JP2015000997A - Soft magnetic metal powder production device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for obtaining a soft magnetic metal powder which is sufficiently fine and is an amorphous state while reducing nozzle jet pressure of high pressure cooling water and gas jet pressure in gas atomization, in which the particle shape of the soft magnetic metal powder is a sphere satisfying an aspect ratio and a slender spheroid, the soft magnetic metal powder has preferable shape distribution, size ratio distribution, and aspect ratio distribution.SOLUTION: Provided is a method for obtaining high speed revolving water flow 18 for quick cooling and pulverization in a cylindrical body 21 while maintaining a method used in a gas atomization method. In the method, a cooling liquid which is jetted by high pressure jet by using an oval hole stenographic nozzle revolves by drawing an arc following to an inner wall curve surface of the cylindrical body 21 and then flows to downstream. Belt-shaped flow whose flow turbulence is suppressed to minimum level is provided, for obtaining preferable distribution of the soft magnetic metal powders.

Description

  The present invention relates to a method and an apparatus for producing metal powder, and more particularly to a cooling technique for a cylindrical swirling water flow in pulverization of a soft magnetic metal powder by an atomizing method.

  Magnetic cores (hereinafter referred to as “magnetic cores”) used in high-frequency magnetic circuits and the like require high magnetic permeability, so it is necessary to use a high-density magnetic core with a high magnetic flux density using soft magnetic metal powder. There is. This technique is to obtain a soft magnetic metal powder for this purpose. In order to obtain high magnetic permeability, it is necessary to reduce the demagnetizing factor of the magnetic powder alone.

  In the conventional method, a metal material is melted and dropped, and a molten metal powder finely pulverized by a gas atomizing method using an inert gas jet is collided and immersed in a cylindrical swirling water flow, and is rapidly cooled. Since the finely pulverized molten metal powder cannot be cooled rapidly only by the ordinary jet atomization technique based on the gas atomization method, the molten metal powder is solidified into a fine spherical powder over a sufficient time due to the surface tension of the molten metal powder.

  In order to mold a magnetic body having a small demagnetizing factor, the soft magnetic metal powder used as the material must be fine, and in order to increase the molding density, it is necessary to have an irregular elongated spheroid shape instead of a spherical shape. There is a need for a shape that can reduce the porosity when compression molding. For this reason, the impact force caused by the collision with the swirling water flow and the rapid cooling of AC speed water are utilized. (Patent Document 1)

  Further, when producing a dust core, it is necessary to reduce the porosity in order to maximize the density, but this greatly depends on the size and shape of the soft magnetic metal powder. The particle diameter is in the range of approximately 3 μm to 300 μm, the average aspect ratio of the soft magnetic metal powder having a small particle diameter is preferably 3.0 or more, and the average aspect ratio of the soft magnetic powder having a large particle diameter is preferably less than 3.0. Has been. The aspect ratio is represented by the ratio L / D between the major axis length L and the minor axis length D of the particles.

  A powder with a small particle diameter fills the space created when compression molding a powder with a large particle diameter, thereby reducing the porosity and increasing the density. In that case, a soft magnetic metal with a small particle diameter that works to fill the space. This is because a flat shape having a large aspect ratio is theoretically preferable. (See Figure 2)

  The molten metal particles pulverized by the gas atomization method immediately collide with the swirling water flow and undergo rapid cooling to solidify into the above particle diameter and particle shape before being crystallized to become a fine soft magnetic metal powder. This swirling water flow is a high-speed jet water swirling (rotating) on the wall of the cylindrical body, and requires a constant thickness of the water flow layer and a constant collision angle with the molten metal particles. Therefore, the cylindrical body has a certain angle of inclination. Is set in the state.

JP-A-5-43920 JP 2001-64704 A

  In the gas atomization method, unlike the water atomization method, a relatively spherical fine powder can be generated. When the water atomization method is used, the molten metal is rapidly cooled at the same time as the fine pulverization, so that the shape of the fine particles becomes an irregular shape including convex concave portions. When forming a magnetic core that requires a high magnetic permeability, such irregularly shaped fine particles having convex and concave portions increase the porosity and cannot provide a high-density magnetic core.

  When the gas atomization method is used, since it is jet jet pulverization with gas (inert gas etc.) instead of liquid that is rapidly cooled, the pulverized molten metal fine particles become relatively spherical fine particles by the action of their surface tension. It is easy to solidify. That is, the molten metal particles finely pulverized by the gas atomization method are crystallized and produced as fine spherical fine powders when cooled slowly without any external force.

  If the shape of the soft magnetic metal powder is mainly composed of a sphere, the demagnetizing field coefficient becomes as large as 0.33 and the effective permeability as a magnetic core is lowered. In the case of a magnetic material, by crystallization, the polarity becomes fine particles and the magnetic permeability is also lowered. The magnetic core having a high magnetic permeability is preferably not an amorphous amorphous state having no polarizability, rather than such a soft magnetic metal powder crystallized by polarization. This is because, in the case of powder particles in an amorphous state, the constituent atomic arrangement is irregular, so that there is no crystal magnetic anisotropy and high magnetic permeability is exhibited.

  Therefore, a soft magnetic metal powder having a substantially spherical shape that is not uneven and having a large particle having an aspect ratio of 3 or less, and a small particle having an aspect ratio of 3 or more is preferably an elongated spheroid and is in an amorphous amorphous state. In order to obtain this, a technique is adopted in which a fine powder pulverized by gas atomization is rushed into a high-speed swirling water flow before it is spherically crystallized for collision crushing and rapid cooling.

The gas injection pressure in the gas atomization pulverization is as large as 15 to 70 kg / cm ^2, and the flow rate of the swirling water flow is required to be as high as 30 m / sec to 100 m / sec.

  In such a method, a method for obtaining a preferable soft magnetic metal powder by lowering the gas jet pressure in the gas atomization method and lowering the flow velocity of the high-speed rotating water flow is necessary from the viewpoint of saving production energy and cost. It is a problem. In pulverization and rapid cooling by high-speed swirling water flow, splashed water from the high-pressure nozzle jet of coolant for obtaining high-speed water flow has an adverse effect on the crushing and pulverization point by gas atomization, and there is unnecessary variation in certain pulverization conditions such as temperature and pressure It becomes a factor to generate.

  Similarly, high-pressure nozzle injection of cooling water tends to easily generate vortex flow, wave flow, firing, etc. in the swirling water flow in the cylinder, and it is difficult to obtain a constant swirling water flow layer thickness and uniform liquid level. This greatly changes the conditions for rapidly cooling the molten metal particles pulverized by the method into the cooling liquid. Therefore, it was very difficult to produce a soft magnetic metal powder having a uniform particle diameter, particle shape and distribution thereof in a timely manner.

  In other words, a sufficiently fine amorphous soft magnetic metal powder can be obtained while reducing the gas jet pressure in gas atomization and the nozzle injection pressure of high-pressure cooling water, and the particle shape is a sphere and an elongated spheroid satisfying the aspect ratio. Thus, it has been a problem to constantly obtain soft magnetic metal powder having a preferable shape distribution, size ratio distribution and aspect ratio distribution. In particular, there is a demand for technology that can reduce the injection pressure energy after securing the required flow rate, uniform liquid level, and the amount of water that meets the required volume, which is a high-speed swirling water flow. Met.

  In order to solve the above problems, a metal powder production apparatus according to the present invention is a method for obtaining a preferable high-speed swirling water flow in a cylindrical body while maintaining the technique in the gas atomization method. It is characterized by using a flat type injection nozzle parallel to the cylinder axis direction.

  The present invention is a structure for generating a swirling water flow on the circumferential surface of a cylindrical body that is cooled by supplying molten metal powder, the tip of the jet nozzle of the swirling water flow penetrating from the circumferential surface tangential direction of the cylindrical body wall toward the inner wall. And the shape of the tip of the spray nozzle has a flat spray shape parallel to the axial direction of the cylinder, and the angle of the tip of the spray nozzle is variable with respect to the tangential direction of the circumferential surface of the cylindrical body wall It is a metal powder manufacturing apparatus having a generating structure.

  The coolant sprayed with high pressure swirls while drawing an arc in accordance with the curved inner wall surface of the cylinder, and flows downstream, so that the pressure loss is reduced most and the flow velocity is not lost. In the case of an elliptical hole flat spray nozzle, which is a kind of flat jet nozzle, the opening shape at both ends is a long and narrow elliptical shape. Can supply.

  In particular, since the water flow injected from the flat injection nozzle has a certain width, a uniform swirling water flow is created on the wall of the cylindrical body in order to create a uniform swirling water flow along the wall surface in a state where the rotational centrifugal force can be most utilized. Thickness, speed, and easy to generate uniform water surface. It can minimize vortex, wave, firing, and scattering involving air. The vertical injection angle of the flat injection nozzle can be arbitrarily set.

  In order to obtain a sufficient amount of swirling water without reducing the flow velocity, it is necessary to set a plurality of injection nozzles. Conventionally, when a plurality of injection ports are used to obtain a sufficient swirling water flow rate, two locations are set on a 180-degree diagonal line on the same circumferential surface of the cylindrical body wall, or plural at equal angular intervals on the same circumferential surface. However, it was very difficult to obtain a stable liquid level by increasing the number of jet nozzles.

  The next feature of the present invention resides in that the positions of a plurality of flat injection nozzles are set in parallel in a state where they are overlapped on the same part of the cylindrical body wall. Also in the case of using two or more spray nozzles, a plurality of sets are installed at one place. Cooling water ejected from the flat injection nozzle suppresses the occurrence of vortex flow, turbulence, and splashing by being superposed on the upper side by cooling water ejected from nozzles that are overlapped so that the jet outlet angle is variable. be able to. Accordingly, a high-speed swirling water flow having a sufficient amount of water and a flowing water speed can be obtained, and a uniform flowing water layer thickness (liquid layer depth) and a uniform water surface can be maintained.

  According to the soft magnetic metal powder manufacturing apparatus according to the present invention having the above-described configuration, a swirling water flow in a cylindrical body having a substantially uniform liquid surface state is obtained, so that the molten metal fine particles after atomization pulverization are sequentially constant. It will rush into the swirling water flow. In other words, the impact crushing force received by the molten metal fine particles and the rapid cooling effect are maintained at a constant condition, so that it is possible to obtain a soft magnetic metal powder having a stable particle size distribution, particle shape distribution, and aspect distribution in comparison with the prior art. it can.

In addition, the injection pressure of the high-pressure coolant can be reduced, and the gas atomization injection pressure can also be halved. In the particle size distribution, a distribution of about 40 μm can be obtained. The gas jet pressure in gas atomization pulverization can be halved from about 60 kgf / cm ² to about 30 kgf / cm ² . As a result, not only high-density soft magnetic metal powder can be used as a magnetic core constituent material, but also a magnetic core with high magnetic permeability can be manufactured at low cost.

It is a figure which shows the cross-sectional schematic structure in the soft magnetic metal powder manufacturing apparatus which concerns on one Embodiment of this invention. It is a figure which shows the state with the low porosity of the shape | molded powder magnetic core. It is a figure which shows the cross-sectional schematic structure which installed the turning water flow injection nozzle in the cylindrical body of the soft magnetic metal powder manufacturing apparatus which concerns on one Embodiment of this invention. It is a figure which shows the cross-sectional schematic structure which installed multiple swirling water flow injection nozzles in the cylindrical body of the soft magnetic metal powder manufacturing apparatus which concerns on one Embodiment of this invention. It is a figure which shows the elliptical hole spray nozzle appearance of the swirling water flow of the soft magnetic metal powder manufacturing apparatus which concerns on one Embodiment of this invention.

  Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings. In the following, the range necessary for the description for achieving the object of the present invention is schematically shown, and the range necessary for the description of the relevant part of the present invention will be mainly described. According to a known technique.

  FIG. 1 is a diagram showing a schematic cross-sectional structure of a soft magnetic metal powder manufacturing apparatus according to an embodiment of the present invention. As shown in the figure, a soft magnetic metal powder manufacturing apparatus 1 according to an embodiment of the present invention includes a gas atomizer 13 and a cylindrical body 21 installed at a certain inclination angle thereto. The gas atomizer 13 has a structure in which the metal charged in the inner container is melted by the heater 24 and dropped from the molten metal hole 11 on the bottom surface of the inner container. The inert gas 32 is supplied from an external high-pressure cylinder to the lowermost injection chamber of the gas atomizer, and is a mechanism for pulverizing the molten metal injected from the gas jet nozzle 14 and dropped at the convergence position P15.

  The tip shape of the gas jet nozzle 14 is a circular thin ring shape, and has a structure in which the injected inert gas is in the injection direction in which it converges in an inverted conical shape at the convergence position P15. The inert gas converged at the convergence position P is then diffused as a conical gas jet 16 and collides with the inner wall of the cylindrical body 21. The above is the structure of the gas atomizer 13 having the gas atomizing function.

  The cylindrical body 21 has a cooling water injection nozzle 20 on the inner wall of the upstream portion, and the tip of the cooling water injection nozzle 20 is installed facing the circumferential direction of the cylindrical body wall surface. Cooling water 33 supplied with high pressure from the outside is injected from the cooling water injection nozzle 20 to form the cooling water swirling water flow layer 17 while swirling the cylindrical body wall 22, and spirally flows downstream to the recovery step 19. It has a structure.

  FIG. 2 is a diagram showing a state in which the porosity of the molded dust core is low. The soft magnetic metal powder having a large particle diameter has an aspect ratio of about 3 or less, and the one with a small particle diameter is a flat having an aspect ratio of about 3 or more, so that the gap can be embedded to maximize the density. The situation is shown as a schematic diagram.

  FIG. 3 is a diagram showing a schematic cross-sectional structure in which a swirling water jet nozzle is installed in a cylindrical body of a soft magnetic metal powder manufacturing apparatus according to an embodiment of the present invention. FIG. 3 shows a cross section of the cylindrical body 21 cut at a portion of the cooling water injection nozzle 20 in FIG. 1, and is a schematic diagram for explaining the cooling water injection nozzle in detail. The cooling water injection nozzle 20 has a structure for causing the tip to protrude in the circumferential direction of the inner wall of the cylindrical body 21 and for injecting the injected cooling water to turn the inside of the cylindrical body 21. The tip angle has a structure in which the injection angle can be varied by approximately ± 20 degrees with respect to the tangential direction of the inner wall circumference of the cylindrical body 21. Details of the mechanism for changing the angle are omitted.

  FIG. 4 is a diagram showing a schematic cross-sectional structure in which a plurality of swirling water jet nozzles are installed in the cylindrical body of the soft magnetic metal powder manufacturing apparatus according to an embodiment of the present invention. FIG. 4 shows a case where two injection nozzles 20 are provided as an example. The tip ends of both injection nozzles 20 have a structure in which they are installed in parallel close to the same circumferential surface of the inner wall of the cylindrical body 21. The high-pressure cooling water 33 supplied from the outside passes through the injection nozzle 20 and is injected into the cylindrical body 21 and swirls in the cylindrical body 21 to form the swirling water flow layer 18.

  FIG. 5 is a view showing the appearance of an elliptical hole spray nozzle for swirling water flow in the soft magnetic metal powder manufacturing apparatus according to an embodiment of the present invention. The shape of the nozzle opening 31 is a flat shape that narrows toward both ends with an elliptical hole.

  Next, the operation and operation of the soft magnetic metal powder manufacturing apparatus according to an embodiment of the present invention will be described with reference to FIG. When the molten metal 12 flowing down from the molten metal hole 11 reaches a single point position (convergence position P) 15 intersecting with the inert gas jet injected from the gas jet nozzle 14 of the gas atomizer 13, the molten metal 12 is fine. It breaks up into droplets. The molten droplets are then carried on a gas jet 16 that spreads downward in a conical shape, enter the cooling water swirling water flow layer 17, and are rapidly cooled and solidified with fracture breaking. Thereafter, the cylindrical body 21 is spirally swirled with the swirling water flow 18 and enters the recovery step 19 at the end of the downstream cylindrical body.

  The cooling water swirling water flow 18 is supplied by high-pressure injection from a cooling water injection nozzle 20 installed upstream of the cylindrical body wall 22. Conventionally, in order to obtain a swirling water flow 18 having a sufficient amount of water and a flow velocity, a plurality of cooling water injection nozzles 20 are provided, and if they are 180 degrees diagonal to the same circumferential surface of the inner wall of the upstream portion of the cylindrical body, 2 In order to make the water flow uniform, it was arranged at three angles, such as three places for a 120 degree diagonal and four places for a 90 degree diagonal arrangement.

  However, the cooling water sprayed at high speed and high pressure from the spray nozzles 20 provided at a plurality of positions is made uniform with the cylindrical body wall 22 as the swirling water flow 18 while keeping the liquid layer thickness, liquid amount, and flow velocity uniform, whirling, It was very difficult to swivel without causing flow, shooting, splashing or splashing. Even if the process conditions from the gas jet crushing in the molten metal gas atomizer 13 to the entry of the swirling water flow can be precisely set, if the state of the swirling water flow 18 is unstable, the swirl water flow of the fine molten droplet 23 The inrush resistance, the pulverization condition by the water flow, the rapid cooling condition, etc. greatly vary, and depending on this, it is very difficult to obtain a good quality cooled solidified product uniformly and stably.

  The present invention solves these problems, and details thereof will be described below. The present invention maintains the swirling water collision condition in the inrush crushing and quenching step of the fine molten droplet 23 into the high-speed swirling water flow 18 in the cylindrical body 21 while maintaining the molten metal crushing step with the inert jet gas in the gas atomization method. It was made for the purpose of setting and maintaining a substantially constant homogeneity.

  The present invention focuses on the shape, position, etc. of the injection nozzle 20 of high-pressure cooling water for producing a stable swirling water flow 18. First, the flat injection in which the nozzle injection port shape is parallel to the cylinder axis direction of the cylindrical body wall surface. It is characterized by using a nozzle. The shape of the opening of the flat injection nozzle is a flat shape assuming the thickness of the swirling water flow layer, and both ends are substantially elliptical. The elongated, elliptical shape at both ends has a small resistance in fluid ejection, and can supply a substantially uniform strip-shaped water flow with minimal disturbance of the swirling water flow. FIG. 5 shows a schematic view of a flat injection nozzle according to the present invention. Hereinafter, it is referred to as an elliptical hole spray nozzle 30.

  Since the water flow ejected from the elliptical hole spray nozzle 30 has a certain width, a swirling water flow is formed substantially uniformly along the wall surface in a state where the rotational centrifugal force can be most utilized at the cylindrical body wall 22. Therefore, the thickness and speed of the constant swirling water flow layer 17 and a substantially uniform water surface are easily generated. It can minimize eddy currents, wave currents, air entrainment, and scattering.

  Next, the elliptical hole spray nozzle 30 is set in a state of penetrating from the arc surface tangent direction of the cylindrical body wall 22 and attaching only the nozzle tip to the inner wall surface. FIG. 3 shows a state of the elliptical hole spray nozzle 30 set on the wall of the cylindrical body in a cross-sectional view in the lateral direction of the cylindrical body. The cooling water injection direction of the elliptical hole spray nozzle 30 has a structure in which the direction can be changed by about 20 degrees in the vertical direction with respect to the tangent to the circular arc surface of the cylindrical body wall. The injected coolant is swirled in a belt-like shape while drawing an arc in accordance with the curved inner wall surface of the cylindrical body and flows downstream.

  In order to obtain a sufficient amount of flowing water without reducing the flow velocity of the swirling water flow 18, a plurality of injection nozzles 20 for supplying high-pressure cooling water are required. Conventionally, when two injection nozzles are necessary to obtain a sufficient swirling water flow rate, two injection nozzles have been installed on the 180 ° diagonal line on the inner wall surface of the same circular arc of the cylindrical body. Further, when three or more nozzles are required, a plurality of injection nozzles are set with uniform angular distribution at uniform angular positions, such as being installed at intervals of 120 degrees on the same circular arc surface. This is because it was considered to be a good method for making the swirling water flow uniform over the entire cylindrical body wall. However, in reality, the more the number of injection nozzles, the more easily the swirling water flow 18 is swirled, waved, air entrained, and scattered, and the water flow is disturbed, and the stable swirling water flow thickness (liquid layer thickness) It was difficult to obtain a uniform liquid level.

  The installation of a plurality of elliptical hole spray nozzles 30 of the present invention is characterized in that the installation positions are collectively set at the same position, in contrast to the above-described conventional concept. Setting the plurality of elliptical hole spray nozzles at the same position means setting them at substantially the same position, for example, by arranging them in a straight line or by placing them in parallel. FIG. 4 shows a schematic diagram of the overlapping parallel installation of the elliptical hole spray nozzle openings.

  The elliptical hole spray nozzle 30, which is a feature of the present invention, has a flat and substantially elliptical nozzle opening shape, so that the jetted water flow is easily connected in parallel and easily overlapped in parallel. It is easy and the flow rate can be increased. In particular, when stacked in parallel, as shown in FIG. 3, by operating the nozzle injection angle, it is possible to adopt a structure in which the upper jet water flow suppresses the turbulence of the lower jet water flow from above, and a uniform swirling water flow is obtained as a whole. Can be obtained.

  In other water volume adjustments, both ends of each injection opening are substantially elliptical, so technical measures such as adjusting the height are possible, but these are various within the range of conventional techniques. I can think.

  According to the present invention, a high-speed swirling water flow having a sufficient amount of water and flowing water can be obtained as described above, and a substantially uniform flowing water layer thickness (liquid layer depth) and a substantially uniform water surface can be maintained. Thereby, the fine molten droplet 23 after gas atomization pulverization can be rushed into the most suitable swirl water flow position of the cylindrical wall 22.

  The fine molten droplets 23 after the gas atomization pulverization are diffused in a circular shape from the convergence position P and spread in a substantially conical shape, but the swirling water flow 18 that receives it is a curved surface rotating in a cylindrical shape. The contact shape when the fine molten droplet 23 enters the swirling water stream 18 is an ellipse, and the contact angle with the swirling water stream 18 varies depending on the position of the ellipse. Further, since the cylindrical body 21 is set with a certain inclination angle with respect to the gas atomizer 13, the contact shape when the fine molten droplet 23 diffused conically as described above enters the swirling water flow 18 is as follows. On top of the ellipse, it spreads in a fan shape along the lower direction of the cylindrical body, forming a so-called tear (s) shape.

  This is because the factors such as the dwell time, angle, impact force, impact direction, and cooling rate are slightly different depending on the position of the fine molten droplet 23 that enters the swirling water flow 18. The final shapes of the soft magnetic metal powders produced by quenching are changed to different shapes, and uniformity can be eliminated.

  That is, particles having different shapes such as particle diameter and size, such as a shape close to a spherical shape and an elongated spheroid, are generated at a constant ratio in a balanced manner. Preferred soft magnetic metal powder particles having a small average aspect ratio of 3.0 or more and particles having a large particle diameter of less than 3.0 are produced in a certain ratio and distribution. Moreover, it leads to maintaining generation | occurrence | production of the soft magnetic metal powder particle which is a microparticle and an amorphous state.

  In order to keep these factors constant, it can be seen that how to keep the state of the swirling water flow substantially uniform is the most important. That is, the water surface height of the swirling water flow, the flow velocity, the temperature, the substantially uniform surface state, etc. are the most important. It is difficult to maintain the above-mentioned uniformity of the swirling water flow created by the jet flow of the high-pressure cooling water. Subtle and best condition settings such as the injection speed, temperature, injection angle, time, hover distance, cylinder angle, contact angle, conical diffusion distance, and distance to the swirling water flow contact and their balance are greatly upset.

  According to the jet nozzle shape and position setting of the cooling water swirling water flow according to the present invention, the swirling water flow is prevented from being disturbed such as vortex flow, wave flow, bubble scattering and scattering, and the water surface height, flow velocity, temperature and water surface state are uniform. Therefore, it is possible to maintain the conditions after the gas atomization pulverization as described above, and to generate a homogeneous soft magnetic metal powder having a preferable particle size, particle shape, and aspect ratio distribution. Leads to.

  In other words, it became possible to set the cooling swirl water flow conditions, which had the largest fluctuation factors in the production of soft magnetic metal powders, to a uniform and stable state. It is possible to confirm the degree of involvement of other fluctuation factors in the ratio distribution fluctuation. It is possible to reset the optimum values of conditions such as the inert gas jet injection pressure in the gas atomization pulverization and the distance between the gas atomizer and the cylindrical body. Similarly, energy-intensive conditions such as gas atomization injection pressure and cooling water flow injection pressure can be reduced to a more simple level, which can greatly contribute to the reduction of manufacturing costs and the like.

As an example of the result of the verification experiment according to the present invention, the particle diameter of the generated soft magnetic metal powder can be reduced to a distribution of about 40 μm, and the gas jet injection pressure in gas atomization is about 60 kgf / cm. ² to about 30 kgf / cm ^2, which contributed to the reduction of manufacturing costs. In addition, since the porosity is further reduced by reducing the particle diameter while maintaining the preferred particle shape and particle aspect ratio, it is easier to obtain a soft magnetic metal powder suitable for a high-density magnetic core with high permeability. It can be said that.

  Here, it is needless to say that the above-described embodiment is merely an example, and various modifications or improvements can be made without departing from the gist of the present invention.

  According to the apparatus for producing soft magnetic metal powder according to the present invention, it is easy to obtain a soft magnetic metal powder suitable for a high-density magnetic core with high magnetic permeability, so that it has great applicability in the magnetic material industry. In addition, the technical and economic significance of cost reduction brought about by the apparatus according to the present invention is great, and it contributes to the improvement of the electromagnetic performance of the magnetic material.

DESCRIPTION OF SYMBOLS 1 ... Soft magnetic metal powder manufacturing apparatus 2 ... Metal powder compression molding 11 ... Molten metal hole 12 ... Molten metal 13 ... Gas atomizer 14 ... Gas jet nozzle 15 ... Convergence position P
16. · Conical gas jet 17 ·· Cooling water swirl flow layer 18 · Swirl water flow 19 ·· Recovery process 20 ·· Cooling water injection nozzle 21 ·· Cylinder body 22 ·· Cylinder body wall 23 24. Heater 25. Lid 30. Elliptical injection nozzle 31. Nozzle opening 32. Inert gas 33. Cooling water 34. Soft magnetic metal powder (large particle diameter: aspect ratio 3 or less)
35. ・ Soft magnetic metal powder (small particle diameter: aspect ratio of 3 or more)
36 ・ ・ Nozzle variable angle

Claims (4)

An apparatus for generating a swirling water flow generating structure on a peripheral surface of a cylindrical body for supplying and cooling molten metal powder pulverized and diffused by a gas atomizing method, wherein the swirling water flow generating structure is
A jet nozzle tip of a swirling water flow penetrating from the substantially circumferential surface tangential direction of the cylindrical body wall toward the inner wall;
An elliptical hole flat shape parallel to the axial direction of the cylinder formed by the tip of the injection nozzle;
A soft magnetic metal powder manufacturing apparatus comprising: a directional angle related to a tip of the injection nozzle, and a directional angle that is variable by approximately ± 20 degrees with respect to a tangential direction of a circumferential surface of a cylindrical body wall.   The soft magnetic metal powder manufacturing apparatus according to claim 1, wherein a plurality of the jet nozzles of the swirling water stream are installed in a superposed manner at one place on a cylindrical body wall part close to the atomizing part. An apparatus for generating a swirling water flow generating structure on a circumferential surface of a cylindrical body that is cooled by supplying molten metal powder,
A jet nozzle tip of a swirling water flow penetrating from the substantially circumferential surface tangential direction of the cylindrical body wall toward the inner wall;
A flat injection shape parallel to the axial direction of the cylinder formed by the tip of the injection nozzle;
A metal powder manufacturing apparatus comprising: a directional angle related to a tip of the injection nozzle, and a directional angle that is variable with respect to a tangential direction of a circumferential surface of a cylindrical body wall.   The metal powder manufacturing apparatus according to claim 3, wherein a plurality of jet nozzles of the swirling water flow are collectively installed at one place on a wall of the cylindrical body.

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