Control method for reducing narrow edge bulging of extra-thick plate blank
Patent Information
- Application Number
- CN202510876704.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-06-27
- Publication Date
- 2025-10-17
AI Technical Summary
During the continuous casting process, the narrow sides of the extra-thick slabs fail to form a sufficiently thick high-temperature shell, resulting in bulging, which affects production and slab quality and may cause equipment wear and steel leakage accidents.
Several pairs of foot rollers are set at the lower part of the narrow-side crystallizer outlet, and the length of the foot roller cooling area and the water flow rate are adjusted according to the required cooling amount of the billet and the solidification characteristics of the cast steel type to increase the cooling intensity, and the taper of the foot roller is set to provide effective support.
The narrow side bulge was successfully reduced from 15mm to less than 5mm, which increased the profit per ton of steel by 526 yuan/ton, and the annual profit can reach 5.256 million yuan/year.
Smart Images
Figure CN120790873A_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The present application relates to the technical field of continuous casting, in particular to a method for controlling the reduction of thick slab narrow edge bulging. BACKGROUND
[0002] In the continuous casting process, the molten steel forms a high-temperature solidified shell in the mold. When the casting leaves the mold, the narrow edge side often bulges due to the inability to form a thick enough high-temperature shell to support the internal molten steel static pressure, thereby affecting the production and quality of the casting.
[0003] Casting bulging is a common casting defect in thick slab production. Casting bulging deformation will promote the flow of residual molten steel between the dendrites to the center of the casting, exacerbating the center segregation of the casting. At the same time, due to the bulging deformation before the shell solidification, it will cause uneven cooling of the casting, resulting in various cracks and internal defects. Casting bulging deformation will cause equipment wear and tear, increase the risk of casting, and even cause serious leakage accidents. SUMMARY
[0004] The technical problem to be solved by the present application is to overcome the shortcomings of the prior art and provide a method for controlling the reduction of thick slab narrow edge bulging.
[0005] To solve the above technical problems, the technical scheme of the present application is as follows: A method for controlling the reduction of thick slab narrow edge bulging, comprising: Based on the thickness of the slab, a plurality of pairs of foot rollers are arranged at the lower part of the narrow edge mold; Based on the required cooling amount of the casting, the length of the narrow edge foot roller cooling area and the narrow edge cooling water flow are determined.
[0006] As a preferred solution to the method for controlling the reduction of thick slab narrow edge bulging, wherein: after determining the length of the narrow edge foot roller cooling area and the narrow edge cooling water flow based on the required cooling amount of the casting, the method further comprises: According to the solidification characteristics of the cast steel, the taper of each pair of foot rollers in the narrow edge is set, so that the shrinkage value of the narrow edge foot roller is greater than the proportion value in the width direction of the casting.
[0007] As a preferred solution to the method for controlling the reduction of thick slab narrow edge bulging, wherein: the plurality of pairs of foot rollers arranged at the lower part of the narrow edge mold based on the thickness of the slab comprises: Six pairs of foot rollers are arranged at the lower part of the narrow edge mold.
[0008] As a preferred scheme of the control method for reducing the narrow edge bulging of the special thick slab, the distance between the pair of the foot rollers adjacent to the outlet of the crystallizer and the outlet of the crystallizer is controlled to be 120 mm, and the distance between any adjacent two pairs of the foot rollers is controlled to be 170 mm.
[0009] As a preferred scheme of the control method for reducing the narrow edge bulging of the special thick slab, the determination of the length of the narrow edge foot roller cooling area and the narrow edge cooling water flow rate based on the required cooling amount of the cast slab comprises: The length of the narrow edge foot roller cooling area is set to be 1035 mm; The narrow edge cooling water flow rate is set to be 25 L / min.
[0010] As a preferred scheme of the control method for reducing the narrow edge bulging of the special thick slab, the setting of the taper of each pair of the narrow edge foot rollers according to the solidification characteristics of the cast steel grade, so that the narrow edge foot roller shrinkage value is greater than the proportional value in the width direction of the cast slab, comprises: When the cast steel grade is any one of the low carbon steel, the peritectic steel and the medium carbon steel, the taper values of the six pairs of the foot rollers are controlled to be 1.61 mm, 2.50 mm, 3.69 mm, 4.88 mm, 6.06 mm and 7.28 mm in sequence; When the cast steel grade is the high carbon steel, the taper values of the six pairs of the foot rollers are controlled to be 1.12 mm, 1.61 mm, 2.03 mm, 2.52 mm, 3.03 mm and 3.62 mm in sequence.
[0011] The beneficial effects of the present application are: The present application sets a plurality of pairs of the foot rollers according to the thickness of the slab, adjusts the taper values of the foot rollers, prolongs the cooling area of the narrow edge foot roller, and increases the cooling intensity of the cast slab, so that the unilateral bulging amount of the narrow edge bulging is successfully reduced from the original 15 mm to within 5 mm, the ton steel profit is increased by 526 yuan / ton, and the annual profit can reach 5.256 million yuan / year. BRIEF DESCRIPTION OF DRAWINGS
[0012] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings needed in the embodiment description will be briefly introduced as follows. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can also be obtained by those skilled in the art without creative labor.
[0013] Figure 1 The figure is a schematic diagram of the narrow edge foot roller assembly of the special thick slab continuous casting machine. DETAILED DESCRIPTION
[0014] In order to make the content of the present application more easily understood, the present application will be further described in detail in the following according to the specific embodiments and in combination with the drawings.
[0015] The embodiment of the present application provides a control method for reducing the bulging of a narrow edge of a super-thick slab, and the method specifically comprises the following steps. Step S101: setting a plurality of pairs of foot rollers at the lower part of the narrow edge crystallizer outlet based on the slab thickness.
[0016] Specifically, a plurality of pairs of foot rollers are arranged at the lower part of the narrow edge crystallizer outlet according to the slab thickness, which mainly plays a role of supporting, guiding and cooling the cast slab which is not completely solidified out of the crystallizer.
[0017] In the embodiment, six pairs of foot rollers are arranged at the lower part of the narrow edge crystallizer outlet, as shown in Figure 1 .
[0018] Step S102: determining the length of the narrow edge foot roller cooling area and the narrow edge cooling water flow based on the required cooling amount of the cast slab.
[0019] Specifically, under the traditional slab secondary cooling spraying structure and water distribution mode, the interval of the narrow edge foot roller is extended, the spraying cooling time of the region is greatly extended, and the thickness of the narrow edge primary shell is increased.
[0020] In the embodiment, the length of the narrow edge foot roller cooling area is set to be lengthened from 905 mm of the traditional one to 1035 mm, as shown in Figure 1 , specifically, the interval between a pair of foot rollers adjacent to the crystallizer outlet and the crystallizer outlet is controlled to be 120 mm, and the interval between any two adjacent pairs of foot rollers is controlled to be 170 mm, as shown in Table 1.
[0021]
[0022] Table 1 Step S103: setting the taper of each pair of narrow edge foot rollers according to the solidification characteristics of the cast steel grade, so that the narrow edge foot roller shrinkage value is greater than the proportional value in the width direction of the cast slab.
[0023] Specifically, In order to meet the support force required by the taper of the narrow edge foot roller for the shrinkage of the shell during the production process, the taper setting value of the six pairs of narrow edge foot rollers of the crystallizer is adjusted to different degrees, so that the narrow edge foot roller shrinkage value is slightly greater than the proportional value in the width direction of the cast slab, and the foot roller always acts on the cast slab shell to provide effective support for the narrow surface solidified shell.
[0024] In the embodiment, the same taper is set for low-carbon steel (L), peritectic steel (P) and medium-carbon steel (M), and different tapers are set for high-carbon steel (H), and the different narrow surface foot roller taper optimization setting values are shown in Table 2.
[0025]
[0026] Table 2 It can be concluded from Table 2 that when the cast steel is any one of low-carbon steel, peritectic steel and medium-carbon steel, the taper values of the six pairs of foot rollers are 1.61 mm, 2.50 mm, 3.69 mm, 4.88 mm, 6.06 mm and 7.28 mm in sequence; and when the cast steel is high-carbon steel, the taper values of the six pairs of foot rollers are 1.12 mm, 1.61 mm, 2.03 mm, 2.52 mm, 3.03 mm and 3.62 mm in sequence.
[0027] The technical solution of the present application obtains a (460, 370) mm×(1800-2600) mm cross-section ultra-thick slab narrow edge bulging control method by increasing the number of narrow edge foot rollers, the cooling intensity, adjusting the taper value and prolonging the cooling area of the narrow edge foot roller. Through the synergistic effect between each step, the unilateral bulging amount of the narrow edge bulging is successfully reduced from the original 15 mm to within 5 mm, the ton steel profit is increased by 526 yuan / ton, and the annual profit can reach 5.256 million yuan / year.
[0028] In addition to the above embodiments, the present application can have other implementation manners; any technical solution formed by equivalent replacement or equivalent transformation falls within the protection scope required by the present application.
Claims
1. A control method for reducing narrow side bulging of extra-thick slabs, characterized by: include: Several pairs of foot rollers are arranged at the lower part of the narrow side crystallizer outlet based on the slab thickness; The length of the narrow side foot roll cooling area and the narrow side cooling water flow rate are determined based on the required cooling amount of the casting.
2. The control method for reducing narrow side bulging of extra-thick slabs according to claim 1, characterized in that: After determining the length of the narrow side foot roller cooling area and the narrow side cooling water flow rate based on the required cooling amount of the cast billet, the method further includes: The taper of each pair of narrow side foot rollers is set according to the solidification characteristics of the casting steel type, so that the contraction value of the narrow side foot rollers is greater than the proportional value in the width direction of the billet.
3. The control method for reducing narrow side bulging of extra-thick slabs according to claim 1, characterized in that: The method of providing a plurality of pairs of foot rollers at the lower portion of the narrow side crystallizer outlet based on the slab thickness includes: Six pairs of foot rollers are arranged at the lower part of the narrow side crystallizer outlet.
4. The control method for reducing narrow side bulging of extra-thick slabs according to claim 3 is characterized in that: The spacing between a pair of foot rollers adjacent to the crystallizer outlet and the crystallizer outlet is controlled to be 120 mm, and the spacing between any two adjacent pairs of foot rollers is controlled to be 170 mm.
5. The control method for reducing narrow side bulging of extra-thick slabs according to claim 3 is characterized in that: Determining the narrow side foot roller cooling area length and the narrow side cooling water flow rate based on the required cooling amount of the slab includes: Set the length of the cooling area of the narrow side foot roller to 1035mm; Set the narrow side cooling water flow rate to 25L / min.
6. The control method for reducing narrow side bulging of extra-thick slabs according to claim 3, characterized in that: The step of setting the taper of each pair of narrow side foot rollers according to the solidification characteristics of the cast steel grade so that the contraction value of the narrow side foot rollers is greater than the proportional value in the width direction of the billet comprises: When the casting steel type is any one of low carbon steel, peritectic steel and medium carbon steel, the taper values of the six pairs of foot rollers are controlled to be 1.61mm, 2.50mm, 3.69mm, 4.88mm, 6.06mm and 7.28mm respectively; When the casting steel type is high carbon steel, the taper values of the six pairs of foot rollers are controlled to be 1.12mm, 1.61mm, 2.03mm, 2.52mm, 3.03mm, and 3.62mm respectively.