JPH11286728A - Slab cooling method after continuous casting - Google Patents

Abstract

PROBLEM TO BE SOLVED: To efficiently and surely cool high-temp. slabs after continuous casting with a simple equipment by laminating plural sheets of the high-temp. slabs, subjecting the front surface of the uppermost stage slab to a water drop adhesion preventive procedure and spraying cooling water to both side surfaces in the longitudinal direction of the high-temp. slabs. SOLUTION: The front surface of the uppermost stage of the laminated high-temp. slabs is subjected to the water drop adhesion preventive procedure and the cooling water is sprayed to the both side surfaces in the longitudinal direction of the slab, thereby, the cooling by adhesion of water drops onto the front surface of the slab of the uppermost stage is prevented and the temp. difference between the front and rear surfaces of this slab is eliminated. The occurrence of the warpage of the slabs is thus prevented. There is no occurrence of a clearance between the rear surface of this slab and the front surface of the slab under the same and the warpage of the slab thereunder may be prevented. While the warpage of the slabs is prevented in such a manner, the cooling water is sprayed to both flanks in the longitudinal direction of the slabs and the cooling is progressed from both flanks in the longitudinal direction to the central part. The entire part of the laminated high-temp. slabs is thus cooled. Planar refractories, such as thick steel plates, may be used as the water drop adhesion preventive material.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for cooling a slab after continuous casting.

[0002]

2. Description of the Related Art As a method for cooling a slab after continuous casting, Japanese Patent Application Laid-Open No. 52-100315 discloses that a high-temperature slab is immersed in cooling water and cooled while controlling a cooling water flow. JP-A-56-33120 discloses that a high-temperature slab is held in a reversing machine, the reversing machine is operated, and the high-temperature slab is immersed in cooling water for cooling.
Further, it has been proposed to transfer a high-temperature slab onto a table and spray cooling water from the upper and lower surfaces of the high-temperature slab to cool the slab.
No. 33810.

[0003]

As described above, in the method for cooling a high-temperature slab, the cooling is performed one by one, and the cooling efficiency of the slab decreases. In addition, there is a problem that a large-sized cooling facility is required and the cost is disadvantageous. The method of the present invention has been made to advantageously solve such a problem, and a method for cooling a slab after continuous casting for efficiently and surely cooling a plurality of high-temperature slabs (slabs) with simple equipment. It is intended to provide.

[0004]

A feature of the method of the present invention is that a plurality of high-temperature slabs after continuous casting are laminated, and an upper surface of the uppermost slab of the laminated high-temperature slab is subjected to a treatment for preventing adhesion of water droplets. This is a method for cooling a slab after continuous casting, characterized by spraying cooling water on both longitudinal side surfaces of a high-temperature slab.

[0005]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In the method of the present invention as described above, a plurality of high-temperature slabs after continuous casting are laminated, and cooling is performed by spraying cooling water on both longitudinal side surfaces of the high-temperature slabs thus laminated. It is. When the high-temperature slab is cooled by spraying the cooling water, a part of the cooling water scatters and adheres to the upper surface of the uppermost high-temperature slab as water droplets. Further, the cooling water sprinkled on both sides in the longitudinal direction of the high-temperature slab is vaporized (water vapor), and a part of the water becomes water droplets, and similarly scatters and adheres to the upper surface of the uppermost high-temperature slab as water droplets.

As described above, when water droplets adhere to the upper surface of the uppermost high-temperature slab, the upper surface of the uppermost high-temperature slab is cooled, but the lower surface is not cooled. Warpage occurs in the high-temperature slab. When the uppermost high-temperature slab is warped, a gap is formed between the lower surface of the uppermost high-temperature slab and the upper surface of the lower (second) high-temperature slab, and cooling water sprinkled into the gap flows into the gap. The upper surface of the lower (second stage) high-temperature slab is cooled, but the lower surface is not cooled, and a temperature difference occurs between the upper surface and the lower surface of the lower (second stage) high-temperature slab, causing warpage. In this manner, the warp is generated sequentially up to the lowermost high-temperature slab. Therefore, the whole of the cooled laminated high-temperature slab becomes defective in shape.

In the method of the present invention, in order to prevent such warpage and to cool a plurality of laminated high-temperature slabs, an upper surface of the uppermost high-temperature slab of the laminated high-temperature slab is subjected to a treatment for preventing water droplet adhesion. By spraying cooling water on both sides in the longitudinal direction of the laminated high-temperature slab, cooling due to water droplets adhering to the upper surface of the uppermost high-temperature slab is prevented, and the temperature difference between the upper and lower surfaces of the uppermost high-temperature slab is eliminated. While cooling. Thus, the occurrence of warpage of the slab can be reliably prevented, and no gap is generated between the lower surface of the uppermost high-temperature slab and the upper surface of the lower (second) high-temperature slab. Warpage can be prevented. In this way, while preventing warpage of the laminated high-temperature slab, the cooling water is sprayed on both longitudinal side surfaces of the laminated high-temperature slab, cooling proceeds from both longitudinal side surfaces to the center, and the entire laminated high-temperature slab is cooled. Things.

[0008] As described above, the water droplet adhesion preventing treatment may be performed so that a part of the cooling water sprinkled on the upper surface of the uppermost high-temperature slab is scattered and cooled, so that there is no temperature difference from the lower surface. For example, a plate-like refractory such as a normal temperature thick steel plate, a stone material, or a porcelain is loaded on the entire surface of the upper surface of the uppermost high-temperature slab as a water droplet adhesion preventing material, and a measure is taken to shut off scattered cooling water and the like.

[0009] In cooling such a laminated high-temperature slab, for example, a slab after continuous casting is cut to a predetermined length, laminated on a bogie, and a cooling water jet nozzle group installed on both sides in the traveling direction of the bogie. By moving to the position of the apparatus, cooling water can be sprayed on both sides in the longitudinal direction of the laminated high-temperature slab and cooled. Thus, cooling can be performed more quickly by cooling both sides in the longitudinal direction and spraying cooling water on both ends of the short side of the laminated high-temperature slab. It is difficult to install a cooling device at both ends of the short side, and cooling can be surely performed by cooling by spraying cooling water on both longitudinal side surfaces of the laminated high-temperature slab. When a high-temperature slab is stacked on such a truck and cooled, the cooled slab can be transported to the next step as it is, and can be transported quickly, which is advantageous. In addition, in addition to laminating the slab on the truck in this way, for example, laminating a high-temperature slab after continuous casting at a predetermined position, installing a cooling device composed of a group of cooling water injection nozzles on both longitudinal sides of the laminated high-temperature slab, Cooling water can be sprayed on both longitudinal sides of the high-temperature slab for cooling.

The cooling temperature of the laminated high-temperature slab differs slightly depending on the processing of the slab after cooling, but it is cooled to a temperature suitable for the processing in the next step, for example, in the production slab or the surface care slab. In the subsequent processing of the slab, it is preferable to cool the slab to about 100 ° C. or less. Further, as a cooling start temperature of the high-temperature slab after the continuous casting, when the slab after the continuous casting is cut into a predetermined length and processed into a high-temperature slab, the surface temperature becomes 700 to 900 ° C., and the cooling is performed from this temperature. Will be.

Next, an example of the method of the present invention will be described with reference to the drawings. As shown in FIGS. 1 and 2, a high-temperature slab 1 after continuous casting is laminated on a carriage 2, and the uppermost high-temperature slab 1 of the laminated high-temperature slab 1 is formed. As a water droplet adhesion preventing treatment, for example, a water droplet adhesion preventing steel plate 3 is mounted on
It moves to the position of the group of cooling devices 5, 5a and stops. Thereafter, the cooling water 6 is sprayed from the cooling water injection nozzle 4 on both sides in the longitudinal direction of the laminated high-temperature slab 1 to be cooled, and after cooling, is conveyed to the next step.

[0012]

Next, examples of the method of the present invention will be described together with comparative examples.

[Table 1]

Note 1: In Examples 1 to 3 and Comparative Example 1, a high-temperature slab (a slab for a thin steel sheet generally cast) after continuous casting was laminated on a bogie. Examples 4 and 5 and Comparative Example 2
In order to prevent water droplets from adhering to the entire upper surface of the uppermost high-temperature slab, the steel plate having a thickness of 245 mm is loaded on the base and then moved to the position of the cooling water spray nozzle to move to the longitudinal side of the high-temperature slab. Was cooled by spraying cooling water (normal temperature) over the entire surface of the sample. Note 2: The slab cooling start temperature is the surface temperature of the slab. Note 3: The cooling water spray nozzles were sprayed with cooling water from a cooling device in which one or a plurality of flat spray nozzle groups were arranged in the height direction at 1.0 m horizontal intervals. Note 4: The amount of cooling water is the amount of cooling water sprayed over the entire surface on both sides in the longitudinal direction of the laminated high-temperature slab (slab). Note 5: In the comparative example, the entire laminated high-temperature slab (cast piece) was warped, resulting in a defective shape.

[0014]

According to the method of the present invention, a plurality of high-temperature slabs can be cooled at once without losing the shape.
In addition, since it can be cooled by a simple cooling device, it is inexpensive and does not require a large space, so that it can be easily cooled near an existing casting factory and transported to the next process. The effect is obtained.

[Brief description of the drawings]

FIG. 1 is a front view showing an example of the method of the present invention.

FIG. 2 is a plan view showing an example of the method of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Hot slab 2 Cart 3 Water drop adhesion prevention plate 4 Cooling water injection nozzle 5 Cooling device 5a Cooling device 6 Cooling water

Claims (3)

[Claims] 1. A method of laminating a plurality of high-temperature slabs after continuous casting, performing a treatment for preventing water droplets from adhering to an upper surface of an uppermost slab of the laminated high-temperature slab, and spraying cooling water on both longitudinal sides of the high-temperature slab. A method for cooling a slab after continuous casting. 2. The continuous casting according to claim 1, wherein a plurality of high-temperature slabs after continuous casting are stacked on a carriage, and cooling water is sprinkled on both longitudinal side surfaces of the stacked high-temperature slabs. Slab cooling method. 3. A water droplet adhesion preventing steel plate is mounted on the upper surface of the uppermost slab of the laminated high-temperature slab.
Or the slab cooling method after continuous casting according to claim 2.