Cast-rolling casting nozzle with electric-magnetic coupling oscillation effect

Abstract

The invention relates to a cast-rolling casting nozzle with an electric-magnetic coupling oscillation effect. Relates to a cast-rolling casting nozzle with an electromagnetic oscillation effect, which is matched with a horizontal double-roller cast-rolling machine in the field of aluminum alloy die casting. The method is used for solving the inevitable internal macrosegregation defect of the high-alloy-content aluminum alloy cast-rolled product. The device comprises an L-shaped electrode pair 1; a side seal 2; an excitation device 3; a guide plate 4; a cooling water pipe (inlet / outlet) 5; a copper enameled wire (excitation) 6; a countersunk self-tapping screw 7; a casting nozzle upper plate 8; a rhombic shunting block 9; a nozzle lower plate 10; and a casting nozzle bottom plate 11. In the casting and rolling process, an oscillating electric field and a steady magnetic field are introduced, electromagnetic coupling force is generated at the outlet end of a casting nozzle, the electromagnetic force effectively stirs a semi-solid aluminum alloy melt, and therefore the purposes that alloy is evenly distributed, and segregation defects are reduced or even eliminated are achieved. The method is used in 4-series, 6-series and 7-series aluminum alloys, and the effect is obvious.

Description

Technical Field

[0001] This invention relates to a casting nozzle with electromagnetic oscillation effect that is electromagnetically coupled for use in horizontal twin-roll casting mills. Background Technology

[0002] As is well known, the casting and rolling working zone of a casting and rolling mill is located between the two casting roll gaps. The continuous and stable operation of the horizontal casting and rolling mill is achieved by the close fit between the casting nozzle and the casting zone. However, for high-alloy aluminum alloy melts, the macroscopic segregation defects in the microstructure of the cast and rolled plate are very obvious. To solve this problem, the main approach is to modify the casting nozzle structure to achieve a mechanical disturbance effect inside the melt.

[0003] Electromagnetic technology provides a novel melt stirring method. It generates electromagnetic oscillation through the coupling of alternating electric and magnetic fields within the casting zone. This electromagnetic oscillation replaces mechanical stirring, aiming to improve the microstructure of the cast plate and effectively suppress segregation defects. This invention enhances the functionality of the casting nozzle by introducing electrode pairs and an excitation device, effectively concentrating the electromagnetic field within the casting zone. This invention achieves electromagnetic stirring of the melt during solidification, and its effectiveness has been validated in practical applications. Summary of the Invention

[0004] This invention discloses a casting nozzle with electromagnetic field coupling oscillation effect, comprising electrodes introduced at the left and right side seals of the nozzle. These electrodes are fixed to the outer side of the front section of the side seal by self-tapping, with the electrode introduction ends exposed on the inner surfaces of both side seals and able to contact the molten casting. The outer side of the electrodes is in contact with an external power supply line. Additionally, an excitation device is formed by winding copper enameled wire in the same direction (clockwise or counterclockwise) to form a multi-turn coil, and fixed in a stainless steel sealed box. This excitation device includes a cooling circulating water circuit and leads out the excitation electrodes. The excitation device is fixed between the lower plate and the bottom plate of the nozzle using self-tapping screws.

[0005] The front edge of the side seal fits tightly against the outer surface of the double casting rolls and can be installed at the lowest point of the roll gap. The left and right side seals are tightly bonded to the upper and lower casting nozzle plates using pressure-sensitive adhesive and refractory mortar. The main body of the casting nozzle consists of double side seals, an upper casting nozzle plate, a guide plate, a lower casting nozzle plate, electrode pairs, an excitation device, and a casting nozzle base plate. The advantage of this invention is that it integrates the electrode pairs and excitation device into a traditional casting nozzle. By modifying the casting nozzle structure, an electromagnetic coupling field is introduced into the casting zone. During operation, by adjusting the frequency and intensity of the oscillation current, the molten metal throughout the casting zone can be subjected to strong electromagnetic oscillation and stirring effects. As the casting equipment operates, the alloy elements inside the cast plate are evenly distributed, resulting in a dense plate structure. Ultimately, this improves the product forming and utilization rate.

[0006] The purpose of this invention is to provide a casting nozzle with electromagnetic field coupling oscillation effect. This nozzle's capability lies in its ability to efficiently introduce electric and magnetic field coupling into the melt during operation, generating a powerful electromagnetic vibration effect by adjusting the form of the pulse current. This results in an ideal microstructure for the cast slab; eliminates the uneven distribution of constituent elements during crystallization; and ultimately effectively improves the microstructure of the cast alloy.

[0007] The design scheme of this invention is as follows: The casting nozzle comprises left and right L-shaped double electrode pairs, left and right side seals, upper and lower insulated nozzle plates, guide plates, excitation devices, and a nozzle base plate. The guide plates are fixed between the upper and lower plates of the insulated nozzle; the excitation device is positioned between the lower plate and the nozzle base plate and is fixed by the left and right side seals; the upper plate of the insulated nozzle is tightly fitted to the chute, with a circular through-hole at the fitting point to introduce molten metal. The L-shaped electrode pairs are fixed to the outer surface of the side seals on the same side. The two side seals are tightly adhered to both sides of the insulated nozzle body, and the joint gaps and the contact area between the nozzle tip and the side seals are ultimately filled with refractory mortar and the overall shape is finished.

[0008] In operation, the modified casting nozzle tip is inserted deep between the two casting rolls, reaching the lowest point of the roll gap. Through the break-in process of the two casting rolls, a sealed and unique melt flow channel is ultimately formed in the casting zone. The L-shaped electrode is connected to an oscillating current of different waveforms, frequencies, or intensities. Additionally, the spiral copper coil in the excitation device is energized and introduced into the circulating water system to cool the coil. During operation, the melt enters the casting zone through the chute and guide plate. Upon contact with the L-shaped electrode pair, a current path is formed. With this current path, the circuit itself has low self-inductance and negligible inductive reactance. The current is concentrated in the solidification zone of the melt, resulting in a high current density. Simultaneously, the excitation device generates a stable magnetic field within the casting zone. The interaction between the oscillating current and the external stable magnetic field generates a strong induced electromagnetic force. This electromagnetic oscillation force has a very significant stirring effect within the melt. Therefore, the superposition of the "electromagnetic induction" and "thermal effect" of the oscillating electromagnetic coupling field effectively improves the alloy solidification structure. Attached Figure Description

[0009] Figure 1 This is a front view of the structure of the present invention; Figure 2 This is a right view of the structure of the present invention; Figure 3 This is the upper plate of the casting nozzle in this invention; Figure 4 This is the lower plate of the casting nozzle in this invention; Figure 5 This invention relates to a nozzle guide plate. Figure 6 This is the casting nozzle base plate of the present invention; Figure 7 This invention relates to the side seal of the casting nozzle. Figure 8 This invention relates to an L-shaped electrode pair for casting nozzles. Figure 9 This invention relates to an excitation device for a casting nozzle; Figure 10 This is a three-dimensional schematic diagram of the casting nozzle used in this invention; in Figure 2 The component numbers are as follows: 1 is the L-shaped electrode pair; 2 is the side seal; 3 is the excitation device; 4 is the guide plate; 5 is the cooling water pipe (inlet / outlet); 6 is the copper enameled wire (excitation); 7 is the countersunk self-tapping screw; 8 is the upper plate of the casting nozzle; 9 is the diamond-shaped flow divider block; 10 is the lower plate of the casting nozzle; 11 is the bottom plate of the casting nozzle. Figure 3 This is the upper plate of the casting nozzle in this invention. Detailed Implementation

[0010] The present invention will be further described in detail below with reference to embodiments: See Figure 1 This invention includes: 1. an L-shaped electrode pair; 2. a side seal; 3. an excitation device; 4. a guide plate; 5. cooling water pipes (inlet / outlet); 6. copper enameled wire (for excitation); 7. self-tapping screws; 8. an upper plate for the casting nozzle; 9. a rhomboid flow divider; 10. a lower plate for the casting nozzle; and 11. a bottom plate for the casting nozzle. The L-shaped electrode pair is fixed to the outer edges of both sides of the side seal 2 by countersunk self-tapping screws 7. The side seal 2 is fixed to the edge of the insulated casting nozzle body (composed of the upper plate 8, guide plate 4, lower plate 10, and bottom plate 11) by pressure-sensitive adhesive and refractory putty. The guide plate 4 and the rhomboid flow divider 9 are fixed in the middle of the upper and lower plates of the casting roll. The molten material is poured through the rear circular opening, flows through the narrow space between the guide plate and the upper and lower plates of the casting roll, passes through the flow divider, the leading edge of the casting nozzle, and enters the casting roll zone. Under the action of the upper and lower rollers of the casting roll, the molten material quickly forms a solidified shell and fills the entire casting roll zone. The exposed air end of the L-shaped electrode pair is connected to an external oscillation current source; the other end of the L-shaped electrode pair contacts the molten metal, forming a current path. Simultaneously, a stable current source is connected to the copper enameled wire at the exposed air end of the excitation device, and the cooling water circulation circuit of the excitation device continuously and stably provides cooling water.

[0011] During operation, the oscillating current source is simultaneously turned on, creating an oscillating current in the casting and rolling zone; a stable excitation current is turned on, creating a stable magnetic field in the casting and rolling zone; and a cooling water pump is turned on to continuously cool the excitation device. In this way, the oscillating current and the stable magnetic field generate a strong electromagnetic force effect. This can improve the melt structure during the production process.

[0012] Using method 1, the casting and rolling process of aluminum alloys, such as some 7XXX series aluminum alloys (7075, 7050), 6XXX series aluminum alloys (6181), and 4xxx series aluminum alloys (AlSi12), the microstructure of the slab after casting and rolling is significantly improved by introducing sinusoidal current or pulsed current.

[0013] Using 2, the casting and rolling process of magnesium alloys, such as AZ series alloys, the microstructure of the slab after casting and rolling is significantly improved by introducing sinusoidal current or pulsed current.

Claims

1. A casting nozzle with electro-magnetic coupling oscillation effect, comprising one electrode pair for current introduction and three excitation devices; characterized in that, It also includes an oscillating power supply and a DC power supply. The oscillating power supply is connected to electrode pair 1 to realize the function of oscillating power supply path under the condition of aluminum alloy melt flow. The DC power supply is connected to excitation device 3 to realize the function of generating static magnetic field around the casting nozzle.

2. The apparatus according to claim 1, characterized in that, The electrode pair is made of graphite and has an L-shaped structure installed on the left and right sealing edges. The working end and the connection end of the oscillation power supply of the electrode pair are exposed to the air, while the rest are insulated.

3. The apparatus according to claim 1, characterized in that, The material of the 3 excitation devices is enameled wire (copper wire). The 3 excitation devices are installed between the lower plate of the 10 casting nozzle and the bottom plate of the 11 casting nozzle. The 3 excitation devices are connected to the DC power supply through a cable with a stainless steel waterproof connector to form a current path.

4. The excitation device claimed in claim 3 is characterized in that it consists of an outer stainless steel box and an inner enameled wire coil (copper wire); the enameled wire coil is composed of multiple turns of coil wound in two layers, one clockwise and one counterclockwise; the empty space between the stainless steel box and the enameled wire can be used to introduce a circulating water system to cool the coil.

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