CN117418109A

CN117418109A - Consumable electrode smelting method and smelting equipment

Info

Publication number: CN117418109A
Application number: CN202311362335.3A
Authority: CN
Inventors: 葛强; 刘少辉; 国斌; 李建明; 王振; 蔡俊杰; 高鹏
Original assignee: Shaanxi Dingyi Titanium Valley New Material Co ltd
Current assignee: Shaanxi Dingyi Titanium Valley New Material Co ltd
Priority date: 2023-10-20
Filing date: 2023-10-20
Publication date: 2024-01-19

Abstract

The invention relates to the technical field of metal smelting, in particular to a consumable electrode smelting method and smelting equipment. The consumable electrode smelting method of the invention firstly smelts to generate a molten pool, utilizes ultrasonic wave to act on the outer part of the molten pool, and causes the outer part of the molten pool to generate compact shrinkage through ultrasonic wave high-frequency vibration. The consumable electrode melting device comprises an outer sleeve body, a crucible, a cooling liquid layer, a vibrator array and an ultrasonic generator. The vibrator array includes a plurality of ultrasonic vibrators distributed in the coolant layer, the ultrasonic vibrators being for generating ultrasonic waves acting on an outer portion of the molten pool. When the method is used, the microstructure of the outer part of the molten pool is more uniform, the shrinkage of the grain units is tighter, the porosity is lower, after the molten pool is cooled to form an ingot, the surface of the obtained ingot is more compact and complete, fewer inclusions are included, the porosity is lower, the oxide layer is thinner, and segregation is not easy to occur on the surface layer of the ingot, so that the yield is improved.

Description

Consumable electrode smelting method and smelting equipment

Technical Field

The invention relates to the technical field of metal smelting, in particular to a consumable electrode smelting method and smelting equipment.

Background

In the production process of a consumable electrode smelting furnace (VAR), a consumable electrode of titanium and titanium alloy is used as a negative electrode, a copper crucible is used as a positive electrode, a smelting technology under the action of 20KA current is a main production technology of titanium alloy cast ingots, the copper crucible is a carrier for generating a titanium molten pool and cooling and solidifying, a cooling liquid layer is arranged between the copper crucible and an external sleeve body, cooling water circularly cools the high-temperature copper crucible through a water layer, a stable arc ring is wound in the water layer, and a magnetic field generated by about 10A current is used for stirring the molten pool in the copper crucible so as to reduce quality accidents of smelting segregation, and meanwhile, production accidents such as arc dispersion and side arcs generated by unstable phenomena are reduced.

When the self-consuming electrode smelting furnace is used for smelting titanium and titanium alloy, firstly, a self-consuming electrode which is formed by pressing titanium sponge or titanium sponge added with alloy elements as raw materials is clamped on an electrode rod (which is a negative electrode of a direct current power supply), in a vacuum or inert gas atmosphere, an arc is generated between the self-consuming electrode and an arc striking material on a water-cooled copper crucible (which is a positive electrode of the direct current power supply), the self-consuming electrode is melted by means of the heat of the arc, the melted electrode enters the crucible in a molten drop form to form a molten pool, the surface of the molten pool is heated by the arc and is always in a liquid state, the bottom and the periphery of the molten pool form a crystallization process from bottom to top under the forced cooling of crucible cooling water, and finally, the cast ingot is obtained. In the process, the electrode is continuously lowered at a proper speed, and the arc melting is continuously carried out until the consumable electrode is melted and exhausted, and the melting is finished. The whole process can be divided into electrode connection, arc establishment melting pool period, normal smelting period, head feeding period and final cooling tapping.

In the smelting process, a copper crucible is immersed in a water jacket, an annular arc stabilizing coil is arranged in the water jacket, the arc stabilizing coil can be divided into a direct current coil and an alternating current coil, when the arc stabilizing coil is electrified, current generates inductance according to the Lorentz magnetic force principle, and the inductance causes a metal molten pool in the crucible to flow directionally, so that stirring and mixing of different elements of a metal solution are promoted.

At present, the stirring and mixing effects of current on a metal molten pool are mainly reflected in the inside of an ingot body and a tissue, and the effect on the surface layer, particularly the surface contacted with a copper crucible, is very weak, so that the porosity of the surface layer of the ingot is high, the tissue is loose, the quality of the ingot is reduced, and the yield is reduced.

Disclosure of Invention

The invention aims to provide a consumable electrode smelting method for solving the problems of high porosity, loose structure and low yield of an ingot surface layer in the prior art, and also provides consumable electrode smelting equipment for solving the problems.

In order to solve the technical problems, the invention provides a consumable electrode smelting method, which comprises the following steps:

smelting to generate a molten pool;

the outer part of the molten pool is enabled to generate compactness shrinkage through ultrasonic high-frequency vibration by utilizing the action of ultrasonic waves on the outer part of the molten pool.

Further, the outer portion of the bath to which the ultrasonic wave acts ranges from the bath surface to a depth of 10 mm.

Further, the frequency range of the ultrasonic wave is 38-45Hz.

Further, the ultrasonic wave is generated by an ultrasonic vibrator disposed in a cooling liquid layer outside the crucible.

The invention also provides a consumable electrode smelting apparatus comprising:

an outer sleeve;

a crucible disposed in the outer jacket, the crucible for containing a molten bath;

a cooling liquid layer disposed between the outer jacket and the crucible for cooling a molten pool in the crucible;

a vibrator array including a plurality of ultrasonic vibrators distributed in the coolant layer, the ultrasonic vibrators for generating ultrasonic waves acting on an outer portion of the molten pool;

and the ultrasonic generator is electrically connected with the ultrasonic vibrator and used for controlling the ultrasonic vibrator to vibrate.

Further, the outer portion of the ultrasonically activated bath ranges from the bath surface to a depth of 10 mm.

Further, the frequency range generated by the ultrasonic vibrator is 38-45Hz.

Further, a gap is formed between the ultrasonic vibrator and the crucible, and the size of the gap is 5-20mm.

Further, the vibrator array further comprises a connecting net, and the connecting net is used for connecting and fixing a plurality of ultrasonic vibrators.

Further, a plurality of the ultrasonic vibrators are arranged in the cooling liquid layer at intervals along the crystallization direction of the molten pool.

Compared with the prior art, the invention has at least the following beneficial effects:

when the device is used, the outer part of the molten pool can generate vertical vibration, the arc-stabilizing electromagnetic induction coil can generate horizontal stirring for the molten pool, so that the outer part of the molten pool can generate binary high-frequency micro-amplitude vibration brought by the cooperation of the two parts, the microstructure of the outer part of the molten pool is more uniform, the shrinkage of a grain unit is more compact, the porosity is lower, the surface of an obtained cast ingot is more compact and complete after the cast ingot is formed by cooling the molten pool, fewer inclusions are generated, the porosity is lower, an oxide layer is thinner, and segregation is not easy to occur on the surface layer of the cast ingot, thereby improving the yield.

Drawings

FIG. 1 is a flow chart of the consumable electrode smelting process of the present invention;

FIG. 2 is a schematic structural view of the consumable electrode melting apparatus of the present invention;

FIG. 3 is a schematic view showing an expanded state of a vibrator array of the consumable electrode melting device of the present invention;

reference numerals:

100. a molten pool; 110. an outer sleeve; 112. a liquid inlet; 114. a liquid outlet; 120. a crucible; 130. a cooling liquid layer; 140. an ultrasonic vibrator; 150. an arc stabilizing coil; 160. casting ingot; 170. and (5) connecting a net.

Detailed Description

A consumable electrode smelting process and apparatus of the present invention will be described in connection with schematic drawings in which preferred embodiments of the invention are shown, it being understood that one skilled in the art may modify the invention described herein while still achieving the beneficial effects of the invention. Accordingly, the following description is to be construed as broadly known to those skilled in the art and not as limiting the invention.

The numbering of components herein, such as "first," "second," etc., is used merely to distinguish between the described objects and does not have any sequential or technical meaning. The terms "coupled" and "connected," as used herein, are intended to encompass both direct and indirect coupling (coupling), unless otherwise indicated. In the description of the present invention, it should be understood that the terms "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, are merely for convenience in describing the present invention and simplifying the description, and do not indicate or imply that the device or element in question must have a specific orientation, be configured and operated in a specific orientation, and thus should not be construed as limiting the present invention.

In the present invention, unless expressly stated or limited otherwise, a first feature "up" or "down" a second feature may be the first and second features in direct contact, or the first and second features in indirect contact via an intervening medium. Moreover, a first feature being "above," "over" and "on" a second feature may be a first feature being directly above or obliquely above the second feature, or simply indicating that the first feature is level higher than the second feature. The first feature being "under", "below" and "beneath" the second feature may be the first feature being directly under or obliquely below the second feature, or simply indicating that the first feature is less level than the second feature.

The invention is more particularly described by way of example in the following paragraphs with reference to the drawings. Advantages and features of the invention will become more apparent from the following description and from the claims. It should be noted that the drawings are in a very simplified form and are all to a non-precise scale, merely for convenience and clarity in aiding in the description of embodiments of the invention.

The consumable electrode smelting process in an embodiment of the first aspect of the invention will now be described with reference to figure 1 of the accompanying drawings.

In one embodiment, the consumable electrode melting method of the present embodiment includes:

s100: smelting to generate a molten pool;

s200: the outer part of the molten pool is enabled to generate compactness shrinkage through ultrasonic high-frequency vibration by utilizing the action of ultrasonic waves on the outer part of the molten pool.

In step S100, a metal raw material to be smelted is first made into a consumable electrode, and the consumable electrode is clamped on an electrode rod, and is used as a negative electrode of a direct current power supply, wherein the metal raw material can be titanium sponge, titanium sponge added with alloy elements, or other metal raw materials which can be smelted by adopting a consumable electrode smelting mode. Then, in vacuum or inert gas atmosphere, arc is generated between the consumable electrode and the striking arc material on the water-cooled copper crucible (which is the positive electrode of the direct current power supply), the consumable electrode is melted by means of the heat of the arc, and the melted electrode enters the crucible in a molten drop form to form a molten pool.

In step S200, ultrasonic waves are applied to the outer portion of the molten pool, and the outer portion of the molten pool is subjected to densification shrinkage by ultrasonic high-frequency vibration. Wherein the ultrasonic wave may be generated by an ultrasonic vibrator.

The ultrasonic wave can enable the outer side part of the molten pool to generate vertical vibration, and the arc-stabilizing electromagnetic induction coil can enable the molten pool to generate horizontal stirring, so that the outer side part of the molten pool can generate binary high-frequency micro-amplitude vibration brought by the cooperation of the ultrasonic wave and the molten pool, the microstructure of the outer side part of the molten pool is more uniform, the shrinkage and the tightening of a grain unit are realized, the porosity is lower, after the molten pool is cooled to form an ingot, the surface of the obtained ingot is more compact and complete, fewer inclusions and the porosity are lower, an oxide layer is thinner, and segregation is not easy to occur on the surface layer of the ingot, thereby improving the yield.

In one embodiment, the outer portion of the bath to which the ultrasonic wave is applied preferably ranges from the bath surface to a depth of 10 mm. The ultrasonic vibration effect is attenuated gradually with the increase of the penetration distance between the crucible and the surface of the ingot, and the ultrasonic wave is mainly used for eliminating defects and shortages on the surface of the ingot, so that defects in the ingot are fewer, and the action depth of the ultrasonic wave is not generally required to be enlarged.

Wherein, the surface porosity of the ingot is reduced by at least 50%, and the surface porosity of the ingot obtained by the consumable electrode smelting method of the embodiment is obviously reduced by more than half through observing the number of pores in the unit area of the ingot.

Because the air holes are obviously reduced, the cutting resistance of the cutter used for peeling the surface of the cast ingot is more uniform, so that the service life of the cutter for peeling the surface is prolonged, and the service life is prolonged by about 100 percent. The surface peeling tool used can be YG6S tungsten steel material or other materials.

As the air holes are reduced, the amount of unqualified surface layers is reduced, the peeling thickness is reduced, and the yield of the cast ingot is improved by 1.0-1.5%.

In addition, the consumable electrode melting method of this example has not found the segregation of the surface layer of the ingot.

Because of the reduction of pores and porosity, ingot oxidation only occurs at the superficial layer, resulting in a reduction of about 50% in oxide layer. In the prior art, the loose air holes on the surface can be completely removed only by peeling the surface by about 20mm on one side, and the consumable electrode smelting method in the embodiment is adopted only by peeling the surface by 9-11mm on one side.

In one embodiment, the frequency range of the ultrasonic wave can be 0-50Hz, the preferred frequency range of the ultrasonic wave is 38-45Hz, and the specific value can be flexibly selected according to the surface condition of the product ingot.

In one embodiment, the ultrasonic waves are generated by ultrasonic vibrators arranged in a cooling liquid layer outside the crucible, and the cooling liquid in the cooling liquid layer can be cooling water or other types of cooling liquid. The ultrasonic vibrator is arranged in the cooling liquid layer, so that the ultrasonic vibrator can be cooled, burning loss of the ultrasonic vibrator due to high-frequency vibration heating is avoided, and the temperature of the cooling liquid layer is required to be kept below 80 ℃. In addition, it is also necessary to ensure a gap between the ultrasonic vibrator and the outer surface of the crucible, and the required gap has a size ranging from 5 to 20mm, so as to prevent the ultrasonic vibrator from being damaged by hard collision with the crucible when vibrating.

The consumable electrode smelting apparatus in an embodiment of the second aspect of the invention will now be described with reference to figures 2 and 3 of the accompanying drawings.

In one embodiment, as shown in fig. 2, the consumable electrode melting apparatus of this embodiment includes an outer jacket 110, a crucible 120, a coolant layer 130, an array of vibrators, and an ultrasonic generator. The crucible 120 is typically a copper crucible 120 and is disposed in the outer jacket 110 for receiving the molten bath 100. The outer jacket 110 is typically formed of a steel material, although other materials having a relatively high structural strength are also possible. In use, the crucible 120 serves as the positive electrode of a DC power supply, and a consumable electrode is made of a metal material (e.g., titanium sponge, or titanium sponge with an alloying element added) and is clamped to an electrode rod to serve as the negative electrode of the DC power supply.

Wherein the cooling fluid layer 130 is disposed between the outer jacket 110 and the crucible 120 for cooling the molten bath 100 in the crucible 120, thereby cooling the molten bath 100 into an ingot 160. The cooling liquid in the cooling liquid layer 130 may be cooling water or other types of cooling liquid, the outer sleeve body 110 is provided with a liquid inlet 112 and a liquid outlet 114 which are communicated with the cooling liquid layer 130, and the cooling liquid in the cooling liquid layer 130 can circulate in and out, so that the ultrasonic vibrator 140 is always in a temperature field below 80 ℃, and the ultrasonic vibrator 140 is prevented from being damaged by high temperature.

The vibrator array includes a plurality of ultrasonic vibrators 140 distributed in the coolant layer 130, the ultrasonic vibrators 140 are used for generating ultrasonic waves acting on the outer portion of the molten pool 100, and the outer portion of the molten pool 100 is subjected to compactness contraction through ultrasonic high-frequency vibration.

The ultrasonic generator is electrically connected to the ultrasonic vibrator 140, and is used for controlling the ultrasonic vibrator 140 to vibrate.

When in use, the metal raw material to be smelted is firstly made into a consumable electrode and clamped on an electrode rod to be used as a negative electrode of a direct current power supply, wherein the metal raw material can be titanium sponge, titanium sponge added with alloy elements or other metal raw materials which can be smelted by adopting a consumable electrode smelting mode. Then, in a vacuum or inert gas atmosphere, arc is generated between the consumable electrode and the striking material on the water-cooled copper crucible 120 (which is the positive electrode of the direct current power supply), the consumable electrode is melted by the heat of the arc, and the melted electrode enters the crucible 120 in the form of molten drops, so as to form a molten pool 100.

Then, the ultrasonic generator is started, the ultrasonic vibrator 140 is controlled by the ultrasonic generator to emit ultrasonic waves with a set frequency, and the outer part of the molten pool 100 is contracted compactly by the ultrasonic high-frequency vibration.

The ultrasonic wave can make the outer part of the molten pool 100 vibrate vertically, and the arc-stabilizing electromagnetic induction coil can make the molten pool 100 stir horizontally, so that the outer part of the molten pool 100 can generate binary high-frequency micro-amplitude vibration brought by the two, so that the microstructure of the outer part of the molten pool 100 is more uniform, the shrinkage of a grain unit is more compact, the porosity is lower, after the molten pool 100 is cooled to form an ingot 160, the surface of the obtained ingot 160 is more compact and complete, fewer inclusions are included, the porosity is lower, an oxide layer is thinner, and segregation does not occur on the surface layer of the ingot 160, thereby improving the yield.

In one embodiment, the ultrasonic waves preferably range from the surface of the bath 100 to a depth of 10mm as an outer portion of the bath 100. Since the effect of ultrasonic vibration is attenuated gradually as the penetration distance between the crucible 120 and the surface of the ingot 160 increases, and the ultrasonic wave is mainly used to eliminate defects and shortages on the surface of the ingot 160, the defects inside the ingot 160 are small, and therefore, it is generally not necessary to enlarge the depth of action of the ultrasonic wave.

Wherein, the surface porosity of the ingot 160 is reduced by at least 50%, and the surface porosity of the ingot 160 obtained by the consumable electrode melting method of this embodiment is found to be significantly reduced by more than half by observing the number of pores per unit area of the ingot 160.

Because the pores are significantly reduced, the cutting resistance experienced by the tool used to strip the surface of the ingot 160 is more uniform, thereby extending the service life of the surface stripping tool and increasing the service life by about 100%. The surface peeling tool used can be YG6S tungsten steel material or other materials.

As the air holes are reduced, the amount of unqualified surface layers is reduced, the peeling thickness is reduced, and the yield of the cast ingot 160 is improved by 1.0-1.5%.

In addition, the consumable electrode melting method of this example has not been found to segregate the surface layer of the ingot 160.

Because of the reduction in porosity and porosity, oxidation of the ingot 160 occurs only in the superficial layers, resulting in a reduction in oxide layer of about 50%. In the prior art, the loose air holes on the surface can be completely removed only by peeling the surface by about 20mm on one side, and the consumable electrode smelting method in the embodiment is adopted only by peeling the surface by 9-11mm on one side.

In one embodiment, the frequency range of the ultrasonic wave may be 0-50Hz, wherein the preferred frequency range of the ultrasonic wave is 38-45Hz, and the specific value can be flexibly selected according to the surface condition of the product ingot 160.

In order to further protect the ultrasonic vibrator 140, in one embodiment, a gap is formed between the ultrasonic vibrator 140 and the crucible 120, and the size of the gap ranges from 5mm to 20mm, so that the ultrasonic vibrator 140 is prevented from being hard collided with the crucible 120 and damaged during vibration, and the service life of the ultrasonic vibrator 140 is prolonged. In addition, since the ultrasonic vibrator 140 is far from the melt pool 100, the ultrasonic vibrator 140 is closer to the crucible 120 than the arc stabilizing ring 150.

In one embodiment, as shown in fig. 2 and 3, the transducer array further includes a connection net 170, the connection net 170 is enclosed in a cylinder shape to wrap around the outside of the crucible 120, and the connection net 170 is used to connect and fix the plurality of ultrasonic transducers 140, so as to fix the ultrasonic transducers 140 at a desired position to form the transducer array. The connection net 170 may be a copper wire net, and the copper wire net is used to increase the service life and vibration effect of the ultrasonic vibrator 140 by utilizing the advantages of rust resistance, durability and good flexibility. In other embodiments, a stainless steel mesh or a high temperature resistant plastic mesh may also be used as the connection mesh 170.

In one embodiment, a plurality of ultrasonic vibrators 140 are arranged in the crystallization direction of the molten pool 100 in the cooling liquid layer 130 to form an array, and the arrangement is regular in such a manner that the ultrasonic vibrators 140 are uniformly arranged at equal intervals along the circumferential direction and the axial direction of the crucible 120, so that more molten pool 100 area can be uniformly covered, and in the formed array, 20-40 ultrasonic vibrators 140 are generally arranged per square meter.

Preferably, the ultrasonic vibrator 140 is in a size of 20mm in diameter, 15mm in length and 5W in power, and the ultrasonic vibrator 140 with the power has a small volume and a long service life, so that the ultrasonic vibrator 140 with different frequencies and power specifications can be selected according to the brand of the ingot 160 and the ratio requirements of different alloys, but the size of the ultrasonic vibrator 140 cannot be too large because the space of the cooling liquid layer 130 outside the crucible 120 is limited, otherwise the ultrasonic vibrator 140 is difficult to arrange.

In one of the embodiments, the consumable electrode melting apparatus of the present embodiment is capable of performing the consumable electrode melting method of the first aspect embodiment described above.

It will be apparent to those skilled in the art that various modifications and variations can be made to the present invention without departing from the spirit or scope of the invention. Thus, it is intended that the present invention also include such modifications and alterations insofar as they come within the scope of the appended claims or the equivalents thereof.

Claims

1. A consumable electrode melting process comprising:

smelting to generate a molten pool;

2. The consumable electrode smelting process according to claim 1, wherein the outer portion of the molten bath to which the ultrasonic waves act ranges from the surface of the molten bath to a depth of 10 mm.

3. The consumable electrode melting process of claim 1 wherein the ultrasonic waves have a frequency in the range of 38-45Hz.

4. The consumable electrode melting method of claim 1 wherein the ultrasonic waves are generated by ultrasonic vibrators disposed in a coolant layer outside the crucible.

5. A consumable electrode melting apparatus comprising:

an outer sleeve;

6. The consumable electrode melting apparatus of claim 5 wherein the outer portion of the ultrasonically active molten bath ranges from the bath surface to a depth of 10 mm.

7. The consumable electrode melting apparatus of claim 5 wherein the ultrasonic vibrator produces a frequency in the range of 38-45Hz.

8. The consumable electrode melting apparatus of claim 5 wherein there is a gap between the ultrasonic vibrator and the crucible, the gap having a size in the range of 5-20mm.

9. The consumable electrode melting apparatus of claim 5 wherein the array of transducers further comprises a connecting net for connecting and securing a plurality of the ultrasonic transducers.

10. The consumable electrode melting apparatus according to any one of claims 5 to 9 wherein a plurality of the ultrasonic vibrators are spaced apart in the crystal direction of the molten pool within the coolant layer.