Patent Grant
12233454
This application claims priority to Chinese Patent Application No. 202311817305.7, filed on Dec. 27, 2023 and to Chinese Patent Application No. 202410012984.9, filed on Jan. 4, 2024, the contents of which are hereby incorporated by reference.
The disclosure belongs to the technical field of metal material processing, and in particular to a casting-rolling side sealing device with an electromagnetic stirring function.
As a light and high-strength metal structural material that may be commercialized at present, magnesium alloy has a great application demand in aerospace, automobile, rail transit and other fields, especially a wide magnesium alloy sheet and strip with a thickness of 0.5 mm-5 mm has a strongest demand in these fields and has become an important development direction of magnesium alloy industry at present.
Compared with traditional open-die hot continuous rolling, casting-rolling magnesium alloy has advantages such as short process, good formability and low cost. However, due to a small specific heat capacity and rapid heat dissipation of magnesium alloy itself, a temperature drop in a three-way heat exchange area at an edge of a casting-rolling zone is faster than that in a two-way heat exchange area at a middle, which makes the edge solidify prematurely and produce boundary viscosity with a side sealing plate, resulting in a large tensile stress. Therefore, it is easy for a casting-rolling sheet to have damage defects such as uneven microstructures, segregation and edge cracks, which leads to its unstable performance and restricts its large-scale application. At present, specific measures and devices for the edge cracks of magnesium alloy casting-rolling are not mature, so it is urgent to develop a shape/property coordinated control process and a device that may effectively control heat dissipation at the edge, inhibit boundary viscosity between the casting-rolling zone and the side sealing plate, and realize microstructure homogenization and grain refinement at the same time.
An objective of the disclosure is to provide a casting-rolling side sealing device with an electromagnetic stirring function, so as to solve the above problems and achieve an objective of improving an effect of controlling a shape and property of a magnesium alloy casting-rolling zone.
In order to achieve the above objective, the disclosure provides a following scheme. A casting-rolling side sealing device with an electromagnetic stirring function is provided, which includes a casting-rolling zone formed by a rotational cooperation of at least one pair of casting rolls, and further includes:
Optionally, the first electromagnetic assembly includes:
Optionally, the adjusting piece includes:
Optionally, the driving mechanism includes:
Optionally, the second electromagnetic assembly includes:
Optionally, the silicon steel piece has a U-shaped structure, and the second electromagnetic coil is symmetrically wound around two arms of the silicon steel piece, and a magnetic pole end face of the silicon steel piece is correspondingly placed at a side end face of the casting-rolling zone to ensure that a magnetic pole connection line is parallel to the side end face of the casting-rolling zone in a vertical direction.
Optionally, the second axis direction is perpendicular to the first axis direction.
Optionally, one side, away from the casting rolls, of the each of the side sealing plates is fixedly connected with a sealing shell, and the first electromagnetic assembly, the second electromagnetic assembly and the adjusting piece are all arranged in the sealing shell, where a heat insulation plate is arranged between the each of the side sealing plates and the sealing shell.
Optionally, the sealing shell includes:
Optionally, one side, close to the casting-rolling zone, of the first casting-rolling sealing plate is provided with a caulking groove.
Compared with the prior art, the embodiment has following advantages and technical effects.
According to the disclosure, the first electromagnetic assembly is arranged on the each of the side sealing plates, so that the pulse end of the first electromagnetic assembly releases the first pulses along the first axis direction, and an induced electromagnetic field is formed at a side end interface position of the casting-rolling zone, and then an induced current is generated in a direction from a side end interface region to the center of the casting-rolling zone. The electromagnetic stirring is used to promote a thermal cycle, and the Joule heat effect is generated to heat a solidification zone at the edge of the casting-rolling zone to make up for a heat loss caused by a rapid heat exchange at the edge. Moreover, an electromagnetic field targeting effect generated under an action of the first pulses may make an edge region and a middle of the casting-rolling zone form a circulating heat exchange, thereby reducing a situation that a large edge tensile stress is generated due to a temperature difference between the edge and the center, resulting in an uneven microstructure and forming defects such as microstructure segregation and edge cracks. In addition, during the heat exchange, crystals formed earlier at the edge fall off and nucleate at the same time with the middle region, so as to realize secondary nucleation of the crystals and promote grain refinement. The second electromagnetic assembly is also arranged on the each of the side sealing plates, and the second electromagnetic assembly generates the second pulses intersecting with the first pulses. Under an action of the second pulses, a repulsive action is formed between the each of the side sealing plates and an adjacent solidified microstructure through a Lorentz force. A fuzzy contact is formed between the solidified microstructure and the each of the side sealing plates by the repulsive force, which further reduces an edge viscous effect between the solidified microstructure and the each of the side sealing plates, and enhances a effect of controlling a shape and property on a magnesium alloy casting-rolling sheet.
In order to explain technical schemes of the present disclosure or technical schemes in the prior art more clearly, drawings needed in embodiments are briefly introduced below. Apparently, the drawings in a following description are only some embodiments of the present disclosure. For a person of ordinary skill in the art, other drawings may be obtained according to these drawings without paying a creative labor:
In the following, technical schemes in embodiments of the disclosure may be clearly and completely described with reference to attached drawings in embodiments of the disclosure. Apparently, the described embodiments are only a part of the embodiments of the disclosure, but not all embodiments. Based on the embodiments in the disclosure, all other embodiments obtained by a person of ordinary skill in the art without a creative efforts belong to a scope of protection of the disclosure.
In order to make above objects, features and advantages of the disclosure more apparent and easier to understand, the disclosure may be further described in detail with the attached drawings and specific embodiments.
Embodiment: with reference to
According to the disclosure, the pair of side sealing plates 1 are respectively arranged at the two sides of the casting-rolling zone to block the casting-rolling zone from the casting-rolling starting end to the casting-rolling ending end, so that a sealing effect on the casting-rolling zone is improved by using the side sealing plates 1 to apply a pre-tightening force to roll casting. The first electromagnetic assembly is arranged on the each of the side sealing plates 1, so that the pulse end of the first electromagnetic assembly releases the first pulses along the first axis direction, and an induced electromagnetic field is formed at a side end interface position of the casting-rolling zone, and then an induced current is generated in a direction from a side end interface region to the center of the casting-rolling zone. The electromagnetic stirring is used to promote a thermal cycle, and the Joule heat effect is generated to heat casting-rolling melts at the edge of the casting-rolling zone to make up for a heat loss caused by a rapid heat exchange at the edge. Moreover, an electromagnetic field targeting effect generated under an action of the first pulses may make an edge region and a middle of the casting-rolling zone form a circulating heat exchange, thereby reducing a situation that a large edge tensile stress is generated due to a temperature difference between the edge and the middle, resulting in an uneven microstructure and forming defects such as microstructure segregation and edge cracks. In addition, during the heat exchange, uniform distribution of heat may make crystals formed earlier at the edge fall off and nucleate at the same time with the middle region, so as to realize secondary nucleation of the crystals and promote grain refinement. The second electromagnetic assembly is also arranged on the each of the side sealing plates 1, and the second electromagnetic assembly generates the second pulses intersecting with the first pulses. Under an action of the second pulses, a repulsive action is formed between the each of the side sealing plates 1 and an adjacent solidified microstructure through a Lorentz force. A fuzzy contact is formed between the solidified microstructure and the each of the side sealing plates 1 by the repulsive force, which further reduces an edge viscous effect between the solidified microstructure and the each of the side sealing plates 1, and enhances a effect of controlling a shape and property on a magnesium alloy casting-rolling sheet.
It is understandable that, the pre-tightening force acts on the side sealing plates 1 to make the side sealing plates 1 adhere to the adjacent casting rolls. The pre-tightening force may be fixed by an external hydraulic drive device or welding and casting the side sealing plates 1 with a support mechanism, so as to limit and fix the side sealing plates 1 on side end faces of the casting rolls. Moreover, the pre-tightening force meets: the pre-tightening force=a pouring pressure at a gate in the casting-rolling zone+a reaction force of the casting rolls to the side sealing plates 1+a lateral component of a casting roll force along an axial direction of the casting rolls.
With reference to
In an embodiment, the first electromagnetic assembly includes:
The first electromagnetic coil 7 wound around the ceramic core 6 is used and connected with the low-frequency pulse generator to form the first pulses, thereby realizing an electromagnetic field action on the casting-rolling zone. The adjusting piece is also arranged relative to the first electromagnetic coil 7 and connected with the first electromagnetic coil 7 through the adjusting end. The number of turns of the first electromagnetic coil 7 connected with the low-frequency pulse generator is controlled by the adjusting piece, thereby realizing an adjustment of the magnetic induction line density of the first pulses, realizing a secondary control of an electromagnetic field intensity and targeted concentration in the casting-rolling zone, and further improving the effect of controlling the shape and properties in the casting-rolling zone. By connecting the first electromagnetic coil 7 with the low-frequency pulse generator, a direction control of the first pulses on the both sides of the casting-rolling zone is realized by using the low-frequency pulse generator to control the current direction.
In an embodiment, the adjusting piece includes:
In an embodiment, the driving mechanism includes:
The ceramic core 6 is provided with the groove. It is understandable that the first electromagnetic coil 7 and the low-frequency pulse generator form a loop connection. The end of the first electromagnetic coil 7, close to the casting rolls, is directly connected with the low-frequency pulse generator, and the other end is connected with the low-frequency pulse generator through the carbon brush 8, so that a physical control of a number of connecting turns between the first electromagnetic coil 7 and the low-frequency pulse generator is realized according to a conductive effect of the carbon brush 8. The stepping motor 9 rotates the screw 12 through a gear set, and the screw 12 is threadedly connected with the carbon brush 8, which drives the carbon brush 8 to slide in the groove in a limited way. Correspondingly, the part of the first electromagnetic coil 7 located in the groove may be directly connected with the carbon brush 8 in a conductive manner.
In an embodiment, the second electromagnetic assembly includes:
The silicon steel piece 10 is fixedly arranged on the side sealing plate 1, and the second electromagnetic coils 11 wound around the silicon steel piece 10 is connected with the high-voltage high-frequency pulse generator, so that the second pulses are released in the second axial direction. The second pulse direction intersects with the first pulse direction, and a Lorentz repulsive force from the side sealing plate 1 to the edge of the solidified microstructure is formed by the second pulses, so that the fuzzy contact is formed between the side sealing plate 1 and the solidified microstructure, and viscosity of the edge of the solidified microstructure is reduced.
In an embodiment, the silicon steel piece 10 has a U-shaped structure, and the second electromagnetic coils 11 are symmetrically wound around two arms of the silicon steel piece 10, and a notch direction of the silicon steel piece 10 faces the casting-rolling zone.
In an embodiment, the second axis direction is perpendicular to the first axis direction.
The silicon steel piece 10 is U-shaped, and the second electromagnetic coils 11 are symmetrically wound around the two arms of the silicon steel piece 10, so that the second pulse direction acts on one arm along the other arm, forming a second pulse action perpendicular to the first axis direction and parallel to side wall surfaces of the casting-rolling zone. It is understandable that, at this time, electromagnetism acts on the edge of the casting-rolling zone, and the Lorentz force with a strong magnetic field effect is generated, and a corresponding effect of blocking the solidified microstructure from sticking to the side sealing plates 1 is the best.
In an embodiment, the side of the side sealing plate 1 away from the casting rolls is fixedly connected with a sealing shell, and the first electromagnetic assembly, the second electromagnetic assembly and the adjusting piece are all arranged in the sealing shell, where a heat insulation plate 2 is arranged between the side sealing plate 1 and the sealing shell.
The sealing shell is used to cover all the assemblies, and the heat insulation plate 2 is arranged between the side sealing plate 1 and the sealing shell, which may not only provide insulation and protection to the sealing shell, but also play a heat preservation effect on the edge of the casting-rolling zone.
In an embodiment, the sealing shell includes:
In this technical scheme, the proximal casting-rolling sealing plate 3 and the distal casting-rolling sealing plate 5 cooperate to secure the silicon steel piece 10, and to improve sealability of a whole structure. In addition, the inner cavity formed by the sealing shell is adapted to a side end face structure of the casting-rolling zone, and a size of the inner cavity is larger than that of the side end face, so that the first pulses generated by the first electromagnetic assembly and the second pulses generated by the second electromagnetic assembly effectively act on the casting-rolling zone, an effect of improving shape control is guaranteed.
In an embodiment, the side of the proximal casting-rolling sealing plate 3 close to the casting-rolling zone is provided with a caulking groove, and the caulking groove penetrates both sides of the proximal casting-rolling sealing plate 3.
The caulking groove facilitates an installation and fixation of the ceramic core 6 and the silicon steel piece 10. Meanwhile, a magnetic pole end face of the silicon steel piece 10 is placed correspondingly to the side end face of the casting-rolling zone, so that the released first pulses and the released second pulses are correspondingly applied to the casting-rolling zone.
A working process of this embodiment is as follows.
Metal is poured along the casting-rolling starting end of the pair of casting rolls to form the sprue, the casting rolls rotate to form the casting-rolling zone, and the two sides of the casting-rolling zone are covered by the side sealing plates 1 respectively. The low-frequency pulse generator and the high-frequency pulse generator are started, the first electromagnetic coil 7 releases first low-frequency pulses along the first axis direction from the side ends to the center of the casting-rolling zone, and the second electromagnetic coils 11 release second high-frequency pulses along the second axis direction at the same time. The electromagnetic stirring is formed at the edge of the casting-rolling zone through the first pulse, which promotes the heat exchange in the microstructure and forms the Joule heat effect at the same time. The second axis direction is perpendicular to the first axis direction, so that the repulsive force action is generated between the casting-rolling zone and the side sealing plate 1 which is formed by the Lorentz force, and the viscous effect between the casting-rolling zone and the side sealing plate 1 is reduced. With reference to
In a description of the disclosure, it should be understood that terms “vertical”, “horizontal”, “up”, “down”, “front”, “back”, “left”, “right”, “vertical”, “horizontal”, “top”, “bottom”, “inside”, “outside”, and other indications of orientation or positional relationships are based on orientation or positional relationships shown in accompanying drawings, solely for a convenience of describing the disclosure, rather than indicating or implying that a device or a component referred to must have a specific orientation, be constructed and operated in a specific orientation, therefore it may not be understood as a limitation of the disclosure.
The above-mentioned embodiments only describe preferred embodiment of the disclosure, and do not limit a scope of the disclosure. Under a premise of not departing from a design spirit of the disclosure, various modifications and improvements made by a person of ordinary skill in the art to the technical scheme of the disclosure shall fall within a protection scope determined by claims of the disclosure.
| Number | Date | Country | Kind |
|---|---|---|---|
| 202311817305 | Dec 2023 | CN | national |
| 202410012984 | Jan 2024 | CN | national |
| Number | Date | Country |
|---|---|---|
| 2649221 | Oct 2004 | CN |
| Entry |
|---|
| Machine translation of CN 2649221 Y (Year: 2004). |
