SU1235627A1 - Method and apparatus for producing hollow ingot - Google Patents

Abstract

I. A method for producing a hollow ingot comprising pouring a melt into a mold using a metal tube rod and a central core, the gap between which is filled with bulk material, characterized in that, in order to expand technological capabilities, from the moment melt pouring starts, a bulk material is passed through the bulk material pressurized gas to form a fluidized bed. sl sd o5

Description

2. Device d, getting a c. 1tk, containing the pallet and the mold formed on it with a rod in the form of meta. ; - Lyceum tube and central hearts. the gap between them is 3an (j, 4HeH bulk material, characterized by that with iie / ibio expansion of technological capabilities, it is equipped with a conical sheath; / 1 and. upper of which, according to McirhiHieMV D 1i and 1ll; .- fixed by jsa core, and the bottom of the rim. To 1I 11 pipe to the mill-: a with a-: iopoM over the surface: the core of the sealing invention The invention relates to the production of cast iron, in particular to the production of castings.

The purpose of the invention is the expansion of technological capabilities.

FIG. 1 shows a device for carrying out the method but; 1 is not a hollow ingot, a cut; in fig. 2 upper conic shell, view Ln FIG. one; in fig. 3 lower conic shell, section B B in FIG. one.

A hollow ingot gluescore includes the installation of an iodine pa.: 1, o1 set forth metal- and 15 cores with the mother;,; | hl-1 .v. And with the beginning of the zatlu from the side of Yuddon in son of matter. Yudayug under pressure gas to obra:. oovii k.pi shs z) s.yu.

In this case, the magnitude of the gas pressure is determined but (L formula P (9-12) Y I, where P is the gas pressure. Pa; Pa;

Y is the specific weight of bulk material,

N / m 1

// - height of bulk material. the annular gap between the meta / myic tube and Erdepec-1K () m, m.

The formula determined experimentally by specifying the formula determines the optimal value of the pressure of the gas fed to the bulk material reagent for its k1P1. If the pressure value is taken as the formula obtained by the formula, then the gas under pressure will find in the bulk material a way of opposing it and will pass through it upwards without useful work but boiling the bulk material.

When the gas pressure is greater than the gas obtained by the formula, it becomes dangerous for the metal to vibrate. IvpoMe addition, and pronouncing. The flow is increased by 1 aza.

The coefficient yyy (9–12) introduced into the formula makes it possible to regulate the pressure ra: ia depending on the width of the annulus. shield reagent, under which axial holes are made in the pan, wherein the upper conical shell relative to the metal pipe and the lower shell relative to the core are arranged with annular gaps.

3. A device according to claim 2, characterized in that the upper conical shell from the side of the metal pipe and the lower conical shell from the core side are extruded with radial slots.

0

five

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gap between the metal pipe and the crossbar. The boundary value of the 9 coefficient is recommended for a ring-shaped gap of 1 ри 25 mm by 30–30 mm, and the limiting value of the 12 coefficient is for a ring-shaped gap with a width of 8-10 mm.

Supply to Sealing reagent 1az reagent Iodine pressure can be both constant and 11y: syrindop1, to it.

The device contains a mold with an extension 2, the inouts of which on the pallet 3 are installed MeTa: ijiH4-ecK; ui pipe 4 and the core is equipped with a cbuiy uiM material. Yum 6 between. As a material, ci niynero of material is, 1o,; 1, for example, sand, magnesite, nja-У10Т, chromite or iron nopoLHOK. The particle size of the ciMnyuero material 6 is 1.5-3.0 mm. Above the bulk material 6 times mixed; |. The conical shells 7 and 8, the upper of which is fixed in diameter 1 to the diameter of the core 5, and the lower one is installed above the surface, 1 of the flowing material 6 with a gap of 32--36 % height of this matter, 1a and bo. diameter: bolted inside a metal pipe 4. Under pressure: with material b in pallet 3 BbUKX ineiio nesko, axial holes 9 for gas pressure from an external source (not shown). The top –G | ND shell 7 with respect to the metal pipe 4 and 1P1LING shell 8 with respect to the core 5 are arranged with annular rings 10 and 1 1 wide up to l,: i mm 1-: then less than n (the size of an hour - 1 tsy bulk material 6.

The upper conic shell of the 7 eo side of the metal pipe 4 is made with) the adial slots 12 of the pyrene no more than the cross-sectional size of one particle synouche | -ohmc-trial 6.

Pizh.chi conical shell 8 from the side of the heart-H | 1ika 5 is made with radial po1:; 13 with a width of not more than one transverse p.-T iMcpia of one particle of loose chagerial n.

Made in the pallet under. with axial holes, on the one hand, are aimed at improving the quality of a hollow ingot due to the fact that gas is fed under pressure under pressure, which causes the bulk material to boil, and, on the other hand, by improving the cooling condition of the material, the holes increase productivity .

Fastening on the core and the metal pipe of the conical shells limits the height of the bales of the first layer from above, and on the L-shaped ceramics provided by Mt. i, y the upper conical shell and the metal pipe, as well as between the lower conical shell and the core, are provided so that only the heated gas comes out of the fluidized bed, which has done useful work both in fluffing the material and cooling it. The lower conical shell is installed above the surface of the sealing protective reagent with a gap of 32–36% of the height of this reagent in order to also increase the quality of the hollow ingot. Placing the lower conical shell with a gap of less than 32% leads to insufficient swelling of the bulk material with gas and does not allow this material to increase its height while reducing the diameter of the metal pipe under the influence of metal pressure and the initial shrinkage forces of the hollow ingot. As a result, the clamping of the core and the formation of internal cracks in the hollow ingot are unavoidable.

Making the gap height more than 36% is not recommended, since the height of the metal pipe and core increases unnecessarily, i.e. the metal consumption of the device increases.

The radial slots are made on the upper and lower conical shells so that gas escapes from the sealing protective reagent after reducing the diameter of the metal pipe under shrinkage of the hardening hollow ingot when the lower conical shell comes into contact with the core and the top with the metal pipe. Due to this, the expansion of the sealing protective reagent does not stop.

The method is carried out as follows.

On the tray 3 of the mold 1, a metal pipe 4 and a core 5 with bulk material 6 between them are installed. Over the bulk material 6 with a gap of 32-36% of the height of this material, a conical shell 8 fixed relative to the core 5 with an annular slot 11 is fixed on the metal pipe 4. In the upper part of the core 5, above the conical shell 8, a conical shell 8 is fixed. shell 7, spaced relative to the metal pipe 4 with the ring 10

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shaped gap 10. With the beginning of the pouring of the metal into the mold 1 through the holes 9 from the side of the pallet 3 through the bulk material 6 is supplied under pressure gas. The gas supply under pressure can be both constant and pulsating. The magnitude of the gas pressure is determined by the indicated formula.

After the metal is poured, the gas is supplied under pressure up to a twofold decrease in the temperature of the outer surface of the hollow ingot to ensure its uniform solidification both from the ingot mold and from the side of the metal pipe. The core 5 with a conical shell 7 is removed from the hollow ingot, and the hollow ingot from the mold.

Example. A hollow ingot is cast from steel 40XA with a height of 2.5 m. In the center of the mold 1, a metal pipe 4 with an outer diameter of 0.32 m and an internal 0.30 m is installed on the tray 3. A steel core with a diameter of 0.26 m is installed inside the metal pipe.

The annular gap between the metal pipe 4 and the core 5 is filled with 2 m of bulk material 6, which is river sand with a specific gravity of 15000 N / m and a transverse size of grains of 1.5-3.0 mm.

In the upper part of the metal pipe 4 and the core, conical shells 7 and 8 are successively fixed, while the conical shell 7 is placed relative to the metal pipe 4 with an annular slot 10, and the conical shell 8 relative to the core 5 with an annular slot 11 and fixed it over the sand 6 with a clearance of 0.7 m, which is 35% of the bulk material 6.

The width of each of the annular slots 10 and 11 is 1.3 mm.

Steel is poured into the mold at 1540 ° C. With the beginning of the steel pouring through the holes 9 from the side of the pallet 3 into the sand 6, nitrogen is fed under pressure. The magnitude of the nitrogen pressure is determined by taking into account the width of the annular gap between the metal pipe 4 of the core 5, equal to 20 mm, according to the indicated formula P 0.3 MPa.

Having done useful work of swelling the sand 6 while simultaneously cooling it, the gas heats up and enters the atmosphere through the annular slots 10 and 11, and the radial slots 12 and 13. After reducing the diameter of the pipe 4 under the influence of shrinkage of the hardened hollow ingot, when the bottom conical shell 8 enters contact with the core 5, and the upper conical shell 7 comes into contact with the pipe 4, the gas enters the atmosphere only through the radial slots 12 and 13. Thanks to this, the swelling and cooling of the sand with gas does not stop.

When the temperature of the hollow ingot is 770 ° C, the gas supply is pre-extracted, core 5 out of 30

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attract from a hollow ingot, and the hollow ingot itself - from the mold 1.

The advantage of the proposed method and device in comparison with the known ones is the expansion of technological capabilities due to the fact that the core is not retained in the hollow ingot before it is processed by pressing, but removed from it after the end of the gas supply to the bulk material, as a result Due to the improved cooling conditions of the bulk material, the time to obtain a hollow ingot is reduced.

Fig.Z

Claims (3)

1. A method of obtaining a hollow ingot, comprising pouring the melt into the mold using a rod in the form of a metal pipe and a central core, the gap between which is filled with bulk material, characterized in that, in order to expand technological capabilities, from the moment the melt is filled in, the bulk material is passed pressurized gas to form a fluidized bed. (L fo phi go FIG. one 2. Device for producing a hollow ingot, containing a tray and mounted on. a mold with a rod in the form of a metal pipe and a central core, the gap between which is filled with bulk material, different K.: that. in order to expand technological capabilities, it is equipped with conical shells. the upper of which is smaller in diameter mounted on the core, and the lower inside the metal is coarse and installed with a gap above the surface of the sealing protective reagent, under which axial holes are made in the pallet, while the upper conical shell relative to the metal pipe and the lower shell relative to the core are located with ring-shaped and I walked mi. 3. The device according to claim 2, characterized in that the upper conical shell on the side of the metal pipe and the lower conical shell on the side of the core are made with radial slots.