CN201436111U - Submerged nozzle for wide slab continuous casting mold - Google Patents

Abstract

The utility model belongs to the continuous casting refractory material field, especially relates to a crystallizer immersion water mouth. A wide slab continuous casting crystallizer immersion water mouth comprises an inserting type water mouth body (1); both sides of the inserting type water mouth body (1) are symmetrically arranged with water mouth side holes (2); the inserting type water mouth body (1) is flat shaped; the water mouth side holes (2) are rectangular holes inclined downwardly; the bottom of the inserting type water mouth body (1) is a sunken bottom (3); The utility model designs all parameters reasonably aiming at the slab continuous casting crystallizer with drawing speed of 0.7-1.3m/min and section area of 220-300 X 1200-2300 mm2, obviously improves the upper molten steel circulation status in the crystallizer, improves the upward-floating rate of impurities in steel, increases the water mouth region slag generating area, improves the melting and flowing uniformity of the protection slag, and improves the surface and internal quality of wide slab casting billet.

Description

Submerged nozzle for wide slab continuous casting mold

technical field

The utility model belongs to the field of continuous casting refractory materials, in particular to a crystallizer submerged nozzle.

Background technique

The development of hot charging and hot delivery, continuous casting and rolling, thin slab (strip) continuous casting, and continuous casting and rolling technology puts forward higher requirements for the surface and internal quality of the slab. Longitudinal cracks are one of the most common quality defects of continuous casting slabs. Slight longitudinal cracks will not affect the next process after the slab is finished. Severe longitudinal cracks will scrap the entire slab. Longitudinal cracks and steel breakouts are caused during the production process, which brings serious harm to equipment and production. There have been many studies on the causes of longitudinal cracks. In summary, the main influencing factors are: the composition and castability of molten steel, the cooling condition of the crystallizer, the entry nozzle, mold slag and the operating parameters of the continuous casting process. Whether the structure of the protruding nozzle meets the requirements of the continuous casting process has an important influence on the quality of the slab. This is because under the conditions of casting speed and pouring section, the structure and size of the protruding nozzle determine the flow behavior of molten steel in the mold, and the flow behavior of molten steel determines the temperature field of molten steel, which in turn affects the initial solidification of molten steel, The function of mold slag and the floating probability of inclusions in molten steel will affect the quality of cast slab. Therefore, the research on the optimization technology of mold entry nozzle that is suitable for it has always been the focus of continuous casting workers' concern and work.

To evaluate whether the extension nozzle of the mold is reasonable, it is mainly considered from three aspects: 1) the fluctuation of the liquid level in the mold and the uniform distribution of mold slag; 2) the circulation of molten steel in the upper area of the mold; 3) the flow of the nozzle The impact depth of strands and the floating status of inclusions. The pouring section of the mold of wide slab continuous casting machine is characterized by a large width-to-thickness ratio. Under the condition that the casting speed is not too high, it is difficult for the stream flowing out of the side hole of the protruding nozzle of the mold to hit the narrow surface of the mold. An upward recirculation zone is formed. There is no upward circulation zone in the mold. On the one hand, it makes it difficult for the inclusions in the steel to float up; at the same time, the more important thing is that the liquid level of the mold is not active, and the mold slag is not melted well, which cannot ensure the formation of a sufficient liquid slag pool, which is unfavorable for the development of the mold. Due to the lubricating and heat transfer control capabilities of mold flux, the probability of longitudinal cracks on the slab surface is high. In addition, if a nozzle with a circular shape is used, the distance between the outer wall of the nozzle and the wall of the mold becomes smaller, which reduces the slag area in this area, and easily causes longitudinal cracks on the surface of the slab near the nozzle of the mold. At present, the protruding nozzles for slab continuous casting molds adopt the structure of double-sided holes. The design factors of the nozzles that affect the flow behavior of molten steel in the mold include: 1) the shape of the nozzle; 2) the bottom form of the nozzle, there are three types: convex bottom , flat bottom and concave bottom; 3) The shape of the side opening, there are three shapes: round hole, oval hole and rectangular hole; 4) The angle of the side opening, there are different upward and downward angles; 5) The area of different side openings .

By changing the shape of the nozzle, the shape of the bottom, the shape of the side opening, the angle of the side opening and the area of the side opening, the design of the extension nozzle can solve the problem of the molten steel circulation in the upper area of the mold during the continuous casting of wide slabs Weak, inactive liquid surface and small slag area near the nozzle cause high probability of longitudinal cracks on the surface of the slab and difficulty in floating inclusions in the steel. Therefore, in order to ensure product quality, it is very important to design mold extension nozzles that meet the requirements of continuous casting of wide slabs.

Utility model content

The technical problem to be solved by the utility model is to provide a wide slab continuous casting crystallizer submerged nozzle, the submerged nozzle satisfies casting speed: 0.7-1.3m/min and crystallizer section: 220-300×1200-2300mm ^2. The extended nozzle of the slab continuous casting mold can enhance the circulation speed of molten steel in the upper part of the mold, promote the probability of floating inclusions in the steel, increase the area of slag near the nozzle, and improve the uniform melting and inflow conditions of mold slag , to achieve the purpose of improving the surface and internal quality of the wide-slab cast slab.

A submerged nozzle for a wide slab continuous casting crystallizer, comprising a protruding nozzle body, side holes of the nozzle are symmetrically arranged on both sides of the protruding nozzle body, the protruding nozzle body is flat in shape, The side hole of the nozzle is a rectangular hole, the hole is inclined downward, and the bottom of the protruding nozzle body is a convex bottom.

The inclination angle α at which the nozzle side hole is inclined downward is 10-20°.

The four sides of the rectangle of the nozzle side hole are rounded transitions, and the radius R of the transition circle is 5-30mm.

The downward slope angle α of the nozzle side hole is 15°, the area of the nozzle side hole is 4800mm ² , the shape is a 48×100mm ² rectangle, and the radius R of the transition circle between adjacent sides of the rectangle is 15mm.

The utility model rationally designs various parameters of the submerged nozzle for the slab continuous casting crystallizer with a casting speed of 0.7-1.3m/min and a cross-section of 220-300× ^1200-2300mm2 , and obviously improves the inner and upper parts of the crystallizer. The circulation of molten steel improves the floating rate of inclusions in steel, increases the slag area in the nozzle area, improves the melting and inflow uniformity of mold slag, and improves the surface and internal quality of wide-slab casting slabs.

Description of drawings

Fig. 1 is the three-dimensional schematic diagram when the submerged nozzle of the wide slab continuous casting crystallizer of the utility model is installed on the crystallizer;

Fig. 2 is the three-dimensional schematic view of the internal structure of the utility model;

Fig. 3 is the vertical sectional schematic diagram of the utility model;

Fig. 4 is the side view of Fig. 3;

Figure 5 is a schematic diagram of the side hole of the nozzle.

In the figure: 1. The body of the protruding nozzle, 2. The side hole of the nozzle, 3. The convex bottom, 4. The crystallizer.

Detailed ways

Below in conjunction with specific embodiment, further set forth the utility model. It should be understood that these embodiments are only used to illustrate the present utility model and are not intended to limit the scope of the present utility model. In addition, it should be understood that after reading the content of the utility model, those skilled in the art can make various changes or modifications to the utility model, and these equivalent forms also fall within the scope defined by the appended claims of the application.

As shown in Figures 1, 2, 3, and 4, a submerged nozzle for a wide slab continuous casting mold includes a protruding nozzle body 1, the shape of the protruding nozzle body 1 is flat, and its two sides There are rectangular nozzle side holes 2 symmetrically arranged, as shown in Figure 5, the four sides of the rectangle are rounded transitions, the transition circle radius R is 5-30 mm, the nozzle side holes 2 are inclined downward, and the inclination angle α is 10-20°. The bottom of the protruding nozzle body 1 is a convex bottom 3, and the flat protruding nozzle body 1 increases the distance between the outer wall of the nozzle and the copper plate of the crystallizer 4, improves the heating conditions for the mold slag, and is beneficial to the mold slag Melt and flow.

Select the submerged nozzle parameters for crystallizers with a section of 220×1200～2300mm ² : the inclination angle of the side hole 2 of the nozzle α=15°, the area of the side hole 2 of the nozzle is 4800mm ² , and the shape is a rectangle of 48×100mm ² . The radius of the transition circle of the adjacent side is R=15mm, and the setting of process parameters: the insertion depth range of the submerged nozzle (the distance from the upper part of the side hole of the nozzle to the molten steel surface) is: 135~175mm; the range of argon blowing volume is: 15~35L min ^{- 1} .

Claims (4)

1. wide plate blank continuous casting crystallizer submersed nozzle, comprise and stretch into formula mouth of a river body (1), the described bilateral symmetry that stretches into formula mouth of a river body (1) is furnished with mouth of a river side opening (2), it is characterized in that: described to stretch into formula mouth of a river body (1) profile be flat, described mouth of a river side opening (2) is a slot, the hole is downward-sloping, and the bottom of stretching into formula mouth of a river body (1) is sunken bottom (3).

2. wide plate blank continuous casting crystallizer submersed nozzle as claimed in claim 1 is characterized in that: the downward-sloping inclined angle alpha of described mouth of a river side opening (2) is 10～20 °.

3. wide plate blank continuous casting crystallizer submersed nozzle as claimed in claim 1 or 2 is characterized in that: rectangular four limits of described mouth of a river side opening (2) are round-corner transition, and transitional radius R is 5～30mm.

4. wide plate blank continuous casting crystallizer submersed nozzle as claimed in claim 3 is characterized in that: the downward-sloping inclined angle alpha of described mouth of a river side opening (2) is 15 °, and the area of mouth of a river side opening (2) is 4800mm ², be shaped as 48 * 100mm ²Rectangle, rectangle adjacent edge transitional radius R is 15mm.

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