A large-scale steel ingot casting and solidification device with an applied electromagnetic field

Abstract

The application discloses a large-scale steel ingot casting and solidification device with an external electromagnetic field and belongs to the technical field of casting equipment. The application mainly solves the key problems, such as easy oxidation of an interface and difficult fusion, which affect the quality of a cast ingot in the existing progressive casting and solidification technology. The technical scheme of the application is as follows: a large-scale steel ingot casting and solidification device with an external electromagnetic field, wherein the device comprises a high-frequency alternating power supply, a supporting platform, a clamping base arranged on the top surface of the supporting platform and a crystallizer arranged on the clamping base, a plurality of hydraulic rod supporting seats are arranged on the bottom surface of the supporting platform, a sealing cover is arranged on the top of the inner cavity of the crystallizer, a metal liquid inlet pipe interface, a wire inlet, a vacuum extraction interface, an exhaust port and an air inlet pipe connecting port are arranged on the sealing cover respectively. The application has the advantages of reasonable structure design, simple operation, high working efficiency and the like.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of casting equipment, and particularly relates to a large-specification steel ingot pouring and solidification device with an applied electromagnetic field. BACKGROUND

[0002] In recent years, China's heavy equipment manufacturing industry has developed rapidly, and the demand for large forgings is strong, especially in nuclear power equipment, which represents the highest level of large forgings. The steel used for such products is generally produced by large steel ingots through processes such as blooming and forging, and the quality of the steel ingot is closely related to the quality of the steel ingot. To obtain high-quality forgings, inherent quality defects such as segregation, shrinkage, and inclusions in the steel ingot must be controlled.

[0003] To solve these problems, a new large steel ingot (billet) progressive pouring and solidification forming technology is proposed, as described in the invention patent "Progressive Solidification Forming Method for Large Steel Ingot or Billet" (Patent No. 201811050552.8). The working principle of the progressive pouring and solidification technology is based on the principle of discrete stacking in additive manufacturing. By pouring a solid core ingot and coating it with a cladding layer, the steel ingot (billet) gradually forms after cooling and solidification, with shape and size meeting the production requirements. The specific operation includes gradually pouring metal melt into different size molds, and using the steel ingot formed in the previous step as the ingot core for the next step. Subsequently, the metal melt is continuously poured around the new ingot core, and the operation is repeated cyclically, eventually accumulating to form a steel ingot with the target size. This technology can achieve product diversity and flexible production, significantly reduce the number and extent of defects in large-specification steel ingots (billet), greatly improve the performance and quality of steel ingots (billet), and can also be used to produce various unconventional castings, such as square and circular, as well as other unconventional castings with diameter fluctuations on the shaft.

[0004] Among them, whether the large-specification steel ingot prepared by the progressive pouring and solidification technology can achieve good metallurgical bonding at the interface between the ingot core and the cladding layer is crucial to the product quality of the final casting. In fact, on the one hand, since the previously prepared ingot core is always exposed to air, the surface of the casting is prone to react with oxygen, resulting in the presence of oxidation scale on the surface of the ingot core, which adversely affects the quality of the metallurgical bonding interface. On the other hand, when the size of the ingot core is too large compared to the cladding layer, after pouring, the ingot core absorbs heat and warms up, but its temperature does not reach the solidus, making it difficult to achieve fusion, affecting the mechanical properties of the final casting, and even causing cracks. From the published patents, existing technologies and equipment still cannot solve these problems. SUMMARY

[0005] The present application aims to overcome the shortcomings of the prior art and provide a large-specification steel ingot pouring and solidification device with an applied electromagnetic field, solving the problems of easy oxidation and difficult fusion at the interface in the existing progressive pouring and solidification forming technology.

[0006] In order to solve the above problems, the technical scheme of the present application is as follows: a large-size steel ingot pouring and solidification device with an applied electromagnetic field, comprising a high-frequency alternating current power supply, a support platform, a clamping base arranged on the top surface of the support platform, and a crystallizer mounted on the clamping base, wherein the bottom surface of the support platform is provided with a plurality of hydraulic rod support seats on both sides; a sealing cover is arranged at the top of the inner cavity of the crystallizer, and the sealing cover is respectively provided with a molten metal inlet pipe interface, a wire inlet, a vacuum extraction interface, an exhaust port, and an air inlet pipe connection port;

[0007] A steel ingot through hole is arranged at the position corresponding to the steel ingot outlet of the bottom of the crystallizer in the middle of the clamping base, and a steel ingot outlet hole is arranged at the position corresponding to the steel ingot through hole on the support platform; a ingot core guide pipe is arranged in the middle of the bottom surface of the sealing cover, and the ingot core guide pipe is in communication with the wire inlet;

[0008] A group of vertical supports is arranged on both sides of the bottom surface of the support platform and the steel ingot outlet hole, and a plurality of cooling nozzles are arranged on the vertical supports;

[0009] A ingot core is arranged in the vertical direction in the inner cavity of the crystallizer, the upper end of the ingot core is arranged in the ingot core guide pipe and connected to the positive terminal of the high-frequency alternating current power supply through a wire, and the wire extending from the negative terminal of the high-frequency alternating current power supply passes through the movable lining at the bottom of the crystallizer and is connected to the lower end of the ingot core.

[0010] A handle is arranged on the top of the sealing cover.

[0011] Lifting lugs are arranged on both sides of the top of the crystallizer.

[0012] A plurality of guide wheels are arranged on the side walls of the steel ingot through hole and the steel ingot outlet hole.

[0013] The above technical scheme is adopted in the present application, and the following advantages are achieved: The arrangement of the sealing cover can introduce inert gas into the crystallizer, reducing the oxidation of the internal ingot core; The skin effect and thermal effect of the electromagnetic field make the temperature of the outer surface of the internal ingot core uniform and in a slightly molten state, ensuring the interface bonding effect; the force effect of the electromagnetic field affects the movement of solute elements, making the solute elements uniformly distributed and reducing macrosegregation in the large-size steel ingot; and the arrangement of the ingot core guide pipe can effectively solve the problems of misalignment and inclination of the ingot core.

[0014] Compared with the prior art, the present application has the advantages of reasonable structure design, simple operation, high working efficiency, etc. BRIEF DESCRIPTION OF DRAWINGS

[0015] Fig. 1 It is an internal structure diagram of the present application at the initial solidification stage;

[0016] Fig. 2 Fig. 3 is a schematic view of the internal structure of the present application in the late solidification stage;

[0017] Fig. 3 Fig. 4 is a schematic view of the external structure of the present application. DETAILED DESCRIPTION

[0018] The present application will be further described in detail below in conjunction with the accompanying drawings and examples.

[0019] As Figs. 1 to 3 shown in the drawings, the present application is a large-scale steel ingot pouring and solidification device with an applied electromagnetic field, wherein: a high-frequency alternating power supply 1, a support platform 2, a clamping base 3 arranged on the top surface of the support platform 2, and a crystallizer 4 mounted on the clamping base 3 are included, a plurality of hydraulic rod support seats 5 are arranged on the bottom surface of the support platform 2 on both sides; a sealing cover 6 is arranged on the top of the inner cavity of the crystallizer 4, and a metal liquid inlet pipe interface 7, a wire inlet 8, a vacuum extraction interface 9, an exhaust port 10, and an air inlet pipe connection port 11 are arranged on the sealing cover 6, respectively;

[0020] A steel ingot through hole 12 is arranged at the position corresponding to the steel ingot outlet of the bottom of the crystallizer 4 in the middle of the clamping base 3, and a steel ingot outlet hole 13 is arranged on the support platform 2 at the position corresponding to the steel ingot through hole 12; a ingot core guide pipe 19 is arranged on the bottom surface of the sealing cover 6, and the ingot core guide pipe 19 is in communication with the wire inlet 8;

[0021] A group of vertical supports 14 is arranged on both sides of the bottom surface of the support platform 2 and the steel ingot outlet hole 13, and a plurality of cooling nozzles 15 are arranged on the vertical supports 14;

[0022] A ingot core 16 is arranged in the vertical direction in the inner cavity of the crystallizer 4, the upper end of the ingot core 16 is arranged in the ingot core guide pipe 19, and the ingot core 16 is connected to the positive electrode end of the high-frequency alternating power supply 1 through the wire, and the wire extending from the negative electrode end of the high-frequency alternating power supply 1 passes through the movable lining 20 at the bottom of the crystallizer 4 and is connected to the lower end of the ingot core 16.

[0023] A handle 17 is arranged on the top of the sealing cover 6.

[0024] Lifting lugs 18 are arranged on both sides of the top of the crystallizer 4.

[0025] A plurality of guide wheels are arranged on the side walls of the steel ingot through hole 12 and the steel ingot outlet hole 13.

[0026] Working process and principle of the present application:

[0027] 1) First, a ingot core 16 of a certain size is prepared, the ingot core 16 is placed in the crystallizer 4 so that the upper end thereof is located in the ingot core guide pipe 19, the positive electrode end and the negative electrode end of the ingot core 16 are respectively connected to the wire, the wire is respectively connected to the positive and negative electrodes of the high-frequency alternating power supply 1, and the sealing cover 6 is closed;

[0028] 2) By vacuum interface 9 to make the crystallizer 4 inside the vacuum tight environment, through the air pipe connection interface 11 into the protective gas argon, while attention to pressure control valve, ensure the pressure of closed space, then according to the current requirements to the ingot core 16 to apply high frequency electromagnetic field.

[0029] 3) The metal liquid is poured into the crystallizer 4 through the metal liquid inlet pipe interface 7, the metal liquid is initially solidified to form a cladding layer. At this time, due to the skin effect and thermal effect of high frequency electromagnetic field, the surface of the preform ingot core 16 is slightly melted during the formation of the cladding layer, which ensures the good metallurgical bonding of the interface. At the same time, due to the force effect of electromagnetic field, the distribution of solute elements in the cladding layer is more uniform, reducing the occurrence of macrosegregation phenomenon.

[0030] 4) After the poured metal liquid forms a certain thickness of solidified shell in the crystallizer 4, the support platform 2, the clamping base 3 and the crystallizer 4 are driven to move upward by the hydraulic rod support seat 5, the ingot core 16 moves downward along the ingot core guide pipe 19, the movable lining 20 and the ingot core 16 and its cladding layer which have been compounded together can enter the cooling stage downward, and the cooling water spray head 15 is opened to spray water cooling on the cladding layer.

[0031] 5) After the completion of this cladding process, the argon in the sealed cover is discharged through the exhaust port 10, the high frequency alternating current power supply 1 is cut off, then the hoisting device is used to replace the crystallizer 4, and the clamping base 3 is moved to ensure that the crystallizer 4 with larger size is placed stably on the clamping base 3. 6) Repeat the above operation until the required large size steel ingot is prepared.

Claims

1. A large-scale ingot casting and solidification apparatus of an electromagnetic field application, characterized by: Including high frequency alternating current power supply (1), support platform (2), clamping base (3) arranged on the top surface of support platform (2) and crystallizer (4) installed on clamping base (3), the bottom surface of support platform (2) is provided with a plurality of hydraulic rod support seats (5) on both sides; The inner cavity of the crystallizer (4) is provided with a sealing cover (6) on the top, the sealing cover (6) is respectively provided with a metal liquid inlet pipe interface (7), a wire inlet (8), a vacuum extraction interface (9), an exhaust port (10) and an air inlet pipe connection port (11), the top of the sealing cover (6) is provided with a handle (17), the bottom surface of the sealing cover (6) is provided with a ingot core guide tube (19), the ingot core guide tube (19) is communicated with the wire inlet (8); The clamping base (3) is provided with a steel ingot through hole (12) at the position corresponding to the bottom of the crystallizer (4), the support platform (2) is provided with a steel ingot outlet hole (13) at the position corresponding to the steel ingot through hole (12); The bottom surface of the support platform (2) and the two sides of the steel ingot outlet hole (13) are each provided with a group of vertical supports (14), and a plurality of cooling nozzles (15) are arranged on the vertical supports (14); The top of the crystallizer (4) is provided with a lifting lug (18) on both sides, and the inner cavity of the crystallizer (4) is provided with an ingot core (16) in the vertical direction, the upper end of the ingot core (16) is arranged in the ingot core guide tube (19) and connected with the positive terminal of the high frequency alternating current power supply (1) through the wire, and the wire connected with the negative terminal of the high frequency alternating current power supply (1) passes through the movable substrate (20) at the bottom of the crystallizer (4) and is connected with the lower end of the ingot core (16); The working process of the large-scale steel ingot pouring and solidification device with an external electromagnetic field is as follows: 1) First, a ingot core (16) of a certain size is prepared, the ingot core (16) is placed in the crystallizer (4) so that the upper end thereof is located in the ingot core guide tube (19), the positive and negative terminals of the ingot core (16) are respectively connected with wires, the wires are respectively connected with the positive and negative terminals of the high frequency alternating current power supply (1), and the sealing cover (6) is closed; 2) A vacuum closed environment is formed in the crystallizer (4) through the vacuum extraction interface (9), argon gas is introduced through the air inlet pipe connection port (11), and the pressure control valve is paid attention to, so as to ensure the pressure of the closed space, and then the ingot core (16) is subjected to a high frequency electromagnetic field according to the current requirement; 3) The metal liquid is poured into the crystallizer (4) through the metal liquid inlet pipe interface (7), the metal liquid is initially solidified to form a cladding layer; at this time, due to the skin effect and thermal effect of the high frequency electromagnetic field, the surface of the prepared ingot core (16) is slightly melted during the formation of the cladding layer; 4) After the poured metal liquid forms a certain thickness of solidified shell layer in the crystallizer (4), the support platform (2), the clamping base (3) and the crystallizer (4) are driven to move upward by the plurality of hydraulic rod support seats (5), the ingot core (16) moves downward along the ingot core guide tube (19), the movable substrate (20) and the ingot core (16) and the cladding layer compounded together move downward into the cooling stage, and the cooling water nozzles (15) are opened to spray water on the cladding layer for cooling; 5) After the end of the present coating process, the argon in the sealing cover is discharged through the exhaust port (10), the high-frequency alternating power supply (1) is cut off, and then the crystallizer (4) is replaced by the lifting device, and the clamping base (3) is moved to ensure that the crystallizer (4) with a larger size is stably placed on the clamping base (3); 6) Repeat the above operation until the required large-size steel ingot is prepared.

2. A large-scale ingot casting and solidification apparatus of an electromagnetic field application according to claim 1, characterized in that: The steel ingot through hole (12) and the steel ingot outlet hole (13) are provided with a plurality of guide wheels on the side walls.

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