WO2013106953A1

WO2013106953A1 - Metallurgical tank electric-pulse device

Info

Publication number: WO2013106953A1
Application number: PCT/CN2012/000121
Authority: WO
Inventors: 于健; 边仁杰
Original assignee: 唐山文丰山川轮毂有限公司; 河北文丰钢铁有限公司
Priority date: 2012-01-21
Filing date: 2012-01-21
Publication date: 2013-07-25

Abstract

A metallurgical tank electric-pulse device (100) comprises: a cover portion (20); a tank portion (30), the bottom of which is provided with a outlet port (17) for casting; and at least two electrode units (12, 12'; 12a, 12b, 12c, 12d; 12e, 12f, 12g), configured to be electrically connected to an electric-pulse generator, the at least two electrode units passing through the cover portion and/or the tank portion and extending to positions near the outlet port of the metallurgical tank electric-pulse device so as to release low voltage electric-pulse. The metallurgical tank electric-pulse device is particularly suitable for a caster intermediate tank electric-pulse device. The electric-pulse device provides an optimal electric pulse modification position before casting of molten metal from the outlet port, thereby achieving a satisfactory modification effect.

Description

Metallurgical tank electric pulse device

The invention relates to the field of metallurgical smelting and casting, in particular to a metallurgical tank electric pulse device. Background technique

In the field of metallurgical smelting and casting, the methods for improving the solidification structure of metals mainly include: chemical growth method, mechanical force method, temperature control field, ultrasonic vibration method, electromagnetic stirring method, electric pulse pregnancy method and the like. Among them, the electric pulse inoculation method is a new technology, and its basic theory is: The electrons applied to the molten metal by the electric pulse act as crystal nuclei at the liquid-solid phase interface, so that the crystal radius becomes smaller, and the grain refinement is realized. State crystal.

It is known that electrical pulse inoculation treatment of molten metal in the laboratory has achieved good results. Figure 1 shows a comparison of solidified microstructures of T8 carbon steel (a) untreated, (b) subjected to low voltage electrical pulse inoculation, and (c) subjected to medium voltage pulse inoculation. It can be seen from the figure that the solidification structure of carbon steel is remarkably refined and homogenized by electric pulse incubation. However, in the tests of these laboratories, the liquids were static and it was difficult to simulate the complex conditions in actual production (especially during continuous casting).

The Chinese invention patent No. 98100543. 8 discloses a method for inoculating a molten metal which is treated by a pulsed electric field after metal melting after casting or continuous casting. The invention patent also discloses that the metal liquid inoculation treatment method can be used on a smelting furnace, a ladle, a tundish and a continuous casting mold which suspend smelting. However, this invention patent only discloses the schematic diagram of the pulse generator, but does not disclose or describe how to apply the electric pulse on the smelting furnace, ladle, tundish or crystallizer, and does not involve the energization method, method, process, etc. Technical disclosures closely related to metallurgical smelting and casting production. Summary of the invention

The present invention is directed to solving the above problems in the prior art, and provides a metallurgical canister electrical pulse device, and more particularly to a continuous casting machine intermediate canister electrical pulse device.

The idea of the present invention is based on the following views of the inventors:

(1) The solidification structure of the as-cast crystal is related to the amount and balance of electrons (by electric pulse) applied to the molten metal, and also related to the electron decay in the molten metal, so Efficient and uniform electron supply to the molten metal and reduction of electron loss/attenuation in the molten metal, which is advantageous for obtaining a satisfactory grain effect;

(2) The flow field of the molten metal in the metallurgical casting tank is disordered, and the electrode arrangement in the prior art makes the molten metal after the electric pulse inoculation process cannot be time-efficiently cast into the crystallizer under the action of the disordered flow field. , causing the electrons carried by the molten metal to be uneven, thereby affecting the grain refining effect. Accordingly, the present invention provides a metallurgical canister electrical pulse device, and more particularly to a continuous casting machine intermediate canister electrical pulse device, the metallurgical canister electrical pulse device comprising: a cover portion; the can portion is provided at the bottom of the can portion a nozzle; and, at least two electrode devices configured to be electrically connected to the electrical pulse generator, the at least two electrode devices extending through the cover portion and/or the can portion to the metallurgical can The vicinity of the nozzle of the electric pulse device is used to apply a discharge pulse. According to the present invention, extending at least two electrode means to the vicinity of the nozzle provides an optimum electric pulse inoculation processing position before the molten metal is cast from the nozzle into, for example, the crystallizer, so that a satisfactory inoculation effect can always be achieved to satisfy industrial production. Demand.

In a preferred embodiment, the distance from the discharge end of the at least two electrode devices to the nozzle is in the range from 3 mm to 70 mm, preferably in the range from 5 mm to 30 mm, more preferably in the range of 5 mm to 30 mm. In the range of mm - 10 mm.

In one embodiment, the metallurgical canister electrical pulse device further includes a stopper rod that extends through the lid portion to a vicinity of a nozzle below the liquid level of the molten metal.

In a preferred embodiment, the discharge surface of the electrode device is orphaned. The above preferred embodiment advantageously makes the pulsed discharge more stable.

In a preferred embodiment, the front end of the electrode device is provided with an electrode cap, and the material of the electrode cap is zirconium dioxide or conductive ceramic. The above preferred embodiment advantageously increases the electrical conductivity and durability of the electrode to avoid failure due to electrical erosion within the molten metal.

In a preferred embodiment (the metallurgical canister electrical pulse device with or without a stopper), the at least two electrode devices form an electrode pair two or two adjacent to the nozzle for applying a discharge pulse.

In a preferred embodiment (in the case where the metallurgical can electric pulse device has a stopper rod), the at least two electrode devices respectively form an electrode pair with the stopper rod near the nozzle for applying a discharge pulse. The stopper is configured for electrical connection to an electrical pulse generator. A compact structural design can be achieved in a particularly advantageous manner in this case.

In a preferred embodiment, the discharge distance between the pair of electrodes is in the range from 3 mm to 70 mm, preferably in the range from 5 mm to 30 mm, more preferably in the range from 5 mm to 10 mm. . The above preferred discharge distance enables stable and effective electrical pulse gestation, and discharge pulses can be applied with a lower voltage.

In a preferred embodiment, the electrical pulse generator of the metallurgical canister electrical pulser outputs an electrical pulse of 29-63 volts, preferably an electrical pulse of 30-55 volts, more preferably an electrical pulse of 36 volts. The above preferred embodiment can achieve good electrical pulse gestation effects using voltages near or within the safe voltage, which is particularly advantageous in terms of production safety.

In a preferred embodiment, the metallurgical canister electrical pulse device is formed with a plurality of said electrode pairs, which in turn are applied with a discharge pulse at predetermined time intervals in a clockwise or counterclockwise direction. In this case, the effective area of the electric pulse treatment can be increased, and the effect of the molten steel being gestated can be improved. DRAWINGS

The various embodiments of the present invention are described below with reference to the accompanying drawings, which are merely illustrative of the invention and are not intended to limit the scope of the invention. In the various figures, the same reference numerals are used to refer to the same or the like. In the figure:

Figure 1 shows the solidification microstructure comparisons for T8 carbon steel (a) untreated, (b) low-voltage pulse inoculation treatment, and (c) medium-voltage pulse inoculation in laboratory tests.

Fig. 2 is a schematic side elevational view, partially in section, of a continuous casting machine intermediate tank electrical pulsing apparatus in accordance with a preferred embodiment of the present invention.

Fig. 3 schematically shows an enlarged detail view of a portion B in Fig. 2.

Fig. 4 is a schematic side elevational view, partly in section, of a continuous casting machine intermediate tank electrical pulse device in accordance with another preferred embodiment of the present invention.

Fig. 5a schematically illustrates an electrode arrangement in accordance with a preferred embodiment of the present invention, wherein the continuous tank intermediate tank electrical pulse device is not provided with a stopper.

Fig. 5b schematically illustrates an electrode arrangement in accordance with another preferred embodiment of the present invention, wherein the continuous tank intermediate tank electrical pulse device is not provided with a stopper.

Figure 6a schematically illustrates an electrode arrangement in accordance with a preferred embodiment of the present invention, wherein the continuous tank intermediate tank electrical pulse device is provided with a stopper. Fig. 6b schematically shows an electrode arrangement according to another preferred embodiment of the invention, wherein the continuous tank intermediate tank electric pulse device is provided with a stopper.

It is to be noted that Figures 2-6b are merely illustrative and the invention is not limited by the details in the figures. detailed description

Fig. 2 schematically shows a side cross-sectional view of a continuous casting machine intermediate tank electric pulse device 100 in accordance with a preferred embodiment of the present invention. The continuous casting machine intermediate tank electric pulse device 100 includes a cover portion 20 and a can portion 30. The cover portion 20 includes a cover case 5 and a refractory material layer 6, and the can portion 30 includes a can body 8, a permanent village 9, and a work lining 10. The bottom of the can 30 is provided with a nozzle 17 penetrating through the can 8, the permanent liner 9 and the working liner 10 (the molten metal flows out through the opening 18 of the nozzle 17). This nozzle 17 can be used for casting.

In this embodiment (as shown in Figure 2), a stopper rod 4 is mounted on the stopper rod switch 3 through the insulated terminal 2, and the stopper rod 4 extends through the cover portion 20 of the intermediate tank electric pulse device 100 to Near the nozzle 17 below the molten metal level 7. It should be understood that in some continuous casting machine intermediate tanks or other metallurgical tanks, a plug rod is not required, and the present invention is equally applicable to a continuous casting machine intermediate tank or other metallurgical tank without a plug.

The intermediate tank electric pulse device 100 of the present invention further includes at least two electrode devices 12 (only one of which is shown in Fig. 2), the at least two electrode devices passing through the cover portion 20 of the intermediate tank electric pulse device 100 (see Fig. 4) and/or the can 30 (see Fig. 2) extends to the vicinity of the nozzle 17 of the intermediate canister electrical pulse device 100 for nurturing the molten metal in the vicinity of the nozzle 17 by electrical pulses. Although the electrode device 12 is shown in Fig. 2 extending from the intermediate portion through the can portion 30 to the vicinity of the nozzle 17, the electrode device 12 may also extend from the top portion through the cover portion 20 to the vicinity of the nozzle 17 (see Fig. 4) or from The bottom portion extends through the can portion 30 to the vicinity of the nozzle 17 (not shown).

The large displacement of the discharge end of the electrode device 12 to the nozzle 17 is preferably in the range of 3 mm to 70 mm, more preferably in the range of 5 mm to 30 nun, more preferably in the range of 5 mm to 10 mm. Within the scope. Thereby, the loss/attenuation of electrons in the molten metal after the electric pulse inoculation treatment can be effectively avoided, and the rotating water flow velocity in the above range is suitable for making the electrons applied to the molten metal more balanced, so that the total satisfaction can be obtained. Inoculation and crystallization effect. In the present invention, the distance from the discharge end of the electrode device 12 to the nozzle 17 refers to the placement of the electrode device 12. The shortest distance from the outer surface of the electric terminal to the outer surface of the nozzle 17.

Fig. 3 schematically shows an enlarged detail view of a portion B of Fig. 2. As shown in FIG. 3, an insulating sleeve 14 and an insulating end cap 15 are provided around the periphery of the electrode unit 12, and are fixed to the can 8 by a flange 16. The electrode assembly 12 can be secured to the can 8 by other fasteners or to the can 8 in other manners commonly used in the art; the electrode assembly 12 can also be secured and passed through the cover 20 of the intermediate canister electrical pulse device 100 ( As shown in Figure 4). Preferably, the tip end of the electrode device 12 is provided with an electrode cap 13. The material of the electrode device 12 is preferably carbon (C), or silicon carbide (S iC ), or cermet, metal or the like. The material of the electrode cap 13 is preferably zirconium dioxide (Zr0 ₂ ) or a conductive ceramic, thereby improving the durability of the electrode and avoiding electrical erosion in the molten metal. In a preferred embodiment, the discharge surface of the electrode assembly 12 is curved, thereby making the pulse discharge more stable.

Fig. 4 is a schematic side elevational cross-sectional view showing another preferred embodiment of a continuous casting machine intermediate tank electric pulse device in accordance with the present invention. As shown in Fig. 4, the first electrode means 12 and the second electrode means 12 extend from the top portion through the cover portion 20 to the vicinity of the nozzle 17. The first electrode means 12 and the second electrode means 12 are mounted on the cover 5 of the cover portion 20 at an angled angle.

In one embodiment (wherein the intermediate tank electrical pulse device is provided with or without a stopper), the first and second electrode devices 12 and 12 constitute an electrode pair for applying a discharge pulse near the gestation nozzle 17 Metallic liquid. The number of the electrode means 12 may also be an even number greater than 2 for forming a plurality of electrode pairs in the vicinity of the nozzle 17, so that the molten metal in the vicinity of the nozzle 17 is sufficiently bred. Alternatively, the number of the electrode devices 12 may also be an integer greater than 2 for forming an electrode pair by control (a person skilled in the art may adopt various control modes according to actual conditions, which will not be described in detail herein). The discharge pulse is applied at intervals so that the molten metal in the vicinity of the nozzle 17 is sufficiently gestated.

In another embodiment (wherein the intermediate tank electric pulse device is provided with a stopper rod), the first and second electrode devices 12 and 12 respectively form two electrode pairs with the stopper rod 4 (ie, the first electrode device) 12 and the stopper rod 4 constitute a first electrode pair, and the second electrode device 12 and the stopper rod 4 constitute a second electrode pair), thereby achieving a compact structural design. In this embodiment, the stopper rod 4 can be electrically connected to a cable lug 1 (shown in Fig. 2) which can be connected to an electric pulse generator via a cable. Of course, other suitable structures can be used to achieve electrical connections. More than two electrode arrangements may also be provided, each forming more than two electrode pairs with the stopper 4 (e.g., Figures 6a and 6b). According to a preferred embodiment of the invention, the discharge distance between each electrode pair (including the electrode pair formed by the electrode means and the electrode means and/or the electrode pair formed by the electrode means and the stopper) is preferably in the range of 3 mm to 70 nun More preferably, it is in the range of 5 mm - 30 mm, more preferably in the range of 5 mm - 10 mm. The application of the discharge pulse by the above discharge distance enables the molten metal to obtain a favorable inoculation effect. In the present invention, the discharge distance of the electrode pair refers to the shortest distance from the outer surface of the discharge end of one electrode device constituting the corresponding electrode pair to the outer surface of the discharge end of the other electrode device (or stopper).

By the discharge distance of the above preferred electrode pairs in the present invention, it is possible to achieve an advantageous gestation effect with a lower voltage electrical pulse. The voltage (output by the electric pulse generator) is in the range of 29-63 V, preferably in the range of 30-55 V, more preferably 36 V. With the above preferred embodiment, it is possible to achieve a good electric pulse gestation effect by using a voltage near or within the safe voltage, which is particularly advantageous in terms of production safety. In a specific preferred embodiment, when the discharge distance of the electrode pair is 5-10 mm, the electric pulse generator outputs an electric pulse of 36 V, thereby (in the electrode supply line, the electrode and the like resistance) can be in the electrode pair An electric pulse voltage of 6-9 V is obtained, and an advantageous gestation effect is achieved. Fig. 5a schematically shows an electrode arrangement (top view) in accordance with a preferred embodiment of the present invention, wherein the continuous tank intermediate tank electrical pulse device is not provided with a stopper. As shown in Fig. 5a, four electrode means 12a-12d are provided around the nozzle 17, and the four electrode means are spaced apart from each other by 90 degrees, and four of the electrode means 12a-12d constitute a pair of electrodes to apply a discharge pulse. In one embodiment, the electrode device 12a and the electrode device 12c constitute one electrode pair, and the electrode device 12b and the electrode device 12d constitute another electrode pair. In another embodiment, the electrode device 12a and the electrode device 12d constitute one electrode pair, and the electrode device 12b and the electrode device 12c constitute another electrode pair. In a preferred embodiment, each electrode pair applies a discharge pulse in a clockwise or counterclockwise direction at predetermined time intervals. A pair of electrodes, or two pairs of electrodes (as shown in Figure 5a), or more pairs of electrodes can be placed in the vicinity of the nozzle in a similar manner. The more pairs of electrodes are provided, the larger the effective area of coverage; and depending on the direction of the water flow (for example, The vortex of the northern hemisphere water outlet is counterclockwise. Applying a discharge pulse at predetermined time intervals can also improve the effect of the molten metal.

Similarly, FIG. 5b schematically shows an electrode arrangement (top view) according to another preferred embodiment of the present invention, wherein the continuous tank intermediate tank electric pulse device is not provided There is a stopper. As shown in FIG. 5b, three electrode devices 12e-12g are disposed around the nozzle 17, and the three electrode devices are spaced apart from each other by 120 degrees, wherein the three electrode devices 12e-12g form a pair of electrodes by controlling two pairs, and discharges at intervals pulse. In a preferred embodiment, each electrode pair is applied with a discharge pulse in a clockwise or counterclockwise direction at predetermined time intervals. Specifically, in one embodiment, first, the electrode device 12e and the electrode device 12g constitute an electrode pair discharge pulse, and after a predetermined time interval, the electrode device 12g and the electrode device 12f constitute an electrode pair discharge pulse, at the predetermined After the time interval, the electrode device 12f and the electrode device 12e constitute an electrode pair to apply a discharge pulse, and thus circulate (i.e., in the clockwise direction). Similarly, embodiments in which the discharge pulse is applied at a predetermined time interval in a counterclockwise direction (e.g., the vortex at the northern hemisphere water outlet is counterclockwise) are just the opposite.

Fig. 6a schematically shows an electrode arrangement according to a preferred embodiment of the invention, wherein the continuous tank intermediate tank electric pulse device is provided with a stopper rod 4. As shown in Fig. 6a, four electrode means 12a-12d are provided around the nozzle 17, and the four electrode means are spaced apart from each other by 90 degrees. In one embodiment, the four electrode devices 12a-12d are paired to form an electrode pair to apply a discharge pulse (as described with reference to Figure 5a). In a preferred embodiment, the four electrode means 12a-12d respectively form four electrode pairs with the plug 4, thereby achieving a compact structural design. Preferably, the electrode pair (including the electrode pair formed by the electrode device and the electrode device and/or the electrode pair formed by the electrode device and the stopper) is sequentially applied with a discharge pulse at a predetermined time interval in a clockwise or counterclockwise direction. A pair of electrodes, or two pairs of electrodes, or three pairs of electrodes (as shown in Figure 6b), or more pairs of electrodes can be placed in the vicinity of the nozzle in a similar manner. The more pairs of electrodes are provided, the larger the effective area of coverage; Applying a discharge pulse at a predetermined time interval according to the direction of the water flow can also improve the effect of the molten metal being bred.

Similarly, Figure 6b schematically illustrates an electrode arrangement in accordance with another preferred embodiment of the present invention, wherein the continuous tank intermediate tank electrical pulse device is provided with a stopper rod 4. As shown in Fig. 6b, three electrode devices 12e-12g are provided around the nozzle 17, and the three electrode devices are spaced apart from each other by 120 degrees. In one embodiment, the three electrode devices 12a-12d are paired to form an electrode pair to apply a discharge pulse (as described with reference to Figure 5b). In a preferred embodiment, the three electrode arrangements 12e-12g form a three-electrode pair with the plug 4, respectively, thereby achieving a compact design. Preferably, the electrode pair (including the electrode pair formed by the electrode device and the electrode device and/or the electrode pair formed by the electrode device and the stopper) sequentially applies a discharge pulse at a predetermined time interval in a clockwise or counterclockwise direction. A metallurgical can electric pulse device according to the present invention includes: a cover portion; a can portion having a nozzle at a bottom thereof; and at least two electrode devices configured to be electrically connected to the electric pulse generator, At least two electrode means are passed through the cover and/or the can, extending to the vicinity of the nozzle of the metallurgical canister electrical pulse device for applying a discharge pulse. The present invention extends at least two electrode means to the vicinity of the nozzle (a preferred distance from the nozzle) for applying a discharge pulse, and an improved technical effect is obtained with respect to the prior art. It should be understood that although an electrical pulse nurturing continuous casting device for placing an electrode on a nozzle (i.e., in an outlet line of a nozzle) has been disclosed in the prior art (see application No. CN 102078948 A), Since the flow rate of the molten metal in the nozzle line is very fast, the discharge pulse by this method causes the metal liquid to be charged less. In contrast, the present invention provides an optimum electric pulse inoculation treatment position before the molten metal is cast from a nozzle into, for example, a crystallizer, so that a satisfactory inoculation effect can always be achieved, and the needs of industrial production are easily understood by those skilled in the art. Although various embodiments of the present invention are described herein with a continuous casting machine intermediate tank electric pulse device as an example, the present invention is also applicable to other metallurgical can electric pulse devices. Although the continuous casting machine intermediate tank electric pulse device of the embodiment has a stopper rod 4, the present invention is equally applicable to a continuous casting machine intermediate tank electric pulse device or other metallurgical tank electric pulse device without a stopper.

One of ordinary skill in the art will readily appreciate that one or more features described in one embodiment of the invention may be used in conjunction with one or more features of other embodiments of the invention. The above specific embodiments do not limit the scope of protection of the present invention. In addition, "first", "second", or "a", "b" in the specification or the claims of the present application merely indicate one-to-one distinction of multiple technical features of the same type, The representation includes other meanings such as sorting.

Claims

Claim

1. A metallurgical canister electric pulse device, in particular to a continuous casting machine intermediate tank electric pulse device, characterized in that the metallurgical canister electrical pulse device comprises:

Cover

a tank having a nozzle at a bottom thereof; and

At least two electrode devices configured to be electrically connected to the electrical pulse generator, the at least two electrode devices extending through the cover portion and/or the can portion to the metallurgical canister electrical pulse device Near the nozzle, for applying a discharge pulse.

2 . The metallurgical can electric pulse device according to claim 1 , wherein a distance from a discharge end of the at least two electrode devices to the nozzle is in a range of 3 mm to 70 mm, preferably 5 In the range of mm - 30 mm, more preferably in the range of 5 mm - 10 mm.

3 . The metallurgical can electric pulse device according to claim 1 , wherein the metallurgical can electric pulse device further comprises a stopper rod, and the stopper rod extends through the cover portion to below the molten metal surface. Near the mouth of the water.

The metallurgical can electric pulse device according to claim 1, wherein the discharge surface of the electrode device is curved.

The metallurgical can electric pulse device according to claim 1, wherein the electrode device is provided with an electrode cap at a front end thereof, and the electrode cap is made of zirconium dioxide or conductive ceramic.

A metallurgical can electric pulse device according to claim 1, wherein said at least two electrode means form an electrode pair two or two in the vicinity of said nozzle for applying a discharge pulse.

The metallurgical can electric pulse device according to claim 3, wherein the at least two electrode devices respectively form an electrode pair with the stopper rod in the vicinity of the nozzle for applying a discharge pulse, The stopper is configured for electrical connection to an electrical pulse generator.

The metallurgical can electric pulse device according to claim 6 or 7, wherein the discharge distance between the pair of electrodes is in the range of 3 mm to 70 mm, preferably 5 mm to 30 mm. Within the range, more preferably in the range of 5 mm - 10 mm.

The electric pulse generator for metallurgical tank according to claim 8, wherein the electric pulse generator of the metallurgical tank electric pulse device outputs an electric pulse of 29-63 V, preferably an electric pulse of 30-55 V, An electrical pulse of 36V is preferably output.

The metallurgical can electric pulse device according to claim 6 or 7, wherein The metallurgical tank electric pulse device is formed with a plurality of the electrode pairs, and the discharge pulses are sequentially applied at a predetermined time interval in a clockwise or counterclockwise direction.