CN111203521B - Annular ingot casting equipment and casting method thereof - Google Patents

Abstract

The invention discloses annular ingot casting equipment and a casting method thereof, and belongs to the field of metallurgical casting. The equipment comprises a pouring system, a rolling system, a casting mould and a supporting column; the casting mould comprises an inner ring and an outer ring, and a mould cavity is formed between the inner ring and the outer ring; the support column penetrates through the inner ring and is in threaded connection with the inner ring; the pouring system is fixedly arranged on the upper part of the support column, and melts are injected into the mold cavity; the rolling system is fixedly arranged on the support column and comprises a roller horizontally arranged in the die cavity, so that various defects in the preparation of the large circular ring-shaped ingot can be effectively reduced, the uniformity of the structure and components of the ingot is increased, and the mechanical performance of the ingot is improved. The casting method adopts the annular ingot casting equipment, and the large annular ingot is prepared by a continuous layered melt laying and rolling leveling method, so that the large annular ingot can be quickly prepared, and the prepared ingot has excellent mechanical properties.

Description

Annular ingot casting equipment and casting method thereof

Technical Field

The invention belongs to the field of metallurgical casting, and particularly relates to ingot casting equipment and a casting method thereof.

Background

The common manufacturing method in the cast metallurgy production is a manufacturing process that the smelted metal liquid is poured into a mould and is cooled and solidified to obtain a part with required shape and performance. The casting manufacturing cost is low, the process flexibility is high, a casting blank with a complex shape and a large size can be obtained, and the casting blank occupies a large proportion in the mechanical manufacturing, for example, 60-80% of parts in the machine tool industry are made by casting, and 60-80% of parts in the automobile industry are made by casting.

In casting, the casting process, the microstructure, structure and properties of the cast strand all have a significant and even decisive influence on the subsequent processing and the quality of the end product. In the conventional casting, a large casting blank is usually finished by one-time pouring, a melt is solidified from an outer layer which has low relative temperature and rapid heat transfer and is in contact with a mold wall, and a solute distribution phenomenon correspondingly occurs, and finally, a solidified core is rich in solute elements and impurity elements with low melting points, so that macro segregation occurs to a large extent. In addition, the casting defects such as shrinkage cavity, porosity, bubbles, thermal stress and the like are easy to occur by adopting the conventional casting process, and the quality of the large casting blank is seriously influenced. For casting large ingots, especially circular large ingots, it is generally necessary to inject molten steel into ingot molds or crystallizers of corresponding shapes and sizes through pouring equipment such as ladles and intermediate ladles, so that the molten steel is solidified into steel ingots or steel billets, and the steel ingots or steel billets are cast and formed in one step, which is prone to the defects of shrinkage cavities, looseness, bubbles, thermal stress and the like mentioned in the above.

For example, the Chinese patent application number is: CN201611268089.5, published date: 2017, 6 and 13, discloses a vacuum casting method of a nickel-based superalloy, which comprises a mold, wherein a water-cooling copper disc is arranged at the bottom of the mold, a circulating cooling water channel is arranged in the water-cooling copper disc to enable a melt to form a longitudinal temperature gradient from bottom to top, water mist cooling spray heads are arranged on one sides of a first side and a second side of the mold, a resistance heating body is arranged at the corner connection position of a third side and a fourth side to enable the melt to form a transverse temperature gradient from one side to the other side, an oblique temperature gradient is formed by the longitudinal temperature gradient and the transverse temperature, a solid-liquid interface is pushed from the bottom of the connection position of the first side and the second side to the top of the connection position of the third side and the fourth side, and finally a solidification position is located near the connection position of the third side and the fourth side to concentrate shrinkage porosity. The scheme concentrates the defects of shrinkage cavities and shrinkage porosity on two sides of the cast ingot, reduces cutting procedures, improves the production efficiency of the cast ingot, but still has the defect problem when the large cast ingot is formed at one time, and is not suitable for the circular cast ingot.

Also, for example, the Chinese patent application number is: cn201610428323.x, published as: the patent document of 2016 month 8 and 31 days discloses an adjustable ring casting mould, including cope match-plate pattern and lower bolster, cope match-plate pattern and lower bolster lock form a cylindrical cavity, be provided with well module in the cavity, well module includes a columniform center pillar and the annular well template in of circle, the center pillar surface is provided with bellied screw thread, well template equals with the cross sectional shape size of cylindrical cavity, the centre of a circle department of well template is the through-hole, the internal diameter of through-hole with the diameter of center pillar equals, have on the inner wall of through-hole with the dimpled grain of the screw thread looks interlock on center pillar surface, well template passes through the through-hole suit on the center pillar. According to the adjustable ring casting die, the size of the cavity can be changed by adjusting the middle die block, ring castings with different thicknesses can be cast, and the production cost is reduced. However, the height of the circular ring casting can be adjusted only, and the problem of defects which can be generated when the large circular ring casting is cast is not solved.

Disclosure of Invention

1. Problems to be solved

Aiming at the problem that the defects such as shrinkage cavities, looseness, bubbles, thermal stress and the like are easy to occur when the existing casting equipment is used for producing large-scale circular ring-shaped ingots, the invention provides circular ring-shaped ingot casting equipment which can effectively reduce various defects in the preparation of the large-scale circular ring-shaped ingots and increase the uniformity of ingot structure components, thereby improving the mechanical properties of the ingots.

The invention also provides a casting method of the annular ingot, and the annular ingot casting equipment can be used for quickly preparing large annular ingots, and the prepared ingots have excellent mechanical properties.

2. Technical scheme

In order to solve the above problems, the present invention adopts the following technical solutions.

A circular ring-shaped ingot casting device comprises a pouring system, a rolling system, a casting mold and a support column; the casting mould comprises an inner ring and an outer ring, and a mould cavity is formed between the inner ring and the outer ring; the support column penetrates through the inner ring and is in threaded connection with the inner ring; the pouring system is fixedly arranged on the upper part of the support column, and melts are injected into the mold cavity; the rolling system is fixedly arranged on the support column and comprises a roller horizontally arranged in the die cavity.

As a further improvement of the technical scheme, the pouring system comprises a material storage device and a melt channel; the storage device is fixedly arranged at the top end of the support column; one end of the melt channel is communicated with the material storage device, and the other end of the melt channel is communicated with the die cavity.

As a further improvement of the technical scheme, the pouring system further comprises a flow distributor; the flow distributor is fixedly connected with one end of the melt channel communicated to the die cavity, is positioned in the die cavity, and is provided with a water outlet.

As a further improvement of the technical scheme, the water outlets are arranged on the side surface of the water distributor and are provided with a plurality of water outlets which are uniformly distributed along the radial direction of the casting mould.

As a further improvement of the technical scheme, the melt channel is provided with a plurality of melt channels which are uniformly arranged along the circumferential direction of the mold cavity.

As a further improvement of the technical scheme, the material storage device is a tundish, and the melt channel is a long nozzle.

As a further improvement of the technical scheme, the rolling system further comprises a roller bracket; the upper end of the roller support is fixedly connected with the upper part of the support column, and the lower end of the roller support is provided with a roller.

As a further improvement of the technical scheme, the casting device also comprises a rotating device which is used for controlling the casting mould to rotate along the supporting column.

The casting method of the circular ring-shaped ingot casting adopts the casting equipment of the circular ring-shaped ingot casting, and comprises the following steps:

firstly, before casting, adjusting a casting mold to a set position, then injecting a melt into a mold cavity by a pouring system, and simultaneously rotating and descending the casting mold along a support column;

and secondly, gradually solidifying the melt in the die cavity to form a casting, increasing the height of the casting along with the descending of the casting die, leveling and rolling the continuously injected melt by using a roller, and stopping the operation of a pouring system and the casting die after the casting die descends to a set height to obtain a large ingot.

As a further improvement of the technical scheme, the height of the casting in the die cavity is increased by 2-50mm every time the casting die rotates along the supporting column, and the descending speed of the casting die is the same as the increasing speed of the height of the casting.

3. Advantageous effects

Compared with the prior art, the invention has the beneficial effects that:

(1) the invention relates to a circular ring-shaped ingot casting device, which skillfully combines a pouring system, a rolling system and a casting mould together through a supporting column, when the pouring system injects melt into a mould cavity of the casting mould, the casting mould rotates and descends along the supporting column through threads, the melt is cooled and rapidly solidified in the mould to form a casting with a certain height and gradually increased height, simultaneously, a roller of the rolling system flattens the unsolidified melt injected into the mould cavity along with the rotation of the casting mould, rolls the preliminarily cooled and solidified melt, the melt is laid on the solidified casting along with the descending of the casting mould without fracture, and the roller also constantly flattens and rolls the newly injected melt, thereby the structure component of the finally formed ingot is uniform, the internal crystal grains are refined, and the defects of the core part of the ingot are effectively reduced or even eliminated, the mechanical property of the cast ingot is improved, the structural arrangement of the equipment is reasonable, and the production efficiency of the annular cast ingot is greatly improved;

(2) according to the annular ingot casting equipment, the plurality of flow distributors are uniformly distributed along the circumferential direction of the casting mould, and the side surfaces of the flow distributors are uniformly distributed with the water outlets along the radial direction of the casting mould, so that a melt can be uniformly distributed in the mould cavity, and the heights of all positions of an ingot are uniform, so that the structure and the components of the ingot are uniform, and the mechanical performance of the ingot is improved;

(3) according to the annular ingot casting equipment, the plurality of rollers are arranged, so that multiple positions of a casting can be rolled flatly at the same time, the integral rolling effect of the rollers is improved, the defects of shrinkage cavity, shrinkage porosity and the like during large ingot production are eliminated, and the quality of a formed ingot is improved;

(4) according to the annular ingot casting equipment, the highest position of the casting mould can be controlled by controlling the position of the threads on the supporting column, so that the bottom of the casting mould is prevented from colliding with the flow distributor and the roller to damage the equipment;

(5) according to the casting method of the annular ingot, the annular ingot casting equipment is adopted, so that the large annular ingot can be rapidly and stably prepared, the tissue defect in the preparation of the large ingot is eliminated, and the ingot with excellent mechanical property is prepared.

Drawings

FIG. 1 is an isometric view of a casting apparatus;

FIG. 2 is a front view structural view of the casting apparatus;

FIG. 3 is a schematic diagram of a gating system;

FIG. 4 is a schematic view of the rolling system;

FIG. 5 is a schematic view of a casting mold;

FIG. 6 is a schematic structural view of a support column;

FIG. 7 is a front view of the flow distributor;

FIG. 8 is a schematic view of the structure of the roll stand;

in the figure: 100. a pouring system; 110. a material storage device; 120. a melt channel; 130. a flow distributor; 131. a water outlet; 200. a rolling system; 210. rolling; 220. a roll stand; 221. a connecting rod; 222. fixing the rod; 300. casting a mold; 310. an inner ring; 320. an outer ring; 330. a mold cavity; 400. and (4) a support column.

Detailed Description

The invention is further described with reference to specific embodiments and the accompanying drawings.

Example 1

As shown in fig. 1 and 2, an annular ingot casting apparatus for casting a large cylindrical ingot mainly includes a gating system 100, a rolling system 200, a casting mold 300, and a support column 400. Wherein, the supporting column 400 is vertically arranged, and the bottom end thereof is fixedly connected to the ground or corresponding equipment; the gating system 100 is used for injecting melt into the casting mold 300, and the casting mold 300 is used for forming an ingot; the rolling system 300 is used to level and roll the upper end surface of the ingot as the melt solidifies into a casting. The specific structure and operation of the apparatus are described in detail below.

As shown in fig. 6, a middle section of the support column 400 is provided with a screw thread for installing the casting mold 300, and upper and lower ends of the screw thread are spaced from upper and lower ends of the support column 400, so that the casting mold 300 can be prevented from colliding with other devices or the ground when being lifted and lowered, and the equipment can be prevented from being damaged.

As shown in fig. 5, the casting mold 300 includes an inner ring 310, an outer ring 310, and a mold cavity 330. Wherein, the outer ring 320 is a hollow cylinder structure with an opening at the upper end; the inner ring 310 is a hollow cylindrical structure which is through up and down, is vertically arranged at the center of the outer ring 320, and has the inner diameter consistent with the diameter of the support column 400; the space between the inner ring 310 and the outer ring 320 is the mold cavity 330, and the melt solidifies in the mold cavity 330 to form an ingot. The inner side surface of the inner ring 310 is provided with threads matching with the middle threads of the support column 400 in cooperation with the middle threads of the support column 400, and the support column 300 passes through the inner ring 310 and is in threaded connection with the inner ring 310, so that when the casting mold 300 rotates along the support column 400, the casting mold 300 can be lifted and lowered in the height direction of the support column 400.

As shown in fig. 3, the gating system 100 includes a stocker 110, a melt channel 120, and a flow distributor 130. In this embodiment, the material storage device 110 is a tundish, and the melt channel 120 is a long nozzle. The tundish is fixedly arranged at the top end of the support column 400, the bottom of the tundish is provided with a melt outlet, one end of the long water gap is connected with the melt outlet, and the other end of the long water gap is connected with the water inlet of the flow distributor 130. The flow distributor 130 is a strip-shaped structure, and is horizontally disposed in the mold cavity 330 as shown in fig. 1, the front and rear ends of the flow distributor are close to the inner ring 310 and the outer ring 320 but keep a certain gap, and the bottom of the flow distributor keeps a certain gap with the bottom surface of the mold cavity 330, so that the melt can conveniently flow into the mold cavity 330 without hindrance. In addition, as shown in fig. 7, a plurality of water outlets 131 are uniformly distributed on the side surface of the flow distributor 130 along the radial direction of the casting mold 300, in this embodiment, each of the long water outlets and the flow distributor 130 has a plurality of water outlets 131, the long water outlets and the flow distributor 130 are uniformly distributed along the circumferential direction of the mold cavity 330 with the support column 400 as a midpoint, and the water outlets 131 are uniformly and densely distributed on the whole side surface of the flow distributor 130, so that the pouring system 100 can uniformly inject the melt into each position of the mold cavity 330, and the melt is uniformly spread in the mold cavity 330 and solidified, thereby making the height of each position of the casting uniform, enhancing the uniformity of the structure and composition of the cast ingot.

As shown in fig. 4, the rolling system 200 includes rolls 210 and roll stands 220. As shown in fig. 8, the roll stand 220 includes a connecting rod 221 and two fixing rods 222 perpendicular to the connecting rod 221, and forms an "F" shape. The connecting rod 221 is horizontally arranged, one section of the connecting rod is fixedly connected with the upper part of the supporting column 400, and the connecting part is positioned below the tundish. Two fixing rods 222 are vertically and downwardly extended and arranged on the connecting rod 221, and a roller 210 is horizontally arranged between one ends of the fixing rods, which are far away from the connecting rod 221. The two ends of the roller 210 are respectively fixedly connected with the two connecting rods 221, or the roller 210 is hinged between the two connecting rods 221 and can rotate along the axis of the roller, so that the solidified casting in the die cavity 330 is prevented from being clamped with the roller 210. The roller 210 is horizontally disposed in the mold cavity 330, and has front and rear ends close to the inner ring 310 and the outer ring 320 while maintaining a gap therebetween, and a bottom portion spaced from a bottom surface of the mold cavity 330 to facilitate the circulation of the melt in the mold cavity 330. In this embodiment, the rollers 210 are provided with a plurality of rollers hinged between the two connecting rods 221, and uniformly distributed along the circumferential direction of the die cavity 330, and further, one side of each flow distributor 130 is correspondingly provided with one roller 210, so that the melt layer can be flattened in time when being laid on a solidified casting, and is rolled when being primarily cooled and solidified, because the hardness of the primarily cooled and solidified melt is not high, the rollers 210 can play a rolling effect on the solidified melt under the action of their own gravity.

The rotation of the casting mold 300 on the supporting column 400 can be driven by manual manipulation (for example, a connecting column is installed outside the casting mold 300, and the rotation of the casting mold 300 is controlled by manually rotating the connecting column) or by a rotary support or the like. However, although the manual operation can realize the rotation of the casting mold 300, the precision is low, the weight of the equipment is heavy, and the manual operation is time-consuming and labor-consuming, so that the casting mold 300 needs to be driven to rotate by a corresponding rotating device. The structure of the rotating device can adopt a structure which is common in the market and drives an object to rotate and lift on the threaded column, and the embodiment only gives one way of realizing the rotation. In this embodiment, a circle of racks is arranged on the outer side surface of the casting mold 300 along the circumferential direction thereof, an installation plate is fixedly installed on the outer side surface below the racks, a motor is fixedly installed on the installation plate, a gear is installed on the output shaft of the motor, and the gear is engaged with the racks on the casting mold 300. Thereby when the motor during operation, gear and rack cooperate and make casting mould 300 rotate and go up and down along the screw thread on the support column 400 to drive the motor wholly along with casting mould 300 along support column 400 rotate and go up and down, and can control the slew velocity of casting mould 300 through the rotational speed of control motor, adjust the inclination of the screw thread on the support column 400 again, can control the lifting speed of casting mould 300.

In summary, in the annular ingot casting apparatus of the present embodiment, the gating system 100, the rolling system 200, and the casting mold 300 are skillfully combined together through the supporting column 400, when the gating system 100 injects the melt into the mold cavity 330 of the casting mold 300, the casting mold 300 rotates and descends along the supporting column 400 through the screw thread, and the melt is cooled and rapidly solidified in the mold, so as to form an ingot with a certain height and gradually increased height. Meanwhile, the roller 210 of the rolling system 200 levels the unsolidified melt injected into the die cavity 330 along with the rotation of the casting die 300, the primarily cooled and solidified melt is rolled, and the melt is laid on the solidified casting along with the descending of the casting die 300 without fault, and simultaneously the roller also levels and rolls the newly injected melt continuously, so that the structure components of the finally formed ingot are uniform, the internal crystal grains are refined, the defects of the core part of the ingot are effectively reduced or even eliminated, the mechanical property of the ingot is improved, the structural arrangement of the equipment is reasonable, and the production efficiency of the annular ingot is greatly increased.

Example 2

A method for casting a circular ring-shaped ingot casting adopts the circular ring-shaped ingot casting equipment of embodiment 1, and comprises the following steps:

first, before casting starts, the height of the casting mold 300 on the supporting column 400 is adjusted so that the bottom of the casting mold 300 is close to the bottom of the roll 210 and the stream distributor 130 but maintains a slight gap, 6mm in this embodiment. After adjustment, the casting system 100 works, the melt is added into the tundish, and is uniformly spread in the mold cavity 330 through the long nozzle and the flow distributor 130, and the melt is cooled and solidified in the mold cavity 330 to form a casting with a certain height. Meanwhile, the casting mold 300 is driven to rotate by the rotating device, and the supporting column 400 is lifted and lowered by the thread fit of the supporting column 400 and the inner ring of the casting mold 300. The roller 210 of the rolling system 200 levels the not-yet-cooled and solidified melt when the casting mold 300 rotates, and rolls the primarily-cooled and solidified melt, so that the upper end surface of the solidified casting becomes flat, the crystal grains in the casting are refined, and the structural components are uniformly distributed.

Secondly, the melt is solidified in the die cavity to form a casting with a certain height, and along with the rotation and the descending of the casting die 300, the pouring system 100 continuously lays new melt on the solidified and cooled casting layer by layer, the roller 210 behind each flow distributor 130 can level and flatten the newly injected melt in time, and the primarily cooled and solidified melt is flattened and rolled, so that the end surface of each layer of casting is kept level and flattened all the time, and the height of the casting in the die cavity 300 meets the requirement until the casting die 300 descends to the set height, and a large-scale circular ring-shaped ingot is formed. In the process of forming the ingot, the roller 210 levels and rolls each layer of casting, so that the finally formed large ingot has compact internal structure and uniform components, the conditions of shrinkage porosity and shrinkage cavity which may occur in the process of casting the ingot are effectively reduced, the defect of the center of the ingot is eliminated, and the manufactured ingot has excellent mechanical properties. It should be noted that the casting of each layer refers to the casting that is added to the cavity 330 during one rotation of the casting mold 300. In order to rapidly cool the melt, the gating system 100 needs to keep a low injection speed to inject the melt into the mold cavity 330, and the height of the casting in the mold cavity 330 is increased by 2-50mm every time the casting mold 300 rotates for one circle, so that the melt can be solidified at a high solidification speed, the obtained casting has a fine structure and uniform components, and has excellent mechanical properties such as high strength and high toughness, and the specific height increase is selected according to the cooling speed of the melt of different materials. The material composition of the desired casting may comprise the following elements and corresponding weight contents: c: 0.03% -2%, Si: 0.05-5.0%, Mn: 0.03% -31%, Al: 0.03% -13%, V: 0.03% -2%, Mo: 0.03% -5%, Cr: 0.05-10%, Cu: 0.05% -5%, S: 0.01-0.02%, Ni: 0.03% -10%, P: 0.03% -0.09%, Mg: 0.06-0.15% and the balance Fe. In the embodiment, the height of the casting in the die cavity 330 is increased by 6mm every time the casting die 300 rotates, the height descending speed of the casting die 300 is consistent with the height increasing speed of the casting, and the roller 210 can continuously perform smooth rolling on the injected melt.

In summary, the annular ingot casting device of this embodiment can rapidly and stably prepare a large annular ingot by using the annular ingot casting device of embodiment 1, so as to eliminate the texture defect during preparation of the large annular ingot, and prepare an ingot with excellent mechanical properties.

The examples described herein are merely illustrative of the preferred embodiments of the present invention and do not limit the spirit and scope of the present invention, and various modifications and improvements made to the technical solutions of the present invention by those skilled in the art without departing from the design concept of the present invention shall fall within the protection scope of the present invention.

Claims (9)

1. The utility model provides a ring form ingot casting equipment which characterized in that: comprises a pouring system (100), a rolling system (200), a casting mould (300), a rotating device and a supporting column (400); the casting mold (300) comprises an inner ring (310) and an outer ring (320), a mold cavity (330) being formed between the inner ring (310) and the outer ring (320); the supporting column (400) penetrates through the inner ring (310) and is in threaded connection with the inner ring (310); the pouring system (100) is fixedly arranged at the upper part of the supporting column (400), and melts are injected into the die cavity (330); the rolling system (200) is fixedly arranged on the support column (400) and comprises a roller (210) horizontally arranged in the die cavity (330); the rotating device is used for controlling the casting mould (300) to rotate along the supporting column (400).

2. The casting equipment of a circular ring-shaped ingot according to claim 1, characterized in that: the pouring system (100) comprises a storage device (110) and a melt channel (120); the storage device (110) is fixedly arranged at the top end of the support column (400); one end of the melt channel (120) is communicated with the material storage device (110), and the other end of the melt channel is communicated with the mold cavity (330).

3. The casting equipment of a circular ring-shaped ingot according to claim 2, characterized in that: the gating system (100) further comprises a flow distributor (130); the flow distributor (130) is fixedly connected with one end of the melt channel (120) communicated with the die cavity (330), is positioned in the die cavity (330), and is provided with a water outlet (131).

4. The casting equipment of a circular ring-shaped ingot according to claim 3, characterized in that: the water outlets (131) are arranged on the side of the flow distributor (130) and are uniformly distributed along the radial direction of the casting mold (300).

5. The casting equipment of a circular ring-shaped ingot according to claim 4, characterized in that: the melt channel (120) is provided in a plurality and is uniformly arranged along the circumferential direction of the mold cavity (330).

6. The casting equipment of a circular ring-shaped ingot according to claim 5, characterized in that: the storage device (110) is a tundish, and the melt channel (120) is a long nozzle.

7. The casting equipment of a circular ring-shaped ingot according to claim 1, characterized in that: the rolling system (200) further comprises a roll stand (220); the upper end of the roller bracket (220) is fixedly connected with the upper part of the supporting column (400), and the lower end is provided with a roller (210).

8. A casting method of a circular ring-shaped ingot, which adopts the casting equipment of the circular ring-shaped ingot in any one of claims 1 to 7, and comprises the following steps:

firstly, before casting, adjusting a casting mold (300) to a set position, then injecting a melt into a mold cavity (330) by a pouring system (100), and simultaneously rotating and descending the casting mold (300) along a supporting column (400);

and secondly, the melt is gradually solidified in the die cavity (330) to form a casting, the height of the casting is increased along with the descending of the casting die (300), meanwhile, the roller (210) performs leveling rolling on the continuously injected melt, and after the casting die (300) descends to a set height, the pouring system (100) and the casting die (300) stop working to prepare a large ingot.

9. The casting method of a ring-shaped ingot according to claim 8, characterized in that: the height of the casting in the die cavity (330) is increased by 2-50mm every time the casting die (300) rotates along the supporting column (400), and the descending speed of the casting die (300) is the same as the increasing speed of the height of the casting.

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