Crystallizer copper mold device with stepped outer surface

Abstract

The utility model discloses a crystallizer copper mold device with a stepped outer surface, and belongs to the technical field of crystallizers. The copper mold comprises at least three sections, and the overall dimensions of the sections are gradually reduced section by section from top to bottom. According to the utility model, the sections of which the overall dimensions are gradually reduced are arranged, so that the water seam of which the sectional area is gradually increased from top to bottom is formed when the copper mold is matched with the water jacket. Therefore, the flow speed of cooling water is gradually increased when the cooling water flows through the water seam from bottom to top, different sections of the copper mold can obtain different heat exchange coefficients, cooling and heat exchange of a high-heat-load section are enhanced, a blank shell is prevented from being excessively cooled in a low-heat-load section, it is guaranteed that the thickness of the blank shell is uniform, and the casting blank stripping, bulging and bleed-out probability is reduced.

Description

Technical Field

[0001] The utility model relates to the technical field of crystallizers, in particular to a copper mold device of a crystallizer with stepped outer surface. Background Art

[0002] The crystallizer used in continuous casting of metals includes a copper mold and a water jacket wrapped around the copper mold. The outer contour of the copper mold and the water jacket form a water gap, in which a heat transfer liquid (usually water) flows at high speed. The molten steel in the copper mold transfers heat to the water in the water gap through the copper mold wall, and the flowing water takes away the heat, thereby cooling and solidifying the molten steel.

[0003] In order to increase the output of low carbon steel such as Q195, Q235, and 08Al, steel mills increase the drawing speed during continuous casting to a very high speed, often requiring a drawing speed of about 3.5m / min. However, since the distance between the solid and liquid phase lines of this type of steel is very short, the shrinkage when it is cooled is particularly severe. Since the temperature of the upper part of the copper mold is higher than that of the lower part and the difference in heat load between the upper and lower parts is large, the billet shell is prone to overcooling at a high drawing speed, resulting in uneven billet shell thickness. Therefore, the existing copper mold has the problem of easily increasing the probability of billet de-squareness, bulging, and steel leakage. Utility Model Content

[0004] The utility model provides a copper mold device with a stepped outer surface, so as to solve the technical problem that the existing copper mold easily increases the probability of the casting blank being out of square, bulging and leaking out.

[0005] In order to achieve the above purpose, the technical solution of the utility model is:

[0006] The outer surface of the stepped crystallizer copper mold device includes at least three sections, and the outer dimensions of the sections decrease gradually from top to bottom.

[0007] Furthermore, in each segment, the heat taken away by the cooling water in the water gap formed between the segment and the water jacket is equal to the heat transferred by the molten steel.

[0008] Furthermore, adjacent segments are transitioned by chamfering.

[0009] Furthermore, the lengths of the segments from top to bottom increase gradually.

[0010] Furthermore, the maximum value of the water gap formed between each segment and the water jacket is less than twice the minimum value.

[0011] Furthermore, the copper mold also includes an upper connecting section and a lower connecting section, and the upper connecting section, at least three sections and the lower connecting section are connected in sequence from top to bottom.

[0012] Furthermore, an annular key groove is provided on the outer contour of the upper connecting section.

[0013] Beneficial effects:

[0014] The outer surface stepped crystallizer copper mold device disclosed in the present application is provided with segments with gradually decreasing outer dimensions, so that a water gap with a gradually increasing cross-sectional area from top to bottom is formed when the copper mold and the water jacket cooperate. As a result, the flow rate of cooling water gradually increases when flowing through the water gap from bottom to top, and different segments of the copper mold can obtain different heat exchange coefficients, thereby strengthening the cooling and heat exchange of high heat load segments, avoiding overcooling of the billet shell in low heat load segments, ensuring uniform thickness of the billet shell, and reducing the probability of billet de-squareness, bulging and steel leakage. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] In order to more clearly illustrate the embodiments of the utility model or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0016] Figure 1 It is a structural schematic diagram of the outer surface stepped crystallizer copper mold device disclosed in the utility model;

[0017] Figure 2 It is a schematic diagram of the coordination between the outer surface stepped crystallizer copper mold device and other parts of the crystallizer disclosed in the utility model;

[0018] Figure 3 for Figure 1 A partial enlarged view of part Ⅰ.

[0019] 1. Copper mold; 11. Segmentation; 12. Upper connecting section; 121. Ring keyway; 13. Lower connecting section;

[0020] 2. Water jacket; 3. Upper flange; 4. Upper pressure cover; 5. Key plate; 6. Lower flange; 7. Lower pressure cover. DETAILED DESCRIPTION

[0021] In order to make the purpose, technical solution and advantages of the embodiment of the utility model clearer, the technical solution in the embodiment of the utility model will be clearly and completely described below in conjunction with the drawings in the embodiment of the utility model. Obviously, the described embodiment is a part of the embodiment of the utility model, not all the embodiments. Based on the embodiment of the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0022] The outer surface stepped crystallizer copper mold device is combined with Figure 1 , Figure 2 and Figure 3As shown, the copper mold 1 includes at least three segments 11, and the outer dimensions of the segments 11 decrease from top to bottom. The copper mold 1 cooperates with the water jacket 2 arranged on the outside thereof to form a water gap whose cross-sectional area gradually increases from top to bottom. After the cooling water enters the water gap from below, the flow rate of the cooling water gradually increases from bottom to top because the flow rate of the cooling water is constant and the cross-sectional area of ​​the water gap gradually decreases. Each segment 11 of the copper mold 1 can obtain a different heat transfer coefficient, strengthen the cooling and heat exchange of the high heat load segment 11, avoid excessive cooling of the billet shell in the low heat load segment 11, ensure uniform thickness of the billet shell, and reduce the probability of de-squareness, bulging and steel leakage of the cast billet. And because the thickness of the existing copper mold 1 is thicker than the thickness of the water jacket 2, the segmented design of the copper mold 1 is conducive to the use of the existing copper mold 1 for transformation, which can save processing costs.

[0023] Preferably, on each segment 11, the heat taken away by the cooling water in the water gap formed between the segment 11 and the water jacket 2 is equal to the heat transferred by the molten steel. This ensures that the heat transferred by the molten steel is just taken away by the cooling water in the water gap, and the blank shell at each segment 11 is not overcooled, ensuring the uniformity of the blank shell thickness. At the same time, this prevents the molten steel from damaging the inner cavity of the copper mold 1 due to the cooling water not being able to take away all the heat.

[0024] Preferably, adjacent segments 11 are transitioned by chamfering to eliminate the steps formed between adjacent segments 11 and prevent the steps from obstructing the passage of cooling water.

[0025] Specifically, the copper mold 1 is 900 mm high and includes 8 sections 11, which are named section 1, section 2, section 3, section 4, section 5, section 6, section 7 and section 8 from top to bottom. The outer dimension of section 2 is 1.4 mm smaller than that of section 1, the outer dimension of section 3 is 0.8 mm smaller than that of section 2, the outer dimension of section 4 is 0.4 mm smaller than that of section 3, the outer dimension of section 5 is 0.8 mm smaller than that of section 4, the outer dimension of section 6 is 0.8 mm smaller than that of section 5, the outer dimension of section 7 is 0.6 mm smaller than that of section 6, and the outer dimension of section 8 is 1.0 mm smaller than that of section 7. That is, it is ensured that the water gap width formed between the first section and the water jacket 2 is 4mm, the water gap width formed between the second section and the water jacket 2 is 4.7mm, the water gap width formed between the third section and the water jacket 2 is 5.1mm, the water gap width formed between the fourth section and the water jacket 2 is 5.3mm, the water gap width formed between the fifth section and the water jacket 2 is 5.7mm, the water gap width formed between the sixth section and the water jacket 2 is 6.1mm, the water gap width formed between the seventh section and the water jacket 2 is 6.4mm, and the water gap width formed between the eighth section and the water jacket 2 is 6.9mm.

[0026] Preferably, the length of the segments 11 increases gradually from top to bottom. In the present embodiment, the length of the first segment is 40 mm, the length of the second segment is 70 mm, the length of the third segment is 85 mm, the length of the fourth segment is 90 mm, the length of the fifth segment is 100 mm, the length of the sixth segment is 110 mm, the length of the seventh segment is 120 mm, and the length of the eighth segment is 150 mm; thereby avoiding large differences in the outer dimensions of the segments 11, preventing the copper mold 1 from being reduced too much in wall thickness in the eighth segment, resulting in a decrease in the strength of the copper mold 1, and avoiding affecting the service life of the copper mold 1.

[0027] Preferably, the maximum value of the water gap formed between each segment 11 and the water jacket 2 is less than twice the minimum value, that is, the difference in heat extracted from the first segment and the eighth segment is ensured to be no more than twice, thereby limiting the width of the water gap formed between the eighth segment and the water jacket 2 and preventing the cooling water from not being able to evenly enter the water gap in all directions around the copper mold 1, resulting in uneven cooling.

[0028] Preferably, the copper mold 1 further comprises an upper connecting section 12 and a lower connecting section 13, and the upper connecting section 12, at least three segments 11 and the lower connecting section 13 are sequentially connected from top to bottom. In this embodiment, the upper connecting section 12, the first segment, the second segment, the third segment, the fourth segment, the fifth segment, the sixth segment, the seventh segment, the eighth segment and the lower connecting section 13 are sequentially connected. The length of the upper connecting section 12 is 100 mm, and the upper connecting section 12 is used to connect the upper flange 3, the upper pressure cover 4 and the key plate 5 of the crystallizer; the length of the lower connecting section 13 is 35 mm, and the lower connecting section 13 is used to connect the lower flange 6 and the lower pressure cover 7 of the crystallizer. The upper connecting section 12 and the lower connecting section 13 ensure the installation and fixation of the copper mold 1, and the upper connecting section 12 and the lower connecting section 13 can be the outer dimensions of the upper and lower ends of the existing copper mold 1, and the upper flange 3, the upper pressure cover 4, the key plate 5, the lower flange 6 and the lower pressure cover 7 and other parts do not need to be remade, which can reduce the modification cost of the copper mold 1.

[0029] Preferably, an annular key groove 121 is provided on the outer contour of the upper connecting section 12 , and the annular key groove 121 cooperates with the key plate 5 , the bottom of the key plate 5 abuts against the upper flange 3 , and the upper pressure cover 4 presses the upper end of the copper mold 1 , thereby fixing the copper mold 1 .

[0030] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the utility model, rather than to limit it. Although the utility model has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the utility model.

Claims

1. A copper mold device with stepped outer surface, characterized in that: The copper mold (1) comprises at least three sections (11), the outer dimensions of the sections (11) decreasing from top to bottom, and the copper mold (1) cooperates with a water jacket (2) sleeved on the outside thereof to form a water gap with a gradually increasing cross-sectional area from top to bottom.

2. The outer surface stepped crystallizer copper mold device according to claim 1, characterized in that: In each of the segments (11), the heat carried away by cooling water in the water gap formed between the segment (11) and the water jacket (2) is equal to the heat transferred by the molten steel.

3. The outer surface stepped crystallizer copper mold device according to claim 1, characterized in that: Adjacent segments (11) are transitioned via chamfers.

4. The outer surface stepped crystallizer copper mold device according to claim 1, characterized in that: The lengths of the segments (11) increase gradually from top to bottom.

5. The outer surface stepped crystallizer copper mold device according to claim 1, characterized in that: The maximum value of the water gap formed between each of the segments (11) and the water jacket (2) is less than twice the minimum value.

6. The outer surface stepped crystallizer copper mold device according to claim 1, characterized in that: The copper mold (1) further comprises an upper connecting section (12) and a lower connecting section (13), wherein the upper connecting section (12), at least three sections (11) and the lower connecting section (13) are connected in sequence from top to bottom.

7. The outer surface stepped crystallizer copper mold device according to claim 6, characterized in that: An annular key groove (121) is provided on the outer contour of the upper connecting section (12).

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