RU2397043C2 - Method for semicontinuous casting of billets and machine for its realisation - Google Patents

Abstract

FIELD: technological processes.

SUBSTANCE: invention refers to the sphere of foundry engineering. Method includes supplying melt from ladle into tundish, then into vertical crystallisers, forming billets, drawing billets down with the help of priming powder, secondary air-water cooling of billets, dismantling of crystallisers, transportation of billets vertically upwards along technological axis of machine and withdrawal of billets. Crystallisers are arranged in the same shaft as secondary cooling. Bar guides are located in additional lower shaft with gap relative to billets. Prior to transportation of billets upwards, ladle and tundish are moved on sliding trolleys to reserve positions oppositely from each other.

EFFECT: invention provides for expansion of functionality in production of cast billets.

9 cl, 10 dwg

Description

The invention relates to ferrous and non-ferrous metallurgy, in particular to the field of semi-continuous casting of metals.

A known method of semi-continuous casting of metal in a vertical double-strand machine for ingots with a diameter of up to 800 mm (I.K. Marchenko // "Semi-continuous casting of steel". M: Metallurgy, 1986, p.208-210). The described method includes feeding the melt from the steel ladle through the intermediate ladles into the molds mounted on the frame, forming ingots in them by means of a swing mechanism, grabbing the ingots with seeds and pulling them down along the parallel rails, secondary air-air cooling in the mine, tilting onto the receiving roller table.

By the above method, it is possible to cast only billets with a diameter of up to 800 mm from two blotted at high altitude machines on which this casting is performed.

The proposed inventions are tasked with expanding the technological capabilities of casting billets, and in particular casting billets of a larger cross section from one intermediate ladle with a shorter technological axis of the machine.

To achieve this technical result, in a method for semi-continuous casting of billets, including feeding the melt from the steel ladle to the tundish, then to vertical molds, forming billets into them by means of a swing mechanism, drawing the billets by seed with a given speed down the beam guides, secondary air-air cooling in the mine is poured the blanks in the molds, which are located in the same shaft, are pulled along the beam rails located in the additional lower shaft and installed with a gap relative to the workpieces, where the workpieces are held until they crystallize completely, then the workpieces with the seed are uncoupled, when they are in the lower position, and the workpieces are transported vertically up the machine’s technological axis after the molds are dismantled and the swing mechanisms of the molds are closed with a protective plate , and they will also be deployed in reserve positions on opposite sides of each other from a steel bucket and a bucket installed on sliding trolleys.

From the same source as the method of semi-continuous casting of metal, a vertical double-strand MPNL is known, which contains a steel ladle, two blades, crystallizers, a swing mechanism for crystallizers with a hydraulic drive, a device for secondary cooling, a mechanism for pulling ingots with a pallet. In double-strand casting, seeds are placed on one carriage or pallet, i.e. streams have a common mechanism for drawing the workpiece. The pallet is made in the form of a cast beam and is moved by cable drive along the guide rails. Seeds are attached to the pallet and both streams have a common pulling mechanism. The drive is carried out by a double-drum winch through a worm-cylindrical gearbox.

The implementation of the guides along which the pallet moves - the seed with the possibility of rotation around the axis perpendicular to the technological axis of the machine, allows to reduce the length of the machine. However, this machine is used for casting small ingots with diameters of 100-220 mm and a length of 8.6 m.

The closest in technical essence is a machine for semi-continuous casting of large workpieces by a.s. USSR No. 854568 (publ. 08/15/1981). The specified machine includes a steel ladle, bucket, molds, swing mechanisms of the molds, a secondary cooling system located in the mine, a workpiece pulling mechanism made in the form of a carriage with supports mounted movably on the column, a carriage moving drive with a counterweight, seed and a seed moving mechanism with the workpiece in parallel rails.

However, on this machine, it is possible to cast only billets with a diameter of up to 800 mm from two oblonged with a high height of the technological axis of the machine.

The task is to expand the technological capabilities of casting billets. In particular, casting billets of a larger cross section from one intermediate ladle with a shorter technological axis of the machine.

To achieve this technical result in a semi-continuous casting machine containing a steel ladle, a bucket, for each stream there is a mold, a rocking mechanism of the mold, a secondary cooling system located in the shaft, a workpiece pulling mechanism made in the form of a carriage with supports mounted movably on the column, a drive the movement of the carriage with a counterweight, the seed and the mechanism for moving the seed with the workpiece in the beam rails, while the steel ladle and the bucket are located in reserve positions in on opposite sides of each other and mounted on sliding trolleys, the mold is located in the same shaft as the secondary cooling system, and the beam guides are installed with a gap relative to the workpiece and are located in an additional lower shaft, while the carriage and the drive of the workpiece pulling mechanism are located outside mines, and the mechanism for pulling the blanks is made in the form of two independent, facing each other mechanisms.

Distinctive features of the proposed machine is that the steel ladle and the tundish are located in reserve positions on opposite sides of each other and are mounted on sliding trolleys, the molds are located in the same shaft as the secondary cooling system, and the beam rails are installed with a gap relative to the workpieces and are located in an additional lower shaft, while the carriages and the drive of the workpiece pulling mechanism are located outside the shafts, and the workpiece pulling mechanism is made in the form of two dependent, facing each other mechanisms. Due to the fact that the drive of the pulling mechanisms is equipped with a self-braking worm pair, it is possible at any time to stop the pulling mechanisms in order to prevent the ingot from falling down during movement.

The presence of these signs allows to improve the casting of billets from one intermediate ladle with a shorter technological axis of the machine.

The following is an embodiment of the invention, not excluding other options within the formula, with reference to the drawings shown in figures 1-10.

Figure 1 - scheme of casting for one workpiece on two streams;

figure 2 - diagram of the casting of two billets on two streams;

figure 3 - scheme of casting in pairs of two workpieces on two streams;

figure 4 shows a General view of the machine;

figure 5 is a section along aa;

Fig.6 is a section along BB (casting on one of the streams of a pair of ingots, and on the other one ingot);

Fig.7 is the same casting on two streams of the same ingot;

in Fig.8 is a section along BB (casting on one of the streams of a pair of ingots, and on the other one ingot);

figure 9 is a section along G-G (casting on one of the streams of a pair of ingots, and on the other one ingot);

figure 10 is the same casting on two streams of the same ingot.

The semi-continuous casting machine 1 contains a steel ladle 2 and a bucket 3, located in reserve positions on opposite sides of each other and mounted on sliding trolleys 4. On each of the two streams below the intermediate ladle 3 there is a mold 5, a swing mechanism of the mold 6, a pulling mechanism 7 the workpieces and the secondary cooling system 8 located in the mine 9. The mechanism for pulling the workpieces 7, made in the form of a carriage with supports 10, is mounted movably on the column 11. When casting workpieces ⌀ 500 ÷ 1000 mm, tries dyaschiesya in position 5 molds are mounted on the individual tilting mechanism 6 for posts crystallizers reciprocation. The swing mechanisms of the molds are equipped with protective plate flooring 12 when transporting the workpiece up.

The mold 5 is located in the same shaft 9 as the secondary cooling system 8, and the beam rails 13 are installed with a gap relative to the workpieces 1 and are located in the additional lower shaft 14. The carriages 15 and the drive of the workpiece pulling mechanism 16 with the counterweight 17 are located outside the shafts 9 , 14. The mechanism for pulling the blanks 7 is made in the form of two independent, facing each other mechanisms. The seeds 18 with the workpieces 1 are located in the beam guides 13 until the crystallization of the workpiece.

Liquid steel from a steel ladle 2 mounted on a retractable trolley 4 is fed into an intermediate ladle 3, which, in turn, is mounted on its trolley 4. The trolley 4 has a lifting and moving drive and is installed on the filling platform of the machine. The bucket trolley 3 can be moved from the reserve position where the bucket is heated using a special device to the working position where the molds are installed 5. The incoming metal from the steel ladle 2 is fed through two holes in the bucket 3 into two molds 5. After filling the mold with liquid metal, At a certain level, the rocking mechanism is simultaneously turned on and the drive of the ingot pulling mechanism is turned on. Due to the low ingot casting speed of ÷ 1000 ÷ 1300 mm, the swing mechanism of the mold is not used, for which the middle cassettes (Fig. 9) of the swing mechanism are dismantled, and the mold is mounted on stationary supports. The initial ingot casting speed ⌀ 1000 ÷ 1300 mm is 0.03 m / min, then the ingot pulling speed increases to a working 0.062 m / min. The maximum weight of each ingot reaches 35 tons with ⌀ 1000 mm and a length of 5700 mm.

Before casting begins, a seed 18 is introduced into each mold 5 from below, which, in turn, is mounted on the pulling mechanism 7 of the workpiece.

Leaving the mold 5, the ingot enters a closed shaft 9, where the secondary air-air nozzle cooling of the ingot is carried out by nozzles of the secondary cooling collectors 8.

The sludge generated during casting goes down, where it is collected in the box of the sludge removal device.

After the ingot leaves the crystallizer, the ingot in an upright position is held in the shaft 9 until it solidifies, and then it is raised up using the ingot pulling mechanism 7. Before the ingot is fed up, the trolley with tundish 3 is moved from the working position to the reserve, where the slag is located. Next, the molds 5 are removed and the upper protective plate flooring is installed 12. The blanks are removed from the casting platform with the overhead crane of the workshop outside the machine using the transport earrings filled in them or using other special devices.

The cooling of the copper shells of the crystallizers 5 is carried out by the water coming from the water folding unit, from which water and air also come to the nozzles of the collectors of air-water cooling of the ingot.

After harvesting the workpiece 1 from the machine, the mechanisms for drawing the ingots 7 are lowered down, the molds 5 are installed again, the protective plate floor 12 is removed, the mechanisms for drawing the ingots 7 are lifted up, leading the seeds 18 to the crystallizers 5. The seeds are sealed around the perimeter of the joint with the copper sleeve of the crystallizers 5. K the working position is served by a trolley with a bucket 3, which was previously heated by a device for drying the bucket. The steel pouring ladle 2 is centered over the bucket 3. The machine is ready for new casting.

Claims (9)

1. The method of semi-continuous casting of billets, including the supply of the melt from the steel ladle to the pit, then to the vertical molds, the formation of billets, drawing the billets by seed with a predetermined speed down the bar rails, secondary air-air cooling in the mine, characterized in that the melt is fed to the crystallizers located in the same shaft as the secondary cooling, the workpieces are pulled along the beam guides located in the additional lower shaft with a gap relative to the workpieces, where billets are prepared until they are completely crystallized, then the billets are uncoupled with the seed when they are in the lower position and the billets are transported vertically up the machine’s technological axis, after the molds are dismantled, and the steel ladle and intermediate ladle are placed in reserve positions on opposite sides of each other mounted on sliding trolleys, and then harvest the workpieces. 2. The method according to claim 1, characterized in that the blanks are pulled using two independent, facing each other pulling mechanisms, while the axis of the blanks are placed in a common plane. 3. The method according to claim 1 or 2, characterized in that the whole melt is cast into one billet with a diameter of 1000-1300 mm and is pulled by pulling mechanisms connected by a common beam, and the operation of the pulling mechanisms is synchronized. 4. The method according to claim 1 or 2, characterized in that two blanks with a diameter of 800-1000 mm are cast and pulled, these blanks are formed by swinging mechanisms of the molds, which will be covered with a protective plate before transporting the blanks vertically up the technological axis of the machine. 5. The method according to claim 1 or 2, characterized in that four blanks with a diameter of 500 ÷ 800 mm are cast and drawn, these blanks are formed by swinging mechanisms of the molds, which will be covered with a protective plate before transporting the blanks vertically up the machine’s technological axis. 6. The method according to claim 1, characterized in that the workpieces are removed with tick grippers or with the help of transport earrings embedded in them. 7. A machine for semi-continuous casting of billets, containing a steel ladle, a ladle, molds for each stream, a secondary cooling system located in the mine, a workpiece pulling mechanism made in the form of a carriage with supports mounted movably on the column, a carriage drive with a counterweight, seed, the mechanism of movement of the seed and the beam rails, characterized in that it is equipped with reserve positions on opposite sides of each other, in which the steel ladle and industrial l, and an additional mechanism for pulling billets, the molds are located in the same shaft as the secondary cooling system, and the beam guides are installed with a gap relative to the billets and are located in the additional lower shaft, while the carriages and drives of the mechanisms for pulling the billets are located outside the shafts and the mechanisms for drawing the blanks are facing each other. 8. The machine according to claim 7, characterized in that the drive of the mechanisms for pulling the workpiece with a diameter of 1000 ÷ 1300 mm is made in the form of hydraulic cylinders, and two independent, facing each other pulling mechanisms are connected by a common beam. 9. The machine according to claim 7, characterized in that it is equipped with swinging mechanisms of molds for workpieces with a diameter of 500 ÷ 800 mm and 800 ÷ 1000 mm located in the same shaft as the molds, and the drive of the pulling mechanisms is equipped with a self-braking worm pair, the swing mechanisms of the molds are protected by plates during transportation of the workpiece up.

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