A combined electromagnetic stirring casting device

Abstract

The present invention provides a combined electromagnetic stirring casting device. The combined electromagnetic stirring casting device includes a billet, an electromagnetic stirrer, a moving platform, a moving support arm and a mover. The billet is arranged in the middle of the moving platform. At least one moving support arm is arranged on the outer periphery of the billet. The moving support arm is installed on the moving platform and can horizontally displace in the forward and reverse directions towards the billet. An electromagnetic stirrer is installed on one side of the moving support arm close to the billet. The outer periphery of the moving platform is installed on the mover, and the mover is used to drive the moving platform and the electromagnetic stirrer and the moving support arm installed thereon to displace up and down. The present invention can overcome the problems of poor traditional electromagnetic stirring effect, especially for large square and round billets, where the strength is too high, which will cause "bright bands", and the electromagnetic stirring strength is too small, which has no effect on improving the quality of the billet.

Description

Technical Field

[0001] The present invention relates to the technical field of foundry metallurgy, and particularly to a combined electromagnetic stirring casting device. Background Art

[0002] At present, in the field of steelmaking, to improve the quality of steel, the most important link is to control the solidification process of the continuous casting billet. Electromagnetic stirring has become a key equipment for improving the flow of molten steel. Electromagnetic stirring generates a rotating magnetic field acting on the molten steel, promoting the movement of the molten steel, dissipating the superheat in the molten steel, promoting the homogenization of solute elements, transforming columnar crystals into equiaxed crystals, thereby improving internal defects such as central segregation and central shrinkage cavity. For such a rotating magnetic field, due to the poor penetration of the electromagnetic stirring magnetic field of the rotating magnetic field, the formed flow field has a high flow rate on the outer side of the continuous casting billet and a low flow rate inside, and the exchange of molten steel between the central molten steel and the molten steel at the solidification front is slow, which can improve central segregation and central shrinkage cavity to a certain extent, but the effect is limited. Especially for large square and large round billets, the practical problem is that if the electromagnetic stirring intensity is too high, it will cause a "bright band" (negative segregation), and if the electromagnetic stirring intensity is too low, it will have no effect on improving the quality of the continuous casting billet. Summary of the Invention

[0003] The purpose of the present invention is to provide a combined electromagnetic stirring casting device to overcome the problem that the traditional electromagnetic stirring has poor effect, especially for large square and large round billets, where too high intensity will cause a "bright band", and too low intensity will have no effect on improving the quality of the continuous casting billet.

[0004] The technical solution of the present invention is: a combined electromagnetic stirring casting device includes a continuous casting billet, an electromagnetic stirrer, a moving platform, a moving support arm and a mover. The continuous casting billet is arranged in the middle of the moving platform. At least one moving support arm is arranged on the outer periphery of the continuous casting billet. The moving support arm is installed on the moving platform and can horizontally displace in both forward and reverse directions towards the continuous casting billet. An electromagnetic stirrer is installed on the side of the moving support arm close to the continuous casting billet. The outer periphery of the moving platform is installed on the mover, and the mover is used to drive the moving platform and the electromagnetic stirrer and the moving support arm installed thereon to move up and down.

[0005] Preferably, the installation angle of the electromagnetic stirrer on the moving support arm is adjustable, and the adjustment direction is to rotate along the horizontal axis.

[0006] Preferably, at least one installation position is provided vertically on the moving support arm, and 6 through holes are evenly arranged at the installation positions;

[0007] m rotating holes are arranged in a circle on the electromagnetic stirrer, m = 360÷60×n, where n is a natural number greater than or equal to 1. After the electromagnetic stirrer rotates a certain angle, the through hole is aligned and installed with the rotating hole at the corresponding position.

[0008] Preferably, when there are multiple moving support arms, one of the electromagnetic stirrers is installed on each moving support arm, and each moving support arm can be horizontally displaced separately or simultaneously.

[0009] Preferably, when there are multiple installation positions, the multiple electromagnetic stirrers are installed at the installation positions at the same height, or the multiple electromagnetic stirrers are installed at the installation positions at different heights.

[0010] Preferably, when there are multiple installation positions, 6 through holes are evenly arranged on each installation position respectively.

[0011] Compared with the related technology, the beneficial effects of the present invention are as follows: By adjusting the relative position between the electromagnetic stirring and the billet in real time, adjusting different forms of electromagnetic force, the direction of the electromagnetic force, and the angle of the electromagnetic force, the movement of the metal or alloy melt is promoted, forming a multi-dimensional and multi-directional flow pattern, completely eliminating the superheat between the center of the billet and the solidification front, so as to achieve the purpose of simultaneous solidification of the solidified liquid core, and eliminating internal quality problems such as coarse and uneven dendrites, composition segregation, porosity and shrinkage cavities. Description of the Drawings

[0012] Figure 1 Schematic horizontal installation diagram of the combined electromagnetic stirring casting device provided by the present invention;

[0013] Figure 2 Schematic diagram of the structure of the moving support arm;

[0014] Figure 3 Schematic diagram of a single electromagnetic stirrer;

[0015] Figure 4 Schematic diagram of the horizontal rotating flow field combined by four electromagnetic stirrers;

[0016] Figure 5 Schematic diagram of the horizontal double-circulation flow field combined by four electromagnetic stirrers;

[0017] Figure 6 Schematic diagram of the horizontal rotating flow field combined by two electromagnetic stirrers;

[0018] Figure 7 Schematic diagram of the plug flow field combined by two electromagnetic stirrers;

[0019] Figure 8 Schematic vertical installation diagram of the combined electromagnetic stirring casting device;

[0020] Figure 9 Schematic diagram of four electromagnetic stirrers pushing upwards simultaneously;

[0021] Figure 10Schematic diagram of two electromagnetic stirrers pushing up and two pushing down among four electromagnetic stirrers;

[0022] Figure 11 It is Figure 9 Schematic diagram of vertical double circulation flow field under electromagnetic thrust;

[0023] Figure 12 It is Figure 10 Schematic diagram of vertical rotating flow field under electromagnetic thrust;

[0024] Figure 13 Schematic diagram of electromagnetic force under inclined installation of combined electromagnetic stirring device;

[0025] Figure 14 Schematic diagram of electromagnetic force under layered installation of combined electromagnetic stirring device;

[0026] Figure 15 It is Figure 14 Schematic diagram of lower flat-pushing flow field + upper rotating flow field formed under electromagnetic thrust;

[0027] Figure 16 It is Figure 14 Top view of the formed flow field;

[0028] Figure 17 It is the relationship diagram between the phase of the inductor and the electromagnetic force in the electromagnetic stirrer.

[0029] In the accompanying drawings: 1. Cast billet; 2. Electromagnetic stirrer; 3. Moving platform; 4. Moving support arm; 5. Mover; 6. Cooling water pipe; 7. Cable joint; 8. Junction box; 9. Inductor; 10. Rotating hole; 11. Electromagnetic force; 12. Flow field; 13. Upper rotating flow field; 14. Lower flat-pushing flow field; 15. Upper position; 16. Lower position; 17. Through hole. Specific embodiments

[0030] The present invention will be described in detail below with reference to the accompanying drawings and in combination with embodiments. It should be noted that, without conflict, the embodiments in the present invention and the features in the embodiments can be combined with each other. For the convenience of narration, words such as "upper", "lower", "left", and "right" in the following text only represent the same directions as the upper, lower, left, and right directions of the accompanying drawings themselves, and do not limit the structure.

[0031] As Figure 1As shown in the figure, a combined electromagnetic stirring casting device provided in this embodiment includes a casting blank 1, an electromagnetic stirrer 2, a moving platform 3, a moving support arm 4, and a mover 5. The casting blank 1 is arranged in the middle of the moving platform 3. At least one moving support arm 4 is arranged on the outer periphery of the casting blank 1. The moving support arm 4 is installed on the moving platform 3 and can horizontally displace in the forward and reverse directions towards the casting blank 1. An electromagnetic stirrer 2 is installed on one side of the moving support arm 4 close to the casting blank 1. The outer periphery of the moving platform 3 is installed on the mover 5, and the mover 5 is used to drive the moving platform 3 and the electromagnetic stirrer 2 and the moving support arm 4 installed thereon to displace up and down. The above horizontal displacement and vertical displacement can be realized by linear guides and lead screw nuts (or worm gears and worm wheels, rack and pinions), etc.

[0032] Through the horizontal displacement of each electromagnetic stirrer 2 by the moving support arm 3, the relative position between the electromagnetic stirrer 2 and the casting blank 1 can be adjusted in real time, different forms of electromagnetic force, the direction of the electromagnetic force, and the electromagnetic force angle can be adjusted, and the superheat degree between the center of the casting blank and the solidification front can be completely eliminated, so as to achieve the purpose of simultaneous solidification of the solidifying liquid core and eliminate internal quality problems such as thick and uneven dendrites, composition segregation, porosity, and shrinkage cavities.

[0033] The electromagnetic stirring casting device can be composed of one or more electromagnetic stirrers 2. The direction of the electromagnetic force of each electromagnetic stirrer 2 is controllable, and the angle between each electromagnetic stirrer and the flow direction of the casting blank can be adjusted, with an adjustment range of 0 - 180°; multiple electromagnetic stirrers can be arranged at the same plane height, or can be arranged at two or more plane heights; the relative position between the electromagnetic stirrer 2 and the casting blank 1 can be adjusted in real time.

[0034] According to the size of the casting blank 1, the moving support arm 4 can drive the electromagnetic stirrer 2 to move back and forth to adjust the gap between the electromagnetic stirrer 2 and the casting blank 1. The electromagnetic stirrer 2 and the moving support arm 4 can rotate relative to each other, so as to adjust the angle between the electromagnetic stirrer and the flow direction of the casting blank, with an adjustment range of 0 - 180°. Along the vertical direction of the casting blank 1, the moving support arm 4 can have two or more positions up and down to install the electromagnetic stirrer 2.

[0035] As Figure 2 shown, the moving support arm 4 is provided with an upper position 15 and a lower position 16 in the vertical direction. Both the upper position 15 and the lower position 16 are composed of 6 uniformly distributed through holes 17, and the distance between adjacent holes is 60°. In addition to the embodiments of the upper position 15 and the lower position 16, only one installation position or more than 2 installation positions can also be set in the vertical direction of the moving support arm 4 to expand the adjustment range.

[0036] As Figure 1As shown, the movable support arm 4 is on the movable platform 3. Driven by the mover 5, it can push the movable platform 3 to move up and down according to metallurgical requirements. The movement speed and position are adjustable, so as to drive the relative movement between the electromagnetic stirrer 2 and the billet 1.

[0037] The mover 5 is the driving part of the movable platform 3. The mover 5 adopts hydraulic drive or variable-frequency motor drive, which can better meet metallurgical requirements and control the position and movement speed of the movable platform in real time.

[0038] As Figure 3 shown, the electromagnetic stirrer 2 is composed of a junction box 8, a cooling water pipe 6, and an inductor 9. There are three cable connectors 7 on the junction box 8 for connecting the power supply. The cooling water pipe 6 is connected to external cooling water for cooling the electromagnetic stirrer 2. By controlling the phase angle of the power supply, the direction of the electromagnetic force 11 of the inductor 9 can be controlled. As Figure 17 shown, when U, V, and W are connected to alternating current with phase angles of 0°, 240°, and 120°, the electromagnetic force 11 is to the right. When U, V, and W are connected to alternating current with phase angles of 240°, 120°, and 0°, the electromagnetic force 11 is to the left. The electromagnetic stirrer 2 includes a coil and a magnetic conductor core. It is an off-the-shelf component or a mature product. Its internal structure and specific working principle are not the improvement points of this patent and will not be elaborated here.

[0039] As Figure 4 shown, it is the horizontal rotating flow field formed when four electromagnetic stirrers 2 are horizontally installed at the same plane height. The four electromagnetic stirrers 2 are horizontally installed, and the directions of the electromagnetic forces 11 are all counterclockwise, forming a horizontal rotating flow field 12.

[0040] As Figure 5 shown, it is the horizontal double-circulation flow field formed when four electromagnetic stirrers 2 are horizontally installed at the same plane height. The four electromagnetic stirrers 2 are horizontally installed. The directions of the electromagnetic forces 11 of two of them are counterclockwise, and the directions of the electromagnetic forces 11 of the other two are clockwise, forming a horizontal double-circulation flow field 12.

[0041] As Figure 6 shown, it is the flat-pushing flow field formed when two electromagnetic stirrers 2 are horizontally installed at the same plane height. The two electromagnetic stirrers 2 are horizontally installed, and the directions of the electromagnetic forces 11 are all to the left, forming a horizontal flat-pushing flow field 12.

[0042] As Figure 7 shown, it is the horizontal rotating flow field formed when two electromagnetic stirrers 2 are horizontally installed at the same plane height. The two electromagnetic stirrers 2 are horizontally installed, and the directions of the electromagnetic forces 11 are all counterclockwise, forming a horizontal rotating flow field 12.

[0043] As Figure 3As shown, there are m rotating holes 10 arranged circumferentially on the electromagnetic stirrer 2, where m = 360÷60×n and n is a natural number greater than or equal to 1. When n = 2, the spacing between adjacent screw holes is 30°, so the angle can be adjusted every 30°; when n = 3, the spacing between adjacent screw holes is 20°, and the angle can be adjusted every 20°, and so on. After the electromagnetic stirrer 2 rotates by a certain angle, the through hole 17 is aligned and installed with the rotating hole 10 at the corresponding position (such as the vertical installation shown in Figure 8 shown, such as the inclined installation shown in Figure 13 ).

[0044] Figure 8 Figure is a schematic diagram of the vertical installation of four combined electromagnetic stirring casting devices. The principle of the change in the electromagnetic force direction after vertical installation is as follows:

[0045] Figure 9 Figure is a schematic diagram of four electromagnetic stirrers 2 being pushed up simultaneously. Under the installation conditions of Figure 7 , the thrusts of all four electromagnetic stirrers 2 are upward, and the formed flow field 12 is the vertical double-circulation flow field shown in Figure 11 .

[0046] Figure 10 Figure is a schematic diagram of two of the four electromagnetic stirrers being pushed up and two being pushed down. Under the installation conditions of Figure 8 , the thrusts of two electromagnetic stirrers 2 are upward, and the thrusts of two electromagnetic stirrers 2 are downward. The formed flow field 12 is the vertical rotating flow field shown in Figure 12 .

[0047] Figure 13 Figure is a schematic diagram of the electromagnetic force under the inclined installation of the combined electromagnetic stirring casting device. By adjusting the position of the rotating hole 10, the direction of electromagnetic stirring can be rotated, and the adjustment range is 0 - 180°. Since there is a certain angle between the electromagnetic force 11 and the direction of the casting blank 1, a spiral flow field will be generated.

[0048] Figure 14 Figure is a schematic diagram of the electromagnetic force under the layered installation of the combined electromagnetic stirrer. Two electromagnetic stirrers are installed at the upper position, and two electromagnetic stirrers are installed at the lower position. The thrust directions of the two upward electromagnetic stirrers 2 are counterclockwise, generating an upward rotating flow field 13 as shown in Figure 15 , Figure 16 . The thrust directions of the two downward electromagnetic stirrers 2 are all to the left, generating a downward flat-pushing flow field 14 as shown in Figure 15 , Figure 16 . The downward flat-pushing flow field 14 can strengthen the exchange between the central molten steel and the molten steel at the solidification front, and the upward rotating flow field 13 can further move circumferentially to strengthen the dissipation of superheat.

[0049] The above are only embodiments of the present invention, and thus do not limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made by using the content of the specification and drawings of the present invention, or directly or indirectly applied in other related technical fields, shall be similarly included in the patent protection scope of the present invention.

Claims

1. A combined electromagnetic stirring casting device, characterized in that, It includes a billet (1), an electromagnetic stirrer (2), a moving platform (3), a moving support arm (4) and a mover (5). The billet (1) is arranged in the middle of the moving platform (3). At least one moving support arm (4) is arranged on the outer periphery of the billet (1). The moving support arm (4) is installed on the moving platform (3) and can horizontally displace forward and backward in the direction of the billet (1). An electromagnetic stirrer (2) is installed on one side of the moving support arm (4) close to the billet (1). The outer periphery of the moving platform (3) is installed on the mover (5), and the mover (5) is used to drive the moving platform (3) and the electromagnetic stirrer (2) and the moving support arm (4) installed thereon to displace up and down. The installation angle of the electromagnetic stirrer (2) on the moving support arm (4) is adjustable, and the adjustment direction is to rotate along the horizontal axis. At least one installation position is provided vertically on the moving support arm (4), and 6 through holes (17) are evenly arranged at the installation positions. m rotating holes (10) are arranged in a circle on the electromagnetic stirrer (2), where m = 360÷60×n and n is a natural number greater than or equal to 1. After the electromagnetic stirrer (2) rotates by a certain angle, the through hole (17) is aligned and installed with the rotating hole (10) at the corresponding position. The mover (5) is driven by hydraulic pressure or a variable frequency motor.

2. The combined electromagnetic stirring casting device according to claim 1, wherein When there are multiple moving support arms (4), an electromagnetic stirrer (2) is installed on each moving support arm (4), and each moving support arm (4) can horizontally displace separately or simultaneously.

3. The combined electromagnetic stirring casting device according to claim 2, characterized in that, When there are multiple installation positions, multiple electromagnetic stirrers (2) are installed at the installation positions at the same height, or multiple electromagnetic stirrers (2) are installed at the installation positions at different heights.

4. The combined electromagnetic stirring casting device according to claim 1, characterized in that, When there are multiple installation positions, 6 through holes (17) are respectively arranged at each installation position.

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