SU1245407A1 - Method of continuous casting of billets - Google Patents

Description

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The invention relate to metallurgy, more specifically to the continuous casting of metals, in particular to the production of continuously cast bimetallic billets.

The purpose of the invention is to improve the quality of continuously cast billets.

Figure 1 shows a diagram of an apparatus for carrying out a method for continuous casting of metals, a longitudinal section; Fig. 2 is a diagram of the temperature of a crystallized ingot; Fig. 3 is a diagram of an apparatus for carrying out a method for continuous metal casting, a variant longitudinal section; FIG. 4 is a diagram of the templet of a crystallized ingot.

Improvement in the quality of continuously cast billets is achieved due to the absence of axial segregation and friability due to the installation of a package of metal sheets along the ingot axis. In addition, when two packages of metal sheets are installed in the volume between them, by reducing the heat sink, the two-phase zone increases, the area decreases.

columnar crystals, which also reduces the development of axial segregation and friability. The marginal areas of the ingot are of high quality in the macrostructure due to the crystallization triangle arising along the edges of the ingot due to heat removal during the crystallization process in three directions. These sections of the ingot after slitting can be used independently. At the same time, several bimetallic billets clad on one or two sides are obtained after cutting. The quality of welding of homogeneous packages and the elimination of their warping is achieved by heating the package from two sides.

The range of the total thickness of the sheet package within 1 / 8-1 / 20 of the ingot thickness is explained by the condition of welding of the sheets and the crystallizing metal. With a smaller thickness, it is possible to podpavlenie sheet package and the displacement of metals, which makes it impossible to obtain bimetallic billets. With greater thickness, there is a significant decrease in the temperature of the liquid metal, which leads to a deterioration in the quality of the macrostructure of the core ion ion. This range is set in direct proportion to the ingot thickness.

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The need to install sheet packages symmetrically with respect to its longitudinal and transverse axes of the ingot is explained by the laws of formation and crystallization of the axial part of the ingot. In the opposite case, the heat sink from the central zone of the ingot will not be symmetrical, which will cause a violation of the uniform distribution of properties

to ingot thickness.

The range of the distance between the packages of metal sheets within 1 / 2-1 / 3 of the ingot thickness is explained by the conditions of formation and crystallization of the axial zone of the ingot. With a smaller thickness, the temperature of the molten metal in the axial part of the ingot will significantly decrease, which will cause a decrease in the size of the two-phase zone and the formation of axial segregation. At high values, the zone of columnar crystals will increase, which also leads to the formation of axial segregation and friability. The specified range is set to

25 directly proportional to the ingot thickness ..

The reduction in the width of the package of metal sheets in comparison with the ingot 1-inch width by 0.1-0.5 of its thickness, with each side, is explained by the need to feed the metal into the crystallizer in one jet. In this case, the metal has the ability to flow into all parts of the working cavity of the crystallizer. Supply of metal with several jets will complicate the process of continuous casting and complicate the maintenance of the metal meniscus in the mold. In this case, it becomes possible to obtain, after cutting the edge blanks, a bloom mix with a high-quality macrostructure:

The cutting off of the marginal sections of the ingot with sh: iris in the range of 0.1-0.5 from each side is explained by the dimensions of the crystallization triangle, having a height equal to half of the TOL1EDIN of the rectangular ingot. At high values, the cut will be of low quality due to the axial segregation of the ingot. At lower values, it will be difficult to fill the entire area of the working cavity of the mold with an odd metallic plate.

The process of dividing the ingot into separate continuously cast billets is possible both after the ingot is completely solidified and after its rolling35

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ki in this case, flat strips of the required thickness are obtained.

A device for carrying out the method of casting continuous bimetallic billets consists of a crystallizer 1 and packages of metal sheets 24. In addition, FIGS. 1-4 show a stream of metal 3, sections 4-6 of ingot cross-section, borders 7 of crystallization triangle

The method is carried out as follows.

Example 1. In the process of continuous casting of metals into the mold 1, a bag 2 consisting of two metal sheets is fed, steel is poured in a jet and an ingot of section 200x 1600 mm with a speed of 0.8 m / min is drawn from the crystal mold 1. Metal sheets 2 are made of stainless steel. The total thickness of the sheet package 2 is set equal to 1/20 of the ingot thickness or 10 mm. The thickness of each sheet is set to 5 mm. The width of the package of metal sheets 2 is set equal to the width of the ingot, reduced by its thickness or 1400 mm. The package of sheets 2 is installed symmetrically to the longitudinal and transverse axis of the ingot.

After the ingot is crystallized, the edge sections 6 with a width equal to half the thickness of the ingot or 100 mm are cut off from its edge sections. The ingot sections 4 are divided between each other and individually form bimetallic ingots, cladding with one hundred, four, 100 mm thick and 1400 mm wide.

When two packets of sheets 2 are fed into the mold 1, the distance between them is set equal to 1/3 of the ingot or 66.6 mm. The width of the Pack of Sheets 2 is set equal to the width of the ingot, reduced on each side by 0.3 of the thickness of the ingot or equal to 1480 mm. After the ingot is fully crystallized, the edge sections 6 with a width equal to 0.3 times the ingot THICKNESS or 60 mm are cut off from its edge sections. Sections 4 and 5 of the ingot are divided between each other, which separately form bimetallic-blanks: two edge 4, clad on one side, 61.7 mm thick, and one central 5, clad on both sides, 76.6 mm thick . The width of the bimetallic blanks is 1,480 mm.

2A54074

Before being fed into the mold 1, the contacting surfaces of the sheets 2 in the bag are lubricated with MgO magnesia solution in liquid glass. The outer surfaces of sheets 2 in the package are crushed with ammonium chloride (head) NHyCl. In the first case, lubrication is necessary to facilitate the separation of bimetallic blanks. In the second

10, a coating is necessary to prevent the outer surfaces of the sheets 2 from being oxidized in the bag.

As the ingots are drawn, the SHEETS 2 bags are served in succession.

15 one after another.

As a result of the application of the proposed method, bimetallic billets, as well as unalloyed bloom sections, are obtained.

2Q high quality due to the presence in their body of a crystallization triangle 7 ..

And p Imper 2. In the process of continuous casting of metals into the crystal, the mash 1 serves a bag 2 consisting of two metal sheets, pours steel 3 with a jet 3 and draws out an ingot of the crystallizer 1 ingot with a section of 250x xlBOO mm at a speed of 0.6 m / min. Metal sheets 2 are made of stainless steel. The total thickness of the sheet package 2 is set equal to 1/16 of the ingot thickness or 15 mm. The thickness of each ingot is set to 7.5 mm. The width of the package of metal sheets 2 is set equal to the width of the ingot, reduced by 0.4 of its thickness on either side or 1600 mm. The package of sheets 2 sets the symmetrical longitudinal and transverse axis of the ingot.

After complete crystallization of the ingot from its edge areas cut off. marginal areas 6 with a width equal to half the thickness of the ingot or 100 mm.

45 The ingot sections 4 are divided among themselves, which individually form bimetallic billets clad on one side with a thickness of 100 mm and a width of 1600 mm.

50 When two sheets of sheets 2 are fed into the mold 1, the distance between them is set to 1 / 2.5 the thickness of the ingot or 100 mm. The width of the stack of sheets 2 is set equal to

55 ingot width, reduced on each side by 0.3 ingot thickness and equal to 1650 mm. After complete crystallization of the ingot from its marginal areas

thirty

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Edge sections 6 are cut to a width equal to 0.3 of the ingot thickness or 75m 3 each. Parts 4 and 5 of the ingot are divided among themselves, which separately form bimetallic billets: two edge 4, clad with one side, 67.5 mm thick, and one central 5, clad with 75 mm thick 75 mm. The width of the bimetallic ingots is 1650 mm.

Before installing in the mold sheets 2 are treated as in example 1.

As the ingots are drawn, packs of sheets 2 are fed one after the other.

As a result of applying the proposed method, bimetallium is obtained. high quality billets

also continuously cast blu-20 billets which individually form a bime30

A new section of high quality due to the presence in them of a crystallization triangle 7.

Example 3. In the process of continuous casting of metals into the crystal- 25 mash 1, a stack 2 consisting of two metal sheets is fed, steel is poured over with jet 3 and an ingot with a section of 300) 2000 mm is drawn from the mold 1 at a speed of 0.4 m / min. Metal sheets 2 are made of stainless steel. The total thickness of the sheet package 2 is set equal to 1/8 of the ingot thickness or 37.5 mm. Sheet thickness is set to 20 and 17.5 mm. The width of the package of metal sheets 2 is set equal to the width of the ingot, reduced by 0.1 of its thickness, on either side or 1940 mm. The package of sheets 2 is installed symmetrically to the longitudinal and transverse axis of the ingot.

After complete crystallization of the ingot from the edge sections cut off the edge section 6 of a width equal to 0.1 year

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ingot thickness or 130 mm. The ingot sections 4 are divided among themselves, which separately form a bimeta-clad billet, clad with. on the one hand, a mass of 150 mm and. 1940 mm wide.

When applying two packets of sheets 2 to the mold. 1 the distance between them is set equal to 1/2 the thickness of the ingot or 150 mm. The width of the packet of sheets 2 is set equal to the width of the sheet, reduced by 0.1 thick on each side, and the ingot size equal to 1940 mm.

After the ingot is completely crystallized, the edge sections are cut off from its edge sections: 6 of a width equal to 0.1 of an ingot thickness or 30 mm each. Slits 4 and 5 are divided among themselves,

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five

tallic blanks; two edge 4, clad on one side, 57 „5 mm thick, and one central 5, clad on both sides, 185 mm thick. The width of the bimetallic blanks is 1940 mm.

Before serving in the mold 1 sheets 2 are treated as in example 1.

As the ingots are drawn, packs of sheets 2 are fed one after the other.

The application of the proposed method allows to eliminate axial liquation and friability in the workpieces, to obtain high-quality bimetallic billets that do not segregate during rolling, as well as billet of varietal and bloom assortment with high quality of the macrostructure, to reduce the scrap of the blanks by the quality of the macrostructure by 0.2% , and for the bimetallic billets separation by 0.3%, the amount of trimmed should be reduced by 0.25%.

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Editor S.Pekar

Compiled by L. Dymshits Tehred V. Kadar

Order 3944/7 Circulation 757 Subscription

VNIIPI USSR State Committee

for inventions and discoveries 113035, Moscow, Zh-35, Raushsk nab., 4/5

Production and printing company, Uzhgorod, st. Project, 4

Proofreader G. Reshetnik

Claims (2)

1. METHOD FOR CONTINUOUS CASTING OF PREPARATIONS, mainly bimetallic, including feeding liquid metal and metal sheets into the mold, drawing an ingot from the mold and cutting it into billets, characterized in that, in order to improve the quality of continuously cast billets, metal sheets are fed in pairs into in the form of a package with a thickness of 1 / 8-1 / 20 of the thickness of the ingot symmetrically to the longitudinal and transverse axes of the mold with a gap relative to its narrow walls of 0.1-0.5 thickness of the ingot. 2. The method according to claim 1, characterized in that the metal sheets are fed in two packets with a distance between them of 1 / 2-1 / 3 of the thickness of the ingot. rm Figure 1