RU2431540C1 - Catalyst cartridge for continuous casting of round billets - Google Patents

Abstract

FIELD: process engineering.

SUBSTANCE: invention relates to metallurgy. Crystalliser cartridge comprises cylindrical sleeve 1 made from beryllium bronze with its inner chamber provided with funnel and shaping sections 2 and 4, respectively. Funnel section 2 is located at sleeve top and features length L₁=0.7…0.8 L, where L is sleeve length, and taper making 2.0…2.5 %/m. Shaping section 4 features length L₂=0.2…0.3 L and outlet section with back taper of 3-5 %/m, and length L₃=0.05…0.1 L. Sleeve outer surface has vertical heat pickup 3-5 mm-deep grooves arranged regularly along sleeve edges.

EFFECT: higher stability.

4 cl, 6 dwg

Description

The invention relates to ferrous metallurgy, directly to continuous casting machines for round billets (CCM), and can be used in non-ferrous metallurgy.

As an analog, a mold sleeve with concavities in the upper part in the form of a circle is given (US Pat. EP 0498296 B1).

The disadvantage of the analogue is that during casting, due to the high conicity and length of the section with concavities, the formed crust of a continuously cast round billet turns out to be uneven in thickness, as a result the ovality of the billets occurs, the shell of the ingot hangs in the mold, entailing breakouts.

Known cited as a prototype of the mold sleeve with concavities in the upper part and changing the geometry along the length of the sleeve and having at least two forming concentric sections with different tapers (application: 2006135214/02, 10/06/2006, patent 2308348).

The disadvantage of the prototype is that during the casting process, the forming crust of a continuously cast round billet destroys the forming concentric sections with different tapers, thereby losing the initial technical effect. Also, this sleeve is difficult to manufacture.

The technical result of the present invention is the production of mold sleeves increased resistance in the presence of the forming part.

The technical result is achieved by the fact that the inner cavity of the sleeve is made with a ratio of sizes, funnel-shaped part

L ₁ = 0.7 ... 0.8 L,

Where

L is the length of the sleeve, with a taper of 2.0 ... 2.5% / m,

and forming part

L ₂ = 0.2 ... 0.3 L,

while the sleeve is made of beryllium bronze, and the molding part is made in the form of a calibrator with a length

L ₃ = 0.05 ... 0.1 L,

Where

L is the length of the sleeve and the outlet section with the inverse taper of 3 ... 5% / m,

in this case, heat-removing grooves are made on the outer surface of the cylindrical sleeve, for example, in the form of radial vertical grooves evenly spaced around the perimeter of the sleeve at a depth of 3 to 5 mm and the size of the chords of the grooves equal to the distance between the edges of the grooves.

The proposed mold sleeve is depicted in the following graphic materials, where:

figure 1 shows a section of a sleeve;

figure 2 shows a view of figure 1;

figure 3 shows a section of a sleeve with a calibrating and output sections;

figure 4 shows a view B of figure 3;

5 shows a sleeve with heat-removing grooves;

6 is a view In figure 5.

The proposed mold sleeve is made in the form of a cylindrical sleeve 1 with a funnel-shaped section 2 when the diameter inside the sleeve changes with a taper of 2 ... 2.5% and the ratio of the sizes of the funnel-shaped section is 2 L ₁ = 0.7 ... 0.8 L, where L is the length of the sleeve, wherein the cylindrical sleeve 1 is made with the inner cylindrical part 3, the concentric outer surface of the sleeve 1 and which is the forming part 4 with a length L ₂ = 0.2 ... 0.3 L, where L is the length of the sleeve. The forming part 4 can be made with a calibrator 5 and an outlet section with a reverse taper of 6 to 3 ... 5%, and also on the outer surface of the sleeve 1 can be made of heat-removing grooves 7 in the form of radial vertical grooves uniformly located along the perimeter of the sleeve 1 with a depth of 3 mm (pos. 8) to 5 mm (pos. 9) with the size of the chords of the grooves 7 equal to the distance between the edges of the grooves 7. The sleeve 1 is made of beryllium bronze.

The claimed device operates as follows. Liquid steel from the intermediate ladle enters the funnel-shaped part 2 of the sleeve 1, where the solidification and formation of a solid crust of the continuously cast ingot takes place. The shell in the funnel-shaped portion 2 hardens and therefore has a close contact, which helps to center the shell of the ingot in the mold. In the forming part 3, the shape of the blank shell becomes round, i.e. this section is the beginning of the shaping of the round billet. With calibrator 5, the round ingot obtains accurate geometry and surface quality.

At a distance of 150-200 mm from the lower end of the sleeve 1, the greatest wear of the walls is observed, therefore, it is recommended that the lower part of the mold of beryllium bronze be cylindrical-forming, because the combination of high hardness of the wall material and low hardness of the crust at the transition section of the cone-cylinder allows to reduce the wear of the walls of the liner.

The proposed sleeve is made of beryllium bronze, for example, MNS 2.0-0.4 with dimensions:

- length 800 mm;

- outer diameter 285 mm;

- inner diameter 250 mm from the beginning of the place of pouring metal.

At OJSC Metallurgical Plant Elektrostal, the parameters of a beryllium bronze mold of the mold were tested, confirming the receipt of a technical result.

Reducing the length L _{1 of the} funnel-shaped section according to the equation L ₁ = 0.7 ... 0.8 L leads to an unacceptable decrease in the thickness of the crust of the ingot in the forming part of the mold sleeve and frequent breakthroughs of the molten metal.

An increase in the length L _{1 of the} funnel-shaped portion according to the equation L ₁ = 0.7 ... 0.8 L leads to an unacceptable increase in the thickness of the ingot in the forming part of the mold sleeve and, accordingly, to increased wall wear in the forming part of the mold sleeve and the worsening of the geometry of the cross-section of the round billet.

Thus, the proposed mold sleeve increased resistance allows for the production of continuously cast billets:

- due to the use for the production of mold sleeves of molds of continuous casting of high-hardness bronze blanks MNB 2.0-0.4, with a change in the design of the sleeves from conical to conical-cylindrical;

- it improves the quality of the ingots while stabilizing the structure of the ingot and reducing its internal stresses in the cylindrical part of the sleeve;

- as well as the high hardness of the wall material allows you to calibrate and improve the surface of the ingot;

- the combination of high hardness of the wall material and low hardness of the ingot crust at the transition section of the cone-cylinder allows to reduce the wear of the walls of the sleeve;

- uniform wall thickness on the cylindrical section of the sleeve stabilizes the heat transfer process, which, in turn, improves crystallization processes.

As a result of changes in the design of the sleeve and the use of high-hard bronze MNB 2.0-0.4 as the material of the walls of the sleeve, they can increase the intensity of electromagnetic mixing of the melt due to

- reduced, relative to copper, electrical conductivity of the wall material;

- uniform wall thickness in a cylindrical section.

Claims (4)

1. The mold sleeve for the continuous casting of round billets, containing a cylindrical sleeve with an internal cavity open on both sides and made with a funnel-shaped and shape-forming sections, while the funnel-shaped section is made in the upper part of the sleeve from the pouring side of the metal with a decrease in its diameter inside the sleeve, characterized the fact that the length L _{1 of the} funnel-shaped section is L ₁ = 0.7 ... 0.8 L, where L is the length of the sleeve, while the taper of the funnel-shaped section is 2.0 ... 2.5% / m, and the length L _{2 of the} forming section SOS ulation L ₂ = 0.2 ... 0.3 L, wherein the forming portion is formed concentrically of the outer surface of the sleeve, wherein the sleeve is made of beryllium bronze. 2. The mold sleeve according to claim 1, characterized in that the forming section has an outlet section with an inverse taper of 3-5% / m and a length L ₃ = 0.05 ... 0.1 L. 3. The mold sleeve according to claim 1, characterized in that heat-removing grooves are made on the outer surface of the cylindrical sleeve. 4. The mold sleeve according to claim 3, characterized in that the heat-removing grooves are made in the form of radial vertical grooves with a depth of 3 to 5 mm, evenly spaced around the perimeter of the sleeve.

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