JPH0737447U - Casting nozzle for thin sheet continuous casting - Google Patents

Abstract

(57) [Summary] [Purpose] To provide a casting nozzle that can be processed with high precision and that is easy to set. [Structure] In a casting nozzle 1 used for continuous casting of single-roll type and twin-roll lateral pouring type thin plate continuous casting for rapidly solidifying molten steel to produce thin plate continuous slabs, a flat plate shape in which a surface in contact with a casting roll 2 is formed on a lower surface on a tip side The side nozzle member 12 and a bottom nozzle member 11 which has a surface in contact with the casting roll 2 at its tip 11b and which can be attached to both sides of the side nozzle member 12 are formed.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a casting nozzle in single-roll type and twin-roll horizontal pouring type thin plate continuous casting.

[0002]

[Prior art]

 From the viewpoint of manufacturing difficult-to-process materials and simplifying the rolling process, the molten metal continuously supplied from the tundish is rapidly cooled and solidified on the surface of a rotating roll (hereinafter referred to as "casting roll") to continuously cast thin plates. The method is widely adopted.

As the above casting roll, a single roll or a twin roll is used. Figures 4 and 5 show the structure of the casting part of a single-roll type thin plate continuous casting machine. A casting roll 2 and a tundish 3 are connected through a casting nozzle 1 in which a bottom portion 1a and a side wall portion 1b are integrally formed. The bottom surface of the casting nozzle 1 at the tip of the bottom portion 1a and the tip of the side wall portion 1b is It has a curved surface formed with the same curvature as the casting roll 2 so as to be in direct contact with the casting roll 2, and is generally formed of ceramics.

In this single roll type thin plate continuous casting apparatus, when the molten metal 4 is continuously injected into the tundish 3, it is guided by the casting nozzle 1 and continuously solidified on the surface of the casting roll 2 to form a slab 5 Is manufactured.

FIGS. 6 and 7 show the structure of the casting part of a twin roll lateral pouring type thin plate continuous casting device. Comparing this with a single-roll type thin plate continuous casting device, the casting roll 2 has a structure in which a pair of upper and lower rolls 6 and 7 are substituted, and the molten metal 4 continuously injected into the tundish 3 is the surface of the rolls 6 and 7. The thin plate 8 is manufactured by rolling the slab that is continuously solidified by the method.

[0006]

The inventors of the present invention conducted casting using a single roll type thin plate continuous casting device, and obtained the following knowledge when setting a casting nozzle and a casting roll. In order to prevent molten metal leakage, it is necessary to set the gap between the casting nozzle and the casting roll to zero or maintain it at a very small gap within the surface tension range of the molten metal. In order to prevent meandering of the slab and damage to the inner surface of the nozzle side wall, the inner surface of the nozzle side wall must be perpendicular to the axis of the casting roll. If the inner surface of the side wall of the casting nozzle is not at right angles to the axis of the casting roll, as shown in FIG. 8, unevenness of the edges of the slab and meandering of the slab will occur. In the figure, the solid line shows the unevenness of the slab edge and the broken line shows the meandering of the slab.

In order to satisfy the above conditions, as shown in FIG. 9, the casting nozzle is machined such that the extension lines 1 and m on the inner surface of the nozzle side wall are orthogonal to the axis Z-Z in the longitudinal direction of the casting roll cylinder. In addition, the extension line n of the nozzle tip must be parallel to the axis Z--Z in the casting roll cylinder length direction.

However, the conventional ceramic casting nozzle in which the bottom portion and the side wall portion are integrated has the following problems. The inner surface of the nozzle side wall is perpendicular to the axial center of the casting roll cylinder and the tip of the nozzle is parallel to the axial length of the casting roll cylinder while adjusting the curvature of the casting roll to the extent that no pouring or leakage occurs. It has to be processed and is difficult to process. This is because the larger the diameter of the casting roll and the longer the length of the cylinder, the worse the machining accuracy becomes, and the machining cost becomes high even if machining is possible.

Generally, the casting nozzle is manufactured by casting, and the larger the size, the more likely it is that internal defects will occur. Since the width of the inner wall of the nozzle becomes the width of the cast piece, it is necessary to prepare a casting nozzle for each product width when manufacturing products with different cast piece widths.

Therefore, an object of the present invention is to solve the above-mentioned problems, to provide a casting nozzle that can be processed with high accuracy and that is easy to set.

[0011]

[Means for Solving the Problems]

 In order to achieve the above-mentioned object, the casting nozzle for continuous thin plate casting of the present invention is a casting nozzle used for continuous casting of single roll type and twin roll side pouring type thin plate continuous casting for rapidly solidifying molten steel to produce a thin plate continuous cast piece. Since a flat side nozzle member having a surface contacting the casting roll formed on the lower surface on the tip side and a surface contacting the casting roll at the tip is formed, the side nozzle member is composed of a bottom nozzle member attachable on both sides. is there .

[0012]

[Action]

 The casting nozzle for continuous casting of thin plates according to the present invention comprises a flat side nozzle member having a surface contacting the casting roll on the lower surface on the tip side and a surface contacting the casting roll at the tip, and the side nozzle member is provided on both sides. Since the bottom nozzle member is attachable, the side nozzle member and the bottom nozzle member can be independently processed with high precision.

[0013]

【Example】

 Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings. FIG. 1 is a perspective view showing the construction of a casting nozzle for continuous thin plate casting of the present invention, and FIG. 2 is a view showing a state when the casting nozzle for continuous thin plate casting of the present invention is used.

In the drawings, a casting nozzle 1 is composed of a bottom nozzle member 11 that is in contact with a casting roll 2 in the cylinder length direction, and side nozzle members 12 attached to both side wall surfaces 11 a of the bottom nozzle member 11. The tip end portion 11b of the bottom nozzle member 11 is precision-machined to form a surface in contact with the casting roll 2, and the side surface of the side nozzle member 12 on the tip end side is the same as the casting roll 2. The curved surface portion 12a is formed with a curvature.

Since the casting nozzle for continuous casting of thin plates of the present invention has the above-mentioned structure, the bottom nozzle member 11 requires only the tip portion 11b for precision machining, and the side wall portion is the same as the conventional casting nozzle. Since it is not necessary to machine at the same time, the machining range becomes smaller and machining can be done easily in a short time. Further, the side nozzle member 12 can be processed easily because only the curved surface portion 12a in contact with the casting roll 2 needs to be precision processed.

Generally, the diameter of the casting roll 2 used in an industrial-scale thin plate continuous casting apparatus is 1000 mm or more, while the length at which the bottom of the nozzle tip is in contact with the casting roll 2 is 10 to 20 mm. is there. Considering this, the contact surface of the bottom of the nozzle tip with the casting roll 2 is not a curved surface that matches the diameter of the casting roll 2, and there is no fear of pouring or leaking even if it has a flat shape.

FIG. 3 shows the relationship between the tip 11b and the casting roll 2 when the tip 11b of the bottom nozzle member 11 constituting the casting nozzle 1 of the present invention is processed into a flat surface. The radius r of the casting roll 2 is shown in FIG. Is 500 mm and the length s of the contact surface with the tip 11b is 20 mm, the gap Δd between the tip 11b and the casting roll 2 is about 0.1 mm. With such a gap, it is possible to avoid a jug or leak.

Since the casting nozzle for continuous casting of thin plates of the present invention can reduce the working range, not only the processing becomes easy, but also the processing time can be shortened. Further, when manufacturing products with different slab widths, the bottom nozzle member 11 only needs to be replaced, so the side nozzle member 12 does not have to be changed.

SUS304 was cast at a casting speed of 20 m / min for 10 minutes with a single roll type thin plate continuous casting apparatus using the casting nozzle shown in FIGS. The diameter of this casting roll 2 is 1000 mm, the width of the slab to be produced is 600 mm, and the radius of the curved surface portion 12 a formed on the lower surface of the side nozzle member 12 on the tip side and in contact with the casting roll 2 is 500.3 mm.

As a result of using the above casting nozzle, the defect occurrence rate inside the nozzle is 1% or less, and there is no jug or leak during casting, and the nozzle set time is 37% compared with the conventional nozzle. It can be shortened and the manufacturing cost can be reduced by 48%.

Casting was performed under the same conditions with the above-described single-roll type thin plate continuous casting apparatus using a casting nozzle in which the tip length of the bottom nozzle member 11 was processed into a flat surface of 20 mm. As a result, there was no hot water leak or hot water leak from the tip 11b of the bottom nozzle member 11.

[0022]

[Effect of device]

 As explained above, since the casting nozzle for continuous thin plate casting of the present invention is composed of the bottom nozzle member and the side nozzle member, it is easy to process each member, and the nozzle set time and manufacturing cost are compared with the conventional nozzle. I was able to improve significantly. At the same time, the defect occurrence rate inside the nozzle, and the hot water bottle and hot water leakage are improved. Further, the same effect can be obtained even if the tip end surface of the bottom nozzle member that contacts the casting roll is processed into a flat surface.

[Brief description of drawings]

FIG. 1 is a perspective view showing the structure of a casting nozzle for continuous casting of thin plates according to the present invention.

FIG. 2 is a view showing a state when a casting nozzle for continuous casting of thin plates of the present invention is used.

FIG. 3 is a diagram showing a relationship between a nozzle tip bottom and a casting roll when the nozzle tip bottom is processed into a flat surface.

FIG. 4 is a cross-sectional view showing a structure of a casting part of a single roll type thin plate continuous casting device.

FIG. 5 is a perspective view showing a structure of a casting unit of a single roll type thin plate continuous casting apparatus.

FIG. 6 is a cross-sectional view showing a structure of a casting part of a twin roll lateral pouring type thin plate continuous casting device.

FIG. 7 is a perspective view showing a structure of a casting part of a twin roll lateral pouring type thin plate continuous casting device.

FIG. 8 is a diagram showing a situation of defects occurring in a slab.

FIG. 9 is an explanatory diagram of setting conditions of a casting nozzle.

[Explanation of symbols]

 1 Casting Nozzle 2 Casting Roll 3 Tundish 4 Molten Metal 5 Cast Piece 11 Bottom Nozzle Member 12 Side Nozzle Member

Claims (1)

[Scope of utility model registration request] 1. A casting nozzle used for continuous casting of single roll type and twin roll lateral pouring type thin plate continuous casting for rapidly solidifying molten steel to produce thin plate continuous cast slabs, and a flat plate shape in which a surface in contact with the casting roll is formed on the lower surface on the tip side. A casting nozzle for continuous thin plate casting, comprising a side nozzle member and a bottom nozzle member having a tip contacting surface for contact with a casting roll, the side nozzle member being mountable on both sides.