CN105132705A - Method and device for remelting and refining metals by vacuum magnetic-control arc - Google Patents

Abstract

The invention discloses a method and device for vacuum magnetron arc remelting and refining metal. A magnetic field generator is applied at the end of the vacuum arc remelting electrode and the periphery of the metal molten pool to provide an axial magnetic field. The magnetic field generator consists of two sets of same The core coil is composed of DC current and AC current respectively, and the stable magnetic field component generated by the DC current inhibits the charged particles moving in the radial direction, delays the phenomenon of ion poverty between the electrodes and the generation of anode spots, and reduces the arc voltage and Arc energy, to prevent the formation of concentrated arc for remelting, resulting in excessive local temperature of the electrode and severe melting and vaporization, which will affect the metallurgical quality. At the same time, the alternating magnetic field component generated by the alternating current can form a certain pressure gradient in the molten metal pool, and generate pressure waves to break dendrites. In addition, there will always be a certain angle between the alternating magnetic field and the DC arc current, so a certain oscillating Lorentz force will be formed, which will help break dendrites, refine solidified structures, and reduce ingot segregation.

Description

Method and device for vacuum magnetron arc remelting and refining metal

technical field

The invention relates to an out-of-furnace refining method and device, in particular to a method and device for secondary refining of electromagnetic metallurgy, which are applied in the technical fields of electromagnetic metallurgical preparation of metal materials and quality control of metal materials.

Background technique

The traditional vacuum arc remelting process is to quickly melt the metal electrode rod prepared by the common smelting method through the high temperature of the DC arc under the condition of slag-free vacuum and then re-solidify it in the water-cooled copper mold crystallizer. When the liquid metal forms a droplet in the form of a thin layer and passes through the arc region of nearly 5000K to the crystallizer and solidifies, a series of physical and chemical reactions occur. The melting under vacuum and slag-free conditions eliminates external air and slag, etc. The pollution of steel and alloy can also reduce the gas and low melting point harmful metal impurities in steel and alloy, and improve the cleanliness of remelted metal. The vacuum arc remelting process can effectively reduce hydrogen, lead, bismuth, silver in metal and other content, and has a certain denitrification ability. Under the condition of extremely low oxygen partial pressure in the melting chamber, the burning loss of active elements such as aluminum and titanium is small during the remelting process. Due to the high temperature in the arc zone, refractory alloys can be smelted. As an ideal secondary refining technology for special materials, during the vacuum arc remelting process, the sequential solidification of the molten metal from bottom to top and the fast speed make the regenerated inclusions in the solidification process small in size and evenly distributed. Through reasonable control of the solidification and crystallization process of the alloy, the solidification structure of the alloy can be improved, and a high-quality ingot with low segregation degree and high density can be obtained.

Vacuum arc remelting is one of the key technologies for smelting special materials such as high-temperature alloys that are easy to segregate and refractory, and has been widely used in industrial production. However, there are still some deficiencies in the traditional vacuum arc remelting. Because the arc remelting generated under vacuum conditions can be divided into two types according to the shape: diffuse vacuum arc and concentrated vacuum arc, the former mainly appears in the process of low current, and the latter The latter occurs under higher current conditions. According to relevant theories, the generation of vacuum arc is mainly caused by the emission of electrons and the generation of metal vapor by the spots formed on the cathode. The electrons collide with the metal vapor to generate new electrons and positive ions, thus forming arc plasma. The charged particles in the vacuum arc column move towards the anode. Diffusion will occur in the middle, thus forming a conical arc column with a cone apex angle of 60 degrees. As the current increases, the number of cathode spots increases, the adjacent cones overlap, and the increasing number of particles bombards the anode, causing the surface temperature to rise rapidly and produce anode spots, thereby ejecting positively charged metal vapor and positive ions, making the vacuum The charged particles in the arc column increase sharply, the conductivity increases, and the arc column voltage of the arc column where the anode spot is located drops, causing the arc column voltage corresponding to the other cathode spots to be extinguished, leaving only the surface of the cathode directly opposite to the anode spot. The cathode spot, thus forming a concentrated vacuum arc. The concentrating vacuum arc makes the surface of the anode and cathode heat up violently locally, resulting in serious melting and vaporization, serious loss of alloy composition and serious impact on metallurgical quality. Superalloys represented by nickel-based superalloys have complex chemical compositions, and the control of the composition content is very strict. Therefore, how to strengthen the prevention of concentrated vacuum arc during the remelting process and further improve the metallurgical quality is still a technical problem to be solved urgently in the vacuum arc remelting process.

Contents of the invention

In order to solve the problems of the prior art, the object of the present invention is to overcome the deficiencies of the prior art, and provide a method and device for vacuum magnetron arc remelting and refining metal, which is especially suitable for high-efficiency secondary refining of superalloys, and can effectively improve the quality of superalloys. The refining effect and reduce ingot segregation. Due to the excessive divergence of the arc in the traditional vacuum arc remelting process, resulting in the lack of ions between the electrodes, the arc voltage and arc energy rise sharply, and the formation of anode spots is induced to form a concentrated vacuum arc, which makes the surface temperature of the electrode uneven and local heating. Severe, resulting in severe melting and vaporization, serious loss of alloy composition and great impact on metallurgical quality. After the present invention adds a stable and constant magnetic field, the vacuum arc current is subjected to the Lorentz force to suppress the radially moving charged particles, which plays a role in stabilizing the arc, delays the phenomenon of ion poverty between electrodes and the generation of anode spots, and avoids the formation of agglomeration The "overburning" phenomenon in which the local temperature of the electrode is too high due to the vacuum arc. In addition, the invention also produces electromagnetic extrusion on the molten metal pool through an external alternating magnetic field, effectively breaks the dendrites, and plays a role in grain refinement, which is beneficial to the homogenization of the chemical composition of the alloy and reduces the segregation of the ingot.

In order to achieve the above-mentioned invention creation purpose, the present invention is conceived as follows:

A magnetic field generator is applied to the periphery of the vacuum arc remelting water-cooled copper mold crystallizer to provide a magnetic field, and the interaction between the magnetic field and the current is used to generate the Lorentz force. The stable and constant magnetic field can effectively avoid the phenomenon of electrode "overburning" caused by the formation of a concentrated vacuum arc. The invention also induces an induced current in the metal melt through an alternating magnetic field, and forms an electromagnetic extrusion effect on the metal melt through the electromagnetic force, which is beneficial to breaking dendrites, refining metal solidification structure, and reducing ingot segregation.

According to above-mentioned inventive concept, the present invention adopts following technical scheme:

A method for vacuum magnetron arc remelting and refining metal, using a vacuum arc remelting device, using metal electrode rods to be remelted and refined as self-consumable electrodes, and setting a magnetic field generator around the vacuum arc remelting device to control the generation of the magnetic field The device provides a magnetic field to the vacuum arc remelting device, so that the bottom end area of the consumable electrode, the metal molten pool position area in the mold, and the area between the bottom of the consumable electrode and the metal molten pool in the mold are all under the action of the magnetic field , including the following steps:

a. Install the metal electrode rod to be refined into the vacuum chamber of the vacuum arc remelting device, and place a layer of metal pad with the same composition as the metal electrode rod to be refined at the bottom of the inner cavity of the crystallizer set in the vacuum arc remelting device The vacuum arc remelting device is connected with an external vacuum pump to evacuate the vacuum chamber into a vacuum, and the magnetic field generator is adjusted to provide a magnetic field to complete the preparation for vacuum arc remelting;

b. After completing the preparatory work for vacuum arc remelting in step a, drive the metal electrode rod down through the electrode feeding mechanism of the vacuum arc remelting device, and make the bottom of the metal electrode rod and the pre-laid bottom of the inner cavity of the crystallizer The metal pad is triggered, an arc is generated, and vacuum arc remelting begins;

c. After step b vacuum arc remelting starts, in the follow-up process of vacuum arc remelting of metal electrode rods, by adjusting the relative position between the magnetic field action area, metal electrode rods and remelting ingots, keep the metal electrode rods The melting zone, the arc zone and the solid-liquid interface of the remelting ingot are all located in the area where the magnetic field acts. At the same time, the arc melting current and the feeding speed of the metal electrode rod are controlled to generate a stable arc at the bottom end of the metal electrode rod to keep the metal electrode rod continuously Melting, with the continuous melting of the metal electrode rod and the continuous upward growth of the remelted ingot, the area of the magnetic field is gradually moved up, and the melting process of the metal electrode rod and the solidification process of the remelted ingot are always under the action of the magnetic field until the completion of the vacuum arc. The melting process is to obtain the vacuum arc remelting ingot.

As a preferred technical solution of the present invention, the magnetic field generator provides a magnetic field with a magnetic induction intensity of 0.01-30T, and the magnetic field generator can generate any one of a constant magnetic field, an alternating magnetic field with a frequency of 0.01-10000 Hz and a pulsed magnetic field with a frequency of 0.01-10000 Hz. A magnetic field or a mixed magnetic field of any several magnetic field components, the direction of the magnetic field and the axial direction of the metal electrode rod form an angle of 0 to 180 degrees.

As a preferred technical solution among the above technical solutions, the magnetic field generator generates a magnetic field using any of the following methods or a combination of any of several methods: one is to use permanent magnets to gather magnetism, and the other is to use electromagnetic Coils, electromagnets or iron yokes generate magnetic fields, and another type uses superconducting coils and Bitter coils alone or in combination.

As the preferred technical solution among the above-mentioned technical solutions, the magnetic field generator is composed of two sets of concentric coils, which pass DC current and AC current respectively into the coils, and the two sets of concentric coils simultaneously provide secondary magnetic field lines along the axial direction of the metal electrode rod. The stable and constant magnetic field and axial alternating magnetic field, by controlling the magnetic field strength, use the oscillating Lorentz force generated by electromagnetic interaction to electromagnetically stir the molten metal pool on the top of the remelting ingot, and refine the solidification structure of the remelting ingot.

As a preferred technical solution among the above technical solutions, the material of the metal electrode rod to be remelted and refined is any active metal among titanium, zirconium, molybdenum and tungsten or an alloy of any several metals.

As a preferred technical solution among the above technical solutions, the material of the metal electrode rod to be remelted and refined is heat-resistant steel, stainless steel, tool steel or bearing steel.

The present invention also provides a vacuum arc remelting device, which includes an electrode feeding mechanism, a vacuum cover, an air extraction hole, a water-cooled copper mold crystallizer, a crystallizer cooling water jacket device and a power supply, and the vacuum cover is used as the outer shell of the vacuum arc remelting device to seal A vacuum chamber is formed, and the pumping hole is set on the vacuum cover. The vacuum chamber is connected to the vacuum pump through the pumping hole. During the metal remelting process, the vacuum chamber is continuously evacuated, and the metal electrode rod to be remelted and refined is installed in the vacuum chamber as a consumable electrode. The bottom fixed end of the electrode feeding mechanism in the room, the metal electrode rod is controlled by the electrode feeding mechanism for position control and lifting speed control, the crystallizer cooling water jacket device is installed around the outer wall of the water-cooled copper mold crystallizer, and the crystallizer cooling water jacket device is set There are water inlet and outlet for circulating water, the water inlet is connected to the water source of circulating water, and the water outlet is connected to the external water tank. The wall of the water-cooled copper mold crystallizer is cooled by circulating water. In the water-cooled copper mold crystallizer, after the metal electrode rod is melted The molten metal formed by dripping solidifies to form a remelting ingot. The positive and negative electrodes of the power supply are electrically connected to the metal electrode rod and the wall of the water-cooled copper mold crystallizer respectively, so that the arc melting process is carried out in a vacuum chamber, and the electrode is sent to the mechanism through the control. And the power supply keeps the arc in the vacuum chamber stable, and a magnetic field generator is installed on the periphery of the vacuum cover to form a vacuum magnetron arc remelting system. The metal melt position area in the mold crystallizer and the arc generation area between the bottom of the metal electrode rod and the metal molten pool in the water-cooled copper mold mold are all under the action of a magnetic field. A layer of metal gasket with the same composition as the metal electrode rod to be refined is placed at the bottom of the inner cavity, and the metal electrode rod is driven down by the electrode feeding mechanism, and the bottom end of the metal electrode rod is connected to the bottom of the inner cavity of the water-cooled copper mold crystallizer. The pre-laid metal pad is triggered to generate an arc, and the vacuum arc remelting starts. During the subsequent vacuum arc remelting process, the relative position of the magnetic field action area, the metal electrode rod and the remelting ingot is adjusted to maintain the metal electrode rod. The melting zone, the arc zone, and the solid-liquid interface at the top of the remelting ingot are all located in the area where the magnetic field acts. At the same time, the arc melting current output by the power supply and the feeding speed of the metal electrode rod are controlled to generate a stable arc at the bottom end of the metal electrode rod. The electrode rod continues to melt, and with the continuous melting of the metal electrode rod and the continuous upward growth of the remelted ingot, the magnetic field action area gradually moves up, keeping the metal electrode rod melting process and the remelting ingot solidification process always under the action of the magnetic field for vacuum arcing remelting process.

As a preferred technical solution among the above technical solutions, the magnetic field generator uses permanent magnets to generate magnetic fields, or uses electromagnetic coils, electromagnets or iron yokes to generate magnetic fields, or uses superconducting coils and Bitter coils to generate magnetic fields individually or in combination.

As the preferred technical solution among the above-mentioned technical solutions, the magnetic field generator is composed of two sets of concentric coils, which pass DC current and AC current respectively into the coils, and the two sets of concentric coils simultaneously provide secondary magnetic field lines along the axial direction of the metal electrode rod. The stable and constant magnetic field and the axial alternating magnetic field, by adjusting the magnetic field generator to control the magnetic field strength, using the oscillating Lorentz force generated by electromagnetic interaction to electromagnetically stir the molten metal pool on the top of the remelting ingot, refine the remelting ingot primary coagulated tissue.

As a preferred technical solution among the above technical solutions, the power supply adopts a voltage-regulated DC power supply to provide DC current for the vacuum arc remelting process.

Compared with the prior art, the present invention has the following obvious outstanding substantive features and significant advantages:

1. Compared with the traditional vacuum arc remelting process, the present invention controls the vacuum arc remelting through an external magnetic field, wherein the mixed magnetic field is used to control the stable magnetic field component of the vacuum arc remelting, which can stabilize the arc and prevent excessive divergence or excessive accumulation of the arc, and then It delays the generation of ion deficiency and anode spots between electrodes, and avoids the "overburning" phenomenon caused by the formation of concentrated vacuum arcs that cause excessive local temperature of electrodes, thereby effectively inhibiting local melting and vaporization of metal electrodes, preventing serious loss of alloy components and metallurgical quality is affected;

2. In the vacuum arc remelting process of the present invention, the arc length is an important parameter affecting the remelting and refining effect. It not only determines the electrical parameters of the power supply circuit, but also determines the melting rate of the metal electrode. Under the premise of maintaining the stability of the arc, proper Short arc remelting is beneficial to improve remelting efficiency, reduce energy consumption, and reduce arc fluctuations, thereby improving the quality of remelted ingots. causing a short circuit;

3. The present invention acts on the arc remelting process by adding a mixed magnetic field, in which the alternating magnetic field component induces an induced current in the molten droplet to form a squeezing effect on the molten droplet, and uses the principle of electromagnetic induction to form an electromagnetic excitation effect on the molten droplet , promote the dripping of molten droplets, prevent the aggregation of large molten droplets and realize short-arc melting, improve the refining effect and reduce energy consumption;

4. The alternating magnetic field component in the external mixed magnetic field of the present invention can induce an induced current in the molten metal, and the electromagnetic force generated by the electromagnetic recombination will form an electromagnetic extrusion effect on the molten metal, effectively breaking the dendrites and refining the solidification of the metal structure, accelerate heat transfer in molten pool, and reduce ingot segregation.

Description of drawings

Fig. 1 is a schematic structural view of a vacuum arc remelting device in a preferred embodiment of the present invention.

Fig. 2 is a schematic diagram of the shape of the vacuum arc before and after applying a magnetic field when the arc disperses outward in the preferred embodiment of the present invention.

Fig. 3 is a schematic diagram of the shape of the vacuum arc before and after applying a magnetic field when the arc is excessively concentrated in a preferred embodiment of the present invention.

Fig. 4 is a schematic diagram of the solidification principle of the longitudinal section of the ingot in the preferred embodiment of the present invention when the external mixed magnetic field acts on the fine grain of the metal melt.

Fig. 5 is a view along the direction A-A in Fig. 4 .

Detailed ways

Preferred embodiments of the present invention are described in detail as follows:

In this embodiment, referring to Figures 1 to 5, a vacuum arc remelting device includes an electrode feeding mechanism 1, a vacuum cover 2, an air extraction hole 4, a water-cooled copper mold crystallizer 6, a crystallizer cooling water jacket device and Power supply 11, the power supply 11 adopts a voltage-regulated DC power supply, and the vacuum cover 2 is used as the outer shell of the vacuum arc remelting device to form a vacuum chamber 3. The air extraction hole 4 is arranged on the vacuum cover 2. During the remelting process, the vacuum chamber 3 is continuously evacuated, and the metal electrode rod 5 to be remelted and refined is installed on the bottom fixed end of the electrode feeding mechanism 1 in the vacuum chamber 3 as a consumable electrode, and the metal electrode rod 5 passes through the electrode The feeding mechanism 1 performs position control and lifting speed control. The inner diameter of the water-cooled copper mold crystallizer 6 is Φ500mm. The crystallizer cooling water jacket device is installed around the outer wall of the water-cooled copper mold crystallizer 6. The crystallizer cooling water jacket device is equipped with circulating water. The water inlet 9 and the water outlet 10, the water inlet 9 is connected to the water source of the circulating water, and the water outlet 10 is connected to the external water tank, and the wall of the water-cooled copper mold crystallizer 6 is cooled by the circulating water. In the water-cooled copper mold crystallizer 6, the metal electrode rod 5. The molten metal formed by dripping after melting solidifies to form a remelting ingot 8. The positive pole and negative pole of the power supply 11 are electrically connected to the metal electrode rod 5 and the wall of the water-cooled copper mold crystallizer 6 respectively by cables, so that the arc melting process is in the vacuum chamber 3 To carry out, the electric arc 12 generated in the vacuum chamber 3 is kept stable by controlling the electrode feeding mechanism 1 and the power supply 11, and a magnetic field generator 7 is arranged on the periphery of the vacuum cover 2 to form a vacuum magnetron arc remelting system, and the magnetic field generator 7 is controlled to the vacuum A magnetic field is applied in the arc remelting device, so that the metal electrode rod 5 bottom end area, the metal melt position area in the water-cooled copper mold crystallizer 6, and the metal molten pool between the bottom of the metal electrode rod 5 and the water-cooled copper mold crystallizer 6 The arc generation area is all under the action of the magnetic field. When vacuum arc melting is performed, a layer of metal gasket with the same composition as the metal electrode rod 5 to be refined is placed on the bottom of the inner cavity of the water-cooled copper mold crystallizer 6 in advance, and is fed through the electrode. Mechanism 1 drives the metal electrode rod 5 to descend, and triggers the bottom end of the metal electrode rod 5 and the pre-laid metal pad at the bottom of the inner cavity of the water-cooled copper mold crystallizer 6 to generate an arc 12 and start vacuum arc remelting. During the remelting process, by adjusting the relative position between the magnetic field action area, the metal electrode rod 5 and the remelting ingot 8, the melting zone, the arc region of the metal electrode rod 5 and the solid-liquid interface at the top of the remelting ingot 8 are all located in the magnetic field. In the region, the arc melting current output by the power supply 11 and the feeding speed of the metal electrode rod 5 are simultaneously controlled to generate a stable arc 12 at the bottom end of the metal electrode rod 5, and the metal electrode rod 5 is continuously melted. The melting and remelting ingot 8 is continuously growing upwards, so that the magnetic field action area gradually moves upwards, and the melting process of the metal electrode rod 5 and the solidification process of the remelting ingot 8 are always under the action of the magnetic field to carry out the vacuum arc remelting process.

In this embodiment, referring to Fig. 1 to Fig. 5, the magnetic field generator 7 is composed of two groups of concentric coils, which pass DC current and AC current respectively into the coils, and the two groups of concentric coils simultaneously provide the direction of the secondary magnetic force line along the metal The axial constant magnetic field and the axial alternating magnetic field of the electrode rod 5 are controlled by adjusting the magnetic field generator 7 to control the magnetic field intensity, and the oscillating Lorentz force 15 generated by electromagnetic interaction is used to electromagnetically conduct the molten metal pool on the top of the remelting ingot 8 . Stir to refine the primary solidified structure of the remelted ingot 8. During the arc remelting process, an axially constant magnetic field and an alternating magnetic field are applied to the periphery of the crystallizer at the same time, and the combined effect of the magnetic field and the current is used to stabilize the arc 12, avoiding the formation of a concentrated vacuum arc and causing "overburning" "Phenomenon, it forms an electromagnetic extrusion effect on the molten metal pool, effectively breaks dendrites, refines the solidified structure, reduces ingot segregation, and improves the secondary refining effect. In this embodiment, by controlling the intensity of the magnetic field, the generation of concentrated electric arcs is suppressed, and the dendrites are broken by using the electromagnetic extrusion effect, so as to refine the solidified structure of the remelted ingot.

In this embodiment, referring to Fig. 1 to Fig. 5, a method for vacuum magnetron arc remelting and refining metal, adopting the vacuum arc remelting device of this embodiment, and using the GCr15 bearing steel to be remelted and refined as the consumable electrode The material is to cast GCr15 bearing steel into a metal electrode rod 5 with a diameter of 300 mm and a length of 1000 mm to keep the arc generated in the vacuum arc remelting device stable, and set a magnetic field generator 7 around the vacuum arc remelting device to control the magnetic field generator 7 Apply a magnetic field to the vacuum arc remelting device, so that the metal electrode rod 5 bottom end area, the metal molten pool position area in the water-cooled copper mold crystallizer 6, and the metal at the bottom of the water-cooled copper mold crystallizer 6 and in the water-cooled copper mold crystallizer 6 The areas between the molten pools are all under the action of a magnetic field, which specifically includes the following steps:

a. Install the metal electrode rod 5 to be refined in the vacuum chamber 3 of the vacuum arc remelting device, place a layer at the bottom of the cavity of the water-cooled copper mold crystallizer 6 provided in the vacuum arc remelting device and the metal to be refined The GCr15 bearing steel gasket with the same composition as the electrode rod 5 is used to evacuate the vacuum chamber 3 into a vacuum through the vacuum pump hole of the vacuum arc remelting device, and the vacuum chamber 3 is evacuated, and the cooling water is introduced from the water inlet 9, and the upper end of the metal electrode rod 5 and the water-cooled copper mold The crystallizer 6 connects the positive pole and the negative pole of the power supply 11 with cables respectively, and passes direct current and alternating current to the two groups of concentric coils in the magnetic field generator 7 respectively, so that the two groups of coils generate the axially constant magnetic field and the alternating magnetic field respectively at the same time, Adjust the magnitude of the current to produce a steady magnetic induction of 0.5T, an alternating magnetic field of 0.8T, and a direction parallel to the axial direction of the metal electrode rod 5 to be refined to complete the preparation for vacuum arc remelting;

b. After completing the preparatory work for vacuum arc remelting in step a, the metal electrode rod 5 is driven down by the electrode feeding mechanism 1 of the vacuum arc remelting device, and the bottom of the metal electrode rod 5 is connected to the water-cooled copper mold crystallizer 6 The pre-laid GCr15 bearing steel pad at the bottom of the inner cavity is triggered to generate an arc and start vacuum arc remelting;

c. after step b vacuum arc remelting starts, in the follow-up process of vacuum arc remelting of the metal electrode rod 5, by adjusting the relative position between the magnetic field action area, the metal electrode rod and the remelting ingot, so that the to-be-refined The melting zone, arc zone, and solid-liquid interface at the top of the remelted ingot 8 of the metal electrode rod 5 of GCr15 bearing steel are all located in the magnetic field action area, and the electric arc melting current and the feeding speed of the metal electrode rod 5 are controlled at the same time. A stable arc is generated at the bottom end to continuously melt the metal electrode rod 5 and control the magnetic field strength. With the continuous melting of the metal electrode rod 5 and the continuous upward growth of the remelted ingot, the magnetic field action area is gradually moved up to keep the metal electrode rod 5 melted The process and the solidification process of the remelting ingot are always under the action of the magnetic field. When the arc remelting ends, turn off the power supply 11; when the solidification ends, turn off the magnetic field generator 7, and when the remelting ingot 8 is completely cooled, turn off the water inlet 9 And the water outlet 10, take out the remelting ingot 8 from the water-cooled copper mold crystallizer 6, you can get the GCr15 bearing steel vacuum arc remelting ingot with high purity, low segregation degree and grain refinement.

Adopt the method for refining superalloy of the present invention, apply a magnetic field generator 7 on the periphery of the crystallizer, apply the axial constant magnetic field and the axial alternating magnetic field at the periphery of the water-cooled copper mold crystallizer 6 at the same time, the magnetic field lines 13 that the constant magnetic field produces can be The vacuum arc 12 is constrained to avoid arc divergence. As shown in Figures 2 to 5, when no magnetic field is applied, charged particles tend to diverge radially outward or excessively concentrate inward in the vacuum arc, which will lead to the appearance of concentrated arcs and serious damage to metal elements. "Burning loss" is due to the action of Lorentz force in the steady magnetic field, which forces the trajectory of charged particles to change, so that they fly to the metal melt in a spiral trajectory, so that the arc 12 is relatively stable and evenly dispersed in the metal Between the electrode rod 5 and the metal melt. At the same time, the magnetic force lines 18 generated by the alternating magnetic field can induce an induced current 14 in the molten metal, and the induced current 14 interacts with the magnetic force lines 13 generated by the steady magnetic field to generate an overall centripetal alternating Lorentz force 15. Under the vibration of the variable Lorentz force 15, a pressure wave 16 is generated in the metal melt 8, and under the combined action of the alternating Lorentz force 15 and the pressure wave 16, the growing dendrite 17 at the front of the solidification interface of the metal melt is broken. The stable magnetic field component generated by the direct current in the coil of this embodiment inhibits the charged particles moving in the radial direction, delays the ion impoverishment phenomenon between the electrodes and the generation of anode spots, reduces the arc voltage and arc energy, and prevents the formation of agglomeration The remelting of the arc causes the local temperature of the electrode to be too high, resulting in severe melting and vaporization, which affects the metallurgical quality. At the same time, the alternating magnetic field generated by the alternating current in the coil can form a certain pressure gradient in the molten metal pool, and generate pressure waves to break dendrites. In addition, there is always a certain angle between the alternating magnetic field and the DC arc current, so a certain oscillating Lorentz force15 will be formed, which will help break up dendrites, refine solidified structures, and reduce ingot segregation.

The embodiments of the present invention have been described above in conjunction with the accompanying drawings, but the present invention is not limited to the above-mentioned embodiments, and various changes can also be made according to the purpose of the invention of the present invention. The changes, modifications, substitutions, combinations or simplifications should be equivalent replacement methods, as long as they meet the purpose of the invention, as long as they do not deviate from the technical principles and inventions of the method and device for vacuum magnetron arc remelting and refining metals of the present invention design, all belong to the protection scope of the present invention.

Claims (10)

1. the method for a vacuum magnetic control electric arc remelting refining metal, adopt vacuum electric arc remelting apparatus, to treat that the metal electrode bar of remelting refining is as consumable electrode, it is characterized in that, in vacuum electric arc remelting apparatus periphery, magnetic field generator is set, controlling magnetic field producer provides magnetic field to vacuum electric arc remelting apparatus, to make bottom the metal pool band of position in consumable electrode bottom end region, crystallizer and consumable electrode and between the metal pool in crystallizer, region is all under the action of a magnetic field, specifically comprise the steps:

A. will treat that the metal electrode bar of refining is installed in the vacuum chamber of vacuum electric arc remelting apparatus, place one deck bottom the crystallizer internal cavity arranged in vacuum electric arc remelting apparatus and the metallic pack-ing that the metal electrode bar composition of refining is identical will be treated, by the aspirating hole of vacuum electric arc remelting apparatus external vacuum pump, vacuum chamber is evacuated, regulate magnetic field generator to provide magnetic field, complete the preparation work of vacuum arc remelting;

B. after the preparation work of vacuum arc remelting completing described step a, metal electrode bar is driven to decline by the electrode feed mechanism of vacuum electric arc remelting apparatus, and the metallic pack-ing that in the bottom of metal electrode bar and crystallizer internal cavity, bottom is laid in advance is triggered, produce electric arc, start vacuum arc remelting;

C. after described step b vacuum arc remelting starts, in the subsequent process of the vacuum arc remelting of metal electrode bar, by adjustment the action of a magnetic field region, relative position between metal electrode bar and resmelting ingot, keep the melting area of metal electrode bar, the solid-liquid interface of arc district and resmelting ingot is all arranged in the action of a magnetic field region, control arc melting electric current and metal electrode bar feed rate simultaneously, bottom metal electrode bar, termination produces stable electric arc, metal electrode bar is continued fusing, constantly to melt along with metal electrode bar and resmelting ingot constantly upwards grows, make the action of a magnetic field region gradually on move, metal electrode bar melting process and resmelting ingot process of setting is kept to be in all the time under the action of a magnetic field, until complete vacuum arc remelting process, namely vacuum arc remelting ingot is obtained.

2. the method for vacuum magnetic control electric arc remelting refining metal according to claim 1, it is characterized in that: magnetic field generator provides magnetic induction density to be the magnetic field of 0.01 ~ 30T, the alternating magnetic field that magnetic field generator can produce stationary magnetic field, frequency is 0.01 ~ 10000Hz and frequency are the mixed magnetic field of any one magnetic field in the pulsed magnetic field of 0.01 ~ 10000Hz or any several magnetic field components, and field direction and metal electrode bar axial direction due are the angle of 0 ~ 180 degree.

3. the method for vacuum magnetic control electric arc remelting refining metal according to claim 2, it is characterized in that, the mode that magnetic field generator produces magnetic field adopts the combined method of any one method following or any several method: one adopts permanent magnet to gather magnetic mode to produce, also have one to be adopt solenoid, electro-magnet or iron yoke to produce magnetic field, separately have one be adopt superconducting coil and Bitter coil separately or mixing produce.

4. according to the method for vacuum magnetic control electric arc remelting refining metal described in any one in claims 1 to 3, it is characterized in that: magnetic field generator forms with core coil by two groups, respectively to galvanic current logical in coil and alternating current, two groups provide time magnetic line of force direction to be steady magnetic field along metal electrode bar axis and axial alternating magnetic field with core coil simultaneously, by controlling magnetic field intensity, the concussion lorentz's force utilizing electromagnetic interaction to produce carries out induction stirring to the metal pool at resmelting ingot top, the solidified structure of refinement resmelting ingot.

5., according to the method for vacuum magnetic control electric arc remelting refining metal described in any one in claims 1 to 3, it is characterized in that: described in treat that the material of the metal electrode bar of remelting refining is the alloy of any one active metal in titanium, zirconium, molybdenum and tungsten or any several metal.

6., according to the method for vacuum magnetic control electric arc remelting refining metal described in any one in claims 1 to 3, it is characterized in that: described in treat that the material of the metal electrode bar of remelting refining is high temperature steel, stainless steel, tool steel or bearing steel.

7. a vacuum electric arc remelting apparatus, comprise electrode feed mechanism (1), vacuum (-tight) housing (2), aspirating hole (4), water cooled copper mould crystallizer (6), cooling water jacket of crystallizer device and power supply (11), described vacuum (-tight) housing (2) becomes vacuum chamber (3) as the shell closed of vacuum electric arc remelting apparatus, described aspirating hole (4) is arranged on vacuum (-tight) housing (2), vacuum chamber (3) connects vacuum pump by aspirating hole (4), in For Remelting Metals process, vacuum chamber (3) is continued to vacuumize, to treat that the metal electrode bar (5) of remelting refining is installed on the bottom inboardend of the electrode feed mechanism (1) in vacuum chamber (3) as consumable electrode, metal electrode bar (5) carries out position control by described electrode feed mechanism (1) and rising or falling speed controls, described cooling water jacket of crystallizer device is arranged at described water cooled copper mould crystallizer (6) outer wall surrounding, described cooling water jacket of crystallizer device is provided with water-in (9) and the water outlet (10) of recirculated water, described water-in (9) connects the water source of recirculated water, described water outlet (10) connects outer water trough, by recirculated water, described water cooled copper mould crystallizer (6) wall is cooled, in described water cooled copper mould crystallizer (6), the molten metal that after metal electrode bar (5) fusing, drippage is formed solidifies and forms resmelting ingot (8), the positive pole of described power supply (11) and negative pole to conduct electricity with described metal electrode bar (5) and described water cooled copper mould crystallizer (6) wall with cable respectively and are connected, arc melting process is in vacuum chamber (3) carry out, it is characterized in that: keep vacuum chamber (3) interior electric arc (12) to stablize by control electrode feed mechanism (1) and power supply (11), and magnetic field generator (7) formation vacuum magnetic control electric arc remelting system is set in vacuum (-tight) housing (2) periphery, control described magnetic field generator (7) and apply magnetic field in vacuum electric arc remelting apparatus, make metal electrode bar (5) bottom end region, the metal melt band of position in water cooled copper mould crystallizer (6) and metal electrode bar (5) bottom and water cooled copper mould crystallizer (6) in metal pool between electric arc formation zone be all under the action of a magnetic field, when carrying out vacuum arc melting, in water cooled copper mould crystallizer (6) inner chamber, bottom is placed one deck and will be treated the metallic pack-ing that metal electrode bar (5) composition of refining is identical in advance, metal electrode bar (5) is driven to decline by electrode feed mechanism (1), and the metallic pack-ing that in metal electrode bar (5) bottom end and water cooled copper mould crystallizer (6) inner chamber, bottom is laid in advance is triggered, produce electric arc (12), start vacuum arc remelting, in follow-up vacuum arc remelting process, by adjustment the action of a magnetic field region, relative position between metal electrode bar (5) and resmelting ingot (8), keep the melting area of metal electrode bar (5), arc district and resmelting ingot (8) top solid-liquid interface are all arranged in the action of a magnetic field region, control arc melting electric current that power supply (11) exports and metal electrode bar (5) feed rate simultaneously, stable electric arc (12) is produced in termination, metal electrode bar (5) bottom, metal electrode bar (5) is continued fusing, along with metal electrode bar (5), constantly fusing and resmelting ingot (8) constantly upwards grow, make the action of a magnetic field region gradually on move, keep metal electrode bar (5) melting process and resmelting ingot (8) process of setting to be in all the time under the action of a magnetic field and carry out vacuum arc remelting process.

8. vacuum electric arc remelting apparatus according to claim 7, it is characterized in that: described magnetic field generator (7) adopts permanent magnet to gather magnetic mode and produces magnetic field, or adopt solenoid, electro-magnet or iron yoke to produce magnetic field, or adopt superconducting coil and Bitter coil separately or mixing produce magnetic field.

9. vacuum electric arc remelting apparatus according to claim 8, it is characterized in that: described magnetic field generator (7) forms with core coil by two groups, respectively to galvanic current logical in coil and alternating current, two groups provide time magnetic line of force direction to be along the axial steady magnetic field of metal electrode bar (5) and axial alternating magnetic field with core coil simultaneously, by regulating magnetic field generator (7) controlling magnetic field intensity, the metal pool of concussion lorentz's force (15) to resmelting ingot (8) top utilizing electromagnetic interaction to produce carries out induction stirring, the nascent solidified structure of refinement resmelting ingot (8).

10. according to vacuum electric arc remelting apparatus described in any one in claim 7 ~ 9, it is characterized in that: described power supply (11) adopts adjusting pressuring dc power, for vacuum arc remelting process provides galvanic current.