transfer flux of the narrow-surface copper plate is equal to a product of a flow rate of cooling waterof the narrow-surface copper plate and a specific heat capacity of the water as well as a temperature difference between inlet water and outlet water of the cooling water of the narrow-surface copperplate; and finding out the optimal flow rate of the cooling water of the narrow-surface copper plate of the crystallizer with the maximum heat transfer flux by regulating the flow rate of the coolingwater of the narrow-surface copper plate for multiple times and cooling the narrow-surface copper plate of the crystallizer through the cooling water in the flow rate which does not exceed the optimal flow rate of the cooling water. According to the method for preventing the narrow surface of the continuous casting sheet billet from bulging, the narrow-surface copper plate of the crystallizer is cooled by adopting the cooling water with the maximum heat transfer flux, the cooling effect is good, the contact between the narrow-surface copper plate and a billet shell of the sheet billet can be always kept, and the thick billet shell can be further formed, so that the billet shell of the sheet billet can be prevented from generating a bulging phenomenon under the static pressure of molten steel.

Description

technical field [0001] The invention relates to a metallurgical technology, in particular to a method for preventing continuous casting slab belly. Background technique [0002] In continuous casting production, in order to meet the needs of products with different specifications, the width of the crystallizer often needs to be adjusted. There are two modes of off-line adjustment and off-line adjustment for crystallizer width adjustment. Off-line adjustment is safe and simple, but takes a long time. Therefore, online adjustment is used in the prior art. [0003] However, the phenomenon of bulging of the narrow surface of the slab is prone to occur in the production of the online cold-adjustment wide mold, and the bulging defect tends to be serious with the increase of the thickness of the slab. Severe bulging of the narrow side of the slab will not only easily lead to longitudinal cracks and crack propagation on the wide side, but also tend to cause longitudinal cracks and ...

AI Technical Summary

Problems solved by technology

[0005] 1. The adjustment mechanism for adjusting the copper plate on the narrow side of the crystallizer cannot guarantee the stability of the inverted taper of the copper plate on the narrow side. Under the static pressure of the molten steel, the taper of the copper plate changes, resulting in the bulging of the narrow side of the slab.

[0006] 2. The amount of cooling water introduced into the cooling water tank is not reasonable enough, resulting in insufficient thickness of the slab shell, and the rigidity of the slab shell cannot resist the static pressure of the molten steel, resulting in bulging of the slab

[0007] 3. The rigidity of the billet shell formed after the molten steel is solidified and the supporting force of the foot rolls received by the billet shell are not enough to resist the hydrostatic pressure, resulting in a bulging of the narrow surface of the billet shell under the action of the hydrostatic pressure

[0008] 4. The setting position of the foot roll is not reasonable enough, and the solidification and shrinkage of the molten steel cause the foot roll to fail to provide sufficient supporting force, causing the narrow surface of the shell to bulge under the static pressure of the molten steel

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