Slab continuous casting mould and method of using same

Abstract

The present application relates to a kind of slab continuous casting crystallizer and its use method, belong to continuous casting technical field.It includes two wide copper plates of opposite arrangement and the narrow side copper plate being arranged between wide copper plate, and wide copper plate and narrow side copper plate form casting cavity, the downside of casting cavity is crystallization cavity, and the upper side of casting cavity is provided with refractory material, and refractory material forms V-shaped cavity, and the side of the cross section of V-shaped cavity smaller is towards crystallization cavity setting.Casting production, submerged entry nozzle is inserted into the V-shaped cavity of crystallizer, and molten steel is cooled to form shell by crystallization cavity, and the copper plate of crystallizer is flat, and in the thickness direction of cast blank, the cross-sectional area of V-shaped cavity is much larger than the cross-sectional area of the cavity of conventional thin slab continuous casting crystallizer, and liquid level fluctuation in crystallizer is less affected by pulling speed, and the thin slab continuous casting machine crystallizer of V-shaped cavity is more suitable for high speed casting machine.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of continuous casting, and relates to a slab continuous casting crystallizer and a use method thereof. BACKGROUND

[0002] The crystallizer is the heart of the continuous casting machine, is the core equipment for liquid-solid conversion of molten steel, and is the key to the quality control of the cast slab. The reasonable shape of the copper plate cavity of the crystallizer and the small liquid level fluctuation during production are very beneficial to the improvement of the quality of the cast slab.

[0003] The typical feature of the thin slab continuous casting crystallizer is that the cavity of the crystallizer is small, and it is difficult for the submerged nozzle to be directly inserted into the cavity of the crystallizer, and the casting speed is particularly sensitive to the liquid level fluctuation of the molten steel in the cavity of the crystallizer. Generally, the casting speed of the thin slab continuous casting machine is very high, which can reach 6-7 m / min, and it is very challenging to maintain stable production of the continuous casting machine and stable quality of the cast slab.

[0004] In order to enable the submerged nozzle to be inserted into the cavity of the thin slab continuous casting crystallizer, continuous casting people have made a lot of efforts, mainly in the following two aspects: 1. reducing the size of the submerged nozzle in the thickness direction of the cast slab, which can be controlled at about 50 mm, which is not suitable for the crystallizer of the continuous casting machine with thinner cast slab thickness; 2. adopting a funnel-shaped crystallizer, in which the middle part of the wide copper plate is concave in a funnel-shaped curve, and the curve is topologically composed of a horizontal curve family and a vertical curve family.

[0005] At present, the thin slab continuous casting crystallizer mostly adopts a funnel-shaped crystallizer, which is suitable for a wider range of cast slab thickness. However, the funnel-shaped crystallizer also has many limiting factors: first, the wide copper plate with various funnel-shaped curves can only reduce the cracks caused by the additional stress on the billet shell in the crystallizer, but cannot completely avoid it; second, the wide copper plate with a funnel-shaped curve has high manufacturing precision and is very difficult to manufacture, and the processing and maintenance cost is high; third, the cavity thickness direction section of the funnel-shaped crystallizer is also small, which is particularly sensitive to the casting speed, and the casting speed has a particularly obvious effect on the liquid level fluctuation of the molten steel in the cavity of the crystallizer, which is not conducive to improving the quality of the cast slab. SUMMARY

[0006] Therefore, the purpose of the present application is to provide a slab continuous casting crystallizer and a use method thereof to improve the quality of the cast slab and control the cost.

[0007] To achieve the above purpose, the present application provides the following technical solutions:

[0008] A slab continuous casting crystallizer comprises two opposite wide side plates and a narrow side plate arranged between the wide side plates, the wide side plates and the narrow side plate form a casting cavity, the lower side of the casting cavity is a crystallization cavity, the upper side of the casting cavity is provided with a refractory material, the refractory material forms a V-shaped cavity, and the side with a smaller cross section of the V-shaped cavity is arranged towards the crystallization cavity.

[0009] Optionally, the liquid surface of the molten steel in the V-shaped cavity is 200mm to 400mm in the thickness direction.

[0010] Optionally, the opening angle of the V-shaped cavity is 40° to 70°.

[0011] Optionally, the wide side plate and the narrow side plate are both flat plates.

[0012] Optionally, the wide side plate and the narrow side plate are both copper plates.

[0013] Optionally, the refractory material is composed of an insulating plate, a knotted material and a daubed material.

[0014] Optionally, the wide side plate and the narrow side plate are both flat plates.

[0015] A use method of a slab continuous casting crystallizer, the slab continuous casting crystallizer is provided above.

[0016] During the casting process, the molten steel does not solidify in the V-shaped cavity, and the molten steel forms a shell when passing through the crystallization cavity.

[0017] Optionally, the submerged nozzle is inserted into the molten steel in the V-shaped cavity for casting.

[0018] Optionally, the width of the cast slab produced by the crystallizer is 900mm to 1650mm.

[0019] The beneficial effects of the present application are as follows:

[0020] 1. In some embodiments of the present application, flat copper plates are used to make the crystallization cavity, which is beneficial to improve the surface quality of the cast slab; and flat copper plates are used to make the wide side plate and the narrow side plate to reduce the processing difficulty and reduce the maintenance cost.

[0021] 2. In some embodiments of the present application, the V-shaped cavity with a cross-sectional area in the thickness direction much larger than that of a conventional thin slab continuous casting crystallizer cavity makes the liquid level fluctuation in the crystallizer less affected by the pulling speed, and the liquid level fluctuation in the crystallizer is easier to control, thereby better stabilizing the production and improving the quality of the cast slab, and being beneficial to improve the pulling speed.

[0022] 3. In some embodiments of the present application, the refractory material of the V-shaped cavity is composed of insulating board, knotted material and daubing material, which is resistant to erosion and thermal shock, and can meet the process requirements of multi-furnace continuous casting.

[0023] Other advantages, objects, and features of the present application will be understood by those skilled in the art from the following specification in conjunction with the accompanying drawings. The present application's objects and other advantages will be achieved by the specification. BRIEF DESCRIPTION OF DRAWINGS

[0024] In order to make the objects, technical solutions and advantages of the present application clearer, the preferred embodiments of the present application will be described in detail below with reference to the accompanying drawings, in which:

[0025] Fig. 1 is a schematic view of the positional relationship between the V-shaped cavity and the submerged nozzle;

[0026] Fig. 2 is a schematic view of the structure of the V-shaped cavity;

[0027] Fig. 3 is a schematic view of the structure of the wide edge plate and the wide edge refractory material;

[0028] Fig. 4 is a schematic view of the structure of the narrow edge plate and the narrow edge refractory material;

[0029] Reference signs: 1 wide edge plate, 2 wide edge refractory material, 3 narrow edge plate, 4 narrow edge refractory material, 5 submerged nozzle, 6 molten steel liquid level. DETAILED DESCRIPTION

[0030] The embodiments of the present application are described below through specific examples, and those skilled in the art can easily understand other advantages and effects of the present application from the disclosure. The present application can also be implemented or applied through different specific embodiments, and various modifications or changes can be made to the details in the specification based on different views and applications without departing from the spirit of the present application. It should be noted that the diagrams provided in the following embodiments only illustrate the basic concept of the present application in a schematic manner, and the following embodiments and features in the embodiments can be combined with each other without conflict.

[0031] The accompanying drawings are only used for exemplary illustration, and the representation is only a schematic diagram, not a physical diagram, and cannot be understood as a limitation on the present application; in order to better illustrate the embodiments of the present application, some components in the drawings may be omitted, enlarged or reduced, and do not represent the actual size of the product; it can be understood by those skilled in the art that some known structures and their descriptions in the drawings may be omitted.

[0032] The same or similar reference numerals in the drawings of the embodiments of the present application correspond to the same or similar components; in the description of the present application, it is understood that if the orientations or positional relationships indicated by the terms “upper”, “lower”, “left”, “right”, “front”, “back” and the like are based on the orientations or positional relationships shown in the drawings, they are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, therefore the terms describing the positional relationship in the drawings are only used for exemplary illustration, and cannot be understood as a limitation on the present application, for those skilled in the art, the specific meanings of the above terms can be understood according to the specific circumstances.

[0033] Please refer to Figs. 1-4 A slab continuous casting crystallizer, the crystallizer is composed of wide edge plate 1 and narrow edge plate 3 to form a casting cavity, the upper opening of the casting cavity is of an expanding type, the upper opening of the casting cavity is surrounded by a knot refractory material to form a V-shaped cavity, the wide edge plate 1 and the narrow edge plate 3 are provided with water cooling structures on the lower side. The V-shaped cavity is provided with wide edge refractory material 2 and narrow edge refractory material 4 around the V-shaped cavity, which is heat-insulated and heat-preserved, and the molten steel in the V-shaped cavity will not solidify, the molten steel is cooled to form a shell through the crystallization cavity, the copper plate of the crystallization plate is flat, and the overall strain of the shell on the surface of the cast slab is small and constant, and the strain rate is low during the solidification and forming of the molten steel, which is beneficial to improve the surface quality of the cast slab.

[0034] The V-shaped cavity is much larger than the thickness of the cast slab in the thickness direction, and the submerged nozzle 5 is inserted below the molten steel liquid surface 6 in the V-shaped cavity of the crystallizer for casting. The cross-sectional area of the V-shaped cavity in the thickness direction is much larger than that of the cavity of the conventional thin slab continuous casting crystallizer, the liquid level fluctuation in the crystallizer is less affected by the pulling speed, and it is easy to control the liquid level fluctuation in the crystallizer, thereby better stabilizing the production and improving the quality of the cast slab.

[0035] The wide edge plate 1 and the narrow edge plate 3 of the crystallizer are flat plates, which have low processing difficulty and low processing and maintenance cost.

[0036] In the embodiment, the wide edge plate 1, the narrow edge plate 3, the wide edge refractory material 2 and the narrow edge refractory material 4 are used to form a casting cavity; the submerged nozzle 5 is inserted into the V-shaped cavity for casting, and in the thickness direction, the cross-sectional area of the V-shaped cavity is large, and it is easy to control the liquid level fluctuation, and the molten steel liquid surface 6 in the cavity is stable. The molten steel is cooled to form a shell through the crystallization cavity below the V-shaped cavity, the crystallization plate is a flat copper plate, the overall strain of the shell on the surface of the cast slab is small and constant, and the strain rate is low during the solidification and forming of the molten steel, which is beneficial to improve the quality of the cast slab.

[0037] Finally, it is to be explained that the above embodiments are only used to illustrate the technical solutions of the present application but not to limit the present application. Although the present application is described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present application can be modified or equivalently replaced without departing from the purpose and scope of the present application, and all should be covered in the scope of the claims of the present application.

Claims

1. A slab continuous casting mould, characterized in that: The slab continuous casting crystallizer comprises two oppositely arranged wide side plates (1) and a narrow side plate (3) arranged between the wide side plates (1), the wide side plates (1) and the narrow side plate (3) form a casting cavity, the lower side of the casting cavity is a crystallization cavity; the upper side of the casting cavity is provided with wide side refractory material (2) and narrow side refractory material (4), the wide side refractory material (2) and the narrow side refractory material (4) form a V-shaped cavity, the side of the V-shaped cavity with smaller cross section is arranged towards the crystallization cavity; the liquid surface of the molten steel in the V-shaped cavity is 200mm to 400mm in the thickness direction; the opening angle of the V-shaped cavity is 40°~70°; the wide side plate (1) and the narrow side plate (3) are both flat plates; the slab produced by the crystallizer has a width of 900mm~1650mm.

2. The slab continuous casting mold according to claim 1, characterized in that: The wide side plate (1) and the narrow side plate (3) are both copper plates.

3. The slab continuous casting mold according to claim 1, characterized in that: The wide side refractory material (2) and the narrow side refractory material (4) are composed of heat insulation plates, knotted materials and daubed materials.

4. The slab continuous casting mold according to claim 1, characterized in that: The lower side of the wide side plate (1) and the narrow side plate (3) is provided with a cooling structure away from the molten steel. 5.A method for using a slab continuous casting crystallizer, characterized in that: providing the slab continuous casting crystallizer according to any one of claims 1-4; in the casting process, the molten steel does not solidify in the V-shaped cavity, and the molten steel is cooled to form a shell when passing through the crystallization cavity; immersing a submerged nozzle (5) into the molten steel in the V-shaped cavity for casting.

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